The antihypertensive effect of the berberine derivative 6-protoberberine in spontaneously hypertensive rats

Efficacy and safety of berberine for several cardiovascular diseases: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Berberine has been widely used for the adjuvant therapy of several cardiovascular diseases (CVDs). However, evidence for its efficacy remains controversial.

PURPOSE

This study aimed to evaluate the efficacy and safety of berberine in CVDs.

STUDY DESIGN

A systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

We searched ten electronic databases for articles from inception to December 23, 2022. RCTs comparing berberine alone or combined with statins versus statins or routine for CVDs were included. Meta-analysis was performed according to the Cochrane Handbook.

RESULTS

Forty-four RCTs were included with 4606 patients. There were no differences between berberine alone and routine or statins in improving total cholesterol (TC) (SMD, 0.43; 95% CI, -0.39 to 1.24; p = 0.30; I² = 95%), triglyceride (TG) (SMD, -0.14; 95% CI, -0.49 to 0.21; p = 0.44; I² = 76%), low-density lipoprotein cholesterol (LDL-C) (SMD, 0.69; 95% CI, -0.23 to 1.60; p = 0.14; I² = 96%), high-density lipoprotein cholesterol (HDL-C) (SMD, 0.55; 95% CI, -0.48 to 1.57; p = 0.30; I² = 96%), and Crouse score levels. Berberine alone significantly reduced National Institute of Health Stroke Scale (NIHSS) score, high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and intima-media thickness (IMT) levels than routine therapy. Berberine plus statins significantly reduced TC, TG, LDL-C, NIHSS score, hs-CRP, TNF-α, IMT, Crouse score, and number of unstable plaques levels than routine or statins. However, no differences were found between groups in improving HDL-C and IL-6 levels. There were no significant differences between groups in the incidence of adverse reactions.

CONCLUSION

This study suggests that berberine may be a promising alternative for CVDs with no serious adverse reactions. However, our results may be limited by the quality of existing research. High-quality RCTs are needed to provide more convinced evidence.

Berberine exerts protective effects on cardiac senescence by regulating the Klotho/SIRT1 signaling pathway

Berberine (BBR), an isoquinoline alkaloid, exerts protective effects on various cardiac injuries, and also extends the lifespan of individuals. However, the cardioprotective effect of BBR on cardiac senescence remains unknown. This study investigated the effects of BBR on cardiac senescence and its underlying mechanism. Senescent H9c2 cells induced by doxorubicin (DOX) and naturally aged rats were used to evaluate the protective effects of BBR on cardiac senescence. The results showed that BBR protected H9c2 cells against DOX-induced senescence. Exogenous Klotho (KL) exerts similar effects to those of BBR. BBR significantly increased in protein expression of KL, while transfection with KL-specific siRNA (siKL) inhibited the protective effect of BBR against senescence. Both BBR and exogenous KL decreased the levels of reactive oxygen species, inhibited apoptosis, and alleviated mitochondrial dysfunction in these cells; and transfection with siKL attenuated these effects of BBR. In naturally aged rats, BBR indeed protected the animals from cardiac aging, at least partially, through lowering the levels of cardiac hypertrophy markers, and increased the expression of KL in cardiac tissue. Additionally, BBR markedly reversed downregulation of sirtuin1 (SIRTI) in the aged heart. In vitro experiments revealed that BBR and exogenous KL also increased the expression of SIRT1, whereas siKL limited this effect of BBR in senescent H9c2 cell. In summary, BBR upregulated KL expression and prevented heart from cardiac senescence through anti-oxidative and anti-apoptotic effects, as well as alleviation of mitochondrial dysfunction. These effects may be mediated via regulation of the Klotho/SIRT1 signaling pathway.

