Berberine improves glucose metabolism through induction of glycolysis

Current knowledge and pharmacological profile of berberine: An update

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 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.

Metformin and metabolic diseases: a focus on hepatic aspects

Metformin has been widely used as a first-line anti-diabetic medicine for the treatment of type 2 diabetes (T2D). As a drug that primarily targets the liver, metformin suppresses hepatic glucose production (HGP), serving as the main mechanism by which metformin improves hyperglycemia of T2D. Biochemically, metformin suppresses gluconeogenesis and stimulates glycolysis. Metformin also inhibits glycogenolysis, which is a pathway that critically contributes to elevated HGP. While generating beneficial effects on hyperglycemia, metformin also improves insulin resistance and corrects dyslipidemia in patients with T2D. These beneficial effects of metformin implicate a role for metformin in managing non-alcoholic fatty liver disease. As supported by the results from both human and animal studies, metformin improves hepatic steatosis and suppresses liver inflammation. Mechanistically, the beneficial effects of metformin on hepatic aspects are mediated through both adenosine monophosphate-activated protein kinase (AMPK)-dependent and AMPK-independent pathways. In addition, metformin is generally safe and may also benefit patients with other chronic liver diseases.

Increased skeletal muscle glucose uptake by rosemary extract through AMPK activation

Stimulation of the energy sensor AMP-activated kinase (AMPK) has been viewed as a targeted approach to increase glucose uptake by skeletal muscle and control blood glucose homeostasis. Rosemary extract (RE) has been reported to activate AMPK in hepatocytes and reduce blood glucose levels in vivo but its effects on skeletal muscle are not known. In the present study, we examined the effects of RE and the mechanism of regulation of glucose uptake in muscle cells. RE stimulated glucose uptake in L6 myotubes in a dose- and time-dependent manner. Maximum stimulation was seen with 5 μg/mL of RE for 4 h (184% ± 5.07% of control, p < 0.001), a response comparable to maximum insulin (207% ± 5.26%, p < 0.001) and metformin (216% ± 8.77%, p < 0.001) stimulation. RE did not affect insulin receptor substrate 1 and Akt phosphorylation but significantly increased AMPK and acetyl-CoA carboxylase phosphorylation. Furthermore, the RE-stimulated glucose uptake was significantly reduced by the AMPK inhibitor compound C, but remained unchanged by the PI3K inhibitor, wortmannin. RE did not affect GLUT4 or GLUT1 glucose transporter translocation in contrast with a significant translocation of both transporters seen with insulin or metformin treatment. Our study is the first to show a direct effect of RE on muscle cell glucose uptake by a mechanism that involves AMPK activation.

Modulation of glucose transporter protein by dietary flavonoids in type 2 diabetes mellitus

Diabetes mellitus (DM) is a metabolic diseases characterized by hyperglycemia due to insufficient or inefficient insulin secretory response. This chronic disease is a global problem and there is a need for greater emphasis on therapeutic strategies in the health system. Phytochemicals such as flavonoids have recently attracted attention as source materials for the development of new antidiabetic drugs or alternative therapy for the management of diabetes and its related complications. The antidiabetic potential of flavonoids are mainly through their modulatory effects on glucose transporter by enhancing GLUT-2 expression in pancreatic β cells and increasing expression and promoting translocation of GLUT-4 via PI3K/AKT, CAP/Cb1/TC10 and AMPK pathways. This review highlights the recent findings on beneficial effects of flavonoids in the management of diabetes with particular emphasis on the investigations that explore the role of these compounds in modulating glucose transporter proteins at cellular and molecular level.

Potential benefits of berberine in the management of perimenopausal syndrome

Cardiovascular diseases are one of the leading causes of morbidity and mortality in women after menopause and 56% of all causes of death in Western European countries. Nowadays, with increasing life span, women spend approximately one-third of their life-time in postmenopausal state; therefore, the development of new strategies to improve the prevention and treatment of menopause-associated pathologies is important topic in clinical practice. The studies to assess the safety of hormone replacement therapy in women with estrogen deficiency have not been conclusive due to the relative contraindications; therefore, hormone replacement therapy is prescribed only in selected cases and for a limited time. For this reason, today women are encouraged to use naturally available compounds to prevent or to attenuate menopausal symptoms and correlated pathologies, with fewer side effects. Among these compounds, berberine, an isoquinoline alkaloid derived from plants of the generis Berberis, has been recognized as being capable of decreasing oxidative stress, LDL, triglycerides, and insulin resistance and of improving the mood. This review describes the cellular and clinical effects associated with the use of berberine, which suggest that this molecule could be an effective natural supplement to ensure a smooth peri- and postmenopausal transition.

Application of berberine on treating type 2 diabetes mellitus

Traditional Chinese medicine (TCM) performs a good clinical practice and is showing a bright future in the treatment of diabetes mellitus (DM). TCM treatment has certain advantages of less toxicity and/or side effects, and herbs could provide multiple therapeutic effects. Berberine (BBR) is a classical natural medicine. In this review, we summarize the application of BBR in the treatment of DM from two aspects. First, modern pharmacological effects of BBR on glucose metabolism are summarized, such as improving insulin resistance, promoting insulin secretion, inhibiting gluconeogenesis in liver, stimulating glycolysis in peripheral tissue cells, modulating gut microbiota, reducing intestinal absorption of glucose, and regulating lipid metabolism. BBR is used to treat diabetic nephropathy (DPN), diabetic neuropathy (DN), and diabetic cardiomyopathy due to its antioxidant and anti-inflammatory activities. Second, the clinical application of BBR is reviewed, such as listing some clinical trials on the effectiveness and safety of BBR, explaining applicable stage and syndrome, the reasonable dose and dose formulation, and the toxicity and/or side effects. This review provides scientific evidence about BBR, as well as introducing some traditional Chinese medical theory and clinical experience, in order to guide clinician to use BBR more suitably and reasonably.

