Antioxidant and Antihyperlipidemic Effects of the Bark Extract of Pinus eldarica in Dexamethasone-Induced Dyslipidemic Rats

Background: Pinus eldarica is a widely growing pine in Iran consisting of biologically active components. Since little is known about the pharmacological effects of the bark extract of this plant, the present study aimed to investigate the in vivo antioxidant activity and also the possible beneficial effects of the bark extract of P. eldarica on dexamethasone-induced dyslipidemia in rats. Methods: Total phenolic content was determined using Folin-Ciocalteu method. The in vivo antioxidant assays included the measurement of hydroperoxides level and ferric reducing antioxidant power (FRAP) value in plasma samples of rats receiving i.p. injections of plant extract (100, 200 and 400 mg/kg) for 28 days. For induction of dyslipidemia, dexamethasone was injected 10 mg/kg/day, S.C. for 8 days. In the test groups, animals received dexamethasone and different doses of extract orally. Serum lipids, blood glucose and malondialdehyde (MDA) levels and livers histopathology were assessed. Results: High total phenolic content was determined as 375 ± 1.2 mg gallic acid equivalent/ g of dried plant extract. The bark extract significantly decreased plasma hydroperoxides level at all doses and increased FRAP value at the dose of 400 mg/kg during in vivo antioxidant analysis. The plant extract also reduced serum blood glucose, triglyceride, and total cholesterol and MDA levels and improved liver histopathological changes at the doses of 200 and 400 mg/kg in dyslipidemic rats. Conclusions: These findings suggest the potential antioxidant, antihyperlipidemic and antihyperglycemic activities for the bark extract of P. eldarica which may be due to high amounts of phenolic compounds.

Keywords:

Pinus eldarica , antioxidant , hyperlipidemia , lipid peroxidation , dexamethasone