Current knowledge and pharmacological profile of berberine: An update

Author’s Accepted Manuscript Current knowledge and pharmacological profile of berberine: An update Anil Kumar, Ekavali, Kanwaljit Chopra, Madhurima Mukherjee, Raghavender Pottabathini, Dinesh K. Dhull www.elsevier.com/locate/ejphar

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S0014-2999(15)30057-1 http://dx.doi.org/10.1016/j.ejphar.2015.05.068 EJP70047

To appear in: European Journal of Pharmacology Received date: 28 February 2015 Revised date: 27 May 2015 Accepted date: 29 May 2015 Cite this article as: Anil Kumar, Ekavali, Kanwaljit Chopra, Madhurima Mukherjee, Raghavender Pottabathini and Dinesh K. Dhull, Current knowledge and pharmacological profile of berberine: An update, European Journal of Pharmacology, http://dx.doi.org/10.1016/j.ejphar.2015.05.068 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.

Current knowledge and Pharmacological profile of berberine: An update Anil Kumar*, Ekavali, Kanwaljit Chopra, Madhurima Mukherjee, Raghavender Pottabathini, Dinesh K. Dhull

Neuropharmacology Division, University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Studies (UGC-CAS), Panjab University, Chandigarh 160014, India.

*Correspondance Prof. Anil Kumar. Neuropharmacology Division, . University Institute of Pharmaceutical Sciences, . UGC Centre of Advanced Study. Panjab University, Chandigarh 160014, India Phone +91-1722534106, Fax +91-172-2543101, . Email: [email protected]

Abstract Berberine, a benzylisoquinoline alkaloid, occurs as an active constituent in numerous medicinal plants and has an array of pharmacological properties. It has been used in Ayurvedic and Chinese medicine for its antimicrobial, antiprotozoal, antidiarrheal and antitrachoma activity. Moreover, several clinical and preclinical studies demonstrate ameliorative effect of berberine against several disorders including metabolic, neurological and cardiological problems. This review provides a summary regarding the pharmacokinetic and pharmacodynamic features of berberine, with a focus on the different mechanisms underlying its multispectrum activity. Studies regarding the safety profile, drug interactions 1

and important clinical trials of berberine have also been included. Clinical trials with respect to neurological disorders need to be undertaken to exploit the beneficiary effects of berberine against serious disorders such as Alzheimer's and Parkinson's disease. Also, clinical studies to detect rare adverse effects of berberine need to be initiated to draw a complete safety profile of berberine and strengthen its applicability. Keywords Berberine, immunomodulation, oxidative stress, pharmacodynamics, pharmacokinetics Chemical Compounds studied in this article Berberine (PubChem CID: 2353); Berbamine (PubChem CID: 10170); Verapamil (PubChem CID: 2520); Daunomycin (PubChem CID: 30323); Thalifendine (PubChem CID: 3084288); Berberrubine (PubChem CID: 72704); Jatrorrhizine (PubChem CID: 72323); Streptazotocin (PubChem CID: 29327); 6-OHDA (PubChem CID: 4624); Mitoxantrone (PubChem CID: 4212); 5-hydroxytryptamine (PubChem CID: 5202); Abbreviations 5-HT, 5-hydroxytryptamine; 6-OHDA, 6-hydroxydopamine; AChE, acetylcholinesterase; AD, Alzheimer's disease; AMPK, AMP-activated protein kinase; BBB, blood brain barrier; BChE, butyrylcholinestesrase; CD, cluster of differentiation; Cdk, cyclin-dependent kinase; Cmax, maximum serum concentration; CNS, central nervous system; COX, cyclooxygenase; DA, dopamine; DMBA, 7,12-Dimethylbenz(a)anthracene; ERK, extracellular signalregulated kinase; GFAP, glial fibrillary acidic protein; GPx, glutathione peroxidase; GSK, glycogen synthase kinase; HIV, human immunodeficiency virus; ip, intra-peritoneal; IC, inhibitory concentration; IGF, Insulin-like growth factor; iNOS, inducible nitric oxide synthase; JNK, Jun N-terminal kinase; ka, apparent first-order absorption rate constant; ke, apparent first-order elimination rate constant; MAO, monoamine oxidase; MAPK, mitogen 2

activated protein kinase; MDA, malondialdehyde MIC, minimum inhibitory concentration; MMP, matrix metalloproteases; MPTP, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; NE, nor-epinephrine; NF-kB, nuclear factor-kB; Nrf2, nuclear factor erythroid 2-related factor 2 ; po, per oral; PD, parkinson's disease; PGE2, prostaglandin E2; P-gp, P-glycoprotein; PI3K, phosphatidylinositol-3kinase; SD, Spargue-Dawley; SOD, superoxide dismutase; STZ, streptozotocin; TDS, ter die sumendum; TGF-β1, transforming growth factor-β1; TNF-α, tumour necrosis factor-α. 1. Introduction Berberine is a nonbasic, quaternary benzylisoquinoline plant alkaloid with a proven medicinal history in Ayurvedic and Chinese medicinal systems. Berberine occurs as an active constituent in the root, rhizome and stem bark of many medicinally important plants, including Hydrastis canadensis (goldenseal), Coptis chinensis (Coptis or goldenthread), Berberis aquifolium (Oregon grape), Berberis vulgaris (barberry), and an Indian species Berberis aristata (Tree turmeric). Berberis aristata, (fam. Berberidaceae) known by common names such as "Daruhaldh, Daruharidra, Kashmal, Chitra" is a spinous shrub of upto 3 meters that grows at an altitude of 2000 to 3000 meters with a wide distribution in the Himalayan region and Nilgiri hills in South India (Komal et al., 2011). Its active constituents include berberine, berbamine and palmatine (Singh and Kakkar, 2009). However, berberine is now manufactured by chemical synthesis. Chloride or sulfate salt of berberine is generally used for clinical purposes. It is an intense yellow powder, odorless with a characteristic alkaloidal bitter taste. It is very slightly soluble in water, slightly soluble in ethanol, sparingly soluble in methanol; however, the salt forms are relatively more soluble (Battu et al., 2010).

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Over the years, attention has shifted towards natural products as a source of alternative medicines. Natural products have a reputation of strong potency with minimum side effects. Berberine has a 3000 years long history of usage as an Ayurvedic and Chinese medicine for its potent antimicrobial, antiprotozoal, antidiarrheal and antitrachoma action (Birdsall and Kelly, 1997). However, clinical investigations on berberine over the years have demonstrated wide spectrum of pharmacological effects. Several reports highlighting significant antihypertensive, antiarrhythmic, antihyperglycemic, anticancer, antidepressant, anxiolytic, neuroprotective, antioxidant, anti-inflammatory, analgesic, hypolipidemic activity of berberine are available (Battu et al., 2010; Bhutada et al., 2010; Kulkarni and Dhir, 2010). Several studies depict the nephroprotective (Domitrovic et al., 2013), hepatoprotective (Li et al., 2014a; Othman et al., 2014), cardioprotective (Li et al., 2014b) and cerebroprotective (Kulkarni and Dhir, 2010) potential of berberine. Therapeutic efficacy against methicilin resistant Staphylococcus aureus (Tillhon et al., 2012), multidrug resistant enterovirulent Escherichia coli (Bopadhyay et al., 2013) and H1NI influenza A virus (Cecil et al., 2011), inhibition of HIV protease inhibitor (Zha et al., 2010) and HIV-I reverse transcriptase (Gudima et al., 1994) signifies the growing potential of berberine against challenging microbial infections. This review attempts to summarize the pharmacokinetic and pharmacodynamic picture of berberine with the help of recent studies. Central focus has been maintained on the underlying mechanisms and pathways reflecting the multispectrum activity of berberine. Major clinical studies conducted to explore the applicability of berberine in various diseases have also been included in this review. 2. Pharmacokinetic profile of berberine Pharmacokinetic profile of berberine and its metabolites has been well studied in humans and rats (Baoxin et al., 1995; Kulkarni and Dhir, 2010; Zuo et al., 2006). Berberine 4

