Green Tea (Camellia sinensis) Supplementation to Diabetic Rats Improves Serum and Hepatic Oxidative Stress Markers

Diabetes is one of the most common metabolic disorders and is interrelated to oxidative stress-induced diseases. According to the role of dietary antioxidants in control and prevention of diabetes, this study was aimed to evaluate the effect of green tea extract on serum glucose levels and serum and hepatic total antioxidant capacity (TAC) and lipid (MDA) in diabetic rats. Experimental diabetes in rats was induced by intraperitoneal injection of streptozotocin (55 mg/Kg). Alcoholic extract of green tea (100, 200 mg/Kg) was given by oral gavage to normal and diabetic rats for 4 weeks. Finally, serum glucose and serum and hepatic levels of MDA and TAC were measured and analyzed statistically. Data showed that green tea extract at dose of 200 mg/Kg significantly decreased the serum glucose levels, serum and hepatic MDA concentration and increased the total antioxidant capacity in diabetic rats (p < 0.05). Green tea supplementation also increased hepatic TAC in normal rats (p < 0.05). The antihyperglycemic and antioxidative features of green tea make it an attractive candidate for the prophylactic treatment of diabetes, although further investigation is needed to determine exact dose and duration of supplementation.