PROTECTIVE EFFECT OF QUERCETIN ON THE MORPHOLOGY OF PANCREATIC β-CELLS OF STREPTOZOTOCIN-TREATED DIABETIC RATS

This study was undertaken to investigate the protective effects of quercetin (QCT) on the morphology of pancreatic β-cells against diabetes mellitus and oxidative stress experimentally-induced by streptozotocin (STZ) treatment in Wistar rats. Fifty male and female Wistar rats (200–250 g) were randomly divided into three experimental groups (i. e., control, STZ-treated, and STZ + Quercetin-treated groups). Diabetes was induced in the diabetic groups (B and C) of animals, by a single intraperitoneal injection of STZ (75 mg/kg), while each of the rats in the ‘control’ group received equal volume of citrate buffer (pH 6.3) solution intraperitoneally. In group C rats, quercetin (QCT, 25 mg/kg/day i. p.) was injected daily for 3 days prior to STZ treatment, and QCT administration continued until the end of the study period (30 days). Diabetes mellitus was confirmed by using Bayer’s Glucometer Elite® and compatible blood glucose test strips. The rats were sacrificed serially until the end of the study period (after 30 days). The pancreases of the sacrificed rats were excised and randomly processed for histological staining and biochemical assays for antioxidant enzymes [such as glutathione peroxidase (GSHPx), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and serum nitric oxide (NO)]. In the diabetic state, pancreatic β-cells of STZ-treated group B rats histologically demonstrated an early chromatin aggregation, cytoplasmic vesiculation in the central β-cells, nuclear shrinkage, and lysis of β-cells with distortion of granules. The morphology of QCT-treated rats’ pancreases showed viable cellularity with distinct β-cell mass. STZ treatment significantly decreased (