(300 mg, p.o., single dose) in healthy human male volunteers reported several pharmacokinetic parameters including t1/2 (ka) as 0.87±0.03h, t1/2 (ke) as 2.94±0.14h, tpeak as 2.37±0.04h, Cmax as 394.7±155.4 mu-g/L and the area under the concentration-time curve (ANC) as 2799.0±1128.5 mu-g/Lh (Baoxin et al., 1995). Studies have reported improved BBB permeability after berberine administration (10, 40 mg/kg) via activation of Akt/GSK pathway and increase in the expression of claudin-5, an integral component of tight junctions found in the endothelial cells of BBB. This highlights the neuroprotective role of berberine and its use in brain damage injuries like cerebral ischemia (Zhang et al., 2012). Furthermore its neuroprotective role is substantiated by its ability to block potassium channels in hippocampal CA1 neurons leading to suppression of apoptosis (Wang et al., 2004). This suggests its ability to accumulate in hippocampus however the underlying mechanisms needs further investigation. In animal studies performed using rats, berberine (3 mg/kg, i.v.) exhibited a rapid plasma elimination (t1/2=1.13 h) with a slower elimination from hippocampus (t1/2=12.0 h) reaching a peak concentration of 272 ng/g at 3.67 h indicating that berberine could have a direct action on neurons and it accumulates in the hippocampus (Wang et al., 2005). 2.1. Absorption One of the major disadvantages with berberine is its poor oral bioavailability which is attributed to its poor aqueous solubility and dissolution (Zhang et al., 2013). Aqueous and pH-dependent solubility of berberine chloride is temperature dependent and increases with an elevation in temperature (Battu et al., 2010). The aqueous solubility of the drug at 25 and 37°C is reported to be 5.27±0.29 and 8.50±0.40 mM, respectively and maximum solubility of the drug was observed in phosphate buffer pH 7.0 (4.05±0.09 and 9.69±0.37 mM at 25 and 37°C, respectively). Studies prove that berberine acts as a substrate for the multidrug efflux pump, P-gp which limits its clinical applications (Maeng et al., 2002; Zhang et al., 2013). 5

Well-documented P-gp substrates such as verapamil, daunomycin, and rhodamine inhibit the efflux of berberine, suggesting that P-gp is involved in its carrier mediated transport. In addition, the uptake of daunomycin into Caco-2 cells, a representative model of biological membranes, was decreased as a result of berberine pretreatment suggesting that repeated administration of berberine may up-regulate P-gp functions in Caco-2 cells (Maeng et al., 2002). Several formulations have been devised aimed at improving its bioavailability. An oral berberine-loaded microemulsion was reported to have 6.47 times greater bioavailability than tablet suspensions (Gui et al., 2008). An anhydrous reverse micelle system of berberine prepared through lyophilization of water-in-oil emulsions was also reported to show enhanced bioavailability and anti-diabetic efficacy (Wang et al., 2011). 2.2. Distribution Although berberine is present at a very low level in blood (Hua et al., 2007) and its bioavailability was reported to be less than 1% (Kheir et al., 2010; Liu et al., 2010), the pharmacological effect of berberine can be correlated with its high tissue distribution. It was previously reported that berberine can easily penetrate the blood-brain barrier, with a rapid accumulation in the hippocampus region after intravenous administration, followed by slow elimination (Wang et al., 2005). Moreover, the concentration of berberine as well as its bioactive metabolites was found to be higher in organs as compared to its concentration in the blood after oral administration. The organ distribution of berberine is rapid with maximum distribution in liver, followed by kidneys, muscle, lungs, brain, heart, pancreas and with least distribution in fat where it remains relatively stable for 48h (Tan et al., 2013). 2.3. Metabolism Berberine is metabolized in the liver, in both rats and humans, undergoing demethylation in phase I followed by conjugation with glucuronic acid or sulfuric acid to

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form phase II metabolites (Qiu et al., 2008). Final sulfate or glucuronide metabolites formed are polar and easily excreted. Three sulfate metabolites namely jatrorrllizine-3-sulfate, thalifendine-10-sulfate and demethyleneberberine-2-sulfate, with the latter being the major metabolite were identified in healthy male urine samples after oral administration of berberine chloride at a dose of 0.9 g per day for three days. In addition, six new metabolites have been identified in urine samples of male Wistar rats (100 mg/kg, p.o.), collected after 48h and humans (300 mg, p.o.), collected from 0 to 72h. These include jatrorrhizine-3-O-βD-glucuronide; thalifendine-10-O-β-D-glucuronide; berberrubine-9-O-β-D-glucuronide; 3,10-demethylpalmatine-10-O-sulfate; columbamin-2-O-β-D-glucuronide and demethyleneberberine-2,3-di-O-β-D-glucuronide (Qiu et al., 2008). In another extensive pharmacokinetic study performed on male SD rats, phase I metabolites were reported in bile, urine, and feces, including thalifendine, berberrubine, demethyleneberberine, jatrorrhizine, palmatine, columbamine, 3,9-demethyl-palmatine, hydroxylated berberine, and hydroxylated demethyleneberberine. Phase II metabolites included glucuronic acid-conjugated: thalifendine, berberrubine, jatrorrhizine and demethyleneberberine metabolites and sulfate-conjugated: berberrubine, thalifendine and diglucuronide-conjugated demethyleneberberine (Ma et al., 2013b). It has been suggested through preclinical studies that the metabolites may be the in-vivo active forms after oral administration of berberine (Cao et al., 2013; Zhou et al., 2014). 2.4. Excretion Oral administration of berberine at 200 mg/kg dose in rats resulted in excretion of berberine and its metabolites in bile, urine and feces with a total recovery rate of berberine as 22.83% (19.07% of prototype and 3.76% of its metabolites) with 9.2 x 10-6 % in bile (24 h), 0.0939% in urine (48h), and 22.74% in feces (48h), respectively. Maximum amount of berberine (84%) and its metabolites were excreted in the feces. Nearly 83% of Berberine was 7

excreted mainly as thalifendine from bile, and as thalifendine and berberrubine occupying 78% of urinary excretion (Ma et al., 2013b). 3. Pharmacodynamic profile of berberine Berberine exhibits a multi-spectrum pharmacological action ranging from antioxidative action to modulation of neurotransmitters, enzymes, molecular targets and immunomodulation. Below with the help of recent studies, we try to describe the mechanistic background behind superior therapeutic activities of berberine. 3.1. Modulation of oxidative markers Various clinical studies have well established the antioxidant actions of berberine in various disorders ranging from diabetes, high cholesterol, various inflammatory conditions and CNS disorders such as Alzheimer, cerebral ischemia, etc. The free radical scavenging property of berberine can be verified by its ability to scavenge several free radicals like DPPH (2,2-diphenyl 1-picrylhydrazyl), ABTS (2,2-azino bis(3-ethylbenzothiazoline-6sulfonate)), nitric oxide, superoxide, etc. in a concentration dependent manner (Shirwaikar et al., 2006). In-vitro studies using SH-SY5Y human neuroblastoma cells showed that berberine decreases high glucose-induced reactive oxygen species production by attenuation of cytochrome-c release and elevation of anti-apoptotic Bcl-2 expression which are important markers of apoptosis and oxidative damage. Also, berberine down-regulated IGF-1 expression, PI3K/Akt phosphorylation and upregulated Nrf2 expressions. Berberine was hence shown to promote Nrf2 dependent neurite outgrowth and prevent reactive oxygen species production (Hsu et al., 2013). Improvement of mitochondrial complex (Complex I, II and IV) activity was also observed after berberine (5,10 and 20 mg/kg p.o., 19 days) administration in a rat model of cerebral ischemia (Singh and Chopra, 2013).

