Berberine: bioactivities and possible therapeutic applications

Author: DanieleMichela Camazzola Galata
Date: 14/03/2013



Berberis is a genus of about 450-500 species of deciduous and evergreen shrubs from 1-5 m tall with thorny shoots, found throughout the temperate and subtropical regions of the world (apart from Australia). Species diversity is greatest in South America, Africa and Asia; Europe has a few species, and North America two. The most well-known Berberis species is the so-called European barberry, Berberis vulgaris, which is common in Europe, North Africa, the Middle East, and central Asia.(Berberis)



Berberine is extracted from the bark of Berberis Aristata.Berberine (5, 6-dihydro-9, 10-dimethoxybenzo 1, 3-benzodioxole5,6-aquinolizum) is a natural isoquinoline alkaloid with an intense yellow color present in roots, rhizome and outer bark of an important medicinal plant species, Berberis (B. aquifolium, B. vulgaris, B. aristata, etc.) has been reported to exhibit variety of pharmacological, biochemical and anticancer effects. (Berberine)
Highly purified berberine is prerequisite to research its bioactivities.


Heterocyclic Compounds
Berberine Alkaloids
Berberine D3.


Antioxidant Effect of Berberine

Berberine was reported to have high antioxidant ability.
In vitro experiments, it had significant reductive ability and radicals scavenging capacity. In a concentration dependent manner, it could effectively scavenge 2, 2-azino bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS), 2, 2-diphenyl 1-picrylhydrazyl (DPPH) and nitric oxide radicals, and inhibit lipid peroxidation (Shirwaikar et al., 2006). It could also protect cells from oxidative damage.

(Synthesis, biological evaluation of 9-N-substituted berberine derivatives as multi-functional agents of antioxidant, inhibitors of acetylcholinesterase, butyrylcholinesterase and amyloid-β aggregation,2011)

Anti-microbial Effects of Berberine

Berberine has been used as an anti-microbial reagent for a long history because of its effects on
various microbes, such as virus, bacteria, fungi and protozoans.The mechanisms of berberine-mediated anti-microbial effects remain incompletely understood.Berberine could inhibit influenza
virus growth and infection in cells, probably by inhibiting virus protein trafficking/maturation and
inflammatory substances release-induced pathogenic changes.(Inhibition of H1N1 influenza A virus growth and induction of inflammatory mediators by the isoquinoline alkaloid berberine and extracts of goldenseal (Hydrastis canadensis),2011),(In vivo and in vitro antiviral effects of berberine on influenza virus,2011)
Berberin could have anti-HIV effect. might inhibit HIV protease inhibitor-induced inflammatory response.(Synthesis of 9-substituted derivatives of berberine as anti-HIV agents,2013)
It could also inhibit herpes simplex virus (HSV), probably through interfering with the viral replication cycle.(Anti-herpes simplex virus effects of berberine from Coptidis rhizoma, a major component of a Chinese herbal medicine,2010)
In Escherichia coli, it could interact with FtsZ protein, and destabilize FtsZ protofilaments as
well as inhibit the FtsZ GTPase activity Berberine could inhibit Aspergillus fumigates through the ergosterol biosynthesis pathway.(Domadia PN,Berberine targets assembly of Escherichia coli cell division protein FtsZ,2008). In macrophages, berberine chloride-mediated anti-leishmanial activity was through activating p38 MAPK along with inhibiting ERK1/2.Berberine chloride could also induce Leishmania donovani promastigote apoptosis-like death accompanying with increased generation of reactive oxygen species.
(Berberine Chloride Mediates Its Anti-Leishmanial Activity via Differential Regulation of the Mitogen Activated Protein Kinase Pathway in Macrophages,2011)

Cardiovascular Protective Effect of Berberine

Many studies reported berberine could protect heart and vascular systems. On the one hand, it
could alleviate cardiotoxicity, improve cardiac dysfunction and arrhythmia. On the other hand, it was able to fight against atherosclerosis due to its protective actions, such as inhibiting oxidative stress and vascular inflammation, ameliorating endothelial dysfunction, suppressing vascular smooth muscle cell proliferation and migration, and inhibiting foam cell formation and lipid accumulation.

