Antioxidant Capacities of Herbal Infusions

C H A P T E R

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Antioxidant Capacities of Herbal Infusions Sha Li*, Shu-Ke Li*, Hua-Bin Li*, Xiang-Rong Xu†, Gui-Fang Deng*, Dong-Ping Xu* *Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, China, †Key Laboratory of Marine Bio-resources Sustainable Utilization, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China

of years. One special kind of herbal infusion is called cool tea (‘Liang cha’ in Chinese), which originated from South China. The cool tea is made from different kinds of herbs, and its spread has been from South China to the whole of China, and from China to about 20 countries around the world, such as the USA, Canada, UK, France and Germany. The cool tea has the efficacies of ­clearing away heat, detoxification, dewetting, moistening lungs, and stopping thirst (Fu et al., 2011). Antioxidant ­capacities of many herbal infusions have been evaluated in the literature, and it has been found that some herbal infusions possess high antioxidant capacities, and could be important dietary sources of natural antioxidants for the prevention of diseases caused by oxidative stress (Fu et al., 2011). In this chapter, antioxidant capacities and main antioxidant components of some herbal infusions are summarized.

CHAPTER POINTS • O  xidative stress plays an important role in many chronic and degenerative diseases, such as cardiovascular diseases, cancer, and aging. • Dietary supplements of antioxidants are very important to enhance the body’s antioxidant defenses. • Natural antioxidants may come from fruits, vegetables, and beverages. • Herbal infusions are known to be safe because they have been drunk as beverages for thousands of years. • Some herbal infusions possess high antioxidant capacities, and could be important dietary sources of natural antioxidants for prevention of diseases caused by oxidative stress. • The antioxidant components in some herbal infusions have been identified, and their antioxidant mechanism should be studied further.

ANTIOXIDANT CAPACITIES OF HERBAL INFUSIONS Lemon verbena is used as a primary ingredient in infusions and nonalcoholic drinks because of its good sensorial attributes. The antioxidant activity of lemon verbena infusion as well as the thermal stability of its antioxidant activity and the content of polyphenolic compounds was studied (Abderrahim et al., 2011). The values reflecting the antioxidant activity of lemon verbena infusion, including antioxidant activity index, fast scavenging rate against 2,2-diphenyl-1-picrylhydrazyl, Trolox-equivalent antioxidant capacity (TEAC), and hydroxyl radical scavenging, are higher than those of many herbal infusions and antioxidant drinks estimated from reported data. In addition, the slope lag time and

INTRODUCTION The oxidative stress caused by reactive oxygen species plays an important role in many chronic and degenerative diseases, such as cardiovascular diseases, cancer, aging, and diabetes mellitus. Dietary supplements of antioxidants have become a popular way to enhance the body’s antioxidant defenses. Natural antioxidants may come from vegetables, fruits, and beverages. Herbal infusions have been drunk as beverages for thousands

Processing and Impact on Antioxidants in Beverages http://dx.doi.org/10.1016/B978-0-12-404738-9.00005-2

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© 2014 Elsevier Inc. All rights reserved.

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5.  ANTIOXIDANT PROPERTIES OF HERBAL INFUSIONS

specific oxyradical antioxidant capacity values of lemon verbena infusion are comparable to those of a commercial antioxidant drink based on green tea. In another study, four different oak leaves were analyzed as potential nutraceutical beverages (Rocha-Guzman et al., 2012). The phenolic composition, antioxidant capacity, and sensory preferences of leaf infusions from Quercus resinosa, Q. sideroxyla, Q. eduadii, and Q. durifolia were investigated. Herbal infusions from oak leaves were evaluated for total polyphenol content (TPC), total flavonoid content (TFC), high-performance liquid chromatogra­ phy (HPLC) analysis, TEAC, oxygen radical absorbance capacity (ORAC), soluble solids, pH, color, and consumer preference analysis. Q. resinosa leaves infusions showed the highest TPC, TEAC, and ORAC values but they attained the lowest preference score. Quercus leaf infusions with higher contents of gallic acid and catechins showed the best antioxidant capacity but lower consumer preference. Small centaury (Centaurium erythraea Rafin.) is an herbal species that has long been used in traditional medicine due to its digestive, stomachic, tonic, ­depurative, sedative, and antipyretic properties, and contains considerable amounts of polyphenolic compounds, namely xanthones and phenolic acids as the main constituents. The ability of small centaury infusion to act as a scavenger of the reactive oxygen species hydroxyl radical and hypochlorous acid was studied and compared with that of green tea (Camellia sinensis L.). Hydroxyl radical was generated in the presence of Fe3+-EDTA, ascorbate and H2O2 (Fenton system) and monitored by evaluating hydroxyl radical-induced deoxyribose degradation. The reactivity towards hypochlorous acid was determined by measuring the inhibition of hypochlorous acid-induced 5-thio-2-nitrobenzoic acid oxidation to 5,5′-dithiobis(2-nitrobenzoic acid). The results demonstrated that small centaury infusion exhibited interesting antioxidant properties, expressed both by its capacity to effectively scavenge hydroxyl radical and hypochlorous acid, although with a lower activity against the second than that observed for green tea (Valentao et al., 2003). In another study, the total antioxidant capacity of the aqueous extracts of some endemic herbs—prepared as infusions by steeping these herbs in hot water—was assayed with bis(neocuproine) copper(II) chloride, also known as the cupric-ion-reducing antioxidant capacity (CUPRAC) reagent, which was easily accessible, rapid, stable, and responsive to both hydrophilic and lipophilic antioxidants. The highest antioxidant capacities of some herbal teas available on the Turkish market were observed for scarlet pimpernel (Anagallis arvensis), sweet basil (Ocimum basilicum), green tea (Camellia sinensis), and lemon balm (Melissa officinalis), in the order of 1.63, 1.18, 1.07, and 0.99 mmol Trolox equivalent/g, respectively (Apak et al., 2006).