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Antioxidant effect of berberine (50 and 100 mg/kg/day, p.o., 8 weeks) has been substantiated by studying its inhibitory effect on upregulation of GFAP, a key indicator of astrogliosis which occurs as a result of oxidative insult in STZ induced diabetic rats (Middeldrop and Hol, 2011; Moghaddam et al., 2014). Investigation on endogenous antioxidants, GPx and SOD enzyme concluded that berberine restored the levels of both SOD and GPx thereby reducing the elevated levels of lipid peroxidation in STZ-induced diabetic rats (Lao-ong et al., 2012) and in cyclophosphamide-induced hepatotoxic rats (50 mg/kg, p.o., 11 days) (Germoush and Mahmoud, 2014). The antioxidant effect of berberine is also responsible for its hepatoprotective property. Although the underlying mechanisms have not been clearly understood but it was observed that berberine (12 μM) had a protective effect against H2O2-induced apoptosis which was associated with regulation of sirtuin1 levels (SIRT1), an apoptosis related protein, in hepatic cell line L02 (Zhu et al., 2013). Furthermore it was reported to upregulate the levels of cyclin-dependent kinase 9, cyclin T1 mRNA and protein expression in the liver tissues of STZ-induced diabetes in rats along with increasing the levels of antioxidant enzymes such as catalase, SOD, glutathione peroxidase which further establishes its role as an antioxidant (75, 150, 300 mg/kg, 16 weeks) (Zhou and Zhou, 2010). Berberine (1, 2 and 3mg/kg, p.o., 2 days) has also been reported to ameliorate oxidative/nitrosative stress in a mouse model of cisplatin-induced nephrotoxicity thereby providing a nephroprotective effect as seen by its ability to reduce the expression of renal 4hydroxynonenal (4-HNE), 3-nitrotyrosine (3-NT), cytochrome P450 E1 (CYP2E1) and heme oxygenase (HO-1) expression (Domitrovic et al., 2013). Upregulation of Nrf2 expression and suppression of iNOS contributes to the antioxidant effect of berberine (200 mg/kg/day, i.p., 14 days) against bleomycin-induced lung injury and fibrosis in rats (Chitra et al., 2013). Lowering of renal iNOS expression and restoration of SOD levels after berberine treatment (150 mg/kg/day, p.o., 12 weeks) in rats 9

suffering from atherosclerotic renovascular disease has also been reported (Wan et al., 2013). Lipid peroxidation and oxidative stress inhibitory property has also been postulated behind the anticancer potential of berberine (75 mg/kg, gavage, 26 weeks) as demonstrated by complete prevention of carcinoma formation in DMBA-induced skin carcinogenesis mice model (Manoharan et al., 2010). Restoration of neuronal SOD levels and attenuation of MDA contents has been postulated behind the neuroprotective effect of berberine against chronic brain injury induced by aluminum trichloride in rats, hence ameliorating cognitive dysfunction and hippocampal injury (Zhang et al., 2009). Even its anti-diabetic effect can be credited to its ability to lower serum MDA and increase SOD and GSH-px levels in alloxan induced diabetic rats (100, 200 mg/kg, intragastric, 21 days) (Tang et al., 2006). All the above mentioned studies establish berberine as a potent anti-oxidant molecule due to its ability to scavenge free radicals. 3.2. Immunomodulation Immunomodulatory effect of berberine leading to its potent neuroprotective activities has been appreciated in several preclinical and clinical studies. As a result, effect of berberine treatment on immunological components such as lymphocytes, leukocytes, astrocytes, microglial cells leading to its therapeutic effect against neurological, inflammatory and autoimmune disorders has been well explored. In-vitro study performed using isolated human T-lymphocytes stimulated using phytohemagglutinin alone or phorbol dibutyrate plus ionomycin reported time- and dosedependent inhibition in the expression of activation antigens CD69, CD25 on T-lymphocytes, in addition to inhibition of lymphocyte cell cycle progression by berberine (25-100 μmol/L), thereby suggesting its immunosuppressive effect (Xu et al., 2005). Berberine (200 mg/kg, p.o., 2 weeks) has been suggested as a promising candidate for treating autoimmune diabetes as it inhibits Th17 and Th1 differentiation via ERK1/2 activation and p38 MAPK, JNK 10

inhibition respectively in non-obese diabetic mice (Cui et al., 2009). Protective effect of berberine against diabetic retinopathy was explored in an in-vitro study using leukocytes isolated from diabetic patients. Oral consumption of berberine (0.5 g, twice a day, 1month) by diabetic retinopathy patients, resulted in inhibition of diabetes-induced elevation in leukocyte-mediated killing of human retinal endothelial cells (Tian et al., 2013). Significant reduction of inflammatory cell infiltrate in bronchoalveolar lavage fluid, collagen accumulation and hydroxyproline levels was achieved by berberine treatment (200 mg/kg/day, i.p., 14 days) in bleomycin induced pulmonary fibrosis rat model. Attenuation of TNF-α, NF-ĸβ and TGF-β1 was also reported (Chitra et al., 2013). Berberine inhibits astrocyte mediated oxidative insult by inducing hemeoxygenase-1mRNA expression through PI-3K/Akt pathway in a dose dependent manner (Chen et al., 2012). In STZ induced diabetic rats, berberine treatment (50 and 100 mg/kg/day, p.o., 8 weeks) reduced the number of GFAP-immunoreactive astrocytes in the hippocampus (Moghaddam et al., 2014). Berberine modulates microglial activity presumably through blocking of PI-3K/AKT, MAPK and AMPK pathways (Jia et al., 2012; Lu et al., 2010). These studies suggest that berberine reduces microgliosis and astrogliosis signifying its efficacy against neurological diseases. 3.3. Modulation of enzymatic activity Several studies exploring the effect of berberine on enzymes such as GSK and MMP have been documented. Experimental studies substantiated by docking studies have elaborated the inhibitory effect of berberine through hydrophobic interactions against main neurological enzymes namely AChE, BChE and MAO (Ji and Shen, 2012). Various studies regarding IC50 values report berberine can inhibit AChE, BChE, MAO-A and MAO-B with an IC50 of 0.44, 3.44, 126 and 98.2 μM respectively (Ji and Shen, 2012). Inhibition of MAOA is related to antidepressant activity whereas inhibition of AChE and BChE provides relief from dementia associated with AD (Bhutada et al., 2011) and cerebral ischemia (Singh and 11

Chopra, 2013). Berberine (5 and 30 mg/kg, i.p., 21 days) in 6-OHDA-lesioned rats depleted the tyrosine hydroxylase level in substantia nigra as compared to berberine untreated rats demonstrating a controversial adverse effect of berberine against PD (Kwon et al., 2010). It was reported that berberine treatment (10 and 30 μM) in PC 12 cells is associated with an enhanced cytotoxicity as indicated by increase in apoptotic cell death. Hence, it was concluded that coadministration of L-DOPA therapy along with isoquinoline derivatives should be carefully monitored. GSK and MMP enzymes are known to play a key role in the regulation of numerous physiological signaling pathways. As a result, studies exploring the effect of berberine against these enzymes are gaining momentum. Berberine 24h after the treatment (20μg/ml) reversed the activation of GSK-3β, a major kinase involved in amyloid precursor protein and tau phosphorylation, and also restored protein phosphatase 2A activity in tau-transfected HEK293 cells (Yu et al., 2011). In another study, a profound enhancement of inactive form of GSK3phosphorylated at Ser9 was observed in the brains of the BBR-treated AD transgenic mice compared with vehicle-treated transgenic mice. This GSK-3β inhibitory action of berberine ameliorating β-amyloid pathology, gliosis, and cognitive dysfunction (Durairajan et al., 2012). Moreover, berberine enhanced the phosphorylation of GSK3β in organotypic hippocampal culture exposed to oxygen and glucose deprivation resulting in negative regulation of pro-apoptotic signaling, suggesting the mechanism of berberine mediated neuroprotection in cerebral ischemia (Simoes Pires et al., 2014). Berberine exhibited protective effect against in-vitro (1-100 μM, 24-48h) and in-vivo (75 mg/kg, p.o., 8 days in rats) periodontal tissue degradation by regulating activity of MMPs, including pro-MMP-2, MMP-2 and MMP-9 (Tu et al., 2013). Berberine (100 μM, 24h) has been suggested as a candidate for inhibition of human breast cancer cell metastasis