Promising Antioxidative Effect of Berberine in Cardiovascular Diseases

Berberine (BBR), an important quaternary benzylisoquinoline alkaloid, has been used in Chinese traditional medicine for over 3,000 years. BBR has been shown in both traditional and modern medicine to have a wide range of pharmacological actions, including hypoglycemic, hypolipidemic, anti-obesity, hepatoprotective, anti-inflammatory, and antioxidant activities. The unregulated reaction chain induced by oxidative stress as a crucial mechanism result in myocardial damage, which is involved in the pathogenesis and progression of many cardiovascular diseases (CVDs). Numerous researches have established that BBR protects myocardium and may be beneficial in the treatment of CVDs. Given that the pivotal role of oxidative stress in CVDs, the pharmacological effects of BBR in the treatment and/or management of CVDs have strongly attracted the attention of scholars. Therefore, this review sums up the prevention and treatment mechanisms of BBR in CVDs from in vitro, in vivo, and finally to the clinical field trials timely. We summarized the antioxidant stress of BBR in the management of coronary atherosclerosis and myocardial ischemia/reperfusion; it also analyzes the pathogenesis of oxidative stress in arrhythmia and heart failure and the therapeutic effects of BBR. In short, BBR is a hopeful drug candidate for the treatment of CVDs, which can intervene in the process of CVDs from multiple angles and different aspects. Therefore, if we want to apply it to the clinic on a large scale, more comprehensive, intensive, and detailed researches are needed to be carried out to clarify the molecular mechanism and targets of BBR.

An insight into the medicinal attributes of berberine derivatives: A review

In the last few decades, traditional natural products have been the center of attention for the scientific community and exploration of their therapeutic abilities is proceeding perpetually. Berberine, with remarkable therapeutic diversity, is a plant derived isoquinoline alkaloid which is widely used as a traditional medicine in China. Berberine has been tackled as a fascinating pharmacophore to make great contributions to the discovery and development of new therapeutic agents against variegated diseases. Despite its tremendous therapeutic potential, clinical utility of this alkaloid was significantly compromised due to undesirable pharmacokinetic properties. To overcome this limitation, several structural modifications were performed on this scaffold to improve its therapeutic efficacy. The collective efforts of the community have achieved the tremendous advancements, bringing berberine to clinical use and discovering new therapeutic opportunities by structural modifications on the berberine scaffold. In this review, recent advancements in the medicinal chemistry of berberine and its derivatives in the last few years (2016-2020) have been compiled to represent inclusive data associated with various biological activities of this alkaloid. The comprehensive structure-activity relationship studies along with molecular modelling and mechanistic studies have also been summarized. This article would be highly helpful for the scientific community to get better insight into medicinal research of berberine and become a compelling guide for the rational design of berberine based compounds.

Berberine attenuates mitochondrial dysfunction by inducing autophagic flux in myocardial hypoxia/reoxygenation injury

Berberine (BBR) is routinely prescribed in many Asian countries to treat diarrhea. Evidence from both animal and clinical investigations suggests that BBR exerts diverse pharmacological activities, including antidiabetic, antineoplastic, antihypertensive, and antiatherosclerotic effects. This study aimed to explore the cardioprotective mechanisms of BBR and to elucidate the modulations between autophagy and mitochondrial function during hypoxia/reoxygenation (H/R) in H9c2 cells. The degree of autophagic flux was assessed by pretreating H9c2 cells with BBR prior to H/R exposure and measuring the expression levels of Beclin-1 and green fluorescent protein (GFP)-labeled LC3B fusion proteins as well as the LC3II/LC3I ratio. The mitochondrial membrane potential (△Ψm) in H9c2 cells was evaluated by detecting rhodamine-123 fluorescence using flow cytometry. The results revealed that pretreatment with BBR upregulated autophagic flux and protected against the loss of the △Ψm in H9c2 cells subjected to H/R. We conclude that BBR attenuates mitochondrial dysfunction by inducing autophagic flux.

Berberine in Cardiovascular and Metabolic Diseases: From Mechanisms to Therapeutics

Cardiovascular and metabolic diseases (CVMD) are the leading causes of death worldwide, underscoring the urgent necessity to develop new pharmacotherapies. Berberine (BBR) is an eminent component of traditional Chinese and Ayurvedic medicine for more than 2000 years. Recently, BBR has attracted much interest for its pharmacological actions in treating and/or managing CVMD. Recent discoveries of basic, translational and clinical studies have identified many novel molecular targets of BBR (such as AMPK, SIRT1, LDLR, PCSK9, and PTP1B) and provided novel evidences supporting the promising therapeutic potential of BBR to combat CVMD. Thus, this review provides a timely overview of the pharmacological properties and therapeutic application of BBR in CVMD, and underlines recent pharmacological advances which validate BBR as a promising lead drug against CVMD.

