A Combination of Catechin and Metformin: Its Preclinical Efficacy and Safety in STZ-Induced Diabetic Rats

Objective: This study aimed to assess the combinational antidiabetic effect of catechin and metformin in streptozotocin (STZ)-induced diabetic rats. Methods: Wistar rats were chosen and divided into five groups (n=6). STZ at the dose of 55 mg/kg was used intraperitoneally for the induction of diabetes. The combination of catechin (CTN) and metformin (MET) was administered to diabetic rats. The changes in fasting blood sugar, body weight, Hb, HbA1c, creatinine, lipid profiles (TC, HDL, LDL, and TG), biochemical parameters (SGOT, SGPT, and ALP), and endogenous antioxidant parameters (SOD, GSH, and catalase) were assessed. Histopathological study of the β-cells in islets of the pancreas, kidney tubules, and liver cells was conducted in all groups. Results: The result showed a significant reduction (p < 0.001) in blood sugar in the CTN and METtreated group compared to the control group. The combination of CTN (50 mg/kg) and MET (22.5 mg/kg) significantly restored the creatinine levels and urine volumes, SGOT, SGPT, and ALP, compared to a single administration dose. The abnormal lipid profile levels (TC, LDL, TG, and HDL) and antioxidant enzymes (SOD, GSH, catalase) in diabetic control rats were restored to average levels in a significant manner. Histopathological results revealed significant alterations, including hypertrophy of islets and mild degeneration, renal necrosis, and inflammation of hepatocytes. Conclusion: The findings indicate that a combination of therapy (CTN+MET) improved the protective effect of the pancreas, kidney, and liver, suggesting that the combination shows a potential antidiabetic effect.