Hot water infusions (teas) of air-dried petals of 12 rose cultivars were assayed for antioxidant activity, total phenols, and total anthocyanins contents. Their composition was analyzed by HPLC. Rose petal teas from different cultivars exhibited scavenging capacity toward 2,2′-azino-bis-(3-ethylbenzothiazoline)-6-sulfonate cation radical (ABTS•+) ranging between 712.7 and 1770.7 μM Trolox equivalents (TE) per gram of dry petals, as compared with 1227.6 μM TE/g dry weight in the green tea. The range of total phenol content in rose teas was 50.7 to 119.5 mg gallic acid equivalents (GAE) per gram of dry matter, as compared with 62.1 mg GAE/g dry weight in the green tea. The rose teas were rich in free gallic acid. The highest values of antioxidant activity, total phenols, and gallic acid contents were found in the cultivars San Francisco, Katharina Zeimet, and Mercedes, and in the essential-oil-bearing rose Rosa damascena. The correlation coefficients between antioxidant activity and the contents of total phenols and of gallic acid in various rose cultivars, were 0.79 and 0.81, respectively. No clear relationship between anthocyanin level and radical-scavenging activity was revealed. Teas from different rose cultivars significantly differed in their sensory properties. The dried rose petals may be used for preparing antioxidant-rich caffeine-free beverages, either separately or in combination with other herbal materials (Vinokur et al., 2006). In a study, the antioxidant capacity of six herbal tea infusions (Mentha piperita, Erythroxylum coca, Rosa moschata, Tilia spp, Plantago major, and Aloysia citriodora) was measured by ORAC-type methodologies employing fluorescein (ORAC-FL) and pyrogallol red (ORAC-PGR) as target compounds. Probe consumption profiles were widely different, with neat induction times when FL was employed as target. Relative ORAC values of different herbal infusions depended upon the test molecule employed. Relative ORAC-PGR values followed the order: Rosa moschata > Mentha piperita > Tilia sp > Plantago major > Aloysia citriodora > Erythroxylum coca, while for ORAC-FL the order was: Mentha piperita > ­Aloysia citriodora > Erythroxylum coca > Rosa moschata > Tilia sp > Plantago major (Poblete et al., 2009). In another study, 12 plants used traditionally in ethno-medicine from the South American Andes were investigated. Infusions were compared in terms of their free radical-scavenger properties, using four different methods: AAPH-induced hemolysis, TEAC-DPPH, ferric reducing antioxidant power (FRAP), and TEAC-crocin. All herbal teas showed strong antioxidant capacities, and the results obtained with FRAP and TEAC-DPPH were very similar. When compared at a dilution of 0.03%, Parastrephia lucida, Parastrephia lepidophylla, Senecio nutans, Azorella compacta, and Baccharis tola, showed a protective effect against oxidative damage on human erythrocytes greater than that of Trolox (p < 0.001). Upon correlating the polyphenolic contents with the antioxidant capacity, a positive association for all plants (TEAC-DPPH versus

1.  COMPOSITION AND CHARACTERIZATION OF ANTIOXIDANTS

Antioxidant Capacities of Herbal Infusions

GAE; r2 = 0.7437) was found. Interestingly, there was a better correlation between polyphenolic contents and the protective effect against APPH-induced haemolytic activity (Rojo et al., 2009). Lippia citriodora is an herbal species which contains several flavonoids and phenolic acids. In a study, the superoxide radical, hydroxyl radical, and hypochlorous-acid-scavenging activities of L. citriodora infusion were examined. Superoxide radical was generated either in an enzymatic or in a chemical system, and scavenging ability was assessed by the inhibition of nitroblue tetrazolium reduction. Hydroxyl radical was generated by the reaction of an iron–EDTA complex in the presence of ascorbic acid, and was assayed by evaluating deoxyribose degradation. Hypochlorous acid scavenging activity was tested by measuring the inhibition of 5-thio-2-nitrobenzoic acid oxidation. The results demonstrated that this infusion had a potent superoxide radical scavenging activity and moderate scavenging activities of hydroxyl radical and hypochlorous acid (­ Valentao et al., 2002). Lippia javanica and Lippia scaberrima are used as herbal remedies and are commercially traded as health teas in southern Africa under the brands ‘Mosukujane’ and ‘Musukudu’, respectively. A study evaluated the relationship between the presence of phenolic compounds and the antioxidant activities of infusions prepared from four Lippia species (L. javanica, L. scaberrima, L. rehmannii and L. wilmsii) indigenous to South Africa. Of the four indigenous species, infusions of L. javanica and L. wilmsii exhibited the highest antioxidant activities (EC50: 358 and 525 μg/ml, respectively) and contained the most phenolic compounds (14.8 and 14.5 mg/ml, respectively) (Shikanga et al., 2010). Lippia multiflora, a perennial, aromatic shrub commonly known as bush tea has recently been identified as an African plant with high commercial potential due to its medicinal properties. The plant material was subjected to steam pasteurization to improve its microbial quality. The major compounds of L. multiflora herbal infusion, i.e., the phenylethanoid glycosides, verbascoside, isoverbascoside, nuomioside A and isonuomioside A, and the flavone, luteolin-7-O–glucuronide, were quantified by HPLC. Verbascoside was the most abundant phenylethanoid glycoside. The phenylethanoid glycosides are of interest due to their pharmacological properties. Liquid chromatography tandem-mass spectrometry was used to tentatively identify the compounds. The on-line DPPH (2,2′-diphenyl-1-­picrylhydrazyl radical) scavenging assay (reaction time = 0.45 s) applied to the infusion in ‘quantitative’ mode, showed the relative order of activity: isonuomioside A > isoverbascoside > verbascoside > nuomioside A. In the microplate assay (reaction time = 2 h), isoverbascoside and verbascoside had similar activities. Both compounds were less active in the latter assay than the well-known flavan-3-ol antioxidant, (−)-epigallocatechin gallate, but more active