A quick overview on some aspects of endocrinological and therapeutic effects of Berberis vulgaris L

Many herbaceous plants contain compounds that have biological effects in addition to their medicinal properties. They have compounds with numerous properties, including hypo lipidemic, hypoglycemic, antioxidant, and hepato protective ones, which have been analyzed at different levels. One of these plants, with the scientific name of Berberis vulgaris, is barberry. The most important compounds identified in this plant are berberine, oxycontin, palmatine, bervulcine, berbamine, columbamine, jatrorrhizine, coptisine, and berbamine. In addition to alkaloids, organic acids such as chelidonic acid, citric acid, malic acid, resin, tannin, pectinic, and mucilagic substances are among the ingredients of barberry. In this paper, it was attempted to determine the role and effect of the extract of barberry on various body organs. The results showed that berberine actually increases insulin sensitivity and is capable of inhibiting alpha glucosidase, adipogenesis, and thus acts as an anti-obesity and hypoglycemic agent. Berberine reduces the density of serum cholesterol and triglycerides and can improve the function of liver enzymes, therefore, it can be suggested as a hypo lipidemic and hepato protective plant extract. The hepato protective effects of this extract are probably due to its antioxidant properties. Studies showed that barberry have numerous health benefits, including anti-inflammatory ones. Moreover, it can be used as a medicinal herb to treat a variety of disorders, such as diabetes, liver disease, gallbladder pain, digestive, urinary tract diseases, and gallstones. However, more studies on this issue and doing more focused and intensive researches in this field are recommended.

Berberine reduces ischemia/reperfusion-induced myocardial apoptosis via activating AMPK and PI3K-Akt signaling in diabetic rats

Diabetes increases the risk of cardiovascular diseases. Berberine (BBR), an isoquinoline alkaloid used in Chinese medicine, exerts anti-diabetic effect by lowering blood glucose and regulating lipid metabolism. It has been reported that BBR decreases mortality in patients with chronic congestive heart failure. However, the molecular mechanisms of these beneficial effects are incompletely understood. In the present study, we sought to determine whether BBR exerts cardioprotective effect against ischemia/reperfusion (I/R) injury in diabetic rats and the underlying mechanisms. Male Sprague-Dawley rats were injected with low dose streptozotocin and fed with a high-fat diet for 12 weeks to induce diabetes. The diabetic rats were intragastrically administered with saline or BBR (100, 200 and 400 mg/kg/d) starting from week 9 to 12. At the end of week 12, all rats were subjected to 30 min of myocardial ischemia and 3 h of reperfusion. BBR significantly improved the recovery of cardiac systolic/diastolic function and reduced myocardial apoptosis in diabetic rats subjected to myocardial I/R. Furthermore, in cultured neonatal rat cardiomyocytes, BBR (50 μmol/L) reduced hypoxia/reoxygenation-induced myocardial apoptosis, increased Bcl-2/Bax ratio and decreased caspase-3 expression, together with enhanced activation of PI3K-Akt and increased adenosine monophosphate-activated protein kinase (AMPK) and eNOS phosphorylation. Pretreatment with either PI3K/Akt inhibitor wortmannin or AMPK inhibitor Compound C blunted the anti-apoptotic effect of BBR. Our findings demonstrate that BBR exerts anti-apoptotic effect and improves cardiac functional recovery following myocardial I/R via activating AMPK and PI3K-Akt-eNOS signaling in diabetic rats.

Effects of berberine and red yeast on proinflammatory cytokines IL-6 and TNF-α in peripheral blood mononuclear cells (PBMCs) of human subjects

BACKGROUND AND AIMS

Obesity is a condition associated with chronic or acute inflammatory response characterized by an increase of proinflammatory cytokine levels. Peripheral blood mononuclear cells (PBMCs) migrate in adipose tissue inducing synthesis and secretion of adipocytokines as IL-6 and TNF-α. The aim of this study was to investigate the effect of berberine (a natural alkaloid) and red yeast (a natural antioxidant) on IL-6 and TNF-α cytokines release and gene expression, in circulating lipopolisaccarides (LPS) stimulated PBMCs.

METHODS AND RESULTS

PBMCs isolated from whole blood of healthy donors were stimulated with LPS to induce cytokines production; simultaneously cells were treated with increasing doses of berberine and red yeast. The substances were administered alone or in association. IL-6 and TNF-α protein levels in the culture medium and their mRNA levels were assessed by ELISA and real time PCR, respectively. Berberine and red yeast treatment prevented the LPS induction of IL-6 release in the culture medium of PBMCs. In addition, berberine plus red yeast treatment showed a synergic inhibitory effect on IL-6 release at low concentration. Berberine and red yeast showed an inhibitory effect also on LPS induction of TNF-α release exerting a synergic effect mainly at high concentrations. On the contrary, berberine and red yeast did not significantly affect IL-6 and TNF-α mRNA levels induced by LPS. In this case, only concomitant treatment of PBMCs with high doses of berberine and red yeast inhibits LPS induced IL-6 or TNF-α mRNA levels.

CONCLUSIONS

The results of our study show that both berberine and red yeast were able to carry out anti-inflammatory action through an inhibition of proinflammatory IL-6 and TNF-α protein release. Moreover, when given in combination these substances were able to inhibit IL-6 and TNF-α gene expression in PBMCs activated by LPS. Therefore, these substances could represent a useful pharmacological treatment to reduce the proinflammatory status accompanied with obesity.

Xanthene derivatives increase glucose utilization through activation of LKB1-dependent AMP-activated protein kinase

5′ AMP-activated protein kinase (AMPK) is a highly conserved serine-threonine kinase that regulates energy expenditure by activating catabolic metabolism and suppressing anabolic pathways to increase cellular energy levels. Therefore AMPK activators are considered to be drug targets for treatment of metabolic diseases such as diabetes mellitus. To identify novel AMPK activators, we screened xanthene derivatives. We determined that the AMPK activators 9H-xanthene-9-carboxylic acid {2,2,2-trichloro-1-[3-(3-nitro-phenyl)-thioureido]-ethyl}-amide (Xn) and 9H-xanthene-9-carboxylic acid {2,2,2-trichloro-1-[3-(3-cyano-phenyl)-thioureido]-ethyl}-amide (Xc) elevated glucose uptake in L6 myotubes by stimulating translocation of glucose transporter type 4 (GLUT4). Treatment with the chemical AMPK inhibitor compound C and infection with dominant-negative AMPKa2-virus inhibited AMPK phosphorylation and glucose uptake in myotubes induced by either Xn or Xc. Of the two major upstream kinases of AMPK, we found that Xn and Xc showed LKB1 dependency by knockdown of STK11, an ortholog of human LKB1. Single intravenous administration of Xn and Xc to high-fat diet-induced diabetic mice stimulated AMPK phosphorylation of skeletal muscle and improved glucose tolerance. Taken together, these results suggest that Xn and Xc regulate glucose homeostasis through LKB1-dependent AMPK activation and that the compounds are potential candidate drugs for the treatment of type 2 diabetes mellitus.

