The rhizome of Gastrodia elata Blume – An ethnopharmacological review

Author’s Accepted Manuscript The rhizome of Gastrodia elata Blume - an ethnopharmacological review Hong-Dan Zhan, Hai-Yu Zhou, Xin-Liang Du, Yun-Peng Sui, Wei-hao Wang, Li Dai, Feng Sui, Hai-Ru Huo, Ting-Liang Jiang www.elsevier.com/locate/jep

PII: DOI: Reference:

S0378-8741(16)30417-2 http://dx.doi.org/10.1016/j.jep.2016.06.057 JEP10259

To appear in: Journal of Ethnopharmacology Received date: 13 November 2015 Revised date: 22 June 2016 Accepted date: 24 June 2016 Cite this article as: Hong-Dan Zhan, Hai-Yu Zhou, Xin-Liang Du, Yun-Peng Sui, Wei-hao Wang, Li Dai, Feng Sui, Hai-Ru Huo and Ting-Liang Jiang, The rhizome of Gastrodia elata Blume - an ethnopharmacological review, Journal of Ethnopharmacology, http://dx.doi.org/10.1016/j.jep.2016.06.057 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

The rhizome of Gastrodia elata Blume - an ethnopharmacological review Hong-Dan Zhan1, Hai-Yu Zhou1, Xin-Liang Du2, Yun-Peng Sui3, Wei-hao Wang1, Li Dai1, Feng Sui1*, Hai-Ru Huo1* Ting-Liang Jiang1 1. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; 2. Graduate School of China Academy of Chinese Medical Sciences, Beijing 100700, China; 3. Beijing Tian Tan Hospital, Capital Medical University, Beijing 100050, China.

ABSTRACT Ethnopharmacological relevance: Gastrodia elata Blume (Orchidaceae) is commonly called Tian ma in Chinese and mainly distributed in the mountainous areas of eastern Asia, such as China, Korea, Japan and India. It is an extensively used traditional Chinese herbal medicine in the clinical practice of traditional Chinese medicine, to treat headache, migraine, dizziness, epilepsy, infantile convulsion, tetany and so on. The present paper reviews the advancements in investigation of botany and ethnopharmacology, phytochemistry, pharmacology, toxicology and quality control of Gastrodia elata Blume. Finally, the possible tendency and perspective for future investigation of this plant are also put forward. Materials and methods: The information on Gastrodia elata Blume was collected via piles of resources including classic books about Chinese herbal medicine, and scientific databases including Pubmed, Google Scholar, ACS, Web of science, ScienceDirect databases, CNKI and others. Plant taxonomy was validated by the databases “The Plant List”, and “Mansfeld's Encyclopedia”. Results: Over 81 compounds from this plant have been isolated and identified, phenolics and polysaccharides are generally considered as the characteristic and active constituents of Gastrodia elata Blume. Its active compounds possess wide-reaching biological activities, including sedative, hypnotic, antiepileptic, anticonvulsive, antianxietic, antidepressant, neuroprotective, antipsychotic, anti-vertigo, circulatory system modulating, anti-inflammationary, analgesic, antioxidative, memory-improving and antiaging, antivirus and antitumor effects. Conclusion: Despite the publication of various papers on Gastrodia elata Blume, there is still, however, the need for definitive research and clarification of other bioactive compounds using bioactivity-guided isolation strategies, and the possible mechanism of action as well as potential synergistic or antagonistic effects of multi-component mixtures derived from Gastrodia elata Blume need to be evaluated. It is also necessary and important to do more quality control and toxicological study on human subjects in order to maintain its efficacy stable in the body and validate its safety in clinical uses. In addition, more investigations on other parts of this plant beyond the tubers are needed. Further studies on Gastrodia elata Blume will lead to the development of new drugs and therapeutics for various diseases, and how to utilize it better should be paid more attention to. *Corresponding author. Tel.: +86 10 64041008; fax: +86 10 64041008. E-mail addresses: [email protected] (F. Sui), [email protected] (H.-R. Huo). 1

Chemical compounds studied in this article          

Gastrodin (PubChem CID: 115067); Hydroxybenzyl alcohol (PubChem CID: 125); 4-hydroxybenzaldehyde (PubChem CID: 126); Vanillyl alcohol (PubChem CID: 62348); Vanillin (PubChem CID: 1183); Parishin (PubChem CID: 44421666); Parishin B (PubChem CID: 44715528); Parishin C (PubChem CID: 46173915); β-sitosterol (PubChem CID: 222284); Gastrodamine (PubChem CID: 5702160)

Keywords: Gastrodia elata Blume; Tian ma; Ethnopharmacology; Phytochemistry; Pharmacology; Clinical applications

Contents 1. Introduction ....................................................................................................................... 3 2. Botany and ethnopharmacology ......................................................................................... 3 2.1. Botany ..................................................................................................................... 3 2.2. Ethnopharmacology ................................................................................................ 3 3. Phytochemistry................................................................................................................... 3 3.1. Phenolics and its glycosides .................................................................................... 3 3.2. Polysaccharides ....................................................................................................... 3 3.3. Sterol and organic acids .......................................................................................... 3 3.4. Other compounds .................................................................................................... 3 4. Pharmacological activities ................................................................................................. 3 4.1. Sedative and hypnotic activities .............................................................................. 3 4.2. Antiepileptic and anticonvulsive activities.............................................................. 3 4.3. Anti-anxiety and antidepressant activities ............................................................... 3 4.4. Neuroprotective activities ....................................................................................... 3 4.4.1. Protection of neuronal cells and anti-apoptoticaction activities ................. 3 4.4.2. Anti-oxidative activities ............................................................................. 3 4.4.3. Protection of neuro-synaptic plasticity ....................................................... 3 4.5. Anti-cardio-cerebral-vascular diseases activities .................................................... 3 4.6. Antipsychotic activities ........................................................................................... 3 4.7. Anti-vertigo activities.............................................................................................. 3 4.8. Effect on circulatory system .................................................................................... 3 4.8.1. Anticoagulant and antithrombotic activities ............................................... 3 4.8.2. Anti-atherosclerotic activities .................................................................... 3 4.8.3. Antihypertensive activities ......................................................................... 3 2

4.9. Anti-inflammatory and analgesic activities ............................................................. 3 4.10. Improve memory and anti-aging activities ............................................................ 3 4.11. Antivirus and antitumor activities ......................................................................... 3 4.12. Other pharmacological activities ........................................................................... 3 5. Quality control ................................................................................................................... 3 6. Toxicology ......................................................................................................................... 3 7. Concluding remarks ........................................................................................................... 3 Acknowledgments ..................................................................................................................... 3 References ................................................................................................................................. 3

Introduction 3

Gastrodia elata Blume (G. elata, Orchidaceae), commonly called Tian ma (天麻) in Chinese, is a perennial parasitic herb also called Chi jian (赤箭) or Ming tian ma (明 天麻). It is considered as a top grade herbal medicine that has been used for a long history described to enter the liver meridian in the Shennong’s Classic of Materia Medica (Shen nong ben cao jing). Generally, after the beginning of winter to the following year before the Tomb-sweeping Day, excavate the rhizome of G. elata, wash it immediately, and braise it well and then dry it at low temperature for the clinical use (Chinese Pharmacopoeia Commission, 2015). G. elata has nine synonyms (G. elata f. alba S.Chow, G. elata f. elata, G. elata f. flavida S.Chow, G. elata f. glauca S.Chow, G. elata var. gracilis Pamp., G. elata var. pallens Kitag., G. elata f. pilifera Tuyama, G. elata f. viridis (Makino) Makino, and G. elata var. viridis (Makino) Makino) (The Plant List., 2013). To search by using these nine names, only two Chinese articles (Jiang et al., 2001; Zhang et al., 2014) regarding Gastrodia elata f. elata, and one English article (Wang et al., 2007) covering Gastrodia elata f. glauca S.Chow were obtained. However, it was found that G. elata was used in more than 200 publications (both in English and Chinese). There are also many Chinese articles in which the plant was just defined as Tian ma (Li et al., 2015; Luo et al., 2012) To communicate more effectively and internationally, it is suggested that G. elata should be used instead of Tian ma in all publications in the future. Currently, over 81 compounds from this plant have been isolated and identified, and they are phenolics, polysaccharides, sterols and organic acids, and so on. (Ojemann et al., 2006). In the theory of traditional Chinese medicine (TCM), G. elata is considered to suppress the hyperactive liver, arrest endogenous wind and stop tetany. In the aspect of clinical practice, G. elata is mainly applied for neurasthenia, insomnia, dizziness, epilepsy, convulsions, nervous headache, Alzheimer's disease, hypertensive and others (Hou et al., 2012). Modern pharmacological experiments have demonstrated that the extracts of G. elata or its active compounds possess wide-reaching

biological

activities,

including

antitumor,

anti-virus,

memory-improving, antioxidation, and anti-aging actions (Huang et al., 1985; Heo et al., 2007; Hu et al., 2014). It is commonly used in traditional medicine as a tonic and aphrodisiac in China and other Asian countries as well as used as a functional food by adding to alcoholic beverages or porridge to improve sexual potency and vision and to prevent abortion (Zhang, 1981). A large number of investigations have been conducted on G. elata in the past few decades, but only a short review of G. elata as a herbal medicine has been published by Chen et al. (Chen and Sheen, 2011), in which its biological activities and antidepressant mechanisms are briefly mentioned, and another review written by Jang et al. (Jang et al., 2015), in which only the neuropharmacological potential of G. elata was covered. In this review, using various databases search and library search to 4

provide constructive information on the ethnopharmacology, phytochemistry, pharmacology, toxicology and quality control of G. elata as well as the structure-activity relationships of the active ingerdients derived from G. elata, aims to coherently unite these aspects and to encourage further research. 2. Botany and ethnopharmacology 2.1. Botany G. elata (Fig. 1) belongs to the genus Gastrodia, family Compositae. There are about twenty-two species in the genus Gastrodia, and most of the species grow in China (Table 1). However, only G. elata is used as medicinal material in the clinical practice of TCM and registered in the Pharmacopeia of People’s Republic of China. G. elata is found primarily in eastern Asia, specifically in the mountainous areas of China, Korea, Japan and India (Shuan and Chen, 1983; Jones, 1991). Characterized by a fleshy tuber or coralloid underground stem and absence of leaves, it grows in the forest at 400-3200 meters above sea level and has a complex relationship with the fungus Armillaria mellea, which invades the sprouted tuber and provides nutrients and energy (Wang, et al., 2007). The plant lives underground during its life cycle except for florescence. Four subspecies, including G. elata Bl. f. elata, G. elata Bl. f. flavida S.chow, G. elata Bl. f. glauca S. chow and G. elata Bl. f. viridis Makino have been found in G. elata species (Zhou et al., 1987). Except for the subspecies of G. elata Bl. f. viridis Makino which is becoming increasingly rare in the wild, the other three subspecies have successfully been cultivated in fields both in China and other countries such as Korea (Lee et al., 2014). Recent studies have shown that G. elata is a small genus composed of 16-31species (Table 1). Among them, the most abundant species is distributed in Taiwan (Chung and Hsu, 2006; Dressler, 1993; Meng et al., 2007). As the unique botanical characters, G. elata grows to the height of 60-100 cm and the whole plant does not contain chlorophyll. The tubers of G. elata are pachyntic, oblong, about 10 cm long and its diameter is 3-4.5 cm. The stems are vertical, cylindrical, and red. The leaves are scalelike, membranous, 1-2 cm long, nervulose. Its inflorescence is fringy raceme, 10-30 cm long and golden colored (Chinese materia medica, 1999). G. elata is harvested in winter or spring; the excavated in winter is named Gastrodia hiemalis T. P Lin, the quality of which is relatively excellent, and the dredged in spring is called Gastrodia fontinalis T. P Lin, the quality of which is inferior to Gastrodia hiemalis (Lei et al, 2015). After digged out, removed the stems and fibrous root, washed the dirt, soaked in water and wiped off the coarse skin, then soaked in water or alum, next boiled or steamed and when the white dots in the center dispeared, took it out and dried it (Chinese materia medica, 1999). The dried tubers are oval shaped, long, slightly flat, and exhibit signs of shrinkage and bending. The residual stem base at one end, commonly known as "Ying ge zui" is red to reddish brown in colour, and the other end has rounded root marks. They are 6-10cm long, 2-5cm in diameter, and 0.9-2cm thick. Its surface is yellowish-white to yellowish-brown and translucent. It has residual flakes of the light coloured skin, lots 5

No.

