Quercetin And Exercise Treatment On The Morphology Of Pancreatic Β-Cells Of Streptozotocin-Treated Diabetic Rats

Abstract

Modern chronic diseases, including cardiovascular diseases, type 2 diabetes, metabolic syndromes, and cancer, are the leading killers in Westernized societies and are rampantly increasing in developing nations. Considerable amount of clinical and experimental evidence now exists suggesting that many biochemical pathways, strictly associated with diabetes, increase the production of reactive oxygen species (ROS). However, daily moderate exercise and diet supplementation can be beneficial to diabetes. This study was therefore undertaken to investigate the effects of exercise and quercetin on lipid peroxidation (MDA), scavenging enzyme activity, and morphology of pancreatic β-cells as against experimentally-induced diabetes and oxidative stress by streptozotocin (STZ) treatment in Wistar rats. Diabetes was induced in the diabetic animal groups (B, C and D), by a single intraperitoneal injection of STZ (75 mg/kg body weight), while the ‘control' animal group (A) received equal volume of citrate buffer (pH 6.3) solution intraperitoneally. Quercetin (25 mg/kg/day, i.p.) was injected for 3 days prior to administration of STZ; these injections were continued for four weeks, but in addition, animals in group D were subjected to moderate exercise. In the diabetic state, pancreatic β-cells of STZ treated rats showed a highly weak immunostaining. The morphology of the quercetin + exercise treated group showed viable cellularity with distinct β-cell mass. STZ significantly decreased GSH-Px, SOD, CAT and pancreatic insulin content, increased blood glucose concentration, serum NO, and pancreatic MDA. The quercetin + exercise treated group showed a significant decrease in the elevated blood glucose, serum NO and pancreatic MDA (p<0.05), and also increased the antioxidant enzyme activities as well as pancreatic insulin content (p<0.05). In conclusion, the results obtained in the present study suggest that quercetin + exercise had much beneficial effect on pancreatic tissue subjected to STZ-induced oxidative stress. Combined quercetin and exercise treatment also has a therapeutic and/or protective effect by decreasing oxidative stress and preserving pancreatic β-cell integrity.

Keywords: Quercetin, Exercise, Streptozotocin, Oxidative stress, Diabetes

Journal of Mining and Geology Vol. 5 (1&2) 2006: pp. 52-72