Berberine inhibits cardiac remodeling of heart failure after myocardial infarction by reducing myocardial cell apoptosis in rats

The effects of berberine on cardiac function of heart failure after myocardial infarction and its possible mechanism were investigated. The anterior descending branches of 50 female Wistar rats were ligatured to establish the model of heart failure after myocardial infarction. At 4 weeks after successful modeling, the rats were randomly divided into two groups receiving 4-week gavage with saline (Sal group) and berberine (Ber group), while the sham-operation group (Sham group) was set up. After 4 weeks, the hemodynamics and serum BNP in rats were measured. The hearts of rats were taken to detect the degree of myocardial fibrosis. The myocardial cell apoptosis was detected. The expressions and changes in myocardial apoptosis-related proteins, including Bcl-2, Bax and caspase-3, were detected. The expression and changes in GRP78, CHOP and caspase-12 in myocardial tissue were detected. The results showed that Berberine improved the cardiac function of rats after myocardial infarction. After myocardial infarction, myocardial fibrosis and apoptosis were observed around the infarction area, berberine improved the myocardial fibrosis and reduced cell apoptosis. Furthermore, berberine alleviated endoplasmic reticulum stress (ERS) after myocardial infarction. In conclusion, Berberine can inhibit the myocardium cell apoptosis of heart failure after myocardial infarction, and its mechanism may be realized by affecting the ERS in myocardial tissue of heart failure after myocardial infarction and CHOP and caspase-12 apoptotic signaling pathway, upregulating Bcl-2/Bax expression and downregulating caspase-3 expression, thus inhibiting the cardiac remodeling and protecting the cardiac function.

Natural products targeting ER stress pathway for the treatment of cardiovascular diseases

Endoplasmic reticulum (ER) is the main organelle for the synthesis, folding, and processing of secretory and transmembrane proteins. Pathological stimuli including hypoxia, ischaemia, inflammation and oxidative stress interrupt the homeostatic function of ER, leading to accumulation of unfolded proteins, a condition referred to as ER stress. ER stress triggers a complex signalling network referred as the unfolded protein response (UPR). Extensive studies have demonstrated that ER stress plays an important role in the pathogenesis of various cardiovascular diseases such as heart failure, ischemic heart disease and atherosclerosis. The importance of natural products in modern medicine are well recognized and continues to be of interests as a source of novel lead compounds. Natural products targeting components of UPR and reducing ER stress offers an innovative strategic approach to treat cardiovascular diseases. In this review, we discussed several therapeutic interventions using natural products with potential cardiovascular protective properties targeting ER stress signalling pathways.

Melatonin inhibits AP-2β/hTERT, NF-κB/COX-2 and Akt/ERK and activates caspase/Cyto C signaling to enhance the antitumor activity of berberine in lung cancer cells

Melatonin, a molecule produced throughout the animal and plant kingdoms, and berberine, a plant derived agent, both exhibit antitumor and multiple biological and pharmacological effects, but they have never been combined altogether for the inhibition of human lung cancers. In this study, we investigated the role and underlying mechanisms of melatonin in the regulation of antitumor activity of berberine in lung cancer cells. Treatment with melatonin effectively increased the berberine-mediated inhibitions of cell proliferation, colony formation and cell migration, thereby enhancing the sensitivities of lung cancer cells to berberine. Melatonin also markedly increased apoptosis induced by berberine. Further mechanism study showed that melatonin promoted the cleavage of caspse-9 and PARP, enhanced the inhibition of Bcl2, and triggered the releasing of cytochrome C (Cyto C), thereby increasing the berberine-induced apoptosis. Melatonin also enhanced the berberine-mediated inhibition of telomerase reverses transcriptase (hTERT) by down-regulating the expression of AP-2β and its binding on hTERT promoter. Moreover, melatonin enhanced the berberine-mediated inhibition of cyclooxygenase 2 (COX-2) by inhibiting the nuclear translocation of NF-κB and its binding on COX-2 promoter. Melatonin also increased the berberine-mediated inhibition of the phosphorylated Akt and ERK. Collectively, our results demonstrated that melatonin enhanced the antitumor activity of berberine by activating caspase/Cyto C and inhibiting AP-2β/hTERT, NF-κB/COX-2 and Akt/ERK signaling pathways. Our findings provide new insights in exploring the potential therapeutic strategies and novel targets for lung cancer treatment.

