Rosa rugosa polysaccharide

We examined the effects of Rosa rugosa (Rosa rugosa Thunb) on lipid peroxidation, alanine transaminase (ALT), aspartate transaminase (AST), glutathione and protein oxidation levels in carbon tetrachloride (CCl4) treated male Wistar rats. Two control groups and one treatment group of rats were formed. The control groups were fed a standard diet, while the Rosa rugosa group was fed a standard diet enriched with 6% by weight dried Rosa rugosa fruit powder. After 3 months, a single dose of CCl4 was injected intraperitoneally in the Control II and Rosa rugosa groups (1 ml/kg, as 20% in olive oil) and a similar dose of olive oil was administered i.p. to rats in the Control I group. The rats were sacrificed 2 hours later. Lipid peroxide levels in liver, protein oxidation in liver, glutathione (GSH) levels in liver, and ALT and AST in plasma were measured. The rats in the Rosa rugosa group were found to have significantly lower liver peroxide, protein oxidation, glutathione levels and plasma ALT and AST activities compared with the rats in the CCl4 treated control group. These findings suggest that Rosa rugosa possesses antioxidant activity.

The effects of Rosa rugosa on diabetic oxidative stress were investigated using rats with streptozotocin (STZ)-induced diabetes. The diabetic rats showed less body weight gain and heavier kidney and liver weights than normal rats, while the oral administration of Rosa rugosa at a dose of 100 or 200 mg/kg body weight/day for 20 days attenuated the physiological changes induced by diabetes. In addition, administrating Rosa rugosa to diabetic rats resulted in significant and dose-dependent decreases in the serum glucose and glycosylated protein levels, implying that Rosa rugosa improves the abnormal glucose metabolism that leads to oxidative stress. Diabetic rats had higher serum levels of superoxide and nitrite/nitrate. However, the administration of Rosa rugosa dose-dependently reduced the over-production of radicals associated with diabetes, suggesting Rosa rugosa is a radical scavenger that would play a crucial role in protecting against diabetic oxidative stress. Rosa rugosa significantly and dose-dependently reduced thiobarbituric acid-reactive substance levels in serum, hepatic and renal mitochondria, implying that Rosa rugosa would alleviate the oxidative stress associated with diabetes by inhibiting lipid peroxidation. This study provides evidence that Rosa rugosa has potential as a treatment for diabetes through attenuating oxidative stress induced by the diabetic condition