Small molecule adenosine 5'-monophosphate activated protein kinase (AMPK) modulators and human diseases

Adenosine 5'-monophosphate activated protein kinase (AMPK) is a master sensor of cellular energy status that plays a key role in the regulation of whole-body energy homeostasis. AMPK is a serine/threonine kinase that is activated by upstream kinases LKB1, CaMKKβ, and Tak1, among others. AMPK exists as αβγ trimeric complexes that are allosterically regulated by AMP, ADP, and ATP. Dysregulation of AMPK has been implicated in a number of metabolic diseases including type 2 diabetes mellitus and obesity. Recent studies have associated roles of AMPK with the development of cancer and neurological disorders, making it a potential therapeutic target to treat human diseases. This review focuses on the structure and function of AMPK, its role in human diseases, and its direct substrates and provides a brief synopsis of key AMPK modulators and their relevance in human diseases.

Berberine promotes glucose consumption independently of AMP-activated protein kinase activation

Berberine is a plant alkaloid with anti-diabetic action. Activation of AMP-activated protein kinase (AMPK) pathway has been proposed as mechanism for berberine’s action. This study aimed to examine whether AMPK activation was necessary for berberine’s glucose-lowering effect. We found that in HepG2 hepatocytes and C2C12 myotubes, berberine significantly increased glucose consumption and lactate release in a dose-dependent manner. AMPK and acetyl coenzyme A synthetase (ACC) phosphorylation were stimulated by 20 µmol/L berberine. Nevertheless, berberine was still effective on stimulating glucose utilization and lactate production, when the AMPK activation was blocked by (1) inhibition of AMPK activity by Compound C, (2) suppression of AMPKα expression by siRNA, and (3) blockade of AMPK pathway by adenoviruses containing dominant-negative forms of AMPKα1/α2. To test the effect of berberine on oxygen consumption, extracellular flux analysis was performed in Seahorse XF24 analyzer. The activity of respiratory chain complex I was almost fully blocked in C2C12 myotubes by berberine. Metformin, as a positive control, showed similar effects as berberine. These results suggest that berberine and metformin promote glucose metabolism by stimulating glycolysis, which probably results from inhibition of mitochondrial respiratory chain complex I, independent of AMPK activation.

The potential role of GLUT4 transporters and insulin receptors in the hypoglycaemic activity of Ficus lutea acetone leaf extract

Background

Some Ficus species have been used in traditional African medicine in the treatment of diabetes. The antidiabetic potential of certain species has been confirmed in vivo but the mechanism of activity remains uncertain.

The aim was to investigate the hypoglycaemic potential of ten Ficus species focussing on glucose uptake, insulin secretion and the possible mechanism of hypoglycaemic activity.

Methods

The dried and ground leaves of ten Ficus species were extracted with acetone. The dried acetone extract was reconstituted with DMSO to a concentration of 100 mg/ml which was then serially diluted and used to assay for glucose uptake in muscle, fat and liver cells, and insulin secretion in pancreatic cells.

Results

Only the F. lutea extract was able to modulate glucose metabolism. In comparison to insulin in the primary muscle cells, the glucose uptake ability of the extract was 33% as effective. In the hepatoma cell line, the extract was as effective as metformin in decreasing extracellular glucose concentration by approximately 20%. In the pancreatic insulin secretory assay, the extract was 4 times greater in its secretory activity than commercial glibenclamide. With F. lutea extract significantly increasing glucose uptake in the primary muscle cells, primary fat cells, C2C12 muscle and H-4-II-E liver cells, the extract may act by increasing the activity of cell surface glucose transporters. When the 3T3-L1 pre-adipocytes were compared to the primary muscle, primary fat and C2C12 cells, the differences in the former’s ability to transport glucose into the cell may be due to the absence of the GLUT4 transporter, which on activation via the insulin receptor decreases extracellular glucose concentrations. Because the pre-adipocytes failed to show any active increase in glucose uptake, the present effect has to be linked to the absence of the GLUT4 transporter.

Conclusion

Only F. lutea possessed substantial in vitro activity related to glucose metabolism. Based on the effect produced in the various cell types, F. lutea also appears to be a partial agonist/antagonist of the insulin cell membrane receptor. While the clinical effectiveness of F. lutea is not known, this plant species does possess the ability to modify glucose metabolism.

AMPK activation: a therapeutic target for type 2 diabetes?

Type 2 diabetes (T2D) is a metabolic disease characterized by insulin resistance, β-cell dysfunction, and elevated hepatic glucose output. Over 350 million people worldwide have T2D, and the International Diabetes Federation projects that this number will increase to nearly 600 million by 2035. There is a great need for more effective treatments for maintaining glucose homeostasis and improving insulin sensitivity. AMP-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase whose activation elicits insulin-sensitizing effects, making it an ideal therapeutic target for T2D. AMPK is an energy-sensing enzyme that is activated when cellular energy levels are low, and it signals to stimulate glucose uptake in skeletal muscles, fatty acid oxidation in adipose (and other) tissues, and reduces hepatic glucose production. There is substantial evidence suggesting that AMPK is dysregulated in animals and humans with metabolic syndrome or T2D, and that AMPK activation (physiological or pharmacological) can improve insulin sensitivity and metabolic health. Numerous pharmacological agents, natural compounds, and hormones are known to activate AMPK, either directly or indirectly - some of which (for example, metformin and thiazolidinediones) are currently used to treat T2D. This paper will review the regulation of the AMPK pathway and its role in T2D, some of the known AMPK activators and their mechanisms of action, and the potential for future improvements in targeting AMPK for the treatment of T2D.

Berberine moderates glucose metabolism through the GnRH-GLP-1 and MAPK pathways in the intestine

Background

Berberine is known to improve glucose and lipid metabolism disorders, but it poorly absorbed into the blood stream from the gut. Therefore, the exact underlying mechanism for berberine is still unknown. In this study, we investigated the effect of berberine on glucose metabolism in diabetic rats and tested the hypothesis that berberine acts directly in the terminal ileums.