Endoplasmic reticulum stress: a novel mechanism and therapeutic target for cardiovascular diseases

Endoplasmic reticulum is a principal organelle responsible for folding, post-translational modifications and transport of secretory, luminal and membrane proteins, thus palys an important rale in maintaining cellular homeostasis. Endoplasmic reticulum stress (ERS) is a condition that is accelerated by accumulation of unfolded/misfolded proteins after endoplasmic reticulum environment disturbance, triggered by a variety of physiological and pathological factors, such as nutrient deprivation, altered glycosylation, calcium depletion, oxidative stress, DNA damage and energy disturbance, etc. ERS may initiate the unfolded protein response (UPR) to restore cellular homeostasis or lead to apoptosis. Numerous studies have clarified the link between ERS and cardiovascular diseases. This review focuses on ERS-associated molecular mechanisms that participate in physiological and pathophysiological processes of heart and blood vessels. In addition, a number of drugs that regulate ERS was introduced, which may be used to treat cardiovascular diseases. This review may open new avenues for studying the pathogenesis of cardiovascular diseases and discovering novel drugs targeting ERS.

Phytochemical Compounds and Protection from Cardiovascular Diseases: A State of the Art

Cardiovascular diseases represent a worldwide relevant socioeconomical problem. Cardiovascular disease prevention relies also on lifestyle changes, including dietary habits. The cardioprotective effects of several foods and dietary supplements in both animal models and in humans have been explored. It was found that beneficial effects are mainly dependent on antioxidant and anti-inflammatory properties, also involving modulation of mitochondrial function. Resveratrol is one of the most studied phytochemical compounds and it is provided with several benefits in cardiovascular diseases as well as in other pathological conditions (such as cancer). Other relevant compounds are Brassica oleracea, curcumin, and berberine, and they all exert beneficial effects in several diseases. In the attempt to provide a comprehensive reference tool for both researchers and clinicians, we summarized in the present paper the existing literature on both preclinical and clinical cardioprotective effects of each mentioned phytochemical. We structured the discussion of each compound by analyzing, first, its cellular molecular targets of action, subsequently focusing on results from applications in both ex vivo and in vivo models, finally discussing the relevance of the compound in the context of human diseases.

Berberine improves endothelial function by inhibiting endoplasmic reticulum stress in the carotid arteries of spontaneously hypertensive rats

Activation of endoplasmic reticulum (ER) stress in endothelial cells leads to increased oxidative stress and often results in cell death, which has been implicated in hypertension. The present study investigated the effects of berberine, a botanical alkaloid purified from Coptidis rhizoma, on ER stress in spontaneously hypertensive rats (SHRs) and the underling mechanism. Isolated carotid arteries from normotensive WKYs and SHRs were suspended in myograph for isometric force measurement. Protein phosphorylations and expressions were determined by Western blotting. Reactive oxygen species (ROS) level was measured by DHE staining. SHR carotid arteries exhibited exaggerated acetylcholine-triggered endothelium-dependent contractions (EDCs) and elevated ROS accumulation compared with WKY arteries. Moreover, Western blot analysis revealed the reduced AMPK phosphorylation, increased eIF2α phosphorylation, and elevated levels of ATF3, ATF6, XBP1 and COX-2 in SHR carotid arteries while these pathological alterations were reversed by 12 h-incubation with berberine. Furthermore, AMPK inhibitor compound C or dominant negative AMPK adenovirus inhibited the effects of berberine on above-mentioned marker proteins and EDCs. More importantly, ROS scavengers, tempol and tiron plus DETCA, or ER stress inhibitors, 4-PBA and TUCDA normalized the elevated levels of ROS and COX-2 expression, and attenuated EDCs in SHR arteries. Taken together, the present results suggest that berberine reduces EDCs likely through activating AMPK, thus inhibiting ER stress and subsequently scavenging ROS leading to COX-2 down-regulation in SHR carotid arteries. The present study thus provides additional insights into the vascular beneficial effects of berberine in hypertension.

