Effect of Egyptian sage extract on antioxidant activity, hypercholesterolemia and bone calcification in the tibia of rats

ABSTRACT

Osteoporosis [major public health problem in the aging society] has been linked with arteriosclerotic vascular diseases characterized by hypercholesterolemia. Nutrition may appear as an alternative strategy for optimizing health skeleton instead of traditional therapies by hormone replacement treatment which increases the risk of heart disease and cancers. Phytochemicals with antioxidative properties that may act against hypercholesterolemia and positive in the prevention of osteoporosis. The present study was designed to investigate the effects of sage leaves aqueous extract on hypercholesterolemia and bone calcification in rats. Sage leaves aqueous extract was prepared by infusion of leaves in hot water, separation of its volatiles and identification using GC/MS and evaluation the radical scavenging activity of sage aqueous extract by ESR. Three groups of rats were used, group 1 to serve as control, group 2 was fed on diet rich with cholesterol and the third group was fed on diet rich in cholesterol and treated with sage leaves aqueous extract. The experiment continued for 6 weeks. The plasma total cholesterol [TC], triglycerides [TG], HDL-C, LDL-C, urea, creatinine, blood hemoglobin, and enzymes activities of transaminases [ALT and AST] were determined. Different minerals [calcium, magnesium, zinc, phosphorus and Ca/P] were assayed spectrophotometrically using atomic absorption. The GC/MS analysis showed that 1,8-cineol [eucalyptol] [22.34%], thujone [16.31%], camphor [16.9%], humulene [7.53%], alpha pinene [5.77%], borneol [4.59%], p-menthol [4.8%], camphene [4.31%] and bornyl acetate [3.16%] were the main volatile compounds of the sage leaves aqueous extract. Sage volatile extract showed significant antioxidant activity in vitro using ESR assay. Daily administration of sage leaves aqueous extract for 6 weeks to Swiss