Methods

Rats were divided into a control group, diabetic group (DM), low dose of berberine group (BerL) and high dose of berberine group (BerH). Ileum samples were analyzed using a Roche NimbleGen mRNA array, qPCR and immunohistochemistry.

Results

We found that 8 weeks of treatment with berberine significantly decreased fasting blood glucose levels. An oral glucose tolerance test (OGTT) showed that blood glucose was significantly reduced in the BerL and BerH groups before and at 30 min, 60 min and 120 min after oral glucose administration. Plasma postprandial glucagon-like peptide-1 (GLP-1) levels were increased in the berberine-treated groups. The ileum from the BerH group had 2112 genes with significantly changed expression (780 increased, 1332 decreased). KEGG pathway analyses indicated that all differentially expressed genes included 9 KEGG pathways. The top two pathways were the MAPK signaling pathway and the GnRH signaling pathway. Q-RT-PCR and immunohistochemistry verified that glucagon-like peptide 1 receptor (Glp1r) and mitogen activated protein kinase 10 (Mapk10) were significantly up-regulated, in contrast, gonadotropin releasing hormone receptor (Gnrhr) and gonadotropin-releasing hormone 1 (Gnrh1) were down-regulated in the BerH group.

Conclusion

Our data suggest that berberine can improve blood glucose levels in diabetic rats. The mechanisms involved may be in the MAPK and GnRh-Glp-1 pathways in the ileum.

Berberine regulates AMP-activated protein kinase signaling pathways and inhibits colon tumorigenesis in mice

Colorectal cancer, a leading cause of cancer death, has been linked to inflammation and obesity. Berberine, an isoquinoline alkaloid, possesses anti-inflammatory, anti-diabetes and anti-tumor properties. In the azoxymethane initiated and dextran sulfate sodium (AOM/DSS) promoted colorectal carcinogenesis mouse model, berberine treated mice showed a 60% reduction in tumor number (P = 0.009), a 48% reduction in tumors <2 mm, (P = 0.05); 94% reduction in tumors 2-4 mm, (P = 0.001), and 100% reduction in tumors >4 mm (P = 0.02) compared to vehicle treated mice. Berberine also decreased AOM/DSS induced Ki-67 and COX-2 expression. In vitro analysis showed that in addition to its anti-proliferation activity, berberine also induced apoptosis in colorectal cancer cell lines. Berberine activated AMP-activated protein kinase (AMPK), a major regulator of metabolic pathways, and inhibited mammalian target of rapamycin (mTOR), a downstream target of AMPK. Furthermore, 4E-binding protein-1 and p70 ribosomal S6 kinases, downstream targets of mTOR, were down regulated by berberine treatment. Berberine did not affect Liver kinase B1 (LKB1) activity or the mitogen-activated protein kinase pathway. Berberine inhibited Nuclear Factor kappa-B (NF-κB) activity, reduced the expression of cyclin D1 and survivin, induced phosphorylation of p53 and increased caspase-3 cleavage in vitro. Berberine inhibition of mTOR activity and p53 phosphorylation was found to be AMPK dependent, while inhibition NF-κB was AMPK independent. In vivo, berberine also activated AMPK, inhibited mTOR and p65 phosphorylation and activated caspase-3 cleavage. Our data suggests that berberine suppresses colon epithelial proliferation and tumorigenesis via AMPK dependent inhibition of mTOR activity and AMPK independent inhibition of NF-κB.

The antihyperglycemic effects of Rhizoma Coptidis and mechanism of actions: a review of systematic reviews and pharmacological research

Rhizoma Coptidis (Huang Lian in Chinese pinyin) is among the most widely used traditional Chinese herbal medicines and has a profound history of more than 2000 years of being used as a therapeutic herb. The antidiabetic effects of Rhizoma Coptidis have been extensively investigated in animal experiments and clinical trials and its efficacy as a promising antihyperglycemic agent has been widely discussed. In the meantime, findings from modern pharmacological studies have contributed the majority of its bioactivities to berberine, the isoquinoline alkaloids component of the herb, and a number of experiments testing the antidiabetic effects of berberine have been initiated. Therefore, we conducted a review of the current evidence profile of the antihyperglycemic effects of Rhizoma Coptidis as well as its main component berberine and the possible mechanism of actions, in order to summarize research evidence in this area and identify future research directions.

Berberis Fruit Extract and Biochemical Parameters in Patients With Type II Diabetes

Background:

Diabetes mellitus is a common medical problem. There is in fact a growing body of literature on plants used for the treatment of diabetes. Plant materials attracted considerable interest of scientists. In this respect, in the past few years, attempts were made to use natural plant products for the treatment of patients with diabetes.

Objectives:

The aim of this study was to investigate the effect of Berberis fruit extract to achieve glycemic control in patients with Type II diabetes.

Materials and Methods:

This study was performed between July 2010 and April 2013. Thirty patients of type II diabetes admitted to Ayatollah Rohhani hospital were recruited. Patients’ sera were collected for the assessment of glucose and HbA1c values. Biochemical analyses were performed before and after treatment by Berberis fruit extract. Biochemical parameters were measured by spectrophotometric method (Jenway uv/vis, 6505 model, Dunmow, UK). Glucose level was measured by glucose oxidase method kit (Pars Azmoon, Tehran, IR Iran). Serum total cholesterol and triglycerides were measured using standard biochemical kits (Pars Azmoon, Tehran, Iran). Blood glycated hemoglobin level was measured by using Elisa kit (Bioassay technology laboratory, Elisa kit). Experiments were performed in triplicate in at least three separate experiments.

Results:

Our findings demonstrated that patients with type 2 diabetes who received barberry fruit had significant reduction in serum glucose to 136.15 ± 32.8 mg/dL and decreased HbA1c levels to 7.07 ± 1.21 mg/dL, during the 8 weeks of study.

Conclusions:

This investigation revealed that Berberis fruit extract has beneficial metabolic effects in patients with type II diabetes. Barberry may improve glucose catabolism via glycolysis pathway, stimulate insulin secretion or improve insulin function and finally decrease glucose uptake. Our results indicated that Berberis fruit regulates glucose metabolism in patients with type 2 diabetes.