Cardioprotective Effect
In vitro and in vivo studies, berberine was reported to have a potential protective role in heart. In cultured neonatal rodent cardiomyocytes, it was found to be a muscarinic agonist at M2 receptors and could reduce the contraction rate of cardiomyocytes.(Berberine possesses muscarinic agonist-like properties in cultured rodent cardiomyocytes,2011)

Anti-atherosclerosis Effect
Atherosclerosis is a complicated pathological condition in arteries. Many risk factors are found to be associated with the pathophysiological process of atherosclerosis, such as oxidative stress and vascular inflammation, endothelial dysfunction, vascular smooth muscle cell proliferation and migration, foam cell formation and lipid accumulation.(Berberine prevents hyperglycemia-induced endothelial injury and enhances vasodilatation via adenosine monophosphate-activated protein kinase and endothelial nitric oxide synthase,2009)
Recently, increasing studies have found that berberine had multiplyprotective effects against these vascular risk factors, and could be used to prevent and treat with atherosclerosis.
(Anti-atherogenic effect of berberine on LXRalpha-ABCA1-dependent cholesterol efflux in macrophages,2010)

Anti-cancer Effect of Berberine

Recent years, berberine was reported to be a potential candidate for cancer treatment, because it
could effectively fight against a variety of cancer cells. Its anti-cancer effect was mainly attributed to its actions on inducing cancer cell death, suppressing cancer cell growth and inhibiting cancer cell metastasis. In particular a recent study focuses on the role of Berberine in cervical cancer cells, caused by HPV.

Berberine as modulator of AP-1 : suppression of HPV transcription and downstream signaling to induce growth arrest and apoptosis in cervical cancer cells.

Specific types of high risk Human papillomaviruses (HR-HPVs) particularly, HPV types 16 and 18 cause cervical cancer and while the two recently developed vaccines against these HPV types are prophylactic in nature, therapeutic options for treatment and management of already existing HPV infection are not available as yet. Antiviral approach against transcriptional inactivation of HPV using herbal derivatives that show minimal or no systemic toxicity could be a promising option to control HPV infection particularly in an early stage of cervical cancer. In this type of cancer Activator Protein-1 (AP-1) plays a central role in carcinogenesis. Different study have demonstrated overexpression and constitutive activation of AP-1 in cervical cancer cells and the DNA binding affinity of AP-1, as well as the expression of its constituent members, varies as a function of the severity of cervical lesions. Thus transcription factor, AP-1 can be considered as potential therapeutic targets for cervical cancer.The activity of Berberine is the AP-1 inhibition and blocking viral oncoproteins E6 and E7 expression

The constitutive expression of HR-HPV E6 and E7 oncogene is mainly dependent on the availability of host cell transcription factors. Activator protein-1(AP-1) which is functionally related members of the Jun proteins (c-Jun, JunB, JunD) and Fos proteins (c-Fos, FosB, Fra-1 and Fra-2) found to be constitutively active in cervical cancer. Mutational inactivation of AP-1 consensus sequence within the binding sites of the HR-HPV upstream regulatory region (URR) revealed a complete loss of transcriptional activity of the E6/E7 promoter indicating a key role of AP-1 in HPV-mediated carcinogenesis. Animal studies have also shown that berberine can suppress chemical-induced carcinogenesis, tumor promotion and tumor invasion . It also acts as a radiosensitizer of tumor cells but not for normal cells. Though anticancer activity of berberine has been demonstrated but how it mediate these effects is not clearly understood.
In this study is shown the effect of berberine on HPV16-positive cervical cancer cell line, SiHa and HPV18-positive cervical cancer cell line, HeLa using electrophoretic mobility gel shift assays, western and northern blotting which showed that berberine could selectively inhibit constitutively activated AP-1 in a dose- and time-dependent manner and downregulates HPV oncogenes expression. Berberine specifically downregulated expression of oncogenic c-Fos which was also absent in the AP-1 binding complex. Treatment with berberine resulted in repression of E6 and E7 levels and concomitant increase in p53 and Rb expression in both cell types. Berberine also suppressed expression of telomerase protein, hTERT, which translated into growth inhibition of cervical cancer cells. Interestingly, a higher concentration of berberine was found to reduce the cell viability through mitochondria-mediated pathway and induce apoptosis by activating caspase-3.