43

than caffeic acid and an ester, rosmarinic acid. Steam pasteurization of L. multiflora leaves at maximum exposure (150 s at ca. 99°C) for improved microbial quality did not decrease the soluble solids content, phenolic content, and antioxidant activities of the infusion compared to the untreated control (p < 0.05). The phenylethanoid glycoside content of the water-soluble solids was as high as 15%, underscoring the potential of L. multiflora extract as a functional ingredient (Arthur et al., 2011). Hot water extracts of the herbal tea, rooibos, are increasingly used as an ingredient in ready-to-drink beverages and a variety of food products. The extent of variation in total polyphenol, aspalathin, orientin, and isoorientin contents, as well as total antioxidant capacity (TAC) of hot water extract of fermented rooibos was determined and compared with that of the hot-water-soluble solids of infusions, prepared similarly to a cup of tea. Extract preparation from a large number of individual rooibos production batches (n = 74) partly simulated industrial processing, while infusions were prepared from a subset of samples (n = 20). Based on the total polyphenol and aspalathin contents, rooibos extract and infusion were equivalent when compared on a soluble-solids basis. The isoorientin and orientin contents of the soluble solids of the infusion were slightly higher than those of the extract. The TAC of the soluble solids of the infusion, measured with the ORAC assay, was slightly higher than that of the extract, while the opposite was observed for the TAC, measured with the DPPH radical scavenging assay (Joubert and de Beer, 2012). In another study, 15 Thai herbal teas in comparison with teas of Camellia sinensis were investigated for their antioxidant properties in correlation with their total phenolics, flavonoids, and non-flavonoids contents. Significant differences were observed among the tea infusions. Only stevia and sappan herbal teas had primary antioxidant capacities comparable to C. sinensis. However, purple velvet, mulberry, and false mallow herbal teas were exceptionally stronger in metal-chelating capacity than the C. sinensis teas. Principal component analysis showed that total phenolics, particularly flavonoids, highly correlated with primary antioxidants. Cluster analysis showed that the properties of stevia and sappan herbal teas were similar to green, black, and oolong teas. Some common, but rarely mentioned, Thai herbal teas could be choices of interest for healthy beverages and could be new dietary sources for bioactive compounds (Deetae et al., 2012). An in vitro digestion/Caco-2 cell culture model was used to assess the stability and bioavailability of phenolic compounds in aqueous extracts of four herbal infusions traditionally used as functional drinks in Portugal. Alterations in antioxidant power were monitored by ABTS•+, whereas the profile of phenolic compounds was ascertained by HPLC with diodearray detection (HPLC-DAD). The bioavailability of

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5.  ANTIOXIDANT PROPERTIES OF HERBAL INFUSIONS

rutin—an important flavonoid present in such extracts, and thus a representative of those compounds—was assessed across Caco-2 cells via LC-MS/MS. The results indicated that several antioxidant compounds are not affected by the (simulated) digestive process, whereas others undergo decreases in their activity throughout said process; a few have their antioxidant capacity hampered under stomach-like conditions. It was also found that rutin can be transported across the Caco-2 cell barrier (Giao et al., 2012). Infusions (herbal teas) and decoctions are used frequently to administer oral doses of herbs. Although some herbs are used as single ingredients, they are often prepared as mixtures, as reported by numerous ethnobotanical surveys. A study was carried out to identify the different types of interaction (synergistic, additive and antagonistic effects) that may be found in the antioxidant activities of preparations from mixtures of the popular herbs Aloysia citrodora (lemon verbena), Foeniculum vulgare (fennel), and Mentha spicata (spearmint). Herbs were prepared using traditional methods, and the effects after different periods of storage, up to 120 days, were also evaluated. Antioxidant activity was evaluated using DPPH radical scavenging activity, reducing power, and inhibition of lipid peroxidation by the β-carotene-linoleate system and the thiobarbituric acid reactive substances (TBARS) assay. Known antioxidant compounds such as total phenolics, flavonoids, ascorbic acid, and reducing sugars were also determined. Spearmint was found to possess the greatest antioxidant activity and the highest flavonoid content. The most potent antioxidant activity was found in combinations of different herbs, suggesting synergistic effects (Guimaraes et al., 2011). Total phenolic content of 28 kinds of herbal infusions made in China were measured by the Folin–Ciocalteu method, and their antioxidant capacities were evaluated using FRAP and TEAC assays. Generally, these beverages had high antioxidant capacities and total phenolic contents, and could be important dietary sources of antioxidant phenolics for prevention of diseases caused by oxidative stress (Fu et al., 2011). In another study, antioxidant capacities of the infusions from 32 medicinal plants were measured by FRAP and TEAC assays, and total phenolic contents of the extracts were determined using the Folin–Ciocalteu method. The infusion of Rhodiola sacra Fu showed the highest antioxidant activity among the infusions from the 32 plants tested, followed by the infusion of Polygonum multiflorum Thunb stem, and the infusion of P. multiflorum Thunb root (Li et al., 2007). It is very difficult to summarize and compare antioxidant capacities of herbal infusions because different extraction and evaluation methods were used in the literature. The antioxidant capacities and total

phenolic contents of some herbal infusions are summarized in Tables 5.1–5.3, which employed the same evaluation methods (Fu et al., 2011; Li et al., 2007), and correlation between FRAP values and TEAC values as well as correlation between the antioxidant capacities and total phenolic content are shown in Figures 5.1–5.3. A significant correlation between FRAP and TEAC values (Figure 5.1) suggested that antioxidant components in these beverages were capable of reducing oxidants and scavenging free radicals. In addition, the high correlation between antioxidant capacities and total phenolic contents (Figures 5.2 and 5.3) indicated that phenolic compounds could be one of the main components responsible for antioxidant activities of these beverages.