Protection of long-term treatment with huang-lian-jie-du-tang on vascular endothelium in rats with type 2 diabetes mellitus

BACKGROUND

Huang-Lian-Jie-Du-Tang (HLJDT) is the classical traditional Chinese recipe for heat clearance and detoxification and is used in diabetic patients in the clinical practice of traditional Chinese medicine.

OBJECTIVE

The aim of this study was to evaluate the protective effects of long-term treatment with HLJDT on vascular endothelial function in rats with type 2 diabetes mellitus (T2DM).

METHODS

The male T2DM model rats were induced by intraperitoneal injection of low-dose streptozotocin plus a high-fat and high-calorie laboratory diet. The T2DM animals were randomly divided into the T2DM model group, the low-dose HLJDT group (0.42 g/kg/d), and the high-dose HLJDT group (1.25 g/kg/d).

RESULTS

Administration of HLJDT (0.42 or 1.25 g/kg/d) for 8 weeks decreased the levels of serum fasting blood glucose, malondialdehyde, and vascular tissue interleukin 6 but raised the level of serum superoxide dismutase compared with the T2DM model group in a dose-dependent manner. In addition, HLJDT treatment restored the impaired endothelial-dependent vascular relaxation in aortic preparations from the T2DM model group in a dose-dependent manner.

CONCLUSIONS

Early and long-term treatments with HLJDT could have anti-inflammatory, antioxidant properties and could protect vascular endothelium from the cardiovascular complications associated with T2DM.

Interaction of baicalin with berberine for glucose uptake in 3T3-L1 adipocytes and HepG2 hepatocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Baicalin and berberine are important coexisting constituents of the combination of Radix Scutellariae and Rhizoma Coptidis, known as scutellaria-coptis herb couple (SC), which has heat clearing and detoxifying effects. The aims of the present study were to investigate the effects of the combination of baicalin+berberine on glucose uptake in 3T3-L1 adipocytes or HepG2 cells.

MATERIALS AND METHODS

Insulin-resistant adipocytes and hepatocytes models were established. Glucose consumption was assayed to evaluate the effects of berberine, baicalin, and berberine+baicalin on glucose uptake, and the interaction of baicalin with berberine for glucose uptake was evaluated in 3T3-L1 adipocytes or HepG2 cells. Moreover, the effects of baicalin on the dose-effect relationship of berberine for glucose uptake was also evaluated in 3T3-L1 adipocytes.

RESULTS

The results of the present study demonstrated that berberine increased glucose consumption in 3T3-L1 adipocytes and HepG2 hepatocytes in a dose-dependent manner. In contrast, statistical analyses indicated that baicalin (in doses up to 100μmol/L) produced no obvious effect. The effect of berberine+baicalin on glucose uptake was better than that of berberine or baicalin alone, which indicated that berberine and baicalin had the trend of synergetic effect on glucose uptake. Furthermore, these results showed that the synergistic effect occurred in a specific dose range, while the antagonistic effect was present in another dose range in the presence of 10μmol/L baicalin. Interestingly, the entire dose-response curves of berberine shifted down in the presence of 100μmol/L baicalin, and baicalin antagonised the effect of berberine on glucose uptake in 3T3-L1 adipocytes.

CONCLUSIONS

The results of the present study showed that berberine dose-dependently increased glucose consumption in 3T3-L1 adipocytes and HepG2 hepatocytes. Furthermore, interaction of baicalin with berberine was additive at low doses of baicalin and antagonistic at higher baicalin doses. Thus, it is possible that baicalin is a partial agonist. These results provided a basis for the study of the TCM compatibility mechanism and a new insight into the application for Gegen Qinlian Decoction (GGQLD) or SC in the clinic.

Characterization, pharmacokinetics, and hypoglycemic effect of berberine loaded solid lipid nanoparticles

The high aqueous solubility, poor permeability, and absorption of berberine (BBR) result in its low plasma level after oral administration, which greatly limits its clinical application. BBR solid lipid nanoparticles (SLNs) were prepared to achieve improved bioavailability and prolonged effect. Developed SLNs showed homogeneous spherical shapes, small size (76.8 nm), zeta potential (7.87 mV), encapsulation efficiency (58%), and drug loading (4.2%). The power of X-ray diffraction combined with ¹H nuclear magnetic resonance spectroscopy was employed to analyze chemical functional groups and the microstructure of BBR-SLNs, and indicated that the drug was wrapped in a lipid carrier. Single dose (50 mg/kg) oral pharmacokinetic studies in rats showed significant improvement (P<0.05) in the peak plasma concentration, area under the curve, and variance of mean residence time of BBR-SLNs when compared to BBR alone (P<0.05), suggesting improved bioavailability. Furthermore, oral administration of both BBR and BBR-SLNs significantly suppressed body weight gain, fasting blood glucose levels, and homeostasis assessment of insulin resistance, and ameliorated impaired glucose tolerance and insulin tolerance in db/db diabetic mice. BBR-SLNs at high dose (100 mg/kg) showed more potent effects when compared to an equivalent dose of BBR. Morphologic analysis demonstrated that BBR-SLNs potentially promoted islet function and protected the islet from regeneration. In conclusion, our study demonstrates that by entrapping BBR into SLNs the absorption of BBR and its anti-diabetic action were effectively enhanced.

Antitumor effect of novel berberine derivatives in breast cancer cells

Breast cancer is the most common malignancy and the most common cause of cancer death in elderly women. Chemoprevention with dietary compounds and their synthetic analogs has emerged as an attractive strategy to prevent carcinogenic progression to invasive cancer. In this study, we investigated the efficacy of some new synthetic derivatives of berberine, a phytochemical isolated from Barberry and other plants, to induce growth arrest of HER-2/neu overexpressing SK-BR-3 breast cancer cells. Supplementation with berberine or with the synthetic derivatives NAX012, NAX013, NAX014, and NAX035 exerted a dose- and time-dependent inhibition of SK-BR-3 cell viability, with a greater effectiveness of NAX012 and NAX014 compounds with respect to berberine. This cytotoxic effect was related to an increased number of apoptotic cells that reached 71.6% and 68.4% after 72 h treatment with 50 µM of NAX012 and NAX014, respectively, compared with 44.2% of berberine. Real-time PCR analyses showed that berberine, NAX012 and NAX014 compounds increased the expression of some cell-cycle checkpoint molecules involved in cell senescence such as p53, p21(WAF1) , p16(INK4a) , and PAI-1, already after 24 h of 50 µM treatments. Furthermore, berberine, NAX012 and NAX014, all reduced both HER-2/neu expression and phosphorylation on tumor cells, the NAX014 compound showing the higher effectiveness. These results provide novel information on the mechanisms involved in the anticancer effects of berberine and demonstrate the greater effectiveness of NAX012 and NAX014 analogs in inducing apoptosis and cellular senescence in HER-2/neu overexpressing tumor cell lines.