Berberine inhibits the proliferation of human uterine leiomyoma cells

OBJECTIVE

To determine whether berberine (BBR), a naturally occurring plant-derived alkaloid, inhibits the proliferation of human uterine leiomyoma (UtLM) cells.

DESIGN

Laboratory research.

SETTING

Laboratory.

PATIENT(S)

UtLM and normal human uterine smooth muscle (UtSMC) cell lines.

INTERVENTION(S)

Treatment with [1] BBR (10, 20, and 50 μM), [2] BBR (20 and 50 μM) and/or 17β-estradiol (E2; 10 and 100 nM), and [3] BBR (20 and 50 μM) and/or progesterone (P4; 10 and 100 nM) for 24 or 72 hours.

MAIN OUTCOME MEASURE(S)

Cell proliferation, cell cycle, apoptosis, and related genes expression were determined.

RESULT(S)

BBR inhibited UtLM cell proliferation by inducing G2/M cell cycle arrest and apoptosis. Cell cycle G2/M phase-related genes were altered by BBR treatment: the expression of cyclin A1, cyclin B1, and Cdk1 were down-regulated, while Cdk4, p21, and p53 were up-regulated. BBR-treated cells stained positively for annexin V and manifested increased BAX expression. E2- and P4-induced UtLM cell proliferation was blocked by BBR treatment. In marked contrast, even the highest concentration of BBR (50 μM) did not influence cell proliferation in UtSMC cells.

CONCLUSION(S)

BBR selectively inhibits cellular proliferation and blocks E2- and P4-induced cell proliferation in UtLM but not in normal UtSMC cells. In addition, BBR did not demonstrate cytotoxicity effects in normal human UtSMCs. Our results suggest BBR could be a potential therapeutic agent for the treatment of uterine leiomyoma.

Berberine improves pressure overload-induced cardiac hypertrophy and dysfunction through enhanced autophagy

Cardiac hypertrophy is a maladaptive change in response to pressure overload, and is also an important risk for developing heart failure. Berberine is known to have cardioprotective effects in patients with hypertension and in animal models of cardiac hypertrophy. In the current study, we observed that transverse aortic contraction (TAC) surgery induced a marked increase in heart size, the ratio of heart weight to body weight, cardiomyocyte apoptosis, myocardial fibrosis, and hypertrophic marker brain natriuretic peptide, all of which were effectively suppressed by berberine administration. In addition, berberine enhanced autophagy in hypertrophic hearts, which was accompanied by a decrease in heart size, cardiac apoptosis, and the attenuation of cardiac dysfunction. Furthermore, use of autophagy inhibitor 3-methyladenine (3-MA) blocked berberine-induced autophagy level, and abrogated the protection of berberine against heart hypertrophy, cardiac dysfunction, and apoptosis. Berberine ameliorated TAC-induced endoplasmic reticulum stress, which was also abolished by 3-MA. Moreover, berberine significantly inhibited the upstream signaling of autophagy, such as the mammalian target of rapamycin (mTOR), extracellular signal-regulated kinase (ERK1/2), and p38 mitogen-activated protein kinase (MAPK) phosphorylation. We conclude that berberine could attenuate left ventricular remodeling and cardiomyocyte apoptosis through an autophagy-dependent mechanism in a rat model of cardiac hypertrophy, which is, at least in part, associated with enhanced autophagy through inhibition of mTOR, p38 and ERK1/2 MAPK signaling pathways.

