Effects of Stobadine and Vitamin E in Diabetes-Induced Retinal Abnormalities: Involvement of Oxidative Stress

Background. Because hyperglycemia-induced oxidative stress may be a cause of retinopathy, this study examined the hypothesis that administration of exogenous antioxidants, stobadine (ST) and vitamin E (vitE), can restore retinal abnormalities in experimental diabetes. Methods. Normal and streptozotocin (STZ)-induced male Wistar rats received daily intraoral doses of ST (24.7 mg/kg) and vitE (a-dl-tocopherol acetate, 400e500 IU/kg) individually or in combinations for 8 months. The biochemical parameters including aldose reductase enzyme (AR) activity and lipid peroxidation (MDA), and histopathological changes such as retinal capillary basement membrane thickness (RCBMT) and vascular endothelial growth factor (VEGF) expression were evaluated. Results. A 37.99% increase in RCBMT was observed in rats after 8 months diabetes duration. The increase in RCBMT was 12.34% in diabetic rats treated with ST and 23.07% in diabetic rats treated with vitE. In diabetic rats treated with antioxidant combination, just a 4.38% increase was observed in RCBMT. The excess VEGF immunoreactivity and increased MDA and AR activity determined in diabetic retina were significantly attenuated by individual antioxidant treatments. Although both antioxidants decreased blood glucose, HbA1c, fructosamine and triglyceride levels in diabetic rats, poor glycemic control was maintained in all experimental groups during the treatment period. However, the antioxidant combination led to almost complete amelioration in retinal MDA and RCBMT in diabetic rats. Conclusions. The ability of antioxidant combination to arrest retinal abnormalities and lipid peroxidation even in the presence of poor glycemic control might advocate the key role of direct oxidative damage and the protective action of antioxidants in retinal alterations associated with diabetic retinopathy. Ó 2007 IMSS. Published by Elsevier Inc

What is the protective effect of metformin on rat ovary against ischemia-reperfusion injury?

Ozkan, Zehra Sema/0000-0001-9185-3663WOS: 000424844400013PubMed: 29144016AimThe aim of this study was to investigate the protective effect of metformin on the rat ovary against ischemia-reperfusion injury. MethodsThirty-seven female Wistar albino rats were used in the study. The rats were divided into five groups, as follows: sham operation group (group 1); torsion group (group 2); torsion/detorsion+saline group (group 3); torsion/detorsion+low-dose metformin group (group 4); and torsion/detorsion+high-dose metformin group (group 5). The right ovary from each rat was evaluated histologically using hematoxylin-eosin staining, and the left ovaries were evaluated for tissue levels of the reduced-glutathione-to-oxidized-glutathione ratio, malondialdehyde (MDA), and caspase-3 activation. ResultsThe highest damage score was observed in group 3, and the lowest score was observed in group 1. The tissue caspase-3 activity levels of groups 2, 3, and 4 were significantly higher than those of group 1. The difference between group 1 and group 5 in terms of tissue caspase-3 activity was not significant (P=0.4). The reduced-glutathione-to-oxidized-glutathione ratio of group 1 was significantly higher than the ratios found in groups 2, 3, and 4. The tissue MDA level of group 1 was significantly lower than the levels found in groups 2, 3, 4, and 5. The tissue MDA level of group 5 was significantly lower than the levels in groups 3 and 4. ConclusionFrom both histopathological and biochemical analyses, the results of the study demonstrated that metformin has beneficial effects when it comes to attenuating ovarian ischemia-reperfusion injury.Kirikkale University Scientific Research Commission [2015/72]This research was funded by Kirikkale University Scientific Research Commission (project number: 2015/72). The authors are grateful to the staff members of Kirikkale University for their valuable support