Berberine, a natural antidiabetes drug, attenuates glucose neurotoxicity and promotes Nrf2-related neurite outgrowth

Reactive oxygen intermediates production and apoptotic damage induced by high glucose are major causes of neuronal damage in diabetic neuropathy. Berberine (BBR), a natural antidiabetes drug with PI3K-activating activity, holds promise for diabetes because of its dual antioxidant and anti-apoptotic activities. We have previously reported that BBR attenuated H2O2 neurotoxicity via activating the PI3K/Akt/Nrf2-dependent pathway. In this study, we further explored the novel protective mechanism of BBR on high glucose-induced apoptotic death and neurite damage of SH-SY5Y cells. Results indicated BBR (0.1-10 nM) significantly attenuated reactive oxygen species (ROS) production, nucleus condensation, and apoptotic death in high glucose-treated cells. However, AG1024, an inhibitor of insulin growth factor-1 (IGF-1) receptor, significantly abolished BBR protection against high glucose-induced neuronal death. BBR also increased Bcl-2 expression and decreased cytochrome c release. High glucose down-regulated IGF-1 receptor and phosphorylation of Akt and GSK-3β, the effects of which were attenuated by BBR treatment. BBR also activated nuclear erythroid 2-related factor 2 (Nrf2), the key antioxidative transcription factor, which is accompanied with up-regulation of hemeoxygenase-1 (HO-1). Furthermore, BBR markedly enhanced nerve growth factor (NGF) expression and promoted neurite outgrowth in high glucose-treated cells. To further determine the role of the Nrf2 in BBR neuroprotection, RNA interference directed against Nrf2 was used. Results indicated Nrf2 siRNA abolished BBR-induced HO-1, NGF, neurite outgrowth and ROS decrease. In conclusion, BBR attenuated high glucose-induced neurotoxicity, and we are the first to reveal this novel mechanism of BBR as an Nrf2 activator against glucose neurotoxicity, providing another potential therapeutic use of BBR on the treatment of diabetic complications.

Berberine improves insulin resistance in cardiomyocytes via activation of 5'-adenosine monophosphate-activated protein kinase

OBJECTIVE

Insulin resistance plays an important role in the pathogenesis of diabetic cardiomyopathy. Berberine (BBR) is a plant alkaloid which promotes hypoglycemia via increasing insulin sensitivity in peripheral tissues. Little is known of BBR's role in regulating glucose metabolism in heart.

MATERIALS/METHODS

We examined the effect and mechanism of BBR on glucose consumption and glucose uptake in insulin sensitive or insulin resistant rat H9c2 cardiomyocyte cells. H9c2 myoblast cells were differentiated into cardiomyocytes and incubated with insulin for 24h to induce insulin resistance.

RESULTS

BBR-treatment of H9c2 cells increased glucose consumption and glucose uptake compared to controls. In addition, BBR-treatment attenuated the reduction in glucose consumption and glucose uptake in insulin resistant H9c2 cells. Compound C, an inhibitor of AMP-activated protein kinase (AMPK), abolished the enhancement of glucose consumption and glucose uptake mediated by BBR in both insulin sensitive and insulin resistant H9c2 cells compared to controls.

CONCLUSION

BBR significantly increased AMPK activity, but had little effect on the activity of protein kinase B (AKT) in insulin resistant H9c2 cells, suggesting that berberine improves insulin resistance in H9c2 cardiomyocytes at least in part via stimulation of AMPK activity.

Update on berberine in nonalcoholic Fatty liver disease

Berberine (BBR), an active ingredient from nature plants, has demonstrated multiple biological activities and pharmacological effects in a series of metabolic diseases including nonalcoholic fatty liver disease (NAFLD). The recent literature points out that BBR may be a potential drug for NAFLD in both experimental models and clinical trials. This review highlights important discoveries of BBR in this increasing disease and addresses the relevant targets of BBR on NAFLD which links to insulin pathway, adenosine monophosphate-activated protein kinase (AMPK) signaling, gut environment, hepatic lipid transportation, among others. Developing nuanced understanding of the mechanisms will help to optimize more targeted and effective clinical application of BBR for NAFLD.

Phytochemicals targeting genes relevant for type 2 diabetes

Nutrigenomic approaches based on ethnopharmacology and phytotherapy concepts have revealed that type 2 diabetes mellitus (T2DM) may be susceptible to dietary intervention. Interaction between bioactive food components and the genome may influence cell processes and modulate the onset and progression of the disease. T2DM, characterized by insulin resistance and beta cell dysfunction, is one of the leading causes of death and disability. Despite the great advances that have been made in the understanding and management of this complex, multifactorial disease, T2DM has become a worldwide epidemic in the 21st century. Population and family studies have revealed a strong genetic component of T2DM, and a number of candidate genes have been identified in humans. Variations in the gene sequences such as single nucleotide polymorphisms, explain the individual differences in traits like disease susceptibility and response to treatment. A clear understanding of how nutrients affect the expression of genes should facilitate the development of individualized intervention and, eventually, treatment strategies for T2DM. Review of the literature identified many phytochemicals/extracts from traditional medicinal plants that can target diabetogenic genes. This review focuses on the genetic aspects of T2DM, nutrient modification of genes relevant for diabetes, and future prospects of nutritional therapy of T2DM.