ANTIOXIDANT COMPONENTS IN HERBAL INFUSIONS Herbal infusions often contain many different kinds of natural antioxidants. As an important category of phytochemicals, phenolic compounds universally exist in plants. They have attracted increasing attention as potential agents for preventing and treating many oxidative stress-related diseases. The fermented leaves and stems of Cyclopia intermedia are used to brew honeybush tea, an herbal tea indigenous to South Africa. The plant is also used to manufacture a sweet herbal infusion used for its restorative properties such as soothing coughs and alleviating bronchial complaints including tuberculosis, pneumonia, and catarrh. It is claimed to have low tannin content and no caffeine and contains various antioxidants. The leaves and stems of C. intermedia contain tyrosol, 2-{4-[O-α-apiofuranosyl(1″→6′)-β-D-glucopyranosyloxy] phenyl}ethanol, 4-[O-α-apiofuranosyl-(1″→2′)-β-D-glucopyranosyloxy] benzaldehyde, five glycosylated flavonols, two isoflavones, four flavanones, two isoflavones, and two flavones. Because flavonoids are presumed to contribute significantly toward the scavenging effects of active oxygen species, the results indicated that the tentative claimed health-promoting properties may be attributed to the presence of the phenolics in C. intermedia (Kamara et al., 2003). Cyclopia subternata is one of the 24 Cyclopia species that are used to brew honeybush tea, a unique South African herbal beverage with a pleasant taste and flavor. It contains various antioxidants, is very low tannin content, and has no caffeine. Many health properties are associated with regular consumption of the tea. Honeybush infusion has been noted as a tonic for colds and influenza, catarrh, and pulmonic tuberculosis, and is becoming well known for its effectiveness in alleviating menopausal symptoms in women. The unfermented leaves of C. subternata contain pinitol, shikimic acid,

1.  COMPOSITION AND CHARACTERIZATION OF ANTIOXIDANTS

45

Antioxidant Components in Herbal Infusions

TABLE 5.1  Antioxidant Capacities (Ferric Reducing Antioxidant Power, FRAP) of Herbal Infusions

TABLE 5.1  Antioxidant Capacities (Ferric Reducing Antioxidant Power, FRAP) of Herbal Infusions—cont’d

Sample Number

Name of Sample

FRAP Values (mmol Fe(II)/l)

Sample Number

Name of Sample

FRAP Values (mmol Fe(II)/l)

1

Rhodiola sacra Fu

26.575 ± 0.240

35

Ping An Tang shen ju cha

7234 ± 212

2

Polygonum multiflorum Thunb. (Stem)

24.895 ± 0.100

36

Ping An Tang luo han guo wu hua cha

5452 ± 88

3

Polygonum multiflorum Thunb. (Root)

17.165 ± 0.085

37

Ping An Tang suan mei tang

506 ± 11

38

Ping An Tang huo ma ren

1504 ± 101

4

Dipsacus japonicus Miq.

8.515 ± 0.015

39

Ping An Tang li yan cha

30581 ± 1285

5

Epimedium brevicomum Maxim.

8.275 ± 0.135

40

Ping An Tang shi gan cha

26314 ± 63

6

Paeonia lactiflora pall.

5.870 ± 0.255

41

Qing Xin Tang ju hua xue li cha

2722 ± 116

7

Ligustrum lucidum Ait.

6.230 ± 0.305

42

Qing Xin Tang suan mei tang

3114 ± 168

8

Cynomorium songaricum Rupr.

8.335 ± 0.185

43

Rehmannia glutihosa Libosch.

8.115 ± 0.065

Qing Xin Tang mao geng zhu zhe shui

3162 ± 116

9 10

Eclipta prostrata L.

6.585 ± 0.045

44

5246 ± 266

11

Cistanche deserticola Y. C. Ma

3.885 ± 0.395

Qing Xin Tang luo han guo wu hua cha

12

Psoralea corylifolia L.

1.385 ± 0.025

45

Qing Xin Tang gan mao cha

10382 ± 845

13

Astragalus complanatus R. Br.

3.345 ± 0.070

46

Qing Xin Tang zhi ke hua tan tang

11697 ± 777

14

Polygonatum sibiricum Redoute

2.500 ± 0.025

47

Qing Xin Tang hou zheng tang

12490 ± 615

15

Morus alba L.

2.635 ± 0.020

48

Qing Xin Tang jiang huo wang

25454 ± 1175

16

Curculigo orchioides Gaerten.

2.600 ± 0.035

49

Qing Xin Tang er shi si wei

13252 ± 225

17

Cuscuta chinensis Lam.

2.040 ± 0.075

50

Deng lao liang cha

8341 ± 322

18

Angelica sinensis (Oliv.) Diels

1.760 ± 0.020

51

Wang lao ji (ting zhuang)

3508 ± 39

19

Eucommia ulmoides Oliv.

1.965 ± 0.050

52

Wang lao ji (he zhuang)

3764 ± 151

20

Glycyrrhiza uralensis Fisch.

0.575 ± 0.010

53

Qing liang cha (he zhuang)

1550 ± 40

21

Lycium barbarum L.

1.060 ± 0.015

54

Nian ci an run (qing xing lü se ting zhuang)

812 ± 16

22

Alpinia oxyphylla Mig.

1.050 ± 0.020

55

Dendrobium nobile LindL.

0.880 ± 0.005

Nian ci an run (chun cui hong se ting zhuang)

392 ± 14

23 24

Morinda officinalis How

0.945 ± 0.015

56

Bao Qing Tang xue li ju hua cha

1218 ± 28

25

Astragalus membranaceus (Fisch.) Bge.

0.610 ± 0.020

57

Pan Gao Shou liang cha

1159 ± 20

58

Er shi si wei

1785 ± 55

26

Asparagus cochinchinensis (Lour.) Merr

0.460 ± 0.010

59

Bai Yun Shan liang cha

1510 ± 20

27

Atractylodes macrocephala Koidz.

0.870 ± 0.010

60

Ben cao mi liang cha

4279 ± 82

28

Lilium brownii F. E. Brown

0.360 ± 0.005

29

Ophiopogon japonicus Ker-GawL

0.375 ± 0.010

30

Dioscorea opposita Thunb.

0.355 ± 0.005

31

Tremella fuciformis Berk.