Name

Distribution

Part of herb used

Medicinal uses

References

of longitudinal wrinkles, fibrous scar lines and an amount of less visible annulus. Gastrodia hiemalis is with tenuous and less wrinkles and Gastrodia fontinalis is with thick wrinkles. Both of their textures are hard and not easy to be fractured (Chinese materia medica, 1999). In China, wild G. elata is naturally distributed in many provinces. These provinces include Sichuan, Guizhou, Yunnan, Shanxi, Hubei, Gansu, Anhui, Henan, Jiangxi, Hunan, Guangxi, Jilin province and so on. Within these areas, G. elata growing in the western Guizhou, southen Sichuan, northeast of Yunnan and Changbai mountain areas are generally regarded as being of high quality. However, the extensive urbanization of China as a whole has led to serious habitat fragmentation, which may in turn lead to gradual loss of wild G. elata. Further adding insult to this injury is the current exploitation of the limited resources of G. elata (Chinese materia medica, 1999). These wrong actions will lead to the heavy shortages of wild G. elata, which are actually more valuable than the cultivated ones in biological activities. As such, some urgent conservation measures should be taken to protect the G. elata’ natural habitat, in order to guarantee the long-term application of this herbal medicine. Table 1 The ascertained species in the genus Gastrodia.

6

1

G. elata Bl.

Most regions of China

Rhizome

Treating dizziness, limb numbness, infantile convulsion, epilepsy, tetanus, hypertension, etc Treating dizziness, limb numbness, infantile convulsion, epilepsy, tetanus, hypertension, etc

Shuan and Chen(1983); Flora of China (2004)

2

Gastrodia fontinalis T. P Lin.

Taiwan, Yunnan, Sichuan, Guizhou and Hubei in China

Rhizome

3

Gastrodia hiemalis T. P Lin

Taiwan, Yunnan, Sichuan, Guizhou and Hubei in China

Rhizome

Treating dizziness, limb numbness, infantile convulsion, epilepsy, tetanus, hypertension, etc

Flora of China (2004)

4

G. elata Bl. form. glauca S. Chow

Not mentioned

Not mentioned

Shuan and Chen (1983); Flora of China (2004); Chen et al. (2005); Tang (2013)

5

G. elata Bl. f. alba S. Chow G. elata Bl. f. favida S. Chow

Not mentioned

Not mentioned

Not mentioned

Not mentioned

Shuan and Chen (1983); Flora of China (2004) Shuan and Chen (1983); Flora of China (2004); Tang (2013)

Not mentioned

Not mentioned

Not mentioned

Not mentioned

Flora of China (2004)

7

Gastrodia angusta Chou & S. C. Chen

8

Gastrodia tuberculata F. Y. Liu & S. C. Chen

Western of Guizhou, Northeast to the northwest of Yunnan in China Northwest Yunnan in China Henan, Hubei, Western Guizhou, Northeast Yunnan in China Southeastern Yunnan, Sichuan, Shanxi in China Central Yunnan in China

9

Gastrodia menghaiensis Z. H. Tsi & S. C. Chen

Southern Yunnan in China

Not mentioned

Not mentioned

10

Gatrodia wuyishanensis D. M. Li & C. D. Liu

Wuyi mountain of Fujian province in China

Not mentioned

Not mentioned

11

Gastrodia gracilis Bl.

Not mentioned

Not mentioned

Shuan and Chen (1983); Flora of China (2004); Chen et al. (2015)

12

Gastrodia javanica (Bl.) Lindl.

Northern Taiwan, Yunnan, Sichuan, Guizhou and Hubei in China Southern Taiwan

Not mentioned

Not mentioned

Yokota (1998); Flora of China (2004); Aoyama and Yokota (2012)

13

Gastrodia flabilabella S. S. Ying

Central Taiwan

Not mentioned

Not mentioned

Gastrodia peichatieniana S. S. Ying Gastrodia autumnalis T. P Lin

Northern Taiwan

Not mentioned

Not mentioned

Northern Taiwan

Not mentioned

Not mentioned

16

G. elata Bl. f. elata

Huanghe valley and Changjiang valley in China

Not mentioned

Not mentioned

Shuan and Chen (1983); Flora of China (2004); Chen et al. (2005); Tang (2013)

17

G. elata Bl. f. viridis (Makino) Makino

Not mentioned

Not mentioned

Shuan and Chen (1983); Flora of China (2004); Chen et al. (2005); Tang (2013)

18

Gastrodia confuse Honda & Tuyama

Not mentioned

Not mentioned

Flora of China (2004); Yang et al. (2013)

19

Gastrodia appendiculata C. S. Leou & N. J. Chung Gastrodia shimuzuana Tuyama in Acta Phytotax

Northeast to southwest provinces in China Central Taiwan; Yunnan in China Taiwan

Not mentioned

Not mentioned

Yeh et al. (2011)

Northern Taiwan

Not mentioned

Not mentioned

Shanxi

Not mentioned

Not mentioned

Tuyama (1982); Flora of China (2004); Chung and Hsu (2006) Zhang and Ji (2010)

6

14 15

20

21

S.

Gastrodia elata var.obovata Y.J.Zhang

Shuan and Chen (1983); Flora of China (2004); Chen et al. (2015) Shuan and Chen (1983); Liu et al. (1983); Flora of China (2004); Chen et al. (2015) Tsi and Chen (1994); Flora of China (2004); Chen et al. (2015) Li and Liu (2007)

Flora of China (2004); Lok and Ang (2009); Lai (2012) Flora of China (2004); Tian et al. (2010) Flora of China (2004)

7

A

B

C

D

Fig.1 G. elata. (A) seedlings, (B) stem and flowers, (C) dried tubers, and (D) decoction pieces.

2.2. Ethnopharmacology With an extensive scope of biological and pharmacological effects, G. elata has been traditionally used in China for centuries with the dried rhizome (tuber) as the useful part. G. elata was initially recorded in the Shennong’s Classic of Materia written in the period of the Warring States and the Qin and Han Dynasties. In this monograph, G. elata was classified as a “top grade” drug with rejuvenating effect, no toxic and thus can be long-term used without harm. This monograph described that long-time treatment with Gastrodiae elata can tonify qi and strength the body, nourish yin, enhance health, rejuvenate the body, and prolong life (Gu and Yang, 2013). G. elata is also recorded in many other traditional Chinese medicine classics, including the Variorum of the Shennong’s Classic of Materia Medica (Shen nong ben cao jing ji zhu) and the Newly Revised Materia Medica (Xin xiu ben cao). The content of them is the same as that of Shennong’s Classic of Materia Medica (Chinese materia medica, 1999). In Compendium of Materia Medica (Ben cao gang mu), another 8

monograph of TCM, G. elata is charactered as a medicine improving liver meridian and is called “Ding feng cao” as a marvelous medicine in the treatment of the diseases caused by the invasion of wind (Li, 2011). In accordance with the authoritative textbook of Chinese pharmacy, G. elata is sweet in flavor, neutral in nature and attributive to the liver channel. G. elata is described possessing the power to suppress hyperactive liver for calming endogenous wind, dredge the meridians and relieve pain. In the clinical practice, G. elata is primarily applied for dizziness, epilepsy, convulsion, numbness of the limbs, rheumatic arthralgia and headaches by combining with other botanical drugs based on the TCM theory (Chinese materia medica, 1999). On account of its wonderful and specific clinical effects, lots of classic formulations including G. elata created by the ancient famed doctors were spread generation after generation through the refined clinical verification for centuries. For example, Gastrodia and Uncaria decoction was used to treat neurodegenerative disease, such as stroke, brain trauma, and spinal cord injury, Huntington's disease, Alzheimer's disease (AD), and Parkinson's disease (PD) diseases, etc. (Chik et al., 2013). Banxia Baizhu Tianma Decoction was mainly used to treat vertigo in the past, and now it was also used to treat spontaneous hypertensive, vomiting, diarrhea, tinnitus, deafness, migraine headache, stroke, dementia, epilepsy, etc. (Jiang et al., 2011; Dong, 2012). Nowadays, a lot of prescriptions containing G. elata (Table 2) have been applied in the forms of injection, granule, pill and capsule. For example, Tianma Injection was used to treat 53 patients with vertebral basilar artery insufficiency with the total efficiency significantly higher than that of the control group (He et al., 2014). Qiangli Tianma Duzhong Capsule was prescribed for the treatment of acute cerebral infarctions for 36 patients for 28 days, and the obviously effective rate and response rate for the treatment group are 66.67% and 90.00% respectively (Shen et al., 2006). Another study was also conducted to evaluate the clinical effect and safety of Tianmasu Injection in treating vertigo symptom, and the results showed that the significantly effective rate and total effective rate for the tested groups were higher than for the control group (P<0.05) (Gao, 2012). Furthermore, it is also reported that Tianma preparations can be used in combination with other drugs to prevent and treat more diseases or increase therapeutic effects. For instance, Tianmasu Injection was used to treat diabetic neuropathy in combination with Kudiezi Injection with an affirmative effect that is superior to the chemical drugs (Wei and Cui, 2012). Banxia Baizhu Tianma Decoction was effective to treat vertebral-basilar artery insufficiency (VBI) when combined with Shuxuening Injection (Chen, 2010). G. elata not only contains phenolics and polysaccharides that can produce pharmacological activities, but also have a variety of trace elements and amino acids. 9

