Antioxidant and Anti-hyperlipidemic Effects of Bark Extract of Pinus eldarica in Dexamethasone-induced Dyslipidemic Rats

Although Pinus eldarica is considered as a pine with many valuable phytochemical constituents, little is known about the pharmacological effects of its bark extract. Therefore, the present study aimed to evaluate in vivo antioxidant activity and also the possible beneficial effects of the bark extract of P. eldarica on dexamethasone-induced dyslipidemia in rats.

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 intraperitoneal injections (IP) injections of plant extract (100, 200 and 400 mg/kg) for 28 days. For induction of dyslipidemia, dexamethasone (10 mg/kg) was subcutaneously administered during 8 days. Different doses of extract were given orally plus dexamethasone in three groups of animals. Serum lipids, blood glucose and malondialdehyde (MDA) levels and liver histopathology were assessed.

High total phenolic content was determined as 375±1.2 mg gallic acid equivalent/ g of dried bark extract. The 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. P. eldarica led to a significant reduction in serum levels of blood glucose, total cholesterol, triglyceride and MDA and improved liver histopathological changes at the doses of 200 and 400 mg/kg in dyslipidemic rats.

These findings suggest the potential antioxidant, antihyperlipidemic and antihyperglycemic activities for the bark extract of P. eldarica which may be due to the high amounts of phenolic compounds.