Effects of berberine on the expressions of NRF2 and HO-1 in endothelial cells of diabetic rat

Objective: This study aims to investigate the effects of berberine on the expression of nuclear factor erythroid 2-related factor 2 (Nrf2)/Heme Oxygenase 1 (HO-1) in retinal cells of diabetic rats. Methods: The diabetic rat models were established through intraperitoneal injection of streptozotocin. Different concentration (50 mg/kg/d, 100 mg/kg/d, 200 mg/kg/d) of berberine was orally administered to the rats for 4 weeks. After 4 weeks, changes of body weight, blood lipid and glucose were detected, and the expression levels of Nrf2 and HO-1 in retinal tissues were evaluated by immunohistochemistry and Western blot. Results: Four weeks of berberine intervention decreased blood glucose to below 16 mmol/L. Total Cholesterol (TC), Triglyceride (TG), and Low-Density Lipoprotein cholesterol (LDL) was decreased significantly, while High-Density Lipoprotein cholesterol (HDL) was increased significantly than that in the model group (P<0.05). The expressions of Nrf2 and HO-1 were also decreased in retinal cells after berberine treatment compared with those in the model group. Conclusion: Berberine can reduce blood glucose level in diabetic rats, improve blood lipid and decrease retinal vascular injury, suggesting it may be associated with the reduced expressions of Nrf2/HO-1.