Binding of the 9-O-N-aryl/arylalkyl amino carbonyl methyl substituted berberine analogs to tRNA(phe.)

Background

Three new analogs of berberine with aryl/arylalkyl amino carbonyl methyl substituent at the 9-position of the isoquinoline chromophore along with berberrubine were studied for their binding to tRNA^phe by wide variety of biophysical techniques like spectrophotometry, spectrofluorimetry, circular dichroism, thermal melting, viscosity and isothermal titration calorimetry.

Methodology/Principal Findings

Scatchard binding isotherms revealed that the cooperative binding mode of berberine was propagated in the analogs also. Thermal melting studies showed that all the 9-O-N-aryl/arylalkyl amino carbonyl methyl substituted berberine analogs stabilized the tRNA^phe more in comparison to berberine. Circular dichroism studies showed that these analogs perturbed the structure of tRNA^phe more in comparison to berberine. Ferrocyanide quenching studies and viscosity results proved the intercalative binding mode of these analogs into the helical organization of tRNA^phe. The binding was entropy driven for the analogs in sharp contrast to the enthalpy driven binding of berberine. The introduction of the aryl/arylalkyl amino carbonyl methyl substituent at the 9-position thus switched the enthalpy driven binding of berberine to entropy dominated binding. Salt and temperature dependent calorimetric studies established the involvement of multiple weak noncovalent interactions in the binding process.

Conclusions/Significance

The results showed that 9-O-N-aryl/arylalkyl amino carbonyl methyl substituted berberine analogs exhibited almost ten folds higher binding affinity to tRNA^phe compared to berberine whereas the binding of berberrubine was dramatically reduced by about twenty fold in comparison to berberine. The spacer length of the substitution at the 9-position of the isoquinoline chromophore appears to be critical in modulating the binding affinities towards tRNA^phe.

Berberine attenuates doxorubicin-induced cardiotoxicity in mice

This study investigated the effects of berberine, a natural alkaloid, on doxorubicin-induced cardiotoxicity in mice. Mice were injected intraperitoneally with saline 10 ml/kg (n = 10), doxorubicin 2.5 mg/kg (n = 10), 60 mg/kg berberine 1 h before doxorubicin 2.5 mg/kg (n = 10), or 60 mg/kg berberine alone (n = 10) every other day for 14 days. Body weight, general condition and mortality were recorded over the 14-day study period. Electro cardiography was performed before the start of treatment and after 14 days and plasma lactate dehydrogenase (LDH) activity was measured after 14 days. At the end of the study period the heart was excised and examined histologically. An increase in mortality, an initial decrease in body weight, increased LDH activity, prolongation of QRS duration and increased myocardial injury were seen in the doxorubicin-treated group compared with the saline control group. These changes were significantly attenuated by pretreatment with berberine. The study suggests that berberine may have a potential protective role against doxorubicin-induced cardiotoxicity in mice.

Berberine induces cell death in human hepatoma cells in vitro by downregulating CD147

The isoquinoline plant alkaloid berberine has anti-tumor effects on a variety of carcinoma cells, mainly through inhibition of cell proliferation, apoptosis induction and cell cycle arrest. However, the mechanisms underlying its role in tumor progression are unknown. In the present study, we investigated the molecular mechanisms involved in berberine-induced cell death in human hepatoma carcinoma cell (HCC) lines HepG2 and SMMC7721. Our results showed that berberine inhibited tumor cell viability in a dose- and time-dependent manner, and induced cell death via apoptosis and autophagy. Moreover, berberine treatment significantly inhibited CD147 expression by HCC cells in a dose-dependent manner. Overexpression of CD147 protein markedly reduced berberine-induced cell death. Our data provide the first experimental evidence that berberine induces cell death in HCC cells via downregulation of CD147 and suggest a new mechanism to explain its anti-tumor effects.