So it has a high nourishing and edible value and is often used to make medicinal food in folk, such as “Stewd black-bone chicken with Tianma”, a traditional dish in Yunnan province of China that can be used to treat deficiency of both qi and blood or postpartum blood deficiency characterized by dizziness, anemia and hypotension. “Tianma sleeping porridge” possesses medical functions of improving brain and bodies, sedative and sleeping effects, and can thus be used to treat stubborn sex, insomnia, dizziness, and forgetfulness. “Tianma steamed egg” used to treat dizziness, neurasthenia, etc. “Tianma stewed pig brain” has enriching essence and marrow effect, and is often used for headache, dizziness, easily angry, palpitations, and insomnia insulted by liver fire. (Zhao et al., 2013). In addition, a lot of G. elata health care products have been developed and sell well in China, such as Tianma health wine, Tianma health drinks, Tianma candy and so on (Li et al., 2002; Xiao et al., 2009). Influenced by the traditional Chinese culture and the medical system of TCM, application of G. elata as a therapeutic botanical drug is now popular in many Asian countries, especially in South Korea and Japan. In view of this fact, this plant is currently cultivated in a number of cultivation regions distributed in different cities of Korea (such as Chuncheon, Gimcheon, Muju, Sangju, and Asan) (Lee et al., 2014). While in Japan, Kampo, a traditional Japanese medicine, is widely practised and is fully integrated into the modern health-care system. In the clinical practice of Kampo, G. elata is used alone or in combination under the direction of Kampo theory similar to the basic theory of TCM (Yu et al., 2006). Table 2 The traditional and clinical usages of G. elata in China. Formulation name Tian Ma Gou Teng Yin

Dosage form Decoction

Xing Pi Wan

Compositions

Efficacy and application

References

Rhizoma Gastrodiae, Ramulus Uncariae cum Uncis, Conncha Haliotidis,Radix Scutellariae,Radix Cyathulae, Eucommia Ulmoides, Herba Leonuri,Tuber Fleeceflower stem.

Calm liver wind,clear heat, promote blood circulation, tonify liver and kidney, indicated for liver-yang hyperactivity and wind syndrome caused by liver-yang.

Zabing Zhengzhi Xinyi

Pill

Cortex magnoliae officinalis, Atractylodes Macrocephala Koidz, Brimstone, Rhizoma Gastrodiae, Scorpion, Radix Saposhnikoviae Chinese cinnamon, Ginseng.

Indicated for infantile chronic spleen wind, trapped lethargy after vomit, potentially causing seizures.

Puji Benshifang

Yu Zhen San

Powder

Rhizpma Arisaematis, Radix Ledebouriellae Radix Angelicae Dahuricae, Rhizoma Gastrodiae, Rhizoma seu Radix Notopterygii, Rhizoma Aconiti praeparatae.

Dispel pathogenic wind and eliminate phlegm, prevent convulsions and spasm, indicated for tetanus.

Waike Zhengzong

Ban Xia Bai Zhu Tian Ma Tang

Decoction

Dry dampness and eliminate phlegm, calme liver wind, indicated for

Yi xue Xinwu

Pinellia ternate, Atractylodes Macrocephala Koidz,

10

Rhizoma Gastrodiae, Pericarpium Citri Reticulatae, Poria cocos, Radix Glycyrrhizae, Fresh Ginger, Fructus Jujubae.

the syndrome.

wind-phlegm

a

Qin Jiao Tian Ma Tang

Decoction

Gentiana Macrophylla Pall., Rhizoma Gastrodiae, Rhizoma et Radix Notopterygii, Pericarpium Citri Reticulatae, Radix Angelica Sinensis, Rhizoma Ligustici Chuanxiong, Radix Glycyrrhizae preparata, Fresh Ginger, Ramulus Mori

Strengthen body resistance and eliminate evil, relieve pain, dredge the palsy and relieve pain, attending rheumatism pain, adverse joint flexion and extension.

Yi xue Xinwu

Tian Ma Wan

Pill,capsul e

Rhizoma Gastrodiae, Rhizoma seu Radix Notopterygii, Radix Angelicae Dahuricae, Cortex Eucommiae, Achyranthis Bidentatae Radix, Rhizoma Dioscoreae Hypoglaucae, Radix Aconiti preparata, Radix Angelica Sinensis, Radix Rehmanniae, Radix Scrophulariae .

Dispel wind and eliminate dampness, relax muscles and tendons, remove obstruction from meridians, indicated to treat hemplegia spasm ， numbness of extremities and aching lumbus and leg pain.

Zhongguo Yaodian

Tian Ma Tou Tong Pian

Pill

Rhizoma Gastrodiae, Radix Angelicae Dahuricae, Rhizoma Ligustici Chuanxiong, Herba Schizonepetae, Radix Angelica Sinensis, Resina Olibani.

Nourish the blood to expel wind, eliminate cold stop pain, to treat wind-cold headache, or headache due to deficiency of blood and blood stasis headache.

Zhongguo Yaodian

Tian Ma Shou Wu Pian

Pill,capusl e

Rhizoma Gastrodiae, Radix Angelicae Dahuricae, Polygonum Multiflorum, Radix Rehmanniae praeparata, Radix Salviae Miltiorrhizae, Rhizoma Ligustici Chuanxiong, Tribulus Terrestris praeparata, Mulberry Leaf, Herba Ecliptae, Fructus Ligustri Lucidi, Radix Paeoniae Alba, Rhizoma Polygonati, Radix Glycyrrhizae.

Tonify yin and replenish the kidney, nourish blood for calming endogenous wind, liver-kidney yin deficiency caused by dizziness, headache ,tinnitus, mouth-bitterness, throat-drying, soreness and weakness of waist and knees, alopecia, poliothrix and angioneurotic headache, seborrheic aiopecia and so on.

Zhongguo Yaodian

Tian Ma Qu Feng Bu Pian

Pill

Rhizoma Gastrodiae, Angelica sinensis, Radix Aconiti praeparatae, Cortex Eucommiae, Radix Angelicae Pubescentis, Poria, Radix cyathulae, Radix Rehmanniae,Cortex Cinnamoni, Rhizoma seu Radix Notopterygii,Radix Scrophulariae

Tonify kidney, nourish liver, dispel dampness and relieve pain, to treat the deficiency of liver and kidney caused by dizziness, tinnitus, muscle spasm, arthralgia and the numbness of limbs.

Zhongguo Yaodian

Approved by China Food and Drug Administration (CFDA)

11

Tian Ma Su Zhu She Ye

Injection

Gastrodin Used for neurasthenia, neurasthenia syndrome, angioneurotic headache disorder, traumatic brain syndrome, vertigo meniere disease, medicinal with dizziness, vertigo, sudden deafness, vestibular neuronitis, vertebral basilar artery blood supply deficiency, etc.

a

CFDA

a

Tian Ma Zhui Feng Gao

Plaster

Rhizoma Gastrodiae, Radix Aconiti Kusenzoffii, Radix aconite, Radix Aconiti preparata, Radix Clematidis, Herba Ephedrae, Radix Saposhnikoviae, pine nodular branch, Ramulus mori, zaocys dhumnade, Flos Carthami, Resina Olibani. Borneol, etc.

Dispel wind and eliminate dampness, promote blood circulation to remove meridian obstruction, eliminate cold to stop pain.

CFDA

Tian Zhuang Wan

Pill

Rhizoma Gastrodiae, Radix Angelicae Dahuricae, Leopard bone, Ginseng, Herba Asari, Cornu cervi pantotrichum, Cortex Eucommiae, Cortex Acanthopanacis, Radix Gentianae Macrophyllae,Herba Siegesbeckiae, Radix Saposhnikoviae, Radix angelica sinensis, Rhizoma Ligustici Chuanxiong, Radix Stephaniae Tetrandrae, Ramulus Mori, Radix Angelicae Dahuricae, Ligusticum sinense Oliv, Rhizoma seu Radix Notopterygii, Geranium wilfordii, Hedera Helix.

Dispel wind and eliminate dampness, promote blood circulation, reinforce liver and kidney, strengthen the lumbus and knees, indicated for the rheumatism, headache, dizziness, rheumatism pain, lumbar debility, numbness of limbs.

CFDA

Tian Ma Xing Nao Jiao Nang

Capsule

Rhizoma Gastrodiae ,Pheretima, Rhizoma Acori Tatarinowii, Radix Polygala, Radix Rehmanniae Preparata, Herba Cistanche

Nourish liver and kidney, dredge the meridians and relieve pain, indicated for headache, dizziness, memory loss, insomnia, unresponsive, tinnitus and lumbar acid caused by kidney deficiency.

CFDA

Qiang Li Tian Ma Du Zhong Wan

Pill, capuse

Rhizoma Gastrodiae, Cortex Eucommiae, Radix angelica sinensis, Rhizoma seu Radix Notopterygii, Radix Angelicae Dahuricae, Radix Rehmanniae, Radix Cyathulae, Viscum Coloratum,Radix aconiti kusnezoffi preparata, Radix Aconiti preparata,Ligusticum sinense Oliv, Radix Scrophulariae .

Expel the wind and promote blood circulation, relieve swelling and pain, indicated for series of symptoms caused by stroke.

CFDA

Ma Gu

a

a

a

12

a

Tian Ma Tou Feng Ling Pian

Pill,capsul e, chewable tablet

Rhizoma Gastrodiae, Radix Achyranthis Bidentatae, Radix scrophulariae, Rhizoma rehmanniae, Radix Angelica sinensis Cortex Eucommiae, Rhizoma Ligustici Chuanxiong, Viscum Coloratum, Flos Chrysanthemi Indici, Ramulus uncariae cum uncis.

Nourish Yin and suppress Yang, dispel the wind, strengthen muscles and bones, indicated for stubborn headache, chronic lumbocrural pain, long-term numbness in the hands and feet.

CFDA

Ren Sen Tian Ma Yao Jiu

Medicinal liquor

Rhizoma Gastrodiae, Ginseng, Radix Astragali, Radix Cyathulae, Rhizoma Dioscoreae Nipponicae, Flos Cartham.

Tonify Qi and promote blood circulation, relieve swelling and pain, indicated for all kinds of joint pain, waist and leg pain, numbness of limbs.

CFDA

a

a

Cited from the website: http://www.sda.com.cn (The website of China Food and Drug Administration) 3. Phytochemistry Up to now, many chemical components (Table 3), for instance, gastrodins, 4-hydroxybenzyl alcohols, vanillyl alcohols, vanillins, polysaccharides, sterols and orgnic acids, have been isolated from G. elata. Among them, gastrodin and its aglycone gastrodigenin (4-hydroxybenzyl alcohols) are considered as the characteristic and main active constituents of G. elata. The content of total phenolics in G. elata was detected by using the method of Folin-Ciocaileu colorimetry, and found that total phenols reached 0.0485% (Xiong et al., 2013). The polysaccharides content of G. elata produced in Yunnan province of China was determined by the phenol-sulfuric acid method, and showed that the highest content was 21.6% (Wang et al, 2011). In addition, the detection results for gastrodin, amino acid and total flavonoids demonstrated that their biggest contents were 0.24%, 1.92% and 0.24% respectively (Cheng et al., 2009). Other chemical constituents derived from G. elata have not been determined (Fig.2).