Nano-cellulose 3D-networks as controlled-release drug carriers

Bacterial cellulose (BC) membranes are used as the carrier for berberine hydrochloride and berberine sulphate to produce a new controlled release system. Release studies and transdermal experiments were carried out in vitro. Carrier BC can significantly extend the drug release time, in contrast to existing commercial carriers. Freeze-dried BC membranes 10 mm thick were optimized for drug delivery. The lowest release rate was in simulated gastric fluid (SGF) or in H₂SO₄ solution, the highest in simulated intestinal fluid (SIF) and an intermediate rate was found in alkaline conditions. The release curves closely followed the Ritger-Peppas model with free diffusion the most prominent mechanism. Scanning electron microscopy (SEM) analysis demonstrated that BC fibers were swollen in acid and base conditions. ¹H high-resolution magic angle spinning nuclear magnetic resonance (¹H HRMAS NMR) diffusion-ordered spectroscopy (DOSY) analysis showed that there was an interaction between the drugs and BC. The structure of BC, the media and the solubility of the drug all influenced the sustained-release behavior. The results from the release studies, the electron micrographs, and the transdermal experiments were in good agreement.

Berberine attenuates ischemia-reperfusion injury via regulation of adenosine-5'-monophosphate kinase activity in both non-ischemic and ischemic areas of the rat heart

BACKGROUND

Berberine exhibits numerous pharmacological effects, but the mechanism for its protective effects against ischemia-reperfusion cardiac injury is unknown.

METHODS

Male Wistar rats were treated with berberine (100 mg/Kg/day, ig) for 14 days and controls treated with water. Hearts were isolated in vitro and perfused in the Langendorff mode and subjected to 30 min of global ischemia followed by 30 min of reperfusion and hemodynamic data examined. In a separate set of experiments, hearts were subjected in vivo to left anterior descending coronary artery ligation for 30 min followed by 120 min reperfusion and hemodynamic data, type and duration of arrhythmias, and myocardial infarct size determined. AMP-activated protein kinase (AMPK) level, ADP/ATP and AMP/ATP ratios were examined in non-ischemic areas and risk areas of the heart.

RESULTS

Subsequent to ischemia-reperfusion injury, left ventricular developed pressure, left ventricular end diastolic pressure and maximum rate of intraventricular pressure contractility and relaxation were significantly improved in the berberine treatment groups compared to controls. Berberine treatment decreased infarct size and diminished the duration and incidence of arrhythmias compared to controls. Berberine treatment significantly decreased AMPK protein concentration, and the ratio of ADP/ATP and AMP/ATP in the myocardial risk areas. In contrast, berberine treatment significantly increased AMPK protein concentration, and the ratio of ADP/ATP and AMP/ATP in the non-ischemia areas compared to controls.

CONCLUSION

These findings suggest that berberine may exert its cardioprotective effect on ischemia-reperfusion injury via regulation of AMPK activity in both non-ischemic areas and risk areas of the heart.

Activation of AMPK by bitter melon triterpenoids involves CaMKKβ

We recently showed that bitter melon-derived triterpenoids (BMTs) activate AMPK and increase GLUT4 translocation to the plasma membrane in vitro, and improve glucose disposal in insulin resistant models in vivo. Here we interrogated the mechanism by which these novel compounds activate AMPK, a leading anti-diabetic drug target. BMTs did not activate AMPK directly in an allosteric manner as AMP or the Abbott compound (A-769662) does, nor did they activate AMPK by inhibiting cellular respiration like many commonly used anti-diabetic medications. BMTs increased AMPK activity in both L6 myotubes and LKB1-deficient HeLa cells by 20–35%. Incubation with the CaMKKβ inhibitor, STO-609, completely attenuated this effect suggesting a key role for CaMKKβ in this activation. Incubation of L6 myotubes with the calcium chelator EGTA-AM did not alter this activation suggesting that the BMT-dependent activation was Ca²⁺-independent. We therefore propose that CaMKKβ is a key upstream kinase for BMT-induced activation of AMPK.

Mechanisms of insulin resistance in obesity

Obesity increases the risk for type 2 diabetes through induction of insulin resistance. Treatment of type 2 diabetes has been limited by little translational knowledge of insulin resistance although there have been several well-documented hypotheses for insulin resistance. In those hypotheses, inflammation, mitochondrial dysfunction, hyperinsulinemia and lipotoxicity have been the major concepts and have received a lot of attention. Oxidative stress, endoplasmic reticulum (ER) stress, genetic background, aging, fatty liver, hypoxia and lipodystrophy are active subjects in the study of these concepts. However, none of those concepts or views has led to an effective therapy for type 2 diabetes. The reason is that there has been no consensus for a unifying mechanism of insulin resistance. In this review article, literature is critically analyzed and reinterpreted for a new energy-based concept of insulin resistance, in which insulin resistance is a result of energy surplus in cells. The energy surplus signal is mediated by ATP and sensed by adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. Decreasing ATP level by suppression of production or stimulation of utilization is a promising approach in the treatment of insulin resistance. In support, many of existing insulin sensitizing medicines inhibit ATP production in mitochondria. The effective therapies such as weight loss, exercise, and caloric restriction all reduce ATP in insulin sensitive cells. This new concept provides a unifying cellular and molecular mechanism of insulin resistance in obesity, which may apply to insulin resistance in aging and lipodystrophy.

Adrenomedullin attenuates vascular calcification in fructose-induced insulin resistance rats

AIM

To determine the therapeutic effects of adrenomedullin (ADM) on vascular calcification and related molecular mechanism in fructose-induced insulin resistance rats.

METHODS

Rats received ordinary drinking water or 10% fructose in drinking water for 12 weeks and subcutaneous injection of normal saline or ADM (3.6 μg kg(-1) ) twice a day for the last 4 weeks. Levels of ADM, calcitonin receptor-like receptors (CRLR), receptor activity-modifying proteins (RAMP) as well as calcium content, alkaline phosphatase (ALP) activity, osteoblastic and contractile smooth muscle markers in aortic media were measured.

RESULTS

The levels of ADM, CRLR, RAMP2 and RAMP3 in aortic media were increased in fructose-fed rats. ADM treatment attenuated the fructose-induced insulin resistance, increased blood pressure, fasting glucose, insulin, triglycerides and cholesterol levels. It improved VSMCs proliferation and disordered arrangement and hyperplasia of elastic fibres in fructose-fed rats. Calcium deposits, calcium content and ALP activity in the aortic media were increased in fructose-fed rats, which were attenuated by ADM treatment. The osteoblastic markers such as osteopontin (OPN), bone morphogenetic protein 2 (BMP2) proteins and core binding factor alpha-1 (Cbfα-1) protein and mRNA expressions were increased in fructose-fed rats. ADM treatment increased the OPN protein expression, but reduced the BMP2 protein, Cbfα-1 protein and mRNA expression. Contractile smooth muscle markers such as α-actin and smooth muscle 22α (SM-22α) were downregulated in fructose-fed rats, which were recovered by ADM treatment.