Berberine reduces the hypoxic-ischemic insult in rat pup brain

Berberine, an isoquinoline alkaloid extracted from medicinal herbs, has been used as antipyretic, antidiarrheal, bactericide and anti-inflammatory agent. In this study, berberine effects on neuronal damage have been examined. The right carotid artery of seven-day-old rat pups was ligated (ischemic insult), then berberine solution (0.2, 0.5, 1 or 2 mg/kg) was injected intra-peritoneally, and 30 minutes later pups were passed through hypoxic condition with breathing in air containing 10% oxygen and 90% nitrogen(hypoxic insult). The day after that the brains of pups were enucleated for pathologic assessment. Pathologic review of the samples obtained from rats treated with different doses of berberine in comparison with samples from pups treated by normal saline showed that there was a significant reduction of brain injury and edema in the rats treated with berberine. Our study also demonstrates that berberine reduces brain ischemic-hypoxic injury dose-dependently. Therefore, beberine may be considered as useful anti-stroke agent.

Berberine prevents hyperglycemia-induced endothelial injury and enhances vasodilatation via adenosine monophosphate-activated protein kinase and endothelial nitric oxide synthase

AIMS

Endothelial dysfunction is a key event that links obesity, diabetes, hypertension, and cardiovascular diseases. The aim of the present study was to examine the protective effect of the alkaloid drug berberine against hyperglycemia-induced cellular injury and endothelial dysfunction.

METHODS AND RESULTS

In both cultured endothelial cells and blood vessels isolated from rat aorta, berberine concentration dependently enhanced phosphorylation of endothelial nitric oxide synthase (eNOS) at Ser1177 and promoted the association of eNOS with heat shock protein 90 (HSP90), leading to an increased production of nitric oxide. Furthermore, berberine attenuated high glucose-induced generation of reactive oxygen species, cellular apoptosis, nuclear factor-kappaB activation, and expression of adhesion molecules, thus suppressing monocyte attachment to endothelial cells. In mouse aortic rings, berberine elicited endothelium-dependent vasodilatations and alleviated high glucose-mediated endothelial dysfunction. All these beneficial effects of berberine on the endothelium were abolished by either pharmacological inhibition of adenosine monophosphate-activated protein kinase (AMPK) or adenovirus-mediated overexpression of a dominant negative version of AMPK.

CONCLUSION

Berberine protects against endothelial injury and enhances the endothelium-dependent vasodilatation, which is mediated in part through activation of the AMPK signalling cascade. Berberine or its derivatives may be useful for the treatment and/or prevention of endothelial dysfunction associated with diabetes and cardiovascular disease.

Clinical outcomes of diabetic foot management with Circulat

Major and minor lower-extremity amputation is a common complication among diabetics. Various sources indicate diabetic foot ulcer prevalence at between 2.2% and 15% in diabetics. This study evaluates the efficacy and tolerance of a standardized plant extract combination, Circulat, developed for the prevention and treatment of severe manifestations of type 2 diabetes, such as necrotic damage of the foot. Thus, a retrospective cohort study was carried out in 174 patients treated with Circulat with diabetic foot grades D1-D3, according to The University of Texas Wound Classification System, in 50 medical centers, from 2004 to 2007. Circulat obtained 50.57% complete cure of diabetic foot, significant improvement in 37.9% and prevented amputation in 88.5% of the study's total population. The treatment was well tolerated. Four patients (2.3%) had slight gastrointestinal unrest which did not warrant suspension of treatment.

Improvement of vascular remodeling in spontaneous hypertensive rats with traditional Chinese medicine

Qin-Dan-Jiang-Ya-Tang (QDJYT) is a traditional Chinese herbal medicine for the treatment of hypertension. The effect of QDJYT on blood pressure (BP) and vascular remodeling in hypertension was investigated in the model of spontaneous hypertensive rats (SHR). Sixteen SHRs were divided into two groups: the SHR group and the SHR+ QDJYT group. Eight Wistar-Kyoto (WKY) rats were in the normal control group. QDJYT (750 mg/kg) was orally administered daily for 12 weeks to the SHR+QDJYT group. After 12 weeks, thoracic aortas were segregated. The media thickness (MT) and the lumen diameter (LD) of the aortic wall, the ratios of MT to LD, the expression of basic fibroblast growth factor (bFGF) mRNA, and the level of its proteinic production were examined by histology, real-time PCR, and Western blot analysis, respectively. It was observed in our study that MT, MT/LD, the expression of bFGF mRNA, and the level of its proteinic production in aortic walls were higher in SHRs than in WKY rats. However, in the SHRs treated with QDJYT, we found MT, MT/LD, the expression of bFGF mRNA and the level of its proteinic production were lower than SHRs. These results suggest that QDJYT can improve the vascular remodeling in SHRs, and the mechanisms may be related to the suppressive effect of QDJYT on bFGF mRNA and its proteic productions in the aortic walls of SHRs.