1. Total phenolics (0.0485%) 2. Total polysaccharides (21.6%) 3. Total flavonoids (0.235%) 4. Total amino acids (1.92%） 5. Gastrodin (0.240%) 6. β-sitosterol (0.113%) 7. Not determined (77.8%)

13

90 80 70 60 50 40 30 20 10 0 1

2

3

4

5

6

7

Fig. 2 Contents of the chemical components from G. elata

Table 3 The compounds isolated from G. elata Classification Phenolics

No. 1 2~3 4~5 6~7 8~23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Chemical component Parishin Parishin B~C Parishin D~E Parishin F~G Parishin H Vanillin Vanillyl alcohol Gastrodigenin 4-hydroxybenzyl methy lether (4-methoxyphenyl)methanol Benzyl alcohol 4-hydroxy-3-methoxybenzoic acid 4-hydroxybenzyl alcohol 4-hydroxybenzaldehyde 4-hydroxybenzyl ethyl ether 4-(4’-hydroxybenzyl)phenol 4-[4'-(4"-hydroxybenzyloxy)benzyloxy]benzyl methyl ether 1-furan-2-yl-2-(4-hydroxyphenyl)-ethanone 5-(4-hydroxybenzyloxymethyl)-furan-2-carbaldeh yde 2,4-Bis(4-hydroxybenzyl)phenol 5-[4'-(4"-hydroxybenzyl)-30-hydroxybenzyloxyme thyl]-furan-2-carbaldehyde 4-butoxyphenylmethanol 4,4'-methylenediphenol 4,4'-sulfinylbis(methylene) diphenol 4,4'-Dihydroxybenzyl sulfone Bis(4-hydroxybenzyl)sulfide 4-(ethoxymethyl)-glucopyranosyl-phenol 4-O-glucopyranosyl-benzaldehyde Gastrodin Gastrodin A

Part of plant Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome

References Lin et al.(1996） Lin et al.(1996） Yang et al.(2006） Wang et al.(2012） Li et al.(2015) Kim et al. (2007) Kim et al.((2011) Choi et al.(2006) Taguchi et al.(1981) Rohmann et al.(1961) Jang et al.(2010) Jang et al.(2010) Noda et al.(1995) Noda et al.(1995) Yang et al.(2006） Yang et al.(2006） Hye et al.(1998） Lee et al.(2007) Lee et al.(2007) Han et al.(2011) Huang et al.(2014) Rohmann et al.(1961) Ma et al.(2015) Yun et al.(1997) Mi et al.(2004) Huang et al.(2007) Ma et al.(2015) Ma et al.(2015) Baek et al.(1999) Li et al.(2007) 14

49 50 51 52 53 54 55 56

Gastrodin B Gastrol A Gastrol B 5- hydroxymethyl-2-furancarboxaldehyde Cirsiumaldehyde p-Ethoxymethyl phenyI-O-β-D-glucoside N-(p-hydroxybenzyl)-adenosine N6-(4-hydroxybenzyl)adenine riboside N6-(3-methoxyl-4-hydroxybenzyl) adenine riboside 1-furan-2-yl-2-(4-hydroxy-phenyl)-ethane-1, 2-dione 4-hydroxy 3 - 4-hydroxybenzyl) benzyl methyl ether

Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome

60 61 62 63 64 65

57

Rhizome

Li et al.(2014）

Rhizome

Wang et al.(2012）

AGEW

Rhizome

Qiu et al.(2007）

Rhizome Rhizome Rhizome Rhizome Rhizome

Qiu et al.(2007） Chen et al.(2007） Tong K et al.(2010） Wang et al.(2007） Wang et al.(2007） Wang et al.(2012）

67 68 69 70 71 72 73 74 75 76

WGEW WSS25 WSS45 Adenosine glucoside Gastrodin isomer 4-(methoxymethyl) phenyl-1-O-β-D-glucopyranoside Trimethylcitryl-b-D-galactopyranoside 5-(hydroxymethyl)-furfural 5-(hydroxymethyl)-2-furaldehyde β-sitosterol β-sitosterol glucoside 3-O-(4'-Hydroxybenzyl)-13-sitosterol L-pyroglutamic acid 6-methyl citrate 1,5-dimethyl citrate Docosanoic acid oxiranylmethyl ester

77

Gastrodamine

Rhizome

Choi et al.(2006） Ishida et al.(1996） Huang et al.(2014） Lee et al.(2007） Lee et al.(2007） Yun et al.(1998） Hao et al.(2000） Hao et al.(2000） Hao et al.(2000） Liu et al.(2002） Hao et al.(2000）

78 79 80 81

N2-(p-hydroxybenzyl) guanosine P-hydroxybenzyl guanosine P-hydroxybenzyl adenosine S-(4-hydroxybenzyl)glutathione

Rhizome Rhizome Rhizome Rhizome

Wang et al.(2009） Wang et al.(2007） Wang et al.(2007） Andersson et al.(1995）

58 59 Polysaccharid es

66

Sterols

Organic acids

Other components

Rhizome

Zhang et al.(2013) Li et al.(2007) Zhang et al.(2013) Mi et al.(2004) Yun et al.(1997） Huang et al.(2006） Huang et al.(2006） Huang et al.(2007) Shi et al.(2014)

Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Rhizome Aerial Part

3.1. Phenolics and its glycosides G. elata contains several of ingredients that have previously been characterized. Biological and biochemical activities of these constituents are investigated in lots of assays. Recent studies have confirmed the presence of abundant phenolics in G. elata, which have been thought to be the active components of this botanical drug. According to the structures (Fig. 3), these compounds have a unique structure with variants of 4-hydroxybenzyl alcohol with gastrodin (Zhou et al., 1979) and 4-hydroxybenzyl alcohols (4-HA) as principal active constituents. Gastrodin is the phenolic glucoside of 4-HA and is chosen as one of the standard compounds to evaluate the quality of G. elata and G. elata -including preparations due to its extensive pharmacological actions and unique 15

mechanisms. The phenolics constituents were reported to have prominent neuroprotective, anti-inflammatory, anti-oxidant actions and many others (Lee et al., 2012a; Han et al., 2014; Sun et al., 2012).

OH

O CH2

O

C C O CH2 H2C C

CH2

OH OH

C O H2C O HO

O

O

O

O OH OH

C O H2C O

OH

OH

OH

OH HO OH OH

OH

OH

O

O CH2

OH

O

O

O

C C O CH2

O

O OH OH

H2C COOH

OH

OH OH

O OH

1

2 OH

O CH2 C H2C

O

O

O

CH2

OH OH

O

C H2C

OH HO

C COOH H2C C

HO

CH2

O

O

O

CH2

OH OH

O

OH

O

OH

3

4 OH

O CH2 C H2C

C COOH H2C C

OH

O

OH

O

O

O OH OH

O OH

HO

C COOH H2C COOH

5 OH

O CH2

O

OH

O

HO

C C O CH2 H2C C

O

OH OH

C O H2C O O

OH

O

OH

OH OH OH

OH

O

O CH2

OH OH

O

O

OH OH

O OH

6 COOH H2C O

CH2

OH HO

C C O CH2 H2C COOH

OH

O

O

O OH OH

C O H2 C O

O OH OH

O

OH HO

C C O CH2

O

OH H2 C COOH

16 OCH3

OH

O

OH

OH OH

7

8

OH

O CH2

O

OH

O OH O

C O H2 C O OH HO

C C O CH2

O

O OH OH

OH

OH

O OH OH

H2 C COOH

9

OH

OCH3

OH

O COOH H2C O

CH2

C C O CH2 H2C C

O

O

CH3

HO

C C O CH2

OH

OCH3

O

OH

O

OCH3 OH

O CH2

O

O

OH O

C

OH OH OH

OH

O CH2

O

O

O OH OH

OH

OH

13 OH

CH2

OH OH

O

OH OH

O

O

COOH

H2C C

O

O

12

O

O OH

HO

OH O

C H2C

OH

O

O CH2

OH

O

OH OH

C C O CH2

11 CH2

C O H2C O

O CH3

O C O H2C O

OH OH

C O H2C O

OH

OH HO

HO

C C O CH3 H2C C

C C O CH2 H2C C

O

O

CH3

OH OH O

OH

O

14

15 OH

O CH2 C O H2C O

O

CH3

O

HO

O

O OH O OH

OH O OH O OH

OH O OH OH OH

C C O CH3

17 H2C C

O CH3

O

OH

O

CH3

10

H2C C

O

OH OH

H2C C

O

HO

OH OH OH

OH OH O

O

C O H2C O

OH HO

O

16 O CH3 C O H2C O OH HO

C C O CH2 H2C C

O

O OH O

OH O

OH

O

OH O

OH O OH OH

OH

OH

CH3 O

17 OH

O CH2

O

O OH OH

C O H2C O OH HO

C C O CH2

O

OH

O OH OH

H2C C

O

OH

OH OCH2

CH2

O

O

OH

O

OH OH

18

OH

O CH2

O

O OH OH

C O H2 C O

OH

OH HO

C C O CH2

OCH2

O

O

OH OH

H2 C C

O

OH

OH O

CH2

O OH OH

O OH

19 OH

O CH2

O

CH2

OH OH

C O H2C O C C O CH2 H2C C

HO

OH CH2

O

OH OH OH

OH OH

C C O CH2 H2C C

O

O

O

OH

OH

O

O

C O H2C O

OH HO

OH

O

O

OH

O OH OH

O

OH CH2

O

O

OH

18

20

21 OH

O CH2

O

O OH OH

C O H2C O

OH

OH HO

C C O CH2

O

OH

O OH O

H2C C

O

O OH OH

OH OH

COOH O

22 COOH H2C O

CHO

OH HO

C C O CH2 H2C C

O

O OH OH

O

OH

OH CH2

OCH3

OH

HO

O OCH3

OH

23

24

25

OH

CH2OH

CH2OH

HO

OCH3 OCH3

OH

26

27

28

29

COOH

CH2OCH2 CH3

HO

HO

OH

H3CO

O

OH

OH

H

30

HO

31

H2C

32

33

OH

34 HO

CH2O

CH2O

CH2OCH3

19

35 O

OH O

O O

O

H OH

36

37 CHO

O

O

HO

HO

OH

HO

OH

38

39

HO

O

OH

HO

40

41 OH

HO

OH

HO

O

O

O

S

S

42

43

O

OH

OH

CH2SH2C

HO

O HO HO

O HO

44 H

45 OH

O

O

OH O

HO O OH

HO HO

O

HO

OH OH

O HO HO

CH2 OH O

O

OH

O

HO

HO

CH2OH OH

46

47

48 20

OH O HO HO

OH

O HO

49

HOH2C

O

OH

OH

50 OH

HO

O

H

HO O O

O

51

52

O H

H

HO O O

O

O

O

O

OH

O

OH

53

54

OH

N

OCH3

NH

N

HN OH

HO

N

O

N

N

HO HO

N

N

OH

N

O OH

55

OH

OH

56

HO NH

21 N N

N

N

OH O O

O

57

58 O

HO

HO

59

Fig.3 The structures of phenolics from G. elata. 3.2. Polysaccharides Apart from above-mentioned phenolics and its glycosides (Fig. 4), polysaccharides are also a class of important ingredient of G. elata due to their certain pharmacological activities. Recently, more than ten kinds of polysaccharides have been discovered, such as GE-I, GE-II, WGEW, AGEW (Qiu et al., 2007), GBP-I and GEP-I. Its main structure is 1→6 keyed branched chain of α-(1→4)-D-glucan, GPSa, and GBII (Hong et al., 2010), and most of these polysaccharides contain α-(1→4)-D-glucan. Some of them have been evidenced to have anti-dengue virus bioactivities (Tong et al., 2010; Qiu et al., 2007). What is more, some structure-activity relationship study has been conducted, demonstrating that the glycoside from Gastrodia possesses inhibitory activity on GABA transaminase which degrades GABA (γ-aminobutyric acid), a major CNS inhibitory neurotransmitter (Choi and Lee, 2006) and has anti-angiogenesis effect (Chen et al., 2012). HO OH

