The effects of oral vitamin E on induction and consequence of experimental diabetes mellitus in rats

Influence of treatment with quercetin on lipid parameters and oxidative stress of pregnant diabetic rats

Among the numerous coadjuvant therapies that could influence the incidence and progression of diabetic complications, antioxidants and flavonoids are currently being tested in clinical trials. We investigated the effect of quercetin on biochemical parameters in streptozotocin-induced (60 mg/kg body mass, by intraperitoneal injection) diabetic rats. A total of 32 female Wistar rats were distributed among 4 groups as follows: control (G1); control treated with quercetin (G2); diabetic (G3); and diabetic treated with quercetin (G4). Quercetin administered to pregnant diabetic rats controlled dyslipidemia and improved lipid profiles in diabetes mellitus, regulated oxidative stress by reducing the generation of lipid hydroperoxides, and increased the activity of the antioxidant enzyme glutathione peroxidase.

Supplementation with magnesium and vitamin E were more effective than magnesium alone to decrease plasma lipids and blood viscosity in diabetic rats

Although magnesium and vitamin E (VE) have differing effects on diabetes, both are beneficial. We hypothesized that preventive supplementation of magnesium combined with VE could improve the metabolism of lipids and blood viscosity more effectively than the use of magnesium or VE alone. Our objective was to detect the effects of preventive supplementation of magnesium combined with VE on lipid peroxidation, lipid metabolic parameters, and blood viscosity in diabetic rats. Six dietary groups, all fed with high-energy diets, were formed and studied for 8 weeks: control group (C); VE group (E); middle-dose magnesium group (MM); high-dose magnesium group (HM); VE plus middle-dose magnesium group (EMM); and VE plus high-dose magnesium group (EHM). Compared with C group, malondialdehyde was inhibited in the E, EMM, and EHM groups (all P < .05); total cholesterol decreased in all 5 treated groups, and significant differences were found in groups E (P = .004), MM (P = .017), EMM (P = .016), and EHM (P = .020). Compared with the C group, high-density lipoprotein levels were elevated in the HM (P = .027) and EHM (P = .021) groups, and low-density lipoprotein levels were lower in the E (P = .010), EMM (P = .025), and EHM (P = .015) groups. Differences between middle and high shear rates of blood viscosity were significant in all treated groups compared with the C group (all P <or= .001). Statistical analysis showed that there was no interaction between magnesium and VE. We concluded that preventive supplementation of VE combined with magnesium was more beneficial to improve the plasma lipid parameters and blood viscosity in diabetic rats than magnesium alone.