0.245 ± 0.010

32

Polygonatum odoratum (Mill.) Druce

0.095 ± 0.003

33

Ping An Tang xue li ju hua cha

4687 ± 208

34

Ping An Tang mao geng zhu zhe shui

1003 ± 24

p-coumaric acid, 4-glucosyltyrosol, epigallocatechin, gallate, orobol, hesperedin, narirutin, eriocitrin, a glycosylated flavan, luteolin, 5-deoxyluteolin, scolymoside, mangiferin, and C-6-glucosylkaempferol (Kamara et al., 2004). Burrito tea originates from the leaves of Wendita calysina, an indigenous Paraguayan plant, which is commonly consumed in South America and in western countries. Phytochemical investigation of this species has led to the isolation of 14 constituents, among

1.  COMPOSITION AND CHARACTERIZATION OF ANTIOXIDANTS

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5.  ANTIOXIDANT PROPERTIES OF HERBAL INFUSIONS

TABLE 5.2  Antioxidant Capacities (Trolox Equivalent Antioxidant Capacity, TEAC) of Herbal Infusions

TABLE 5.2  Antioxidant Capacities (Trolox Equivalent Antioxidant Capacity, TEAC) of Herbal Infusions—cont’d

Sample Number

Name of Sample

TEAC Values (mmol Trolox/l)

Sample Number

Name of Sample

TEAC Values (mmol Trolox/l)

1

Rhodiola sacra Fu

24.245 ± 0.255

35

Ping An Tang shen ju cha

504 ± 7

2

Polygonum multiflorum Thunb. (Stem)

24.700 ± 0.235

36

Ping An Tang luo han guo wu hua cha

3529 ± 60

3

Polygonum multiflorum Thunb. (Root)

12.895 ± 0.185

37

Ping An Tang suan mei tang

2673 ± 94

38

Ping An Tang huo ma ren

386 ± 7

4

Dipsacus japonicus Miq.

3.915 ± 0.050

39

Ping An Tang li yan cha

19296 ± 692

5

Epimedium brevicomum Maxim.

4.330 ± 0.050

40

Ping An Tang shi gan cha

16269 ± 230

6

Paeonia lactiflora pall.

4.130 ± 0.085

41

Qing Xin Tang ju hua xue li cha

2040 ± 85

7

Ligustrum lucidum Ait.

4.490 ± 0.055

42

Qing Xin Tang suan mei tang

2176 ± 64

8

Cynomorium songaricum Rupr.

3.900 ± 0.120

43

Rehmannia glutihosa Libosch.

4.215 ± 0.095

Qing Xin Tang mao geng zhu zhe shui

2480 ± 74

9 10

Eclipta prostrata L.

4.140 ± 0.010

44

3669 ± 36

11

Cistanche deserticola Y. C. Ma

1.405 ± 0.015

Qing Xin Tang luo han guo wu hua cha

12

Psoralea corylifolia L.

2.075 ± 0.040

45

Qing Xin Tang gan mao cha

6188 ± 238

13

Astragalus complanatus R. Br.

0.580 ± 0.002

46

Qing Xin Tang zhi ke hua tan tang

6695 ± 114

14

Polygonatum sibiricum Redoute

2.195 ± 0.010

47

Qing Xin Tang hou zheng tang

6499 ± 46

15

Morus alba L.

2.355 ± 0.080

48

Qing Xin Tang jiang huo wang

6474 ± 19

16

Curculigo orchioides Gaerten.

1.350 ± 0.002

49

Qing Xin Tang er shi si wei

6310 ± 321

17

Cuscuta chinensis Lam.

1.125 ± 0.010

50

Deng lao liang cha

3438 ± 76

18

Angelica sinensis (Oliv.) Diels

1.365 ± 0.010

51

Wang lao ji (ting zhuang)

2083 ± 85

19

Eucommia ulmoides Oliv.

1.190 ± 0.004

52

Wang lao ji (he zhuang)

2348 ± 13

20

Glycyrrhiza uralensis Fisch.

1.050 ± 0.020

53

Qing liang cha (he zhuang)

637 ± 4

21

Lycium barbarum L.

0.535 ± 0.004

54

Nian ci an run (qing xing lü se ting zhuang)

428 ± 16

22

Alpinia oxyphylla Mig.

0.810 ± 0.015

55

Dendrobium nobile LindL.

0.875 ± 0.015

Nian ci an run (chun cui hong se ting zhuang)

250 ± 6

23 24

Morinda officinalis How

0.460 ± 0.005

56

Bao Qing Tang xue li ju hua cha

445 ± 18

25

Astragalus membranaceus (Fisch.) Bge.

0.430 ± 0.001

57

Pan Gao Shou liang cha

537 ± 13

58

Er shi si wei

825 ± 13

26

Asparagus cochinchinensis (Lour.) Merr

0.475 ± 0.020

59

Bai Yun Shan liang cha

446 ± 9

27

Atractylodes macrocephala Koidz.

0.340 ± 0.004

60

Ben cao mi liang cha

2351 ± 93

28

Lilium brownii F. E. Brown

0.300 ± 0.002

29

Ophiopogon japonicus Ker-GawL

0.245 ± 0.004

30

Dioscorea opposita Thunb.

0.140 ± 0.002

31

Tremella fuciformis Berk.

0.155 ± 0.002

32

Polygonatum odoratum (Mill.) Druce

0.075 ± 0.004

33

Ping An Tang xue li ju hua cha

2988 ± 177

34

Ping An Tang mao geng zhu zhe shui

613 ± 15

them two new flavanonols, dihydroquercetagetin and 3,5,6,7,4’-pentahydroxyflavanonol, in addition to several known methoxyflavones, methoxyflavonols, phenylethanoid glycosides, and benzoic acid derivatives. Quantitative determination of phenolic constituents from burrito water infusions was also performed by HPLCUV-DAD (Piccinelli et al., 2004). In a study, the profile of caffeoylquinic, feruloylquinic, and dicaffeoylquinic acids in 20 different Brazilian herbal infusions was established using a reversed-phase HPLC method. The

1.  COMPOSITION AND CHARACTERIZATION OF ANTIOXIDANTS

47

Antioxidant Components in Herbal Infusions

TABLE 5.3  Total Phenolic Contents (Gallic Acid Equivalent, GAE) of Herbal Infusions

TABLE 5.3  Total Phenolic Contents (Gallic Acid Equivalent, GAE) of Herbal Infusions—cont’d

Name of Sample

Total Phenolic Contents (g GAE/l)

Sample Number

Name of Sample

Total Phenolic Contents (g GAE/l)

1

Rhodiola sacra Fu

2.540 ± 0.069

35

Ping An Tang shen ju cha

53 ± 1

2

Polygonum multiflorum Thunb. (Stem)

2.116 ± 0.059

36

Ping An Tang luo han guo wu hua cha

201 ± 9

3

Polygonum multiflorum Thunb. (Root)

1.696 ± 0.031

37

Ping An Tang suan mei tang

392 ± 9

38

Ping An Tang huo ma ren

128 ± 5

4

Dipsacus japonicus Miq.

