The effect of V. vinifera seeds on carbohydrate metabolizing enzymes and other enzymes of the liver in diabetes is currently unknown. We therefore investigated changes in the activity levels of these enzymes following V. vinifera seed extract administration to diabetic rats. Methods. V. vinifera seed ethanolic extract (250 and 500 mg/kg/day) or glibenclamide (600 μg/kg/day) was administered to streptozotocin-induced male diabetic rats for 28 consecutive days. At the end of treatment, liver was harvested and activity levels of various liver enzymes were determined. Levels of thiobarbituric acid reactive substances (TBARS) were measured in liver homogenates and liver histopathological changes were observed. Results. V. vinifera seed ethanolic extract was able to prevent the decrease in ICDH, SDH, MDH, and G-6-PDH and the increase in LDH activity levels in liver homogenates. The seed extract also caused serum levels of ALT, AST, ALP, ACP, GGT, and total bilirubin to decrease while causing total proteins to increase. Additionally, the levels of ALT, AST, and TBARS in liver homogenates were decreased. Histopathological changes in the liver were reduced. Conclusion. Near normal activity levels of various enzymes and histology of the liver following V. vinifera seed ethanolic extract administration may be due to decrease in liver oxidative stress in diabetes.
Diabetes mellitus has been reported to affect functions of the hippocampus. We hypothesized that Centella asiatica, a herb traditionally being used to improve memory, prevents diabetes-related hippocampal dysfunction. Therefore, the aim of this study was to investigate the protective role of C. asiatica on the hippocampus in diabetes. Methods. Streptozotocin- (STZ-) induced adult male diabetic rats received 100 and 200 mg/kg/day body weight (b.w) C. asiatica leaf aqueous extract for four consecutive weeks. Following sacrifice, hippocampus was removed and hippocampal tissue homogenates were analyzed for Na(+)/K(+)-, Ca(2+)- and Mg(2+)-ATPases activity levels. Levels of the markers of inflammation (tumor necrosis factor, TNF-α; interleukin, IL-6; and interleukin, IL-1β) and oxidative stress (lipid peroxidation product: LPO, superoxide dismutase: SOD, catalase: CAT, and glutathione peroxidase: GPx) were determined. The hippocampal sections were visualized for histopathological changes. Results. Administration of C. asiatica leaf aqueous extract to diabetic rats maintained near normal ATPases activity levels and prevents the increase in the levels of inflammatory and oxidative stress markers in the hippocampus. Lesser signs of histopathological changes were observed in the hippocampus of C. asiatica leaf aqueous extract treated diabetic rats. Conclusions. C. asiatica leaf protects the hippocampus against diabetes-induced dysfunction which could help to preserve memory in this condition.
P. niruri has been reported to possess antidiabetic and kidney protective effects. In the present study, the phytochemical constituents and in vitro antioxidant activity of P. niruri leaf aqueous extract were investigated together with its effect on oxidative stress and antioxidant enzymes levels in diabetic rat kidney. Results. Treatment of diabetic male rats with P. niruri leaf aqueous extract (200 and 400 mg/kg) for 28 consecutive days prevents the increase in the amount of lipid peroxidation (LPO) product, malondialdehyde (MDA), and the diminution of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity levels in the kidney of diabetic rats. The amount of LPO showed strong negative correlation with SOD, CAT, and GPx activity levels. P. niruri leaf aqueous extract exhibits in vitro antioxidant activity with IC50 slightly lower than ascorbic acid. Phytochemical screening of plant extract indicates the presence of polyphenols. Conclusion. P. niruri leaf extract protects the kidney from oxidative stress induced by diabetes.