HO OH OR

HO

OR HO

O

O

O

O

OH

OH OR

HO

OR HO

O

x

x

O

O

OR O

OR

O

O

O HO

HO OH

y H(x+y=14)

O

O

O

OH

O

O

O HO

HO OH

n

y

O OH

n

H(x+y=16)

22

60

61

HO OH

HO OH OR

HO

OR HO

O

O

O

O

OH

OH OR

HO

OR HO

O

x

O

x O

O

OR

OR O

O

O

O HO

HO

O

O

HO

HO

OH

OH

O

O

O

O

OH

OH

y

y

n

n

R=SO32- or H(x+y=16)

R=SO or H(x+y=16)

62

63

OH O

O

NH2

OH OH OH

OH

N

N

O

O OH

N

N

HO

OH

O

OH

HOH2C

OH

OH

64

65 O

HO O HO HO

OH

O

C OH

HO

O

O

O

CH 3

O

CH3

O

CH3

O O

C

HO

C O

OH

66

67

C

O O

O

CHO

OH H

HO

68

69

Fig.4 The structures of polysaccharides from G. elata. 23

3.3. Sterol and organic acids There are relatively few reports on sterol and organic acids constituents in G. elata (Fig. 5). Organic acids include citric acid, succinic acid (Zhou et al., 1979), palmitic acid (Wang et al., 2003), L-pyroglutamic acid, 6-methyl citrate, 1,5-dimethyl citrate (Hao et al., 2000), M-hydroxyhenzoic acid, syringic acid, protocatechu acid (Wu et al., 2013) and citric acid mono-ethyl ester (Wang et al., 2009). Sterols contain β-sitosterol, 4-hydroxy benzyl-β-sitosterol, daucosterol (Wang et al., 2006) and 3-O-(4'-hydroxybenzyl)-β-sitosterol (Yun-Choi et al., 1998). Perhaps due to it's low content in G. elata, its pharmacological action has been little investigated. O

H2C

O

COOH

N

HO

COOH O

C

C

H2C

O

O

CH3

CH3 HO

H

C

C

COOH

COOH

H 2C

H2C

C

O

CH3

O

70

71

O CH3CH2(CH2)17CH2CH2 C

72

O OCH2

HC

CH2

HO

73

74

OH O

O

OH OH HO

OH

CH2O

75

76

Fig.5 The structures of sterol and organic acids from G. elata. 24

3.4. Other compounds In addition, many other constituents (Fig. 6) were isolated from G. elata, such as 4-(methylsulfinylmethyl) phenol, dioctyl phthalate, grossamide (Wang et al., 2013), 4-thoxybenzyl alcohol, anisic alcohol, bis (3, 4-dihydroxyphenyl) methane, 4-(methoxymenthyl) benzene-1, 2-diol (Duan et al., 2013) and gastrodamine [di-(p-hydroxyl benzyl) hydroxylamine] (Hao et al., 2000). Chitinase and β-1, 3-glueanase, isolated and purified from the primary corn of G. elata, are shown to have the activity of inhibiting the growth of Trichoderma viride (Yang and Hu, 1990). What’s more, S-(4-hydroxybenzyl) glutathione was isolated as the major principle responsible for inhibition of the in vitro binding of kainic acid to brain glutamate receptors by water extracts of G. elata (Andersson et al., 1995). Furthermore, gastrodin antifungal proteins (GAFPs, also known as gastrodianins) isolated from the cortex of the terminal corm of G. elata show a strong fungistatic activity against a broad spectrum of fungi (Hu et al., 1988; Hu et al., 1994; Hu et al., 1999). G. elata also contains adenine, adenine nucleoside, AmD2-9, AmD2-20, AmD2-28 and many kinds of amino acids. (Xie et al., 2004). Among trace elements, the content of Fe in G. elata is the highest, followed by Cr, Zn, Mn, Cu, and Se. These essential trace elements have the effects to delay aging and prevention and control of diseases (Fan et al., 1991a; Fan et al., 1991b; Li et al., 2015). Some phenolic components are separated from the fresh G. elata as well, such as, gastrodin, 4-hydroxybenzenemethanol, p-hydroxy benzaldehyde, 4,4'-dihydroxy-Biphenyl methane, 4, 4'-dihydroxy-dibenzyl ether, 3,4-dihydroxy-benzaldehyde, 4-ethoxymethyl phenyl, 4'-hydroxy benzyl ether, 4-ethoxymethyl phenol and parishin ( Zhou et al., 1979; Zhou et al., 1980a; Zhou et al., 1980b; Zhou et al., 1981). Among them, gastrodin and 4-hydroxybenzenemethanol, can produce strong sedative and hypnotic effects (Deng and Mo, 1979; Deng and Mo, 1980).

CH2

HO

N

OH

CH2

OH

77 O

O

H3CO

H2N

N

N

HN

N

N

HO

N

H2N

CH2

O

N

N

O

HOH2C

H2C HO

OH

OH

OH

OH

78

79 HO

HO

NH2

CH2

25

N

N

S

N

N O

O

H

80

81

Fig.6. The structures of other compounds from G. elata.

4. Pharmacological activities 4.1. Sedative and hypnotic activities Up to date, only two active ingredients, N6-(4-hydroxybenzyl) adenine riboside (NHBA, 0.2, 1 and 5 mg/kg i.p.) and its analog N6-(3-methoxyl-4-hydroxybenzyl) adenine riboside (B2, 1 or 5 mg/kg, i.p.), isolated from G. elata, are reported to have significant sedative and hypnotic effects. Further study showed that the molecular mechanism of action for NHBA might be closely related to the activation of adenosine A1/A2A receptors and stimulation to the sleep center in the ventrolateral preoptic area (VLPO) (Zhang et al., 2012), but the molecular mechanism of B2 remains to be determined (Shi et al., 2014). 4.2. Antiepileptic and anticonvulsive activities The aqueous extracts of G. elata can regulate the activator protein 1 (AP-1) expression, thus to further modulate the neuronal plasticity and apoptosis, via the JNK signaling pathway in KA-induced epilepsy (Hsieh et al., 2007). At the same time, the methanol extract of G. elata was shown to inhibit the recovery time and severity of PTZ-induced convulsion rats, and this action might be realized by increasing the GABA content of brain (Hsieh et al., 2007). In addition, 4-hydroxybenzaldehyde (4-HBA), a kind of active component of G. elata, demonstrated an anti-oxidative effect and positive modulation of GABA, which contributes to its antiepileptic and anticonvulsive activity (Ha et al., 2000) 4.3. Anti-anxiety and antidepressant activities

Oral administration of aqueous G. elata extract or injection of its phenolic constituents, 4-HA and 4-HBA, can significantly increase the percentage of the time spent and arm entries into the open arms of the elevated plus maze (EPM) in mice. This observation suggests that they possess the anxiolytic-like effects (Jung et al., 2006). Furthermore, 75% ethanol extract of G. elata exerted antidepressant-like effect 26

comparable to that of fluoxetine in an experimental animal model (Zhou et al., 2006); the Slit−Robo pathway and neuronal cytoskeleton remodeling are possibly key players associated with the antidepressive-like effect of G. elata (Lin et al., 2014). At the same time, in a forced-swimming test (FST), G. elata showed antidepressant-like effect; the possible mechanism might be via regulating both the serotonergic and dopaminergic systems (Chen et al., 2009) or modulating the turnover of DA in rats (Chen et al., 2012). 4.4. Neuroprotective activities 4.4.1. Protection of neuronal cells and anti-apoptoticaction activities Both in vitro and in vivo studies of G. elata extracts or its ingredients on the neuroprotective activities had been conducted in the past few years. In an in vitro experiment, chloroform, methanol or ethanol extracts of G. elata, as well as the pure compounds gastrodin and 4-HBA, were shown to protect against β-amyloid insult, which is one of the major recognized causes for the onset of AD. It was also reported that G. elata has a protective effect on pheo-chromocytoma cells (PC12), primary neuronal cells and BV2 microglia cells; the protective mechanism to BV2 microglia cells is suggested to be the induction of the chaperone ER stress protein GRP78 (Lee et al., 2012a; Kim et al., 2007a; Kim et al., 2011a). Furthermore, 50% alcohol extract of G. elata has a protective effect against neuronal damage in kainic acid-treated rats by reducing neuronal nitric oxide synthase, microglia activation and apoptosis (Hsieh et al., 2005). Not only organic solvent extracts but also the aqueous extracts of G. elata were shown to reduce the β-amyloid-induced neurotoxicity through inhibition of apoptosis and reduction of oxidative stress in both Drosophila and PC12 Cells (Ng et al., 2013). These results strongly suggest that G. elata could be further developed as a promising herbal agent for neuroprotection and novel adjuvant therapies for Alzheimer’s disease. In addition, gastrodin, an active ingredient from G. elata, could induce heme oxygenase-1 (HO-1) expression through activation of p38 MAPK/Nrf2 signaling pathway, thus protecting human dopaminergic SH-SY5Y cells from 1-methyl-4-phenylpyridinium MPP+-induced oxidative cytotoxicity (Jiang et al., 2014) and up-regulating the decreased striatal dopamine (DA) content in IDPN-induced rats and down-regulating the elevated striatal DA content in apo-induced rats (Zhang and Li, 2015). Moreover, gastrodin could significantly and dose-dependently protect dopaminergic neurons against neurotoxicity to prevent dopamine depletion and reduce reactive astrogliosis, and is also effective in preventing neuronal apoptosis by attenuating antioxidant and antiapoptotic activities in these brain areas in experimental PD models (Kumar et al., 2013). These results suggest that it has the potential to be developed as a clinical drug to ameliorate PD symptoms of patients. Other ingredients, such as vanillyl alcohol, was also found to protect dopaminergic MN9D cells against MPP+-induced apoptosis by relieving oxidative stress and modulating the apoptotic process (Kim et al., 2011b). Bis (4-hydroxybenzyl) sulfide (BIS) and NHBA demonstrated the ability to prevent serum 27