1.607 ± 0.355

39

Ping An Tang li yan cha

1395 ± 68

5

Epimedium brevicomum Maxim.

1.186 ± 0.014

40

Ping An Tang shi gan cha

1192 ± 11

6

Paeonia lactiflora pall.

0.946 ± 0.011

41

Qing Xin Tang ju hua xue li cha

249 ± 4

7

Ligustrum lucidum Ait.

1.054 ± 0.006

42

Qing Xin Tang suan mei tang

390 ± 3

8

Cynomorium songaricum Rupr.

0.846 ± 0.014

43

Rehmannia glutihosa Libosch.

0.948 ± 0.030

Qing Xin Tang mao geng zhu zhe shui

347 ± 8

9 10

Eclipta prostrata L.

0.810 ± 0.010

44

572 ± 5

11

Cistanche deserticola Y. C. Ma

0.698 ± 0.006

Qing Xin Tang luo han guo wu hua cha

12

Psoralea corylifolia L.

0.835 ± 0.008

45

Qing Xin Tang gan mao cha

844 ± 13

13

Astragalus complanatus R. Br.

0.814 ± 0.028

46

Qing Xin Tang zhi ke hua tan tang

909 ± 37

14

Polygonatum sibiricum Redoute

0.626 ± 0.005

47

Qing Xin Tang hou zheng tang

875 ± 19

15

Morus alba L.

0.538 ± 0.003

48

Qing Xin Tang jiang huo wang

1028 ± 55

16

Curculigo orchioides Gaerten.

0.512 ± 0.005

49

Qing Xin Tang er shi si wei

1007 ± 39

17

Cuscuta chinensis Lam.

0.455 ± 0.008

50

Deng lao liang cha

443 ± 13

18

Angelica sinensis (Oliv.) Diels

0.376 ± 0.012

51

Wang lao ji (ting zhuang)

147 ± 2

19

Eucommia ulmoides Oliv.

0.290 ± 0.002

52

Wang lao ji (he zhuang)

148 ± 1

20

Glycyrrhiza uralensis Fisch.

0.416 ± 0.004

53

Qing liang cha (he zhuang)

72 ± 1

21

Lycium barbarum L.

0.264 ± 0.003

54

Nian ci an run (qing xing lü se ting zhuang)

56 ± 1

22

Alpinia oxyphylla Mig.

0.205 ± 0.002

55

Dendrobium nobile LindL.

0.240 ± 0.004

Nian ci an run (chun cui hong se ting zhuang)

32 ± 1

23 24

Morinda officinalis How

0.198 ± 0.006

56

Bao Qing Tang xue li ju hua cha

70 ± 1

25

Astragalus membranaceus (Fisch.) Bge.

0.159 ± 0.002

57

Pan Gao Shou liang cha

68 ± 1

58

Er shi si wei

99 ± 1

26

Asparagus cochinchinensis (Lour.) Merr

0.150 ± 0.004

59

Bai Yun Shan liang cha

114 ± 4

27

Atractylodes macrocephala Koidz.

0.184 ± 0.005

60

Ben cao mi liang cha

162 ± 5

28

Lilium brownii F. E. Brown

0.154 ± 0.003

29

Ophiopogon japonicus Ker-GawL

0.129 ± 0.001

30

Dioscorea opposita Thunb.

0.124 ± 0.003

31

Tremella fuciformis Berk.

0.118 ± 0.001

32

Polygonatum odoratum (Mill.) Druce

0.125 ± 0.002

33

Ping An Tang xue li ju hua cha

406 ± 14

34

Ping An Tang mao geng zhu zhe shui

74 ± 3

Sample Number

3-caffeoylquinic acid was found in 75% of the infusions (18–5200 mg/kg), while the 5-caffeoylquinic acid was found in 80% of them (34–9990 mg/kg). The highest concentrations of these isomers were found in ‘Cha mate tostado’. The 4-caffeoylquinic acid appeared in 55% of the herbs (23–1600 mg/kg), with ‘Chapeu-de-couro’ and ‘Carqueja’ being the richer ones. The 4-feruloylquinic acid was found in 35% of the infusions (51–1800 mg/ kg) and the 5-feruloylquinic acid was detected in 45%

1.  COMPOSITION AND CHARACTERIZATION OF ANTIOXIDANTS

48

5.  ANTIOXIDANT PROPERTIES OF HERBAL INFUSIONS

FIGURE 5.1  Correlation between ferric reducing anti-

25000 TEAC value (mmol Trolox/L)

oxidant power (FRAP) values and Trolox equivalent antioxidant capacity (TEAC) values.

y = 0.5157x + 50.443

20000

2

R = 0.8861

15000 10000 5000 0 0

5000

10000

15000

20000

25000

30000

35000

FRAP Value (mmol Fe(II)/L)

FIGURE 5.2  Correlation between the antioxidant capaci-

40000 FRAP value (mmol Fe(II)/L)

ties (FRAP values) and total phenolic content. GAE, gallic acid equivalents.

y = 17.818x - 192.3 R 2 = 0.8694

30000

20000

10000

0 0

200

400

600

800

1000

1200

1400

1600

1400

1600

Total Phenolic Content (g GAE/L)

FIGURE 5.3  Correlation between the antioxidant capaci-

25000 TEAC value (mmol Trolox/L)

ties (TEAC values) and total phenolic content. GAE, gallic acid equivalents.

y = 9.7036x - 147.49

20000

R 2 = 0.8592

15000 10000 5000 0 0

200

400

600

800

1000

1200

Total Phenolic Contents (g GAE/L)

