ABSTRACT

The aim of the present study was the evaluation of possible protective effects of quercetin (QE) against beta-cell damage in experimental streptozotocin (STZ)-induced diabetes in rats. STZ was injected intraperitoneally at a single dose of 45mg/kg for diabetes induction. QE 50mg/kg (for low dosage groups) and 100mg/kg (for high dosage group) was administered orally for four weeks after blood hypergiyeaemia (>200mg/di) where confirmed six days after induction. It has been believed that oxidative stress plays a role in the pathogenesis ofdaibetes mellitus (DM). In order to determine the changes of cellular antioxidant defense system, antioxidant enzymes such as glutathione peroxidase (GSFPx), superoxide dismutase (SOD) and catalase (CAT) activities were measured in pancreatic homogenates. Moreover I also measured pancreatic tissue malondaldehyde (MDA) levels, a marker of lipid peroxidation, if there is an imbalance between oxidant and antioxidant status. STZ induced a significant increase lipid peroxidation and decreased the antioxidant enzyme activity. Pancreatic tissue MDA significantly increased (P<zo.05) and also the antioxidant levels significantly decreased (P<0.05) in diabetic group. QE treatment significantly decreased the elevated MIDA (P<0.05) and also increased the antioxidant enzyme activities (P<0.05). QE treatment has shown protective effect possibly through decreasing lipid peroxidation, and increasing antioxidant enzyme activity.