1)Downregulation of AP-1 in HPV16 positive cervical cancer cells,SiHa

HPV16 positive cervical carcinoma cells, SiHa were treated with different concentrations of berberine for 24 h and the nuclear protein (10 μg) extracted were examined for AP-1 DNA-binding activity by EMSA. Results revealed a dose-dependent decrease of AP-1 DNA binding activity in berberine-treated cells(Figure 2A). Inhibition was apparent at 50 μg/ml and a maximum inhibition was obtained at 250 μg/ml. Further analysis of time kinetics of berberine-induced AP-1 inhibition for different time periods revealed a reduced AP-1 DNA binding activity by 12 h which declined further and disappeared by 24 h (Figure 2B).

2)Berberine downregulates HPV16 and HPV18 transcription, suppressed E6, E7 and hTERT expression and increased p53 and Rb expression in cervical cancer cells

In this part of the study is investigated whether inhibition of AP-1 by berberine has any impact on the viral transcription. Total RNA was extracted from the SiHa and HeLa cells following treatment with different concentrations of berberine for 24 h and northern blotting was performed using HPV16-DNA and HPV18-DNA probes respectively. The results revealed a concentration dependent decline in HPV16-specific transcripts in berberine-treated SiHa cells (Figure 4A). It was found a significant downregulation of viral transcription.
We then proceeded to investigate the expression level of HPV oncogenes, E6 and E7 after berberine treatment. Data from western blotting analysis showed that the expression of HPV16E6, HPV16E7, HPV18E6 and HPV18E7 were significantly suppressed by berberine in cervical cancer cells in a dose-dependent manner (Figure 4B).
The two most essential cell cycle regulators and tumor suppressor proteins, p53 and Rb being the targets of high-risk HPV E6 and E7 oncoproteins respectively, we also examined the status of p53 and Rb expression in SiHa and HeLa cells. Both of these cervical cancer cells expressed p53 and Rb at low levels which showed a dose-dependent increase in expression following treatment with berberine (Figure 4C).
(Berberine modulates AP-1 activity to suppress HPV transcription and downstream signaling to induce growth arrest and apoptosis in cervical cancer cells,2011)

Anti-diabetic Effect of Berberine

There are two types of diabetes mellitus, in which type 1 diabetes is featured with islet damage
and lack of insulin, while type 2 diabetes is a chronic metabolic disease with the characteristics of insulin resistance, hyperglycemia, hyperlipidemia, and severe complications, such as vascular and nephritic injure. Recently has been majority incidence of type 2 diabetes. Most of diabetic patients treated with current therapies develops micro vascular complications such as neuropathies, nephropathies and retinopathies, that with the time leads to a damage of the peripheral nerves with a reduced renal function and to a loss of vision.
The hyperlipoproteinemia, atherosclerosis and other conditions of metabolic syndrome lead to problems such as stroke, myocardial infarction and increased mortality. Therapies that are now available are not effective enough to normalize the metabolism of glucose and lipids, and to prevent complications.Berberine has recently been shown to have protective efficacy in both two type diabetes because of its actions on the protection of islet cells and regulation of glucose, lipid and insulin metabolism.