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due to similar dose dependant suppression of MMP-1 and MMP-9 activity in MCF7 and MDAMB231 human breast cancer cells (Kim et al., 2012). Future works elucidating the effect of berberine in clinical setup against cancer, tissue degeneration diseases and neurodegeneration diseases can therefore be expected on the basis of enzyme modulation. 3.4. Modulation of neurotransmitters In addition to its immunomodulatory and antioxidant properties, modulation of neurotransmitter levels may also be responsible for the promising effect of berberine against diseases such as AD, PD, anxiety and depression. Acute and chronic administration of berberine (5 mg/kg, i.p.) for 15 days in mice was found to be associated with increased levels of NE, DA and 5-HT (Kulkarni and Dhir, 2008). Elevation of NE and 5-HT levels was observed individually in the mouse striatum, hippocampus and cortex regions after berberine administration (10, 20 mg/kg, p.o., single dose) (Peng et al., 2007). These experimental studies indicate the anti-depressant effect of berberine. Similarly, attenuation of NE, DA and 5-HT concentration leading to anxiolytic activity of berberine in mice (100 and 500 mg/kg, p.o., single dose) with decrease in serotonergic activity has also been reported. In addition, berberine blocked the increase of hypothalamic corticotrophin-releasing factor providing relief from complex withdrawal symptoms of morphine in rats (Lee et al., 2012). Berberine in an in-vitro (5 and 30 mg/kg, i.p., 21 days) and in-vivo (10 and 30 μM, 48h) study against 6-OHDA induced neurotoxicity in rats and PC-12 cells respectively, demonstrated inhibition of dopamine biosynthesis, accompanied by reduced levels of DA and NE (Kwon et al., 2010). However, beneficial effect of berberine (20 and 50 mg/kg, i.p., 4 days) against PD by prevention of MPTP induced dopaminergic neuronal loss in the striatal region of mice brain has also been documented (Kim et al., 2014). Presynaptic release of

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acetylcholine was increased by berberine (1 or 10μM/L) resulting in an increase in the rat neurogenic contractile response (Ren et al., 2013). Overall, it can be concluded that berberine modulates some of the prime neurotransmitters involved in the pathology of various neurological disorders. 3.5. Modulation of molecular targets The regulation of the expression level of several inflammatory mediators such as TNF-α, NF-ĸβ, PGE2 and COX-2, by berberine have been held responsible for its antiinflammatory action (Chitra et al., 2013; Jia et al., 2012; Lu et al., 2010). Further, it also found to reduce reactive oxygen species which might be due to AMPK activation mediated negative regulation of NADPH oxidase (Eid et al., 2010) or upregulation of SOD expression (Kukidome et al., 2006; Xie et al., 2008). Moreover, berberine also regulates the activity of telomerase as well as topoisomeras, conferring its role in cancer chemotherapy. Inhibitory effect of berberine has been implicated on topoisomerase I and/or II (Krishnan and Bastow, 2000). Protoberberine alkaloids have a potent inhibitory effect against topoisomerase I. At low concentration, dimeric protoberberines exhibit similar characteristics as camptothecin, a cytotoxic quinoline alkaloid and known to inhibit DNA enzyme topoisomerase I. However, at high concentration, these protoberberines dimers inhibit topoisomerase I relaxation activity. This is further speculated due its binding with plasmid DNA at elevated drug concentration. This binding most likely to cause blocking of enzyme(s) access to plasmid DNA, thus inhibiting its relaxation (Qin et al., 2007). Ability to arrest cell cycle confers berberine with antitumor properties. Berberine is reported to be non-toxic to normal cells but has anticancer effects in various cell lines. Berberine was shown to induce G1 cell cycle arrest resulting in suppression of DU145, PC-3, and LNCaP cells (Mantena et al., 2006), BIU-87 and T24 bladder cancer cell lines (Yan et al., 2011) and A549 cell lung tumors proliferation (James et al., 2011). This was also 14

associated with the inhibition of cyclins and cyclin dependent protein kinases i.e Cdk2 and Cdk4; a serine-threonine kinases which together play an important role in regulating the progression of cell cycle (Mantena et al., 2006). The effect of berberine on cell cycle arrest was mediated by reduced p53 and cyclin D as observed in both in-vitro and in-vivo models of cerebral ischemia in rats (Chai et al., 2013). It diminished markers of senescence as reported in stress-induced cellular senescence caused by mitoxantrone (Zhao et al., 2013). This might be one of the factors which makes berberine a potential treatment option in age-related diseases. Calmodulin has also emerged as a potential target of berberine which decreases phosphorylation of calmodulin kinase II and blocks the activation of MEK1 in Bel7402 cells (Ma et al., 2013a). It was further observed that berberine was able to induce G1 cell cycle arrest in this cell line when coadministered with calmodulin inhibitors. Hence it can be concluded that calmodulin is a target of berberine which plays a role in conferring its anticancer activity. Antiviral effect of berberine was demonstrated by its ability to inhibit posttranslational viral maturation with IC50 of 0.01μM (Cecil et al., 2011) in H1N1 influenza A virus whereas an antibacterial effect has also been reported in a dose dependent manner in a study using five multi-drug resistant strains of enterovirulent E.Coli isolated from yak with hemorrhagic diarrhea having MIC50 values ranging from 1.75 μM to to 3.6 μM (Bandyopadhyay et al., 2013). The 13-position substituted analogs of berberine selectively binded to DNA G-quadruplexes thereby inhibiting telomerase as studied in Plasmodium falciparum during its erythrocytic cycle (Franceschin et al., 2006). This antimicrobial activity of berberine is said to be due to the result of its high binding efficacy to DNA. Blocking of lymphocyte cell cycle progression from Go/G1 to S and G2/M phase (Xu et al., 2005) in Tlymphocytes collected from male donors also exhibits the immunosuppressive effect of berberine. Telomerase activity was also inhibited in a dose-dependent manner over 30–300 15

μM indicating its potential role in malaria chemotherapy (Sriwilaijareon et al., 2002) as reported above. These studies indicate that berberine affects the nuclear machinery and related components which play a crucial role in management of various pathological conditions. The multi-spectrum activity of berberine has been summarized in the figure 1, elaborating the different mechanisms implied in the protective potential of berberine against numerous disorders. 4. Safety profile and drug interactions Effectiveness and safety of berberine containing plants dates back to 3,000 years in the Ayurvedic and Chinese medicinal system. However, due to uterine-stimulatory effect of berberine containing plants, its use in pregnancy is cautioned. Singapore has withdrawn the use of two commonly used berberine-containing Chinese herbs, Rhizoma coptidis and Cortex phellodendri, for the past three decades due to implication of berberine in exacerbating jaundice and kernicterus in neonates with glucose-6-phosphate dehydrogenase deficiency (Linn et al., 2012). It is also reported to cross the placenta and cause harm to the developing fetus. It can also be transferred through breast milk, hence caution is required in berberine administration while breast-feeding. Apart from these indications, no genotoxic, cytotoxic or mutagenic effects have been reported with clinical doses of berberine (Birdsall and Kelly, 1997). Several human clinical trials elaborated in Table 1 reinforce its safety profile with zero death rate and no or minor gastrointestinal adverse effects. However, a number of interactions of berberine with clinically important drugs have been reported with both antagonistic or synergistic effect. Table 2 summarizes the recent clinically significant drug interactions of berberine.

