Effects of stobadine on the oxidative stress markers and paraoxonase-1 activity in diabetic rat liver tissues

Oxidative stress may play an important role in the pathogenesis of early and long term complications of Diabetes Mellitus (DM). Protein glycation and glucose autooxidation can generate free radicals that can cause lipid peroxidation. We aimed to investigate the effects of stobadine on oxidative stress and PON-1 enzyme activity in liver of streptozotocine (STZ) induced diabetic rats. To investigate the oxidative stress, Xanthine oxidase (XO), Glutathione-S-Transferase (GST), Glucose 6 phosphate dehydrogenase (G6PDH), Nitric oxide synthase (NOS) activities and Malondialdehyde (MDA) levels of the liver tissues were studied. Fourteen eight male Wistar rats were used approximately 3 months old, weighing 250- 300 g. at the time of experiment. Wistar rats were randomly divided four groups;controls C, treated with STB (STB), diabetic (D), treated with STB diabetic rat (D+STB). Diabetes was induced by a single IP injection of streptozotocin (55 mg/kg) to animals fasted overnight. Diabetes was verified 48 h later by measuring tail ven blood glucose, and the rats with a blood glucose concentration of 300 mg/dl or more were considered diabetic.STB was administrated to rats as 24.7 mg/kg/day orally. Tissue oxidative stress parameters and PON-1 enzyme activities in the four groups of Wistar-Albino rats were compared using the Mann-Whitney ?U test and p value < 0.05 was taken as significant. When compared to group C, XO and NOS activities and TBARS levels were significantly increased in diabetic rats (p<0.05). NOS activities and TBARS levels were completely recover by STB treatment (p<0.05). Four months diabetes resulted in a significant decrease on GST, G6PD and PON-1 activities. Although STB treatment unchanged GST and XO activities PON-1 and G6PD activities were significantly ameliorated by STB.