Objective To systematically evaluate the effectiveness and safety of berberine in the treatment of type 2 diabetes. Methods The databases including The Cochrane Library, PubMed (1966 to October 2011), Excerpta Medica Database (EMbase, 1974 to October 2011), Chinese National Knowledge Infrastructure databases (CNKI, 1994 to October 2011), the Chinese Scientific and Technical Journals database (VIP, 1989 to October 2011), and China Doctor Dissertation Full-text Database (CDFD, 1979 to 2011) and China Master Dissertation Full-text Database (CMFD, 1979 to 2011) were searched. The randomized controlled trials (RCTs) on berberine in the treatment of type 2 diabetes were screened according to the inclusive and exclusive criteria. The data were extracted, the quality was assessed, and the systematic review was conducted by using Revman 5.0 software. Results Ten RCTs involving 647 Chinese patients with DM 2 were included, and the quality of each study was generally low. The interventions in the treatment groups were berberine or combined with metformin or glipizide. The control groups included placebo, lifestyle intervention, pioglitazone, rosiglitazone or metformin. Because the experiment and control groups in each included trials were different in drug type and dose, disease duration, and treatment regimens, only the results of all trials were reported rather than performing Meta-analysis. The berberine group was superior to the placebo and lifestyle intervention groups in lowering fasting blood glucose (FBG), but it was not so obviously effective in lowering the postprandial blood glucose (PBG), hemoglobin A1c and BMI and regulating lipid metabolism compared with the placebo, lifestyle intervention, and western hypoglycemic agents. In addition, the berberine treatment had no side effects of hypoglycemia although a few patients complained of gastrointestinal adverse reaction, and there was no significant difference when compared with the placebo and lifestyle intervention groups. Conclusion Berberine is effective in lowering FBG, but not better than metformin, glipizide and rosiglitazone. It is undefined in decreasing PBG, HbA1c, BMI and regulating lipid metabolism, and it will not lead to hypoglycemia except for a few and mild gastrointestinal adverse effects. The current clinical studies on berberine for DM 2 are low in methodology and reporting quality, which has to be further proved by more high-quality clinical trails.
ObjectiveTo observe the inhibitory effect of berberine (BBR) on the apoptosis of human retinal vascular endothelial cells (hREC) under high glucose environment.MethodshREC was divided into blank control group (NC group), high glucose group (HG group), BBR treatment group (BN group), and BBR+high glucose treatment group (BH group). The cells of each group were cultured in Dulbecco's modified eagle medium; 5.5 and 30.0 mmol/L glucose were added to the medium of the NC group and HG group, respectively; 5.0 mmol/L glucose and 5.0 mmol/L BBR was added to the BN group; 30.0 mmol/L glucose and 5.0 mmol/L BBR was added to the medium of the BH group. Flow cytometry was used to observe the apoptosis rate of each group. Western blotting was used to detect the relative expression levels of B-cell lymphoma-2 (Bcl-2), Bcl-2 related X protein (Bax), and Cytochrome C (Cyt-C) and cysteine aspastic acid-specific protease 3 (Caspase-3) proteins in each group of cells. The difference between the two groups was tested by t test, and the difference among multiple groups was analyzed by one-way analysis of variance. ResultsThe results of flow cytometry showed that compared with the NC group, the apoptosis rate of the HG group significantly increased, and the difference was statistically significant (P＜0.01); compared with the HG group, the apoptosis rate of the BH group significantly reduced, the difference was statistical significance (P＜0.05). Western blot test results showed that, compared with the NC group, the relative expression of Bax and Caspase-3 protein in the HG group increased, and the relative expression of Bcl-2 protein decreased. The difference was statistically significant (P＜0.01). Compared with the HG group, the relative expression of Bax, Cyt-C, and Caspase-3 protein in BH group cells decreased, and the relative expression of Bcl-2 protein increased, and the difference was statistically significant (P＜0.01). ConclusionBBR can inhibit hREC apoptosis by affecting the expression of apoptotic protein under high glucose environment.