deprivation-induced apoptosis in PC12 cells, in a concentration-dependent manner, and the ability to bind the adenosine A2Areceptor (A2A-R) gene that is highly expressed in GABA striopallidal neurons (Huang et al., 2007). 4.4.2. Anti-oxidative activities It is found that methanol extracts from G. elata also possess a potent neuroprotective effect against oxidative glutamate toxicity in HT22 cells through up-regulating the function of PI3K signaling pathway in association with brain-derived neurotrophic factor (BDNF), indicating that it may be a useful therapeutic agent for the treatment of oxidative neuronal death (Han et al., 2014). Furthermore, gastrodin (100 or 200 mg/ml) can effectively resist hypoxia-induced neurotoxicity in cultured rat cortical neurons, and this mechanism may involve a down-regulation of the extracellular glutamate level (Xu et al., 2007). In addition, vanillin, 4-hydroxybenzyl aldehyde (4-HBAL) and 4-HBA can significantly inhibit oxidative stress and excitotoxicity, and suppress neuronal death in CA1 region (Kim et al., 2007b). 4.4.3. Protection of neuro-synaptic plasticity The solution of G. elata in deionized water may promote neuro-regenerative processes via controlling chaperone/proteasomal degradation pathways (such as CALR, FKBP3/4, HSP70/90) (Ramachandran et al., 2012). Moreover, it also exhibited a significant inhibition on stress-related proteins and neuroprotective genes such as Nxn, Dbnl, Mobkl3, Clic4, Mki67 and Bax with various regenerative modalities and capacities related to neuro-synaptic plasticity (Manavalan et al., 2012a) and protected against lead-induced impairments on synaptic plasticity in the hippocampal CA1 region, like LTP, PPF, and I/O functions (three electrophysiological parameters for evaluation of synaptic plasticity) (Yong et al., 2009). 4.5. Anti-cardio-cerebral-vascular diseases activities G. elata also played an important role in the protection against cerebral ischemia. The water extract of G. elata was found to contribute to the improvement of synaptic plasticity and neurorestorative processes by regulating the brain proteome (Manavala et al., 2012b), and thus might be beneficial to neurodegenerative diseases. As one of the main effective constituents of G. elata, gastrodin was demonstrated to markedly decrease the infarct volume and edema volume, improve the neurological functions on cerebral ischemic injury in rats caused by transient middle cerebral arterial occlusion (MCAO) and also significantly inhibit oxygen/glucose deprivation (OGD) and glutamate-induced neuronal cell death and reduce the extracellular glutamate level following OGD. Moreover, it can significantly inhibit the increase of OGD-induced Ca2+ and NO (Zeng et al., 2006). Meanwhile, 4-HA, the aglycone of gastrodin, can reduce cerebral infarct volumes in a murine model of focal brain ischemia/reperfusion (Elodie et al., 2009). It also ameliorated ischemic injury induced 28

by transient focal cerebral ischemia in rats, and this neuroprotective effect may partly relate to attenuating apoptosis pathway (Yu et al., 2009). In addition, p-hydroxybenzyl alcohol (p-HBA) was found to protect against brain damage by modulating cytoprotective genes, for instance, protein disulphide isomerase (PDI), nuclear factor-E2-related factor2 (Nrf2), and neurotrophic factors (Kam et al., 2011). 4.6. Antipsychotic activities 5-HT1A receptor has been recently regarded as an important therapeutic target of schizophrenia. GR extract was demonstrated to affect phencyclidine (PCP)-induced abnormal behavior in mice, which may be mediated via activation of 5-HT1A receptor (Shin et al., 2011). As one of the main effective constituents of G. elata, parishin C also showed high affinity with 5-HT1A receptor as a 5-HT1A-agonist in an 8-OH-DPAT–stimulated [35S] GTP-γS binding assay (Shin et al., 2010). 4.7. Anti-vertigo activities It was demonstrated that polysaccharides of G. elata could improve food intake of vertiginous mice caused by machinery rotation, and also obviously shorten the escaping time of electrical shock in maze experiment and jumping platform test (Lei et al., 2006). However, the exact molecular mechanisms of their actions still remain to be determined. 4.8. Effect on circulatory system 4.8.1. Anticoagulant and antithrombotic activities Gastrodin has anticoagulant activity and the mechanism mainly involves its interference with the knob-to-hole interactions between fibrin molecules, thereby effectively inhibiting the formation of clots and decreasing the risk of thrombosis (Liu et al., 2006). Futhermore, polysaccharide 2-1 from G. elata has remarkable effects of anticoagulation and antithrembosis (Ding et al., 2007). This result suggested that it may be one of the main components from G. elata for antithrombosis. 4.8.2. Anti-atherosclerotic activities It was found that the ethanol extract of G. elata can suppress the endothelial extracellular matrix degradation induced by tumor necrosis factor (TNF)-α, and decrease TNF-α-induced increase of matrix metalloproteinase (MMP)-2/-9 activities (Jung et al., 2009). These observations provide new insights into the pathophysiological mechanisms for the anti-atherosclerotic properties of G. elata in vascular diseases. 4.8.3. Antihypertensive activities It was evidenced that acidic polysaccharides isolated from G. elata could reduce 29

hypertension and improve serum lipid levels in spontaneously hypertensive rats (SHR) produced by a high-fat diet (Lee et al., 2012b), but the mechanism of this effect still remains to be further studied. 4.9. Anti-inflammatory and analgesic activities Phenolic compounds are a kind of important component that can be extracted from G. elata and possess anti-inflammatory and analgesic properties via inhibiting COX activity. It was also demonstrated that both C-4 hydroxy and C-3 methoxy radicals of benzyl aldehyde from G. elata play an important role in anti-inflammatory effects (Lee et al., 2006). Moreover, the ethanol extract of G. elata was found to inhibit NO production in vivo and in vitro as well as the mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) upon stimulation by lipopolysaccharide (LPS) in RAW264.7 macrophages (Ahn et al., 2007). At the same time, it could also suppress TNF-α-induced vascular inflammatory process via inhibition of oxidative stress and NF-κB activation in HUVEC (Hwang et al., 2009), presenting anti-angiogenic, anti-inflammatory and analgesic activities. In addition, gastrodin was shown to decrease sodium currents and enhance potassium currents in diabetic small DRG neurons (Sun et al., 2012). These results indicate that it may be effective in the treatment of painful diabetic neuropathy (PDN). 4.10. Improve memory and anti-aging activities Oral administration of G. elata powder mixed with drinking water can effectively improve memory functions and normalize GABA levels in rats exposed to AlCl3 suffering from deficits in learning and memory, accompanied by increase in GABA levels in the neocortex (He et al., 2008). But, it might not decrease the content of brain cortex aluminum of rats (Niu et al., 2004) though could ameliorate the learning and memory deficits induced by forced swimming (Chen et al., 2011). In addition, gastrodin was found to improve memory impairments in the Morris water maze test and probe test, and attenuate Aβ deposition and glial activation in brains of mice (Hu et al., 2014), suggesting that gastrodin exerted neuroprotective activity via anti-inflammatory and anti-amyloidogenic effects. It was evidenced that the antioxidant effect of G. elata extract in the rat brain, another important biological function of the herb, may result from the actions of p-HBA and other phenolic compounds such as vanillin at the cellular and molecular level (Liu and Mori, 1993). The order of antioxidation potency was as follows: hydroxybenzyl alcohol > vanillyl alcohol > vanillin > hydroxybenzaldehyde (Jung et al., 2007). Thus G. elata and its main constituents may have a potential in treating neurological disease through the inhibition on lipid peroxidation in the brain. 4.11. Antivirus and antitumor activities Two glucans, WGEW and AGEW, isolated from G. elata and its sulfated derivatives (such as WSS25 and WSS45) were all shown to have strong anti-dengue virus 30

bioactivities. However, the study on structure-activity relationships (SAR) between the polysaccharides and their sulfated derivatives showed that the higher the degree of substitution is, the more potent the impact on the dengue virus infection would be (Qiu et al., 2007; Tong et al., 2010). Furthemore, G. elata extract may have the potential to alleviate tumorigenesis by a GTP-Ras-dependent pathway (Heo et al., 2007); although the precise molecular mechanisms are still unclear. Another study demonstrated that gastrodin could promote NF-κB-mediated gene transcription in CD4+ T cells that is implicated in its anticancer immunomodulatory properties (Shu et al., 2013). However, further studies are required to determine its specific anticancer actions. 4.12. Other pharmacological activities Besides above-mentioned activities, G. elata has been shown to exert other pharmacological effects. In a study on anti-huntingtin aggregations, 70% methanol extracts of G. elata was demonstrated to prevent mutant huntingtin aggregations in PC12 cells in a model of Huntington's disease (HD) and was demonstrated to increase proteasomal activity by targeting the A2A-R through protein kinase A (PKA)-dependent pathway (Huang et al., 2011). Studies on laboratory mice have shown that 30% methanol extract of G. elata protects the gastric mucosa against water immersion restraint (WIR)-induced gastric damage, at least in part by decreasing NO levels via suppression of iNOS mRNA expression (Park et al., 2007). Gastrodin was also found to prevent steroid-induced osteonecrosis of the femoral head in rats by anti-apoptosis and was found to protect against osteoporosis linking to a reduction in reactive oxygen species (Zheng et al., 2014; Huang et al., 2014). Another study found that gastrodin has a protective potential in targeting cardiac hypertrophy and fibrosis through suppression of ERK1/2 signaling (Shu et al., 2012). Besides, BIS, isolated from G. elata was found possessing anti-melanogenesis ability (Chen et al., 2015). Furthermore, the C-4 hydroxy and C-3 methoxy radicals in benzyl alcohols and aldehydes (such as 4-hydroxy-3-methoxybenzyl alcohol, 4-hydroxy-3-methoxybenzoic acid, etc.) play important roles in mediating the anti-asthmatic activities of phenolic compounds obtained from the dried roots of G. elata (Jang et al., 2010). In a recent study, water and ethanol extracts of GR were demonstrated to ameliorate dyslipidemia, hypertension, and insulin resistance. Thus it may be a beneficial therapeutic approach for metabolic syndrome (Kho et al., 2014; Teong et al., 2011). It was also found that the water extract mainly reduced insulin resistance as a result of the action of 4-HBA and vanillin contained in G. elata (Park et al., 2011). All in all, the experimental results that G. elata has remarkable effects on nervous system, cardiocerebral vascular system and blood circulation system have powerfully supported the traditional use of it as a neuroprotective, sedative, hypnotic, anti-epileptic, anti-convulsive, anti-anxiety, anti-depressant and blood circulation regulating herbal medicine. Furthermore, besides its traditional use for nervous system, modern pharmacological experiments have shown more other activities, such as anti-tumor, anti-virus, memory-improving, anti-aging, etc. Although the 31

mechanisms of some of these activities have not been fully clear, there has already been a clue that the therapeutic effectiveness of G. elata on a variety of disorders is somewhat based on its wide-reaching biological activities. Table 4 Bioactivities of the extracts and compounds from G. elata. Pharmacological activities Sedative and hypnotic activities