Efficacy of Berberine in Patients with Type 2 Diabetes with suboptimal glycemic control.

A study was done to investigate the efficacy of berberine in the treatment of type 2 diabetes.
Berberine has been shown to regulate glucose and lipid metabolism in vitro and in vivo.A pilot study was to determine the efficacy and safety of berberine in the treatment of type 2 diabetic patients. In study A, 36 adults with newly diagnosed type 2 diabetes were randomly assigned to treatment with berberine or metformin, a widely-used oral hypoglycemic agent (0.5 g t.i.d.) in a 3-month trial. In study B, 48 adults with poorly controlled type 2 diabetes were treated supplemented with berberine in a 3-month trial.The results of the study A had been showed that the hypoglycemic effect of berberine was similar to that of metformin. Infact compared with metformin, berberine exhibited an identical effect in the regulation of glucose metabolism, such as HbA1c, FBG, PBG, fasting insulin and postprandial insulin.
But in the regulation of lipid metabolism, berberine activity is better than metformin. (Figura)
The results of the study B the berberine exhibited consistent activities in improvement of glycemic and lipid parameters in diabetic patients. (Table)
(Efficacy of Berberine in Patients with Type 2 Diabetes 2008)
Another study, that is published in the 2012, have tested the nutraceutical combination of Berberis aristata extract and Silybum marianumextract (Berberol®) in type 2 diabetes in terms of its additive effect when combined with a conventional oral regimen for patients with suboptimal glycemic control. After 90 days of treatment, the nutraceutical association had a positive effect on glycemic and lipid parameters, significantly reducing glycosylated hemoglobin, basal insulin, homeostatic model assessment of insulin resistance, total and low-density lipoprotein cholesterol, and triglycerides.
Berberol could be considered a good candidate as an adjunctive treatment option in diabetes, especially in patients with suboptimal glycemic control.
(Pilot study on the additive effects of berberine and oral type 2 diabetes agents for patients with suboptimal glycemic control.2012)


Absorption and Metabolism of Berberine

Berberine is mainly absorbed in the intestinal tract.Contrary to what one might expect in relation to good clinical results obtained, berberine doesn’t have complete oral bioavailability that, limits its potential effectiveness. If after intravenous administration Berberine shows in fact linear kinetics with a value of AUC that grows proportionally with the increase of the injected dose, after oral administration, the proportion of berberine found in plasma, is rather low. The limiting factor in the amount of drug that reaches a given target audience is not so much on its ability to enter the cell, but by its tendency to leave. The phenomenon depends on mechanisms extrusion of drug present in the plasma membranes, which play a critical role in limiting the absorption and accumulation of exogenous substances into cells and thereby conferring resistance to different drugs. This phenomenon is called multi Drug Resistance (MDR). The molecules responsible for the phenomenon of MDR transporters are ATP-dependent protein structure encoded genes ABC (ATP-Binding Cassette). The ABCB1 gene, also known as MDR1 encodesa P-glycoprotein (P-gp) of 170 kDa, which plays a important role in the development of resistance. It has been described that P-gp is also particularly abundant on the membrane, especially on the apical side, of enterocytes (intestinal epithelial cells). Here, its activity leads to expulsion, directly in the intestinal lumen, of some compounds, including the berberine, penetrated after oral administration, for passive diffusion inside the cells of the mucosa. So the reduced presence of plasma berberine not is as much due to his lack of direct absorption,as to its massive re-extruded into the intestinal lumen. It was carried out a study in witch was to use the P-glycoprotein (P-glycoprotein) inhibitors cyclosporin A, verapamil and the monoclonal antibody C219 in in vivo and in vitro models of intestinal absorption to determine the role of P-glycoprotein in berberine absorption. P-glycoprotein appears to contribute to the poor intestinal absorption of berberine which suggests P-glycoprotein inhibitors could be of therapeutic value by improving its bioavailability.
(The involvement of P-glycoprotein in berberine absorption,2002)
Recent years, several methods have already been found to increase its absorption and bioavailability Several compounds, such as chitosan, lysergol, D- α-tocopheryl polyethylene glycol 1000 succinate (TPGS) and sodium caprate, were reported to increase the absorption and bioavailability of berberine in animal models.


