Ameolirative effects of garlic (Allium sativum L.,) in streptozotocin induced oxidative stress in diabetic brain of rat

Abstract

The aim of the present study was to evaluate the protective effect of methanol garlic extract on the enzymes related with polyol pathway, advanced glycation end products, markers of oxidative stress and antioxidant status in brain of streptozotocin induced diabetic rats. Antioxidant capability of methanol extract of garlic was evaluated by 2,2-diphenyl-2-picrylhydrazyl hydrate radical and FOX (ferrous ion oxidation-xylenol orange) H2O2 scavenging test. Diabetes was induced by single i.p injection of STZ (32mg/kg per body Wt.,). Blood glucose levels and body wt, were measured on every 7th day over a period of 30 days. The diabetic rats treated with garlic extract at two doses 250mg/kg and 500mg/kg body wt., by oral administration. Diabetic rats showed significant increase in food and water intake, decrease in blood glucose levels, body weights, but could not show any recovery by garlic treatment. Garlic treatment significantly decreased aldose reductase (AR); sorbitol dehydrogenase (SD) and glutathione S-transferase (GST) enzyme activities. A decrease of malndialdehyde (MDA), Protein carbonyls (PC), Pentosidine advance oxidation protein products (AOPP), Advanced glycation end products (AGEs) was also observed. Additionally garlic administration produced a restoration of brain superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and reduced glutathione (GSH) in diabetic rats. Garlic treatment also reduced the free radical formation and progression of hyperglycemia induced diabetic complications by decreasing influx of glucose into the polyol pathway and increased activity of antioxidant enzymes. The current study reveals exerts, efficiently, an attenuating effect of methanol garlic extract exterted antihyperlgycemic, antioxidant and anti-glycating effects in a dose dependent manner in diabetic rats.