Antiepileptic and anticonvulsive activities

Anti-anxiety and antidepressant activities

Extract/Compound

Types

Testing subjects

Dose

Effects

References

N6-(3-methoxyl-4-hyd roxybenzyl) adenine riboside (B2)

in vivo

male ICR mice

1, 5 mg/kg i.p.

shortened the sleep latency, prolonged NREM sleep and shortened wakefulness

Zhang et al., 2012

N6-(4-hydroxybenzyl) adenine riboside (NHBA)

in vivo

0.2, 1, 5 mg/kg i.p.

decreased wakefulness time and increased NREM sleep time

Shi et al., 2014

aqueous extracts of G. elata

in vivo

adult male ICR mice-treated with sodium pentobarbital male SD rats –treated with kainic acid (KA)

0.5, 1.0 g/kg/day for 2 weeks p.o.

regulated the AP-1 expression via the JNK signaling pathway

Hsieh et al., 2007

4-HBA

in vivo

male SD rats –treated with pentylenetetrazole (PTZ)

500 mg/kg p.o.

inhibited the recovery time and severity, increased the brain GABA contents

Ha et al., 2000

aqueous extracts of G. elata

in vivo

elevated plus maze (EPM) in male ICR mice

50, 100, 200, 400 mg/kg p.o.

increased the percentage of time spent and arm entries into the open arms of the EPM

Jung 2006

et

al.,

4-HA

in vivo

the same as above

5, 10, 25, 50, 100 mg/kg i.p.

the same as above

Jung 2006

et

al.,

4-HBA

in vivo

the same as above

5, 10, 25, 50, 100 mg/kg i.p.

the same as above

Jung 2006

et

al.,

75% ethanol extracts of G. elata

in vivo

behavioral models of male kunming mice

100, 200, 300 mg/kg p.o.

reduced the immobility duration in FST and TST

Zhou 2006

et

al.,

aqueous extracts of G. elata

in vivo

male SD rats

500 mg/kg p.o.

Lin et al., 2014

aqueous extracts of G. elata

in vivo

0.5, g/kg

1.0 p.o.

Chen 2009

et

al.,

water extracts of G. elata

in vivo

using forced-swimming test as an animal model of depression (6 weeks old male SD rats) 6 weeks old male SD rats

down-regulated Slit-Robo pathway mediating neuronal cytoskeletal remodeling processes regulated serotonin and dopamine concentration and their metabolism

1.0 p.o.

g/kg

decreased the turnover of DA in striatum

Chen 2012

et

al.,

Neuroprotective activities

32

Protection of neuronal cells and anti-apoptotic activities

chloroform, methanol or ethanol extracts of G. elata, gastrodin, or 4-HBA

in vitro

BV2 microglial treated β-amyloid

50% alcohol extracts of G. elata

in vivo

aqueous extracts of G. elata

in vivo and in vitro

gastrodin

1 mg/ml

against β-amyloid-induced cell death, possibly through the enhancement of protein folding machinery of a representative protein, GRP78, and the regulation of CHOP in BV2 mouse microglial cells

Lee et al., 2012a; Kim et al., 2007a; Kim et al., 2011a

adult male SD rats-treated with KA injection drosophila and PC12 cellstreated with β-amyloid

0.5, 1.0 g/kg p.o. 1 , 5 mg/g 250-1000 µg/ml

mediated the suppression of nNOS and microglia activation upregulated the enzymatic activities of catalase, superoxide dismutase, and glutathione peroxidase

Hsieh et al., 2005

in vitro

human dopaminergic cells-treated with MPP+

1, 5, 25 µM

Jiang 2014

gastrodin

in vivo

Wistar rats (male, 4 weeks old)-treated with apomorphine (Apo)

20 mg/kg/day intraperito neal injection

gastrodin

in vitro and in vivo

six-week-old male C57BL/6 mice and human dopaminergic SH-SY5Y cells-treated with MPP+

10, 30, 60 mg/kg 1, 5, and 25 µM

up-regulated heme oxygenase-1 (HO-1) expression through activation of p38 MAPK/Nrf2 signaling pathway increased the down-regulated striatal DA content in IDPN-induced rats, decreased the up-regulated striatal DA content in Apo-induced rats prevented the ROS generation; augmented SOD activity; regulated Bax/Bcl-2 mRNA, caspase-3, and cleaved poly (ADP-ribose) polymerase (PARP)

in vitro

MN9D dopaminergic cells-treated with MPP+

10, 100, 200 µg/m l

Kim et 2011

in vitro

PC12 cell ischemic/hypoxic model

1×10-10 to

attenuated the elevation of ROS levels, decreased the Bax/Bcl-2 ratio and poly (ADP-ribose)polymerase proteolysis prevent serum deprivation-induced apoptosis in PC12 cells and to bind A2A-R up-regulated the PI3K signaling pathway and inhibited production of ROS inhibited the extracellular glutamate level induced by NMDA insult

Xu et al., 2007

vanillyl

alcohol

BIS and NHBA

Anti-oxidative activities

mouse cellswith

-5

1×10

M

methanol extracts of G. elata

in vitro

HT22 hippocampal cells-treated with glutamate(5 mM)

0.1 to 30 g/ml

gastrodin

in vitro

rat cortical neurons treated with hypoxia

100, 200 mg/ml

Ng et al., 2013

et

al.,

Zhang and Li, 2015

Kumar et al., 2013

al.,

Huang et al., 2007

Han et 2014

33

al.,

Protection of neuro-synaptic plasticity

Anti-cardio-cerebr al-vascular diseases activities

Antipsychotic activities

Vanillin, 4-HBAL and 4-HBA

in vivo

hippocampal CA1 cell death following global ischemia human neuronal SH-SY5Y cells

40 mg/kg i.p.

Suppressed neuronal death in CA1 region. after global ischemia

Kim et 2007b

supernatant of powdered Tianma in water

in vitro

supernatant of G. elata powder in water

1 mg/ml per well

Ramachandran et al., 2012

in vivo

mouse neuronal N2a cells

1 mg/ml per well

controlled chaperone/proteasomal degradation pathways (e.g. CALR, FKBP3/4, HSP70/90) and mobilized neuro-protective genes (such as AIP5) as well as modulated other proteins (RTN1/4, NCAM, PACSIN2, and PDLIM1/5) inhibited stress-related proteins and mobilized neuroprotective genes such as Nxn, Dbnl, Mobkl3, Clic4, Mki67 and Bax

gastrodin

in vitro

wistar rats on postnatal day 22

relieved LTP, PPF, and I/O functions were impaired in lead-exposed rats

Yong 2009

et

al.,

supernatant of G. elata powder in water

in vivo

one-year-old male Wistar Kyoto rats brain tissue

modulated the brain protein metabolism at the proteome level

Manavala al., 2012b

et

phenolic gastrodin

in vitro

transient middle cerebral arterial occlusion (MCAO) model and rat hippocampal neurons injuried byoxygen/glucose deprivation (OGD) or glutamate

50, 100, 200, 400 mg/kg/d intraperito neally injection 2.5 g/kg/day for 3 months p.o. 50, 100 mg/kg (intraperit oneal injection) 15, 30 µg /ml

inhibited OGD-induced NO increases

Zeng 2006

4-HBA

in vivo

C57 black J6 mice MCAO model

25 mg/kg i.e.

reduced total, cortical and sub-cortical infarct volumes by 42%, 28% and 55%

Elodie et al., 2009

4-HBA

in vivo

cerebral ischemic injury rats

25, 50 mg/kg p.o.

increased the expression of Bcl-2 and inhibited the activation of caspase-3 ultimately

Yu et al., 2009

p-HBA

in vitro and in vivo

female SD MCAO model

rats

25 mg/kg p.o.

modulated cytoprotective genes, such as Nrf2 and PDI, and neurotrophic factors

Kam 2011

et

al.,

supernatant of G. elata in 0.5% carboxymethylcellulos e

in vivo

male C57BL/6J mice or male ICR mice- treated with Phencyclidine

500 , 1000 mg/kg/day p.o.

mediated via activation of 5-HT1A in mice.

Shin 2011

et

al.,

glucoside

the Ca2+and

al.,

Manavalan et al., 2012a

34

et

al.,

Parishin C

in vivo

male C57BL/6J mice or male ICR mice

25, 50, 100 mg/kg /day i.p.

activated receptors

Anti-vertigo activities

polysaccharides of G. elata

in vivo

male Kunming mice

50, 10, 200 mg/kg p.o.

obviously shortened the escaping time of electrical shock and increase food intake of mice

Lei et al., 2006

Effect on circulatory system Anticoagulant and antithrombotic activities

gastrodin

in vivo

rats

interference with the knob-to-hole interactions between fibrin molecules

Liu et al., 2006

in vitro and in vivo

male Kunming mice and Wisatr rats

7.5, 15, 30 mg /kg tail intravenou s injection 10, 20, 40 and 30, 60, 120 mg/kg intraperito neal injection

remarkably prolonged CT and BT, increased bleeding capacity

Ding 2007

et

al.,

polysaccharide from G. elata

2-1

5-HT1A

Shin et 2010

al.,

Antihypertensive activities

acidic polysaccharides

in vivo

spontaneously hypertensive rats modle

6 mg/kg p.o.

decreased blood pressure and serum lipid levels

Lee et 2012

al.,

Anti-inflammatoy and analgesic activities

phenolic compounds

in vivo

pathogen-free male SD ratstreated with carrageenan

12.5, 25, 50 mg/kg p.o.

had anti-inflammatory and analgesic properties and inhibited COX activity and silica-induced ROS generation in a dose-dependent manner

Lee et 2006

al.,

ethanol extracts of G. elata

in vivo and in vitro

male ICR mice-treated with 0.7% acetic acid and RAW264.7 macrophages treated with LPS

50, 100, 200 mg/kg p.o. 0, 0.25, 0.5, 1.0 mg/ml

inhibited NO production

Ahn et 2007

al.,

99.0%ethanol extracts of G. elata

in vivo

human umbilical vein endothelial cells

1, 10, 50 µg/ml

inhibited oxidative stress and NF-κB activation

Hwang et al., 2009

gastrodin

in vivo

rats-treated with streptozotocin (STZ)

5, 10 ,20 mg/kg intraperito neal injection

decreased transient sodium currents, increased potassium currents in diabetic small DRG neurons

Sun et 2012

G. elata powder mixed in the water

in vivo

adult male SD rats-treated with aluminum chloride (5 or 10 mg/kg/day (i.p.) for 2 months)

0.4 g/kg p.o.

decreased Al concentrations in the neocortex and increased in cortical GABA levels

He et al., 2008

water decoction of G. elata

in vivo

4 g/kg/d p.o.

in vivo

increased the expression of c-fos mRNA in hippoeampus and cerebellum improved retention by

Hu et al., 2003

water extracts of G.

male Wistar ratstreated with lead acetate(0.2 or 0.1 g/kg/d) four-week-old male

Improve memory and anti-aging activities

0.5,

1.0

Chen

35

et

al.,

al.,

elata

Antivirus antitumor activities

and

Other pharmacological activities

SD rats learning deficits model

g/kg

p.o.

shortening escape latency in the first test session and increasing the time in searching the target zone during the probe test regulated the cholinergic system and the monoaminergic system.

