title: Effects of Nigella sativa on oxidative stress and beta-cell damage in streptozotocin-induced diabetic rats.
abstract: The aim of the present study was to evaluate the possible protective effects of Nigella sativa L. (NS) against beta-cell damage from streptozotocin (STZ)-induced diabetes in rats. STZ was injected intraperitoneally at a single dose of 50 mg/kg to induce diabetes. NS (0.2 ml/kg/day, i.p.) was injected for 3 days prior to STZ administration, and these injections were continued throughout the 4-week study. Oxidative stress is believed to play a role in the pathogenesis of diabetes mellitus (DM). To assess changes in the cellular antioxidant defense system, we measured the activities of antioxidant enzymes (such as glutathione peroxidase (GSHPx), superoxide dismutase (SOD), and catalase (CAT)) in pancreatic homogenates. We also measured serum nitric oxide (NO) and erythrocyte and pancreatic tissue malondialdehyde (MDA) levels, a marker of lipid peroxidation, to determine whether there is an imbalance between oxidant and antioxidant status. Pancreatic beta-cells were examined by immunohistochemical methods. STZ induced a significant increase in lipid peroxidation and serum NO concentrations, and decreased antioxidant enzyme activity. NS treatment has been shown to provide a protective effect by decreasing lipid peroxidation and serum NO, and increasing antioxidant enzyme activity. Islet cell degeneration and weak insulin immunohistochemical staining was observed in rats with STZ-induced diabetes. Increased intensity of staining for insulin, and preservation of beta-cell numbers were apparent in the NS-treated diabetic rats. These findings suggest that NS treatment exerts a therapeutic protective effect in diabetes by decreasing oxidative stress and preserving pancreatic beta-cell integrity. Consequently, NS may be clinically useful for protecting beta-cells against oxidative stress.
authors.affiliation: Department of Medical Histology and Embryology, Faculty of Medicine, Zonguldak Karaelmas University, Zonguldak, Turkey. mehmetkanter65@hotmail.com
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kanter
authors.forename: Omer
authors.initials: O
authors.lastname: Coskun
authors.forename: Ahmet
authors.initials: A
authors.lastname: Korkmaz
authors.forename: Sukru
authors.initials: S
authors.lastname: Oter
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000378:metabolism* / Q000473:pathology*; D007150:Immunohistochemistry / Q000379:methods; D007328:Insulin / Q000097:blood / Q000378:metabolism; D007515:Islets of Langerhans / Q000187:drug effects / Q000473:pathology*; D008297:Male; D008315:Malondialdehyde / Q000037:antagonists & inhibitors / Q000097:blood; D031881:Nigella sativa / Q000737:chemistry*; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000097:blood; D018384:Oxidative Stress / Q000187:drug effects*; D010088:Oxidoreductases / Q000378:metabolism; D010179:Pancreas / Q000378:metabolism; D010938:Plant Oils / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013194:Staining and Labeling
chemical_list: D001786:Blood Glucose; D007328:Insulin; D010938:Plant Oils; D009569:Nitric Oxide; D008315:Malondialdehyde; D010088:Oxidoreductases