Human MDR1 and MRP1 recognize berberine as their transport substrate

To examine whether human ATP-binding cassette (ABC) transporters play a role in the detoxification of plant alkaloid berberine, we investigated berberine transport using multidrug resistance protein1 (MDR1) and multidrug resistance-associated protein1 (MRP1). Cells expressing MDR1 or MRP1 accumulated less berberine. Berberine accumulation depended on the cellular ATP level, and was reversed by typical inhibitors of MDR1, suggesting that human MDR1 and MRP1 directly efflux berberine as their substrate.

Efficacy and safety of berberine for congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy

This study was designed to assess the efficacy and safety of berberine for chronic congestive heart failure (CHF). One hundred fifty-six patients with CHF and >90 ventricular premature complexes (VPCs) and/or nonsustained ventricular tachycardia (VT) on 24-hour Holter monitoring were randomly divided into 2 groups. All patients were given conventional therapy for CHF, consisting of angiotensin-converting enzyme inhibitors, digoxin, diuretics, and nitrates. Patients in the treatment group (n = 79) were also given berberine 1.2 to 2.0 g/day. The remaining 77 patients were given placebo. Symptoms, a 6-minute walk test, left ventricular (LV) ejection fraction (EF), frequency and complexity of VPCs, and quality of life were assessed after 8 weeks of treatment and during a mean 24-month follow-up. After treatment with berberine, there was a significantly greater increase in LVEF, exercise capacity, improvement of the dyspnea-fatigue index, and a decrease of frequency and complexity of VPCs compared with the control group. There was a significant decrease in mortality in the berberine-treated patients during long-term follow-up (7 patients receiving treatment died vs 13 on placebo, p <0.02). Proarrhythmia was not observed, and there were no apparent side effects. Thus, berberine improved quality of life and decreased VPCs and mortality in patients with CHF.

The involvement of P-glycoprotein in berberine absorption

Berberine is an important ingredient in a number of traditional Chinese medicines but has been shown to have poor bioavailability in the dog. The aim of this study 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. In the rat recirculating perfusion model, berberine absorption was improved 6-times by P-glycoprotein inhibitors. In the rat everted intestinal sac model, berberine serosal-to-mucosal transport was significantly decreased by cyclosporin A. In Ussing-type chambers, the rate of serosal-to-mucosal transport across rat ileum was 3-times greater than in the reverse direction and was significantly decreased by cyclosporin A. In Caco-2 cells, berberine uptake was significantly increased by P-glycoprotein inhibitors and by monoclonal antibody C219. 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.

Cardiovascular actions of berberine

Berberine, is an alkaloid from Hydrastis canadensis L., Chinese herb Huanglian, and many other plants. It is widely used in traditional Chinese medicine as an antimicrobial in the treatment of dysentery and infectious diarrhea. This manuscript describes cardiovascular effects of berberine and its derivatives, tetrahydroberberine and 8-oxoberberine. Berberine has positive inotropic, negative chronotropic, antiarrhythmic, and vasodilator properties. Both derivatives of berberine have antiarrhythmic activity. Some cardiovascular effects of berberine and its derivatives are attributed to the blockade of K+ channels (delayed rectifier and K(ATP)) and stimulation of Na+ -Ca(2+) exchanger. Berberine has been shown to prolong the duration of ventricular action potential. Its vasodilator activity has been attributed to multiple cellular mechanisms. The cardiovascular effects of berberine suggest its possible clinical usefulness in the treatment of arrhythmias and/or heart failure.