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5. Conclusion Berberine is a traditional iso-quinoline alkaloid with multifarious mechanism of action which reflects its multispectrum pharmacodynamic profile. Different strategies to evade P-gp efflux and improve the aqueous solubility of berberine will further enhance its pharmacological potential in the future. Preclinical studies have well established its potent antimicrobial, antioxidant, anti-inflammatory, anticancer, neuroprotective, cerebroprotective, nephroprotective and hepatoprotective activity. Presently, berberine has been shown to be effective as an anti-diabetic as a supplement (Dong H et al., 2012, Pierro F.D. et al., 2012). It has been reported that berberine in a dose of 1500 mg taken in three different doses of 500 mg each is equally effective as 1500 mg of metformin or 4 mg of glibenclamide. Clinical studies further substantiate the positive effect of berberine in several diseases including, metabolic syndrome, diabetes, congestive heart failure, diarrhea and oncology support. Clinical studies in humans evaluating the neuroprotective potential of berberine against CNS disorders are lacking in spite of extensive preclinical data supporting its neuroprotective effect. These should be undertaken to exploit the beneficiary effects of berberine against serious disorders such as AD and PD. Also, more studies with a clinical background need to be initiated to evaluate and detect the rare adverse effects of berberine. This is essential to draw a complete safety profile of berberine and to strengthen its applicability. Acknowledgement Authors would like to thank the financial support of UGC, New Delhi for carrying out this work. References Affuso, F., Mercurio, V., Fazio, V., Fazio, S., 2010. Cardiovascular and metabolic effects of berberine. World J Cardiol 2, 71-77. 17

Bandyopadhyay, S., Patra, P.H., Mahanti, A., Mondal, D.K., Dandapat, P., et al. 2013. Potential antibacterial activity of berberine against multi drug resistant enterovirulent Escherichia coli isolated from yaks (Poephagus grunniens) with haemorrhagic diarrhea. Asian Pac J Trop Med. 6(4), 315-319. Baoxin, L., Mingshi, Z., Lihua, B., 1995. Study on the pharmacokinetics of berberine after oral administration in human being. Journal of Harbin Medical University. 29(5), 382-385. Battu, S.K., Repka, M.A., Maddineni, S., Chittiboyina, A.G., Avery, M.A., et al. 2010. Physicochemical Characterization of Berberine Chloride: A Perspective in the Development of a Solution Dosage Form for Oral Delivery. AAPS Pharm Sci Tech. 11(3), 1466-1475. Bhutada, P., Mundhada, Y., Bansod, K., Tawari, S., Patil, S., et al. 2011. Protection of cholinergic and antioxidant system contributes to the effect of berberine ameliorating memory dysfunction in rat model of streptozotocin-induced diabetes. Behav Brain Res. 220(1), 30-41. Bhutada, P., Mundhada, Y., Bansoda, K., Dixit, P., Umathec, S., et al. 2010. Anticonvulsant activity of berberine, an isoquinoline alkaloid in mice. Epilepsy Behav. 18(3), 207-210. Birdsall, T.C., Kelly, G.S., 1997. Berberine: Therapeutic potential of an alkaloid found in several medicinal plants. Altern Med Rev. 2(2), 94-103. Cao, S., Zhou, Y., Xu, P., Wang, Y., Yan, J., et al. 2013. Berberine metabolites exhibit triglyceride-lowering effects via activation of AMP-activated protein kinase in Hep G2 cells. J Ethnopharmacol. 149(2), 576-582. Cecil, C.E., Davis, J.M., Cech, N.B., Laster, S.M., 2011. Inhibition of H1N1 influenza A virus growth and induction of inflammatory mediators by the isoquinoline alkaloid berberine and extracts of goldenseal (Hydrastis canadensis). Int Immunopharmacol. 11(11), 1706-1714.

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Chai, Y.S., Hu, J., Lei, F., Wang, Y.G., Yuan, Z.Y., et al. 2013. Effect of berberine on cell cycle arrest and cell survival during cerebral ischemia and reperfusion and correlations with p53/cyclin D1 and PI3K/Akt. Eur J Pharmacol. 708(1-3), 44-55. Chen, J.H., Huang, S.M., Tan, T.W., Lin, H.Y., Chen, P.Y., et al. 2012. Berberine induces heme oxygenase-1 up-regulation through phosphatidylinositol 3-kinase/AKT and NF-E2related factor-2 signaling pathway in astrocytes. Int Immunopharmacol. 12(1), 94-100. Chitra, P., Saiprasad, G., Manikandan, R., Sudhandiran, G., 2013. Berberine attenuates bleomycin induced pulmonary toxicity and fibrosis via suppressing NF-κB dependant TGF-β activation: a biphasic experimental study. Toxicol Lett. 219(2), 178-193. Cui, G., Qin, X., Zhang, Y., Gong, Z., Ge, B., et al. 2009. Berberine differentially modulates the activities of ERK, p38 MAPK, and JNK to suppress Th17 and Th1 T cell differentiation in type 1 diabetic mice. J Biol Chem. 284(41), 28420-28429. Domitrovic, R., Cvijanović, O., Pernjak-Pugel, E., Škoda, M., Mikelić, L., et al. 2013. Berberine exerts nephroprotective effect against cisplatin-induced kidney damage through inhibition of oxidative/nitrosative stress, inflammation, autophagy and apoptosis. Food Chem Toxicol. 62, 397-406. Dong, H., Wang, N., Zhao, L., Lu, F. 2012. Berberine in the Treatment of Type 2 Diabetes Mellitus: A Systemic Review and Meta-Analysis. Evid Based Complement Alternat Med. 2012,2012:591654. Durairajan, S.S., Liu, L.F., Lu, J.H., Chen, L.L., Yuan, Q., et al. 2012. Berberine ameliorates β-amyloid pathology, gliosis, and cognitive impairment in an Alzheimer's disease transgenic mouse model. Neurobiol Aging. 33(12), 2903-2919. Eid, A.A., Ford, B.M., Block, K., Kasinath, B.S., Gorin, Y., et al. 2010. AMP-activated Protein Kinase (AMPK) Negatively Regulates Nox4-dependent Activation of p53 and Epithelial Cell Apoptosis in Diabetes. J Biol Chem. 285(48), 37503–12.

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Franceschin, M., Rossetti, L., D'Ambrosio, A., Schirripa, S., Bianco, A., et al. 2006. Natural and synthetic G-quadruplex interactive berberine derivatives. Bioorg Med Chem Lett. 16(6), 1707-1711. Germoush, M.O., Mahmoud, A.M., 2014. Berberine mitigates cyclophosphamide-induced hepatotoxicity by modulating antioxidant status and inflammatory cytokines. J Cancer Res Clin Oncol. 140(7), 1103-1109. Gudima, S.O., Memelova, L.V., Borodulin, V.B., Pokholok, D.K., Mednikov, B.M., et al. 1994. Kinetic analysis of interaction of human immunodeficiency virus reverse transcriptase with alkaloids. Mol Biol (Mosk). 28(6), 1308-1314. Gui, S.Y., Wu, L., Peng, D.Y., Liu, Q.Y., Yin, B.P., et al. 2008. Preparation and evaluation of a microemulsion for oral delivery of berberine. Pharmazie 63(7), 516-519. Hsu, Y.Y., Tseng, Y.T., Lo, Y.C., 2013. Berberine, a natural antidiabetes drug, attenuates glucose neurotoxicity and promotes Nrf2-related neurite outgrowth. Toxicol Appl Pharmacol. 272(3), 787-796. Hua, W., Ding, L., Chen, Y., Gong, B., He, J., et al. 2007. Determination of berberine in human plasma by liquid chromatography-electrospray ionization-mass spectrometry. Journal of Pharmaceutical and Biomedical Analysis 44, 931-937. James, M.A., Fu, H., Liu, Y., Chen, D.R., You, M., 2011. Dietary administration of berberine or Phellodendron amurense extract inhibits cell cycle progression and lung tumorigenesis. Mol Carcinog. 50(1), 1-7. Ji, H.F., Shen, L., 2012. Molecular basis of inhibitory activities of berberine against pathogenic enzymes in Alzheimer's disease. The Scientific World Journal 2012, 823201. Jia, L., Liu, J., Song, Z., Pan, X., Chen, L., et al. 2012. Berberine suppresses amyloid-betainduced inflammatory response in microglia by inhibiting nuclear factor-kappaB and