CONCLUSION

Administration of ADM attenuates insulin resistance, calcium deposition and osteogenic transdifferentiation in aortic media in fructose-fed rats.

Berberine analogue IMB-Y53 improves glucose-lowering efficacy by averting cellular efflux especially P-glycoprotein efflux

OBJECTIVE

Cellular efflux transporters, especially P-glycoprotein (P-gp), impel berberine (BBR) out of cells, and therefore reduce bioavailability of the compound. This study was designed to overcome efflux of BBR using P-gp as a target.

MATERIALS/METHODS

Molecular docking study was done to identify BBR analogues that were with low affinity to P-gp. Flow cytometry was used to determine cellular efflux of chemicals. Pharmacokinetic study was performed in Wistar rats, following oral administration of the study compounds. The efficacies of chemicals on glucose homeostasis were determined both in cultured cells and diabetic KK-Ay and db/db mice.

RESULTS

In the molecular docking study, we found that among BBR analogues pseudo-berberine (IMB-Y53) has low affinity to P-gp. IMB-Y53 was retained in Caco-2, HL-7702 and C2C12 cells for a significantly longer period of time than BBR did. P-gp inhibitor tetrandrine (Tet) abolished the efflux of BBR at different extent depending on the expression level of P-gp; however, Tet had no impact on IMB-Y53 efflux. BBR increased P-gp expression dose-dependently in intestinal and liver cells; IMB-Y53 also up-regulated P-gp but at a much lower level as compared with BBR. Administered at equal dose in rats, the maximum plasma concentration (C(max)) and area under concentration-time curve (AUC(0-24)) of IMB-Y53 were 1.61 and 2.27-fold of those of BBR, respectively, indicating an improved bioavailability. IMB-Y53 stimulated glucose utility in cultured cells with a degree similar to that of BBR, but exhibited enhanced glucose-lowering efficacy in KK-Ay and db/db diabetic mice.

CONCLUSIONS

These results suggest that overcoming cellular efflux especially P-gp's function improves bioavailability and hypoglycemic effect of BBR.

Anti-diabetic property of Tinospora cordifolia and its active compound is mediated through the expression of Glut-4 in L6 myotubes

Tinospora cordifolia is a well reported plant possessing numerous medicinal values including anti-diabetic property. Aim of the present study is to study the mechanism of action of Tinospora cordifolia and its active compound in differentiated myocytes, L6 cells. Key marker of diabetes in cells is the insulin dependent glucose transporter-4 (Glut-4) which also responds to exogenous chemicals, and is over expressed up to 5- and 4-fold, by Tinospora cordifolia and palmatine, respectively. Next to Glut-4, the predominant protein influencing glucose metabolism is PPARα and γ whose expressions were also positively modulated. Further, the inhibitors of insulin pathway prevented glucose uptake mediated by Tinospora cordifolia and palmatine which shows that the activity is majorly mediated through insulin pathway.

The role of neuronal AMPK as a mediator of nutritional regulation of food intake and energy homeostasis

Hypothalamic 5'-adenosine monophosphate-activated protein kinase (AMPK) senses intracellular metabolic stress, i.e., an increase in the cellular AMP:ATP ratio, and integrates diverse hormonal and nutritional signals to restore energy balance. Recent evidence suggests that different nutrients can modulate AMPK activity in the hypothalamus, thereby controlling weight gain through a leptin-independent mechanism. Understanding the mechanisms by which nutrients control hypothalamic AMPK activity is crucial to the development of effective nutritional interventions for the treatment of food intake-related disorders, such as anorexia and obesity. This article highlights the current evidence for the intricate relationship between nutrients and hypothalamic AMPK activity.

Berberine ameliorates renal injury by regulating G proteins-AC- cAMP signaling in diabetic rats with nephropathy

Diabetic nephropathy (DN) is a progressive kidney disease that is caused by injury to glomerulus and glomerular mesangial cells (MCs) proliferation play a critical role in the pathogenesis of DN. The current studies were undertaken to investigate the protective effects and the possible molecular mechanism of berberine on streptozotocin (STZ)-induced DN rats. Male Wistar rats were randomly assigned to normal control and DN groups of comparable age. Three DN groups received 50, 100 and 200 mg/kg of berberine for 8 weeks via daily intragastrically, respectively. The G proteins-adenylyl cyclase (AC)-cAMP signaling pathway and glomerular MCs proliferation were examined in STZ-induced diabetic rat kidney. Enhanced MCs proliferation and remarkable renal injury were concomitant with activation of Gαi and inhibition of Gαs and cAMP in DN model group. Berberine treatment for 8 weeks abolished the above changes by upregulating the expression of Gαs protein and downregulating the expression of Gαi protein, increasing cAMP level, and inhibiting MCs proliferation compared with model group. Taken together, for the first time, these results demonstrated that berberine can relieve renal injury in DN rats through mediating G proteins-AC-cAMP signaling pathway and inhibiting the abnormal proliferation of MCs by increasing cAMP level, suggesting that berberine could be a potential therapeutic agent for the treatment of DN.

Berberine‑attenuated monocyte adhesion to endothelial cells induced by oxidized low‑density lipoprotein via inhibition of adhesion molecule expression

Recruitment of monocytes to endothelial cells is important during early stages of atherosclerosis development. This process is predominantly mediated by cellular adhesion molecules, including vascular cell adhesion molecule‑1 (VCAM‑1) and intercellular adhesion molecule‑1 (ICAM‑1), which are expressed by activated endothelial cells in response to a number of inflammatory stimuli, including oxidized low‑density lipoprotein (oxLDL). Previous studies have demonstrated that berberine, a natural extract from Rhizoma coptidis, prevents oxLDL‑induced endothelial cellular apoptosis. However, its effect on the adhesion of monocytes to endothelial cells and the mechanism associated with this process remains unclear. In the present study, berberine was revealed to markedly reduce oxLDL‑induced monocyte adhesion to human umbilical vein endothelial cells. In addition, the inhibitory mechanism of berberine was associated with suppression of adhesion molecule expression, including VCAM‑1 and ICAM‑1. Results indicate that berberine plays a protective role in the early stages of atherosclerosis.