1.  COMPOSITION AND CHARACTERIZATION OF ANTIOXIDANTS

References

of them (39–1300 mg/kg). In spite of the low concentrations (30–560 mg/kg), the 3,5-dicaffeoylquinic acid appeared in 50% of the herbs. The distribution of the other dicaffeoylquinic isomers in the infusions was poor. The 3,4-dicaffeoylquinic acid was detected in 20% of them (190–1700 mg/kg), while only 15% of the herbs comprised the 4,5-dicaffeoylquinic isomer. Considerable amounts of this last isomer were found just in ‘Salvia’ (1100 ± 270 mg/kg) (da Silva et al., 2006). In another study, chromatographic techniques (HPLC and HPTLC) were used for qualitative and quantitative determination of eriocitrin, luteolin 7-O-rutinoside, luteolin 7-O-β-glucuronide, lithospermic acid, rosmarinic acid, and methyl rosmarinate, together with other known compounds in commercial herbal teas from the Lamiaceae family: peppermint leaf (Menthae piperitae folium), melissa leaf (Melissae folium), and sage leaf (Salviae officinalis folium). The investigated herbal teas delivered polyphenols in high amounts, up to 182.2 mg for the infusion of one peppermint tea bag (Fecka and Turek, 2007). In addition, verbena and lemon verbena aqueous preparations were investigated for their constituents, especially polyphenols by HPLC/DAD/ESI/MS analysis because they are used worldwide as herbal teas. The main class of compounds of these plants were phenylpropanoids (from 16 to 120 mg/g of dried extract), and verbascoside was the most abundant in all the preparations up to 97% of the total phenylpropanoids. Iridoids, hastatoside, and verbenalin together with flavonoids, mono- and di-glucuronidic derivatives of luteolin and apigenin were also found (Bilia et al., 2008). Plectranthus barbatus, known as ‘falso boldo’ in Brazil, is used in herbal tea or cooked as a vegetable. Infusions and decoctions of leaves from P. barbatus were analyzed for their antioxidant activities. The decoction showed high antioxidant activity (IC50 = 45.8 ± 0.5 μg of dry extract/ml in the DPPH test; IC50 = 69.8 ± 3.1 μg of dry extract/ml in the β-carotene-linoleic acid test). Rosmarinic acid, scutellarein 4′-methyl ether 7-O-glucuronide and (16S)-coleon E were the main constituents identified (Fale et al., 2009). In another study, phenolic compounds in an aqueous infusion of leaves of Ficus deltoidea (Moraceae), a wellknown herbal tea in Malaysia, were analyzed by HPLC coupled to photodiode array and fluorescence detectors and an electrospray ionization tandem mass spectrometer. Following chromatography of extracts on a reversedphase C12 column, 25 flavonoids were characterized and/or tentatively identified with the main constituents flavan-3-ol monomers, proanthocyanidins, and C-linked flavone glycosides. The proanthocyanidins were dimers and trimers comprising (­epi)catechin and (epi)afzelechin units. No higher-molecular-weight proanthocyanidin polymers were detected. The antioxidant activity of F. deltoidea extract was analyzed using HPLC with online antioxidant detection. This revealed that 85% of the total

49

antioxidant activity of the aqueous F. deltoidea infusion was attributable to the flavan-3-ol monomers and the proanthocyanidins (Omar et al., 2011). In addition, ‘Pichi’ or ‘pichi romero’ (Fabiana imbricata R. et. P., Solanaceae) is a Chilean plant used as a tea in the Andean regions of Chile and Argentina. The phenolic constituents identified in the tea were chlorogenic acid (3-O-caffeoylquinic acid), p-hydroxyacetophenone, scopoletin, and quercetin derivatives. The glycosides were mainly glucosides from p-hydroxyacetophenone and scopoletin while di- and tri-glycosides from quercetin were the main flavonoids. The content of the main phenolic compounds in the tea (g/100 g lyophilized infusion) was 0.8–1.9% for scopoletin, 0.4–6.2% for p-hydroxyacetophenone, and 2.1–4.3% for rutin, respectively. The health-promoting properties reported for this herbal tea can be associated with the presence of several phenolics with known antioxidant, diuretic, and anti-inflammatory activities (Quispe et al., 2012). In order to calculate the dietary exposure to rooibos herbal tea flavonoids and phenolic acids, representative content values for the principal phenolic compounds and total antioxidant capacity of fermented rooibos infusion, taking into account variation caused by production seasons (2009, 2010, and 2011) and quality grades (A, B, C, and D), were determined for samples (n = 114) from different geographical areas and producers. The major phenolic constituents were isoorientin and orientin ( > 10 mg/l), with quercetin-3-O-robinobioside, phenylpyruvic acid glucoside, and aspalathin present at > 5 mg/l. Isovitexin, vitexin, and hyperoside were present at < 3 mg/l. Rutin, ferulic acid, and isoquercitrin were present at < 2 mg/l. Nothofagin was present at < 1 mg/l. Only traces of luteolin-7-O-glucoside and the aglycones quercetin, luteolin, and chrysoeriol were present. Substantial variation was observed in the individual content values of the phenolic compounds and total antioxidant capacity within production seasons and quality grades (Joubert et al., 2012).

References Abderrahim, F., Estrella, S., Susin, C., Arribas, S.M., Gonzalez, M.C., Condezo-Hoyos, L., 2011. The antioxidant activity and thermal stability of lemon verbena (Aloysia triphylla) infusion. J. Med. Food 14, 517–527. Apak, R., Guclu, K., Ozyurek, M., Karademir, S.E., Ercag, E., 2006. The cupric ion reducing antioxidant capacity and polyphenolic content of some herbal teas. Int. J. Food Sci. Nutr. 57, 292–304. Arthur, H., Joubert, E., De Beer, D., Malherbe, C., Witthuhn, R.C., 2011. Phenylethanoid glycosides as major antioxidants in Lippia multiflora herbal infusion and their stability during steam pasteurisation of plant material. Food Chem. 127, 581–588. Bilia, A.R., Giomi, M., Innocenti, M., Gallori, S., Vincieri, F.F., 2008. HPLC-DAD-ESI-MS analysis of the constituents of aqueous preparations of verbena and lemon verbena and evaluation of the antioxidant activity. J. Pharm. Biomed. Anal. 46, 463–470.