2011

methanol extract of G. elata

in vivo

SD rats-treated with aluminum

0.4g/kg p.o.

Niu et 2004

p-HBA ,Vanillin

in vitro

rats brain tissue (8-week-old male SD rats-treated with Fe(Ⅱ)-H2O2)

0, 0.0025, 0.025, 0.25, 2.5%

a dose-dependent inhibition on Fe ( Ⅱ )-H2O2-induced damage to benzoate, deoxyribose, glutamic acid, 2-aminabutyric acid and methionine, as well as benzoate hydroxylation

Liu and Mori, 1993

ether fraction of the methanol extract of G. elata, vanillin, vanillyl alcohol, hydroxybenzaldehyde and hydroxybenzyl alcohol

in vivo

male Mongolian gerbils-treated with H2O2

500 mg/kg/day for 2 weeks p.o.

inhibited auto-peroxidation and H2O2-induced lipid peroxidation; the order of antioxidation potency was as follows: hydroxybenzyl alcohol >vanillyl alcohol >vanillin > hydroxybenzaldehyde

Jung 2007

et

al.,

WSS45

in vitro

BHK cells-treated with DV2 infection

0.1, 1, 10 µg/ml

inhibited DV2 infection in BHK cells with an EC50 value of 0.68±0.17 µg/ml, mainly interfered with virus adsorption

Tong 2010

et

al.,

WGEW and AGEW

in vitro

C6/36 cells

0.6 g WGEW, 1.8 g AGEW

the higher the DS is, the more potent the impact on the dengue virus infection would be

Qiu et 2007

al.,

99.0% ethanol extract of G. elata

in vitro

30, 100 μg/ml

alleviated tumorigenesis, by a GTP-Ras-dependent pathway

Lee et 2009

al.,

methanol extracts of G. elata

in vitro

primary cultured HUVEC and endothelial cell-treated withnecrosis factor-alpha murine melanoma cell line B16-F1 and human umbilical vein endothelial cells (HUVECs)

30, 100 μg/ml

alleviated tumorigenesis in a dose-dependent manner, by a GTP-Ras-dependent pathway; but the precise molecular mechanisms are still being examined

Heo et 2007

al.,

70% MeOH extracts of G. elata

in vitro

Rat PCl2 cells

0 to 500 μg/ml

prevented mutant Htt aggregations targeting the A2A-R through PICA-dependent pathway.

Huang et al., 2011

36

al.,

30% methanol extracts of G. elata

in vivo and in vitro

mouse water immersion restraint (WIR) stress-induced gastric lesion model

20 ml/kg p.o. 30 μg/ml

decreased in serum and gastric musoca nitric oxide (NO) levels to 50 and 28%, respectively

Park et 2007

gastrodin

in vitro

hBMMSCs RAW264.7 cells-treated H2O2

0.1, 1, 10 μM

increased mRNA and protein expression of Bax, Bcl-2, and Caspase-3, decreased the Bcl-2 mRNA and protein expression levels attenuated fibrosis and collagen synthesis through abrogating ERK1/2 signaling pathway the molecular modeling demonstrates that the sulfur atom of BIS coordinating with the copper ions in the active site of tyrosinase is essential for mushroom tyrosinase inhibition and the ability of diminishing the human melanin synthesis

Zheng et al., 2014; Huang et al., 2014

and with

gastrodin

in vivo

adult male C57/B6 mice

100 mg/kg/day p.o.

BIS

in vivo

zebrafish

5, 50 μM

4-hydroxy-3-methoxy benzyl alcohol

in vivo

male dunkinhartley guinea pigs

12.5, 25, 50 mg/kg p.o.

water extracts of G. elata

in vivo

male SD rats

0.3, 1.0 g/kg p.o.

ethanol extracts of G. elata

in vivo

six-to-seven-week-o ld male SD rats

2.5 g/kg for 7 weeks p.o.

al.,

Shu et 2012

al.,

Chen 2015

et

al.,

the C-4 hydroxy and C-3 methoxy radicals in benzyl alcohols and aldehydes play important roles in mediating the anti-asthmatic activities

Jang et 2010

al.,

reduced insulin resistance by decreasing fat accumulation in adipocytes by activating fat oxidation and potentiating leptin signaling in diet-induced obese rats isoprenaline (IPNA)-induced relaxation remained unchanged in –UE strips after Tianma treatment, but the potency of IPNA was lower in Tianma-treated +UE strips in the longitudinal direction

Park 2011

al.,

et

Teong et al., 2011

5. Quality control G. elata can be found all over China and its broad distribution determines its quality variations among the different producing areas. Up to date, there are almost ten representative national GAP (Good Agricultural Practice) bases located in Yunnan, Sichuan, Guizhou, Shanxi and Hubei province. G. elata is one of the botanical drugs 37

that is most prone to adulteration due to its high economic value and there are many instances of fakes on the market. In the Pharmacopeia of Peoples Republic of China, qualitative identification by thin layer chromatography (TLC) and determination of content by high performance liquid chromatography (HPLC) are mainly used to evaluate the quality of G. elata. Gastrodin is chosen as the marker component to control the quality of G. elata, and it’s required that the content of gastrodin should be no less than 0.2% with the specified methods (Chinese Pharmacopoeia Commission, 2015). However, using only one ingredient as the marker might not be sufficient to fully clarify the quality of G. elata due to its complex constituents and multifarious pharmacological activities. In fact, more important bioactive constituents should be integrated into the quality control system of G. elata. Encouragingly, in recent years, the method of HPLC fingerprinting has been developed to describe the chemical constituents and to control the quality of many Chinese herbs, as well as to evaluate the quality of G. elata from different producing areas (Wang et al., 2006b). 6. Toxicology Clinical reports on the toxicity of G. elata are relatively few. It was found that gastrodin was capable of repressing transplanted H22 ascitic hepatic tumor cell growth in vivo with low toxicity (Shu et al., 2013). But according to a recent report, intramuscular injection of gastrodin could cause severe allergic reactions and even allergic shock (Hou and Fang, 2012). Subcutaneous injection of Tianma Injection at the dose of 75g/kg, mice were shown to be quiet without other behavioral changes. However, intravenous injection of Tianma Injection, LD50 of the mice is 39.8g/kg (36.5g/kg-43.5g/kg), but intravenous injection of 1000 mg/kg glycosides from G. elata, no obvious toxic reaction was observed (Huang and Wang, 1985). BIS was found to be a strong competitive inhibitor against mushroom tyrosinase, and an in vivo zebrafish assay reveals that BIS can effectively reduce melanogenesis with no serious side effects. But in an acute oral toxicity study with mice, it was shown to be free of discernable cytotoxicity (Chen et al., 2015). 7. Concluding remarks A large number of investigations of G. elata have been carried out due to its wide use in the healthcare as well as in the clinical pratice of TCM in both China and some Asian countries. To date, more than 81 compounds have been isolated from G. elata, predominantly phenolics and its glycosides, polysaccharides, sterols and organic acids. Among these ingredients, phenolics and their glycosides have been proven to be closely linked to the pharmacological activities of G. elata. As one of the main active ingredients, gastrodin was shown to possess a variety of actions such as protect ion of neuronal cells, anti-apoptotic, anti-oxidative, anticoagulant and antithrombotic, anti-inflammatory, anti-aging and analgesic activities. Although the in vitro and in vivo studies have provided evidence strongly indicating that G. elata is useful in many diseases, pharmacological research validating its traditional uses is still limited. 38

To date, most of the studies that have been performed on G. elata were based on its total extracts (mostly poorly characterized), more promising natural chemical compounds-especially the trace amount but highly effective ingredients, should be extracted and purified with the most advanced chemical technologies. In addition, more studies regarding pharmacodynamics and pharmacokinetics should be conducted using the key natural ingredients derived from this plant in order to clarify the pharmacological mechanism of action and to search for the metabolites responsible for the activities of G. elata. Furthermore, the current study on the phytochemistry of this plant were mainly targeting on its tubers while studies on other parts, such as stem and leaves, are still lacking. In Compendium of Materia Medica (Ben cao gang mu), both stem and leaves of G. elata are regarded as medicinal parts entering liver meridian and also effective in treatment of the diseases caused by invasion of the wind. Therefore, more investigations on the chemical composition and pharmacological actions of these medicinal parts should be encouraged. The current price for G. elata is becoming higher and higher due to its increasing demand in the herbal market, especially the wild sources of G. elata are dwindling dramatically due to exhaustive exploitation. This thus raises concerns about the possible delibrate confusion of this herbal drug with others, such as mirabills jalapa L. (family nyctaginaceae), ahlia plnnata Cav. (family compositae), canna edulis Ker.(family cannaceae), cacalia tangutica (Fr.) H.M. (family composltae) and cacalla davidll (Fr.) H.M.(family compositae). Though quite similar in appearance of dried roots or tubers, their contents in the active ingredients and bioactivities vary greatly. Thus, how to exclusively and accurately monitor and evaluate the quality of samples, by detection of multiple active ingredients instead of only one, to identify G. elata from its confusing herbs to ensure and maintain its clinical efficacy and pharmaceutical stability, should be further studied. Acknowledgments This work was supported by grants from the National Natural Science Foundation of China (81274112; 81373986; 81473372; 81403322; 81403125), Beijing Municipal Natural Science Foundation (7152106), Inheritance Program of China Academy of Chinese Medical Sciences (CM2014GD3002) and Voluntary Program of China Academy of Chinese Medical Sciences (ZZ2014056).

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Graphical Abstract

pharmacological properties Sedative and hypnotic activities Antiepileptic and anticonvulsive Anti-anxiety and antidepressant Neuroprotective activities Antivascular diseases Other activities

Traditional uses Dizziness Epilepsy Convulsion Numbness of the limbs Rheumatic arthralgia Headaches

Phytochemicals Phenolics and its glycosides Polysaccharides Sterol and organic acids Other compounds

Gastrodia elata Blume

49