20

mitogen-activated protein kinase signalling pathways. J Pharm Pharmacol. 64(10), 15101512. Kheir, M.M., Wang, Y., Hua, L., Hu, J., Li, L., et al. 2010. Acute toxicity of berberine and its correlation with the blood concentration in mice. Food Chem Toxicol. 48(4), 1105-1110. Kim, M., Cho, K.H., Shin, M.S., Lee, J.M., Cho, H.S., et al. 2014. Berberine prevents nigrostriatal dopaminergic neuronal loss and suppresses hippocampal apoptosis in mice with Parkinson's disease. Int J Mol Med. 33(4), 870-878. Kim, S., Han, J., Lee, S.K., Choi, M.Y., Kim, J., et al. 2012. Berberine suppresses the TPAinduced MMP-1 and MMP-9 expressions through the inhibition of PKC-α in breast cancer cells. J Surg Res. 176(1), 21-29. Komal, S., Ranjan, B., Neelam, C., Birendra, S., Kumar, S.N., 2011. Berberis aristata: a review. IJRAP 2(2), 383-388. Krishnan, P., Bastow, K.F., 2000. The 9-position in berberine analogs is an important determinant of DNA topoisomerase II inhibition. Anticancer Drug Des. 15(4), 255-264. Kukidome, D., Nishikawa, T., Sonoda, K., Imoto, K., Fujisawa, K., et al. 2006. Activation of AMP-activated protein kinase reduces hyperglycemia-induced mitochondrial reactive oxygen species production and promotes mitochondrial biogenesis in human umbilical vein endothelial cells. Diabetes.55(1), 120-7. Kulkarni, S.K., Dhir, A., 2008. On the mechanism of antidepressant-like action of berberine chloride. Eur J Pharmacol. 589(1-3), 163-172. Kulkarni, S.K., Dhir, A., 2010. Berberine: a plant alkaloid with therapeutic potential for central nervous system disorders. Phytother Res. 24(3), 317-324. Kwon, I.H., Choi, H.S., Shin, K.S., Lee, B.K., Lee, C.K., et al. 2010. Effects of berberine on 6-hydroxydopamine-induced neurotoxicity in PC12 cells and a rat model of Parkinson's disease. Neurosci Lett. 486(1), 29-33.

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Lao-ong, T., Chatuphonprasert, W., Nemoto, N., Jarukamjorn, K., 2012. Alteration of hepatic glutathione peroxidase and superoxide dismutase expression in streptozotocin-induced diabetic mice by berberine. Pharm Biol. 50(8), 1007-12. Lee, B., Sur, B., Yeom, M., Shim, I., Lee, H., et al. 2012. Effect of berberine on depressionand anxiety-like behaviors and activation of the noradrenergic system induced by development of morphine dependence in rats. Korean J Physiol Pharmacol. 16(6), 379-386. Li, G.H., Wang, D.L., Hu, Y.D., Pu, P., Li, D.Z., et al. 2010. Berberine inhibits acute radiation intestinal syndrome in human with abdomen radiotherapy. Med Oncol 27, 919-925. Li, J., Pan, Y., Kan, M., Xiao, X., Wang, Y., et al. 2014a. Hepatoprotective effects of berberine on liver fibrosis via activation of AMPK-activated protein kinase. Life Sci. 98, 2430. Li, M.H., Zhang, Y.J., Yu, Y.H., Yang, S.H., Iqbal, J., et al. 2014b. Berberine improves pressure overload-induced cardiac hypertrophy and dysfunction through enhanced autophagy. Eur J Pharmacol. 728, 67-76. Lin, J., Wang, X., 2011. The synergistic antitumor effects of berberine alpha-hydroxy-betadecanoylethyl sulfonate with hydroxycamptothecine and its effect on topoisomerase. Yao Xue Xue Bao. 46(4), 390-394. Linn, Y.C., Lu, J., Lim, L.C., Sun, H., Sun, J., et al. 2012. Berberine-induced haemolysis revisited: safety of Rhizoma coptidis and Cortex phellodendri in chronic haematological diseases. Phytother Res. 26(5), 682-686. Liu, Y.T., Hao, H.P., Xie, H.G., Lai, L., Wang, Q., et al. 2010. Extensive Intestinal First-Pass Elimination and Predominant Hepatic Distribution of Berberine Explain Its Low Plasma Levels in Rats. Drug Metab Dispos. 38, 1779-1784.

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Lu, D.Y., Tang, C.H., Chen, Y.H., Wei, I.H., 2010. Berberine suppresses neuroinflammatory responses through AMP-activated protein kinase activation in BV-2 microglia. J Cell Biochem. 110(3), 697-705. Luo, F., Li, Y., Tian, J., Li, J., Ma, J., 2011. Influences of total saponins of Panax ginseng combined with Rhizoma Coptidis berberine on neuroendocrine in rats with chronic heart failure. Shizhen Guoyi Guoyao 22(1), 113-114. Ma, C., Tang, K., Liu, Q., Zhu, R., Cao, Z., 2013a. Calmodulin as a potential target by which berberine induces cell cycle arrest in human hepatoma Bel7402 cells. Chem Biol Drug Des. 81(6), 775-783. Ma, J.Y., Feng, R., Tan, X.S., Ma, C., Shou, J.W., et al. 2013b. Excretion of berberine and its metabolites in oral administration in rats. J Pharm Sci. 102(11), 4181-4192. Maeng, H.J., Yoo, H.J., Kim, I.W., Song, I.S., Chung, S.J., et al. 2002. P-glycoproteinmediated transport of berberine across Caco-2 cell monolayers. J Pharm Sci. 91(12), 26142621. Manoharan, S., Muneeswaran, M., Baskaran, N., 2010. Chemopreventive efficacy of berberine in 7,12-dimethylbenz[a]anthracene (DMBA) induced skin carcinogenesis in Swiss albino mice. Int J Res Pharm Sci. 1(4), 521-529. Mantena, S.K., Sharma, S.D., Katiyar, S.K., 2006. Berberine, a natural product, induces G1phase cell cycle arrest and caspase-3-dependent apoptosis in human prostate carcinoma cells. Mol Cancer Ther. 5(2), 296-308. Middeldorp, J., Hol, E.M., 2011. GFAP in health and disease. Prog Neurobiol. 93(3), 421443. Moghaddam, H.K., Baluchnejadmojarad, T., Roghani, M., Khaksari, M., Norouzi, P., et al. 2014. Berberine ameliorate oxidative stress and astrogliosis in the hippocampus of STZinduced diabetic rats. Mol Neurobiol. 49(2), 820-826.

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Othman, M., Safwat, G., Aboulkhair, M., Abdel Moneim, A.E., 2014. The potential effect of berberine in mercury-induced hepatorenal toxicity in albino rats. Food Chem Toxicol. 69C, 175-181. Peng, W.H., Lo, K.L., Lee, Y.H., Hung, T.H., Lin, Y.C., 2007. Berberine produces antidepressant-like effects in the forced swim test and in the tail suspension test in mice. Life Sci. 81(11), 933-938. Pierro, F.D., Villanova, N., Aqostini, F., Marzocchi, R., Soverini, V., et al. 2012. Pilot study on the additive effects of berberine and oral type 2 diabetes agents for patients with suboptimal glycemic control. Diabetes Metab Syndr Obes. 5, 213-7. Qin, Y., Pang, J.Y., Chen, W.H., Zhao, Z.Z., Liu, L., et al. 2007. Inhibition of DNA topoisomerase I by natural and synthetic mono- and dimeric protoberberine alkaloids. Chem Biodivers. 4(3), 481-487. Qiu, F., Zhu, Z., Kang, N., Piao, S., Qin, G., et al. 2008. Isolation and identification of urinary metabolites of berberine in rats and humans. Drug Metab Dispos. 36(11), 2159-2165. Quan, H., Cao, Y.Y., Xu, Z., Zhao, J.X., Gao, P.H., et al. 2006. Potent in vitro synergism of fluconazole and berberine chloride against clinical isolates of Candida albicans resistant to fluconazole. Antimicrob Agents Chemother. 50(3), 1096-1099. Ren, L.M., Zhuo, Y.J., Hao, Z.S., He, H.M., Lu, H.G., et al. 2013. Berberine improves neurogenic contractile response of bladder detrusor muscle in streptozotocin-induced diabetic rats. J Ethnopharmacol. 150(3), 1128-1136. Sack, R.B., Froehlich, J.L., 1982. Berberine inhibits intestinal secretory response of Vibrio cholera and Escherichia coli enterotoxins. Infect Immun 35, 471-475. Shan, Y.Q., Zhu, Y.P., Pang, J., Wang, Y.X., Song, D.Q., et al. 2013. Tetrandrine potentiates the hypoglycemic efficacy of berberine by inhibiting P-glycoprotein function. Biol Pharm Bull. 36(10), 1562-1569.

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Shin, K.S., Choi, H.S., Zhao, T.T., Suh, K.H., Kwon, I.H., et al. 2013. Neurotoxic effects of berberine on long-term L-DOPA administration in 6-hydroxydopamine-lesioned rat model of Parkinson's disease. Arch Pharm Res. 36(6), 759-767. Shirwaikar, A., Rajendran, K., Punitha, I.S., 2006. In Vitro Antioxidant Studies on the Benzyl Tetra Isoquinoline Alkaloid Berberine. Biol. Pharm. Bull. 29(9) 1906-1910. Simões Pires, E.N., Frozza, R.L., Hoppe, J.B., Menezes Bde, M., Salbego, C.G., 2014. Berberine was neuroprotective against an in vitro model of brain ischemia: survival and apoptosis pathways involved. Brain Res. 1557, 26-33. Singh, D.P., Chopra, K., 2013. Verapamil augments the neuroprotectant action of berberine in rat model of transient global cerebral ischemia. Eur J Pharmacol. 720(1-3), 98-106. Singh, J., Kakkar, P., 2009. Antihyperglycemic and antioxidant effect of Berberis aristata root extract and its role in regulating carbohydrate metabolism in diabetic rats. J Ethnopharmacol. 123(1), 22-26. Sriwilaijareon, N., Petmitr, S., Mutirangura, A., Ponglikitmongkol, M., Wilairat, P., 2002. Stage specificity of Plasmodium falciparum telomerase and its inhibition by berberine. Parasitol Int. 51(1), 99-103. Tan, X.S., Ma, J.Y., Feng, R., Ma, C., Chen, W.J., et al. 2013. Tissue Distribution of Berberine and Its Metabolites after Oral Administration in Rats. PLoS One 8(10), e77969. Tan, Y., Wu, A., Tan, B., Wu, J., Tang, L., et al. 2002. Study on the interactions of berberine displace other drug from their plasma proteins binding sites. Zhongguo Yaolixue Tongbao. 18(5), 576-578. Tang, Q.L, Wei, W, Chen, L, Liu, S. 2006. Effects of berberine on diabetes induced by alloxan and a high-fat/high-cholesterol diet in rats. Journal of Ethnopharmacology. 108(1), 109-115.

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Tian, P., Ge, H., Liu, H., Kern, T.S., Du, L., et al. 2013. Leukocytes from diabetic patients kill retinal endothelial cells: effects of berberine. Mol Vis. 19, 2092-2105. Tillhon, M., Guamán Ortiz, L.M., Lombardi, P., Scovassi, A.I., 2012. Berberine: new perspectives for old remedies. Biochem Pharmacol. 84(10), 1260-1267. Tong, N., Zhang, J., Chen, Y., Li, Z., Luo, Y., et al. 2012. Berberine sensitizes mutliple human cancer cells to the anticancer effects of doxorubicin in vitro. Oncol Lett. 3(6), 12631267. Tu, H.P., Fu, M.M., Kuo, P.J., Chin, Y.T., Chiang, C.Y., et al. 2013. Berberine's effect on periodontal tissue degradation by matrix metalloproteinases: an in vitro and in vivo experiment. Phytomedicine. 20(13), 1203-1210. Wan, X., Chen, X., Liu, L., Zhao, Y., Huang, W.J., et al. 2013. Berberine ameliorates chronic kidney injury caused by atherosclerotic renovascular disease through the suppression of NFκB signaling pathway in rats. PLoS One. 8(3), e59794. Wang, F., Zhao, G., Cheng, L., Zhou, H.Y., Fu, L.Y., et al. 2004. Effects of berberine on potassium currents in acutely isolated CA1 pyramidal neurons of rat hippocampus. Brain Research 999, 91-97. Wang, T., Wang, N., Song, H., Xi, X., Wang, J., et al. 2011. Preparation of an anhydrous reverse micelle delivery system to enhance oral bioavailability and anti-diabetic efficacy of berberine. Eur J Pharm Sci. 44, 127-135. Wang, X., Wang, R., Xing, D., Su, H., Ma, C., et al. 2005. Kinetic difference of berberine between hippocampus and plasma in rat after intravenous administration of Coptidis rhizoma extract. Life Sci. 77(24), 3058-3067. Wang, Y., Huang, Y., Lam, K.S., Li, Y., Wong, W.T., et al. 2009. Berberine prevents hyperglycemia-induced endothelial injury and enhances vasodilation via adenosine

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monophosphate-activated protein kinase and endothelial nitric oxide synthase. Cardiovasc Res 82, 484-492. Wei, W., Zhao, H., Wang, A., Sui, M., Liang, K., et al. 2012. A clinical study on the shortterm effect of berberine in comparison to metformin on the metabolic characteristics of women with polycystic ovary syndrome. Eur J Endocrinol 166, 99-105. Wu, X., Li, Q., Xin, H., Yu, A., Zhong, M., 2005. Effects of berberine on the blood concentration of cyclosporin A in renal transplanted recipients: clinical and pharmacokinetic study. European Journal of Clinical Pharmacology 61(8), 567-572. Xie, Z., Zhang, J., Wu, J., Viollet, B., Zou, M. 2008. Upregulation of Mitochondrial Uncoupling Protein-2 by the AMP-Activated Protein Kinase in Endothelial Cells Attenuates Oxidative Stress in Diabetes. Diabetes. 57(12), 3222–30. Xu, L., Liu, Y., He, X., 2005. Inhibitory effects of berberine on the activation and cell cycle progression of human peripheral lymphocytes. Cell Mol Immunol. 2(4), 295-300. Yan, K., Zhang, C., Feng, J., Hou, L., Yan, L., et al. 2011. Induction of G1 cell cycle arrest and apoptosis by berberine in bladder cancer cells. Eur J Pharmacol. 661(1-3), 1-7. Yin, J., Gao, Z., Liu, D., Liu, Z., Ye, J., 2008. Berberine improves glucose metabolism through induction of glycolysis. Am J Physiol Endocrinol Metab 294, E148-E156. Youn, M.J., So, H.S., Cho, H.J., Kim, H.J., Kim, Y., et al. 2008. Berberine, a natural product, combined with cisplatin enhanced apoptosis through a mitochondria/caspase-mediated pathway in HeLa cells. Biol Pharm Bull. 31(5), 789-795. Yu, G., Li, Y., Tian, Q., Liu, R., Wang, Q., et al. 2011. Berberine attenuates calyculin Ainduced cytotoxicity and Tau hyperphosphorylation in HEK293 cells. J Alzheimers Dis. 24(3), 525-535.