1.  COMPOSITION AND CHARACTERIZATION OF ANTIOXIDANTS

50

5.  ANTIOXIDANT PROPERTIES OF HERBAL INFUSIONS

da Silva, A.I., Santana, C.S., Pivato, S.C.L., De Maria, C.A.B., Moreira, R.F.A., 2006. Chlorogenic acid profile of commercial Brazilian herbal infusions. Sci. Alimen. 26, 173–180. Deetae, P., Parichanon, P., Trakunleewatthana, P., Chanseetis, C., Lertsiri, S., 2012. Antioxidant and anti-glycation properties of Thai herbal teas in comparison with conventional teas. Food Chem. 133, 953–959. Fale, P.L., Borges, C., Madeira, P.J.A., Ascensao, L., Araujo, M.E.M., Florencio, M.H., Serralheiro, M.L.M., 2009. Rosmarinic acid, scutellarein 4 ‘-methyl ether 7-O-glucuronide and (16S)-coleon E are the main compounds responsible for the antiacetylcholinesterase and antioxidant activity in herbal tea of Plectranthus barbatus ("falso boldo. Food Chem. 114, 798–805. Fecka, I., Turek, S., 2007. Determination of water-soluble polyphenolic compounds in commercial herbal teas from Lamiaceae: Peppermint, melissa, and sage. J. Agric. Food Chem. 55, 10908–10917. Fu, L., Xu, B.T., Gan, R.Y., Zhang, Y., Xu, X.R., Xia, E.Q., Li, H.B., 2011. Total phenolic contents and antioxidant capacities of herbal and tea infusions. Int. J. Mol. Sci. 12, 2112–2124. Giao, M.S., Gomes, S., Madureira, A.R., Faria, A., Pestana, D., Calhau, C., Pintado, M.E., Azevedo, I., Malcata, F.X., 2012. Effect of in vitro digestion upon the antioxidant capacity of aqueous extracts of Agrimonia eupatoria, Rubus idaeus, Salvia sp and Satureja montana. Food Chem. 131, 761–767. Guimaraes, R., Barros, L., Carvalho, A.M., Ferreira, I.C.F.R., 2011. Infusions and decoctions of mixed herbs used in folk medicine: Synergism in antioxidant potential. Phytother. Res. 25, 1209–1214. Joubert, E., de Beer, D., 2012. Phenolic content and antioxidant activity of rooibos food ingredient extracts. J. Food Compos. Anal. 27, 45–51. Joubert, E., Beelders, T., de Beer, D., Malherbe, C.J., de Villiers, A.J., Sigge, G.O., 2012. Variation in phenolic content and antioxidant activity of fermented rooibos herbal tea infusions: Role of production season and quality grade. J. Agric. Food Chem. 60, S9171–S9179. Kamara, B.I., Brandt, E.V., Ferreira, D., Joubert, E., 2003. Polyphenols from honeybush tea (Cyclopia intermedia). J. Agric. Food Chem. 51, 3874–3879. Kamara, B.I., Brand, D.J., Brandt, E.V., Joubert, E., 2004. Phenolic metabolites from honeybush tea (Cyclopia subternata). J. Agric. Food Chem. 52, 5391–5395.

Li, H.B., Jiang, Y., Wong, C.C., Cheng, K.W., Chen, F., 2007. Evaluation of two extraction methods for the extraction of antioxidants from medicinal plants. Anal. Bioanal. Chem. 388, 483–488. Omar, M.H., Mullen, W., Crozier, A., 2011. Identification of proanthocyanidin dimers and trimers, flavone C-glycosides, and antioxidants in Ficus deltoidea, a Malaysian herbal tea. J. Agric. Food Chem. 59, 1363–1369. Quispe, C., Viveros-Valdez, E., Schmeda-Hirschmann, G., 2012. Phenolic constituents of the Chilean herbal tea Fabiana imbricata R. et P. Plant Food Human Nutr. 67, 242–246. Piccinelli, A.L., De Simone, F., Passi, S., Rastrelli, L., 2004. Phenolic constituents and antioxidant activity of Wendita caiysina leaves (Burrito), a folk Paraguayan tea. J. Agric. Food Chem. 52, 5863–5868. Poblete, A., Lopez-Alarcon, C., Lissi, E., Campos, A.M., 2009. Oxygen radical antioxidant capacity (ORAC) values of herbal teas obtained employing different methodologies can provide complementary data. J. Chilean Chem. Soc. 54, 154–157. Rocha-Guzman, N.E., Medina-Medrano, J.R., Gallegos-Infante, J.A., Gonzalez-Laredo, R.F., Ramos-Gomez, M., Reynoso-Camacho, R., Guzman-Maldonado, H., Gonzalez-Herrera, S.M., 2012. Chemical evaluation, antioxidant capacity, and consumer acceptance of several oak infusions. J. Food Sci. 77, 162–166. Rojo, L.E., Benites, J., Lopez, J., Rojas, M., Diaz, P., Ordonez, J., Pastene, E., 2009. Antioxidant capacity and polyphenolic content of twelve traditionally used herbal medicinal infusions from the South American Andes. Bol. Latin. Carib. Plant. Med. Arom. 8, 498–508. Shikanga, E.A., Combrinck, S., Regnier, T., 2010. South African Lippia herbal infusions: Total phenolic content, antioxidant and antibacterial activities. South Afric. J. Botany 76, 567–571. Valentao, P., Fernandes, E., Carvalho, F., Andrade, P.B., Seabra, R.M., Bastos, M.D., 2002. Studies on the antioxidant activity of Lippia citriodora infusion: Scavenging effect on superoxide radical, hydroxyl radical and hypochlorous acid. Biol. Pharm. Bull. 25, 1324–1327. Valentao, P., Fernandes, E., Carvalho, F., Andrade, P.B., Seabra, R.M., Bastos, M.L., 2003. Hydroxyl radical and hypochlorous acid scavenging activity of small centaury (Centaurium erythraea) infusion: A comparative study with green tea (Camellia sinensis). Phytomedicine 10, 517–522. Vinokur, Y., Rodov, V., Reznick, N., Goldman, G., Horev, B., Umiel, N., Friedman, H., 2006. Rose petal tea as an antioxidant rich beverage: Cultivar effects. J. Food Sci. 71, 42–47.

1.  COMPOSITION AND CHARACTERIZATION OF ANTIOXIDANTS