Hypoglycemic effect of Rehmannie Radix Preparata (Sookjihwang) extract in streptozotocin-induced diabetic rats

Flaxseed Protects Against Diabetes-Induced Glucotoxicity by Modulating Pentose Phosphate Pathway and Glutathione-Dependent Enzyme Activities in Rats

This study investigated the effects of flaxseed (Linum usitatissimum L.) intake on general metabolism, pentose phosphate pathway (PPP) and glutathione-dependent enzymes in diabetic rats. Diabetes was induced by streptozotocin injection (40 mg/kg, i.p.) and the enzyme activities were determined spectrophotometrically. Diabetic and control rats were divided in two subgroups, one untreated, and one treated with flaxseed (0.714 g/kg body weight/day; orally) for 12 weeks. Flaxseed ameliorated decreased body weight (p < .05) and increased blood glucose (p < .001), triglyceride (p < .001), ALT (p < .001) and AST (p < .001) in diabetic rats. Diabetes resulted in increased glucose-6-phosphate dehydrogenase (G6PD) (p < .05) and decreased glutathione-S-transferase (GST) (p < .01), but unchanged 6-phosphogluconate dehydrogenase (6PGD) and glutathione reductase (GR) in the brain of rats. These alterations were partially improved by flaxseed in comparison to diabetic untreated group (p < .05). G6PD, 6PGD, GR were elevated (p < .001), while GST unchanged in the lung of diabetic untreated group compared to control. Flaxseed partially prevented the increase in 6PGD (p < .05) and GR (p < .01), but unaffected G6PD in the lung of diabetic rats. G6PD (p < .001), 6PGD (p < .05), GR (p < .001) were augmented, while GST showed a significant (p < .001) depletion in the pancreas of diabetic untreated rats compared to control. Diabetic alterations observed in pancreatic enzyme activities were significantly prevented by flaxseed. Furthermore, a remarkable decrease in 6PGD (p < .001) and an increase in G6PD (threefold of control) were found in the lens of diabetic untreated group that were completely prevented by flaxseed (p < .001). Flaxseed has beneficial effects against diabetes-induced glucotoxicity by modulating G6PD, 6PGD, GR and GST activities in tissues.

Hypolipidemic and hypoglycemic effects of Orostachys japonicus A. Berger extracts in streptozotocin-induced diabetic rats

The hypolipidemic and hypoglycemic effects of two dietary dosages (0.1% and 0.5%) of water and 80% ethanol extracts from hot-air dried Orostachys japonicus A. Berger were evaluated in the serum and organ tissues of streptozotocin-induced diabetic rats. The STZ-induced diabetic groups supplemented with the O. japonicus extracts showed significantly higher body weight compared to a diabetic control group at the end of experiment. The extracts exhibited substantial hypoglycemic effects by significant reductions of fasting blood glucose levels at all time points tested compared to the initial stage before treatment of the extracts. Declines of serum and hepatic triglyceride levels were greater than declines of total cholesterol in the groups treated with the 0.5% O. japonicus extract (DBW2 and DBE2) when compared to the DBC group. Hepatic glycogen content was higher in the groups treated with O. japonicus extract, while lipid peroxide content was decreased in these treated groups compared to the DBC group. Hepatic antioxidant activity was significantly increased in the groups supplemented with the O. japonicus ethanol extract. The hypolipidemic and hypoglycemic effects of the O. japonicus ethanol extract were significantly greater than the effects of the water extract. Based on this study, it seems that O. japonicus ethanol extract, due to its higher phenolic and flavonoid components than the water extract, may control blood glucose and alleviate hyperlipidemia in diabetes.