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Zeng, X.H., Zeng, X.J., Li, Y.Y., 2003. Efficacy and safety of berberine for congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy. Am J Cardiol 92, 173176. Zha, W., Liang, G., Xiao, J., Studer, E.J., Hylemon, P.B., et al. 2010. Berberine inhibits HIV protease inhibitor-induced inflammatory response by modulating ER stress signaling pathways in murine macrophages. PLoS One. 5(2), 9069. Zhang, C.H., Yu, R.Y., Liu, Y.H., Tu, X.Y., Tu, J., et al. 2014. Interaction of baicalin with berberine for glucose uptake in 3T3-L1 adipocytes and HepG2 hepatocytes. J Ethnopharmacol. 151(2), 864-872 Zhang, H., Wei, J., Xue, R., Wu, J.D., Zhao, W., et al. 2010. Berberine lowers blood glucose in type 2 diabetes mellitus patients through increasing insulin receptor expression. Metabolism 59, 285-292. Zhang, J., Yang, J.Q., He, B.C., Zhou, Q.X., Yu, H.R., et al. 2009. Berberine and total base from rhizoma coptis chinensis attenuate brain injury in an aluminum-induced rat model of neurodegenerative disease. Saudi Med J. 30(6), 760-766. Zhang, X., Zhang, X., Wang, C., Li, Y., Dong, L., et al. 2012. Neuroprotection of early and short-time applying berberine in the acute phase of cerebral ischemia: Up-regulated pAkt, pGSK and pCREB, down-regulated NF-κB expression, ameliorated BBB permeability. Brain Research 1459, 6 1-70. Zhang, Y., Cui, Y.L., Gao, L.N., Jiang, H.L., 2013. Effects of β-cyclodextrin on the intestinal absorption of berberine hydrochloride, a P-glycoprotein substrate. Int J Biol Macromol. 59, 363-371. Zhao, H., Halicka, D., Li, J., Darzynkiewicz, Z., 2013. Berberine suppresses gero-conversion from cell cycle arrest to senescence. Aging. 5(8), 623-636.

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Zhou, J., Zhou, S., 2010. Protective effect of berberine on antioxidant enzymes and positive transcription elongation factor b expression in diabetic rat liver. Fitoterapia. 82(2), 184-189. Zhou, Y., Cao, S., Wang, Y., Xu, P., Yan, J., et al. 2014. Berberine metabolites could induce low density lipoprotein receptor up-regulation to exert lipid-lowering effects in human hepatoma cells. Fitoterapia. 92, 230-237. Zhu, X., Guo, X., Mao, G., Gao, Z., Wang, H., et al. 2013. Hepatoprotection of berberine against hydrogen peroxide-induced apoptosis by upregulation of Sirtuin 1. Phytother Res. 27(3), 417-421. Zuo, F., Nakamura, N., Akao, T., Hattori, M., 2006. Pharmacokinetics of berberine and its main metabolites in conventional and pseudo germ-free rats determined by liquid chromatography/ion trap mass spectrometry. Drug Metab Dispos. 34(12), 2064-2072.

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Tables

Table 1: Summary of clinical trials validating the use of berberine against some important diseases.

Table 2: Recent clinically significant drug interactions of berberine. Table 1:

Route

Activity Study outcome studied

No. of subjects

Period Reference of study

METABOLIC SYNDROME Anti-hyperlipidemic 32 hypercholestrolemic 3 months twice daily, Reduction of TG by 35%, (Affuso et al., 2010) p.o. TC by 29% and LDL by 25% Insulin sensitizing 89 women with polycystic 3 months thrice daily, Reduction in waist (Wei et al., 2012) ovary syndrome with circumference, waist-to-hip insulin resistance ratio, TC, TG and LDL and rise HDL DIABETES Hypoglycemic and i. 116 patients with type 2 Decrease in fasting (FPG) and (Zhang et al., 2010) hypolipidemic diabetes (T2DM) and PP plasma glucose, HbA1c, dyslipidemia TC, TG and LDL ii. 97 T2DM patients Decrease in FPG and PPG, (Yin et al., 2008)

Standard drug

Dose and of Berberine

Placebo treatment

500 mg patients

Metformin

500 mg

(500 mg thrice daily)

p.o.

3 months

Placebo treatment

1 g/day, p.o.

2 months

Metformin

1 g/day, p.o.

(1.5 g/day) HbA1c, TC, TG and LDL

Hypoglycemic 48 poorly controlled 3 months daily Decrease in FPG and PPG, (Wang et al., 2009) T2DM patients HbA1c, TC and LDL

Rosiglitazone (4 mg/day) Metformin

500 mg thrice

(500 mg thrice daily)

p.o.

CONGESTIVE HEART FAILURE

30

Antarrhythmic 156 patients with 2 months g/day, Improvements in cardiac (Zeng et al., 2003)

Conventional therapy

1.2 to 2.0

(ACE inhibitors, digoxin, p.o. function 6-min walking test, diuretics and nitrates) left ventricular ejection fraction, dyspnea-fatigue indexes, resting and blood pressure, congestive heart failure DIARRHEA Antisecretory effect Antisecretory effect on enterotoxins of E. coli and

165 patients (Sack and Froehlich,

24 hours

Placebo treatment

400 mg, p.o.

1982)

V. cholera ONCOLOGY SUPPORT Radiation-induced

36 patients with seminoma

5 weeks

thrice daily, Significant reduction in RIAIS (Li et al., 2010) acute intestinal or lymphomas and (anorexia/nausea, colitis, vomiting, symptoms (RIAIS) 42 with cervical cancer proctitis, weight loss, diarrhea)

-

300 mg p.o.

31

Table 2: Drug

Drug Interaction Reference

Inference

Tetrandine P-gp efflux of berberine is inhibited by tetrandine hypoglycemic activity of berberine (Zhang et al., 2014)

Potentiation of

L-DOPA action

Antagonistic

Berberine leads to degeneration of dopaminergic neuronal (Shan et al., 2013) cells in substantia nigra with chronic L-DOPA administration

Doxorubicin effect

Berberine sensitizes cells to anti-cancer effects of doxorubicin (Shin et al., 2013)

Synergistic

β-lactam antibiotics effect

Berberine increases sensitivity of MRSA (methicillin-resistant (Tong et al., 2012)

Synergistic

Staphylococcus aureus) to oxacillin, cefazolin and ampicillin Hydroxycamptothecine effect

Berberine and hydroxycamptothecine have synergistic anticancer (Lin and Wang, 2011)

Synergistic

effect on tumor cells by inhibiting topoisomerase Panax ginseng heart function in CHF

Berberine combined with total saponins of Panax ginseng (Luo et al., 2011)

Improvement of

decreases plasma brain natriuretic peptide (BNP), angiotensin II (Ang II) and norepinephrine levels Cisplatin cytotoxic effect

Combined treatment with berberine results in loss of (Youn et al., 2008)

Enhanced

mitochondrial membrane potential, release in cytochrome-c and caspase thereby resulting in apoptosis Fluconazole effect

Berberine enhances actvity against fluconazole-resistant (Quan et al., 2006)

Synergistic

Candida albicans Cyclosporin-A Cyclosporin-A

Berberine elevates blood concentration of Cyclosporin-A (Wu et al., 2005)

Reduction of

by inhitibiting CYP3A4 Warfarin, thiopental toxicity

Berberine displaces warfarin and thiopental from their protein (Tan et al., 2002)

Precipitation of

binding sites increasing their free levels in blood

32

Figure Figure 1: Depiction of mechanistic profile of berberine highlighting its potential against various disorders.

33