The intestine and liver are both involved in the metabolism of berberine in vivo. In the
intestine, intestinal bacteria was reported to be responsible for metabolizing berberine, and played an important role in the enterohepatic circulation of its metabolites. Oxidative demethylenation and the subsequent glucuronidation in liver were the major metabolic pathways of berberine in rats. After metabolized in the liver, the metabolites of berberine were mainly excreted in the urine through kidney, and small parts could be excreted through the hepatobiliary tract into the intestinal tract.
Some studies about Berenrine tests its acion as antioxidant, anti-microbial, anti-cancer, cardiovascular protective, anti-diabetic, neuroprotective, anti-obesity, hepatoprotective, gastrointestinal protective,anti-rheumatic, anti-angiogenic and anti-clastogenic effects, and potential mechanisms. The accumulated evidence could provide theoretical basis for its future application in clinic to prevent and treat diseases.
(Bioactivities of Berberine (Vol 1 N.1 2012)

: An Update,2012


Role in AMPK pathway

It is demonstrated that Berberine actives the AMPK cascade, involved in CV disorders and metabolic pathways, propose BBR as a new therapeutic agent in the treatment of type 2 diabetes and metabolic syndrome.

Inhibition of HPV expression
Berberine inhibites the AP-1 and blocking viral oncoproteins E6 and E7 expression.
The activator protein 1 (AP-1) is a transcription factor which is heterodimeric protein composed of proteins belonging to the c-Fos, c-Jun, ATF and JDP families. It regulates gene expression in response to a variety of stimuli, including cytokines, growth factors (figure), stress, and bacterial and viral infections. AP-1 in turn controls a number of cellular processes including differentiation, proliferation, and apoptosis. AP-1 binds to this DNA sequence via a basic amino acid region, while the dimeric structure is formed by a leucine zipper.(AP-1 transcription factor)


Berberine evaluated in the review Berberine in the Treatment of Type 2 Diabetes Mellitus: A Systemic Review and Meta-Analysis generally appeared to be safe. The side effects were commonly gastrointestinal discomforts including constipation, diarrhea, nausea, and abdominal distension. Constipation was one of the most common gastrointestinal complaints among diabetic patients after berberine intake. It was a predictable side effect since berberine had a long history used as a remedy for diarrhea in China. But it was tolerable and relieved after reducing the dose of berberine. No severe hypoglycemia was found in the included trials. The same side effects has been found in a study that try to assess the efficacy of Berberine for congestive heart failure or idiopathic dilated cardiomyopathy."
Efficacy and safety of berberine for congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.2003: .


Berberis has been shown to possess anti-inflammatory and anti-cancer properties with no known toxicity.(Berberine modulates AP-1 activity to suppress HPV transcription and downstream signaling to induce growth arrest and apoptosis in cervical cancer cells,2011)


Until now no case of resistance to berberine has been documented.


Berberine is not recommended in pregnant or breastfeeding women due to a lack of available scientific evidence. Although not well studied in humans, berberine has been suggested to have anti-fertility, abortifacient (abortion inducing), and uterine stimulant activity.
Berberine may cause kernicterus (brain damage) when used in newborn jaundiced babies, such as bilirubin encephalopathy (degenerative brain disease).


berberine has just attracted increasing research interest in recent years due to its various
significant bioactivities. However, most studies on its beneficial effects were based on cell and animal disease models, the effects of berberine on human diseases remain largely uncertain. Therefore, in the future, clinical trials are appreciated to verify the beneficial effects of berberine on human. Besides,this already accumulated evidence can also provide important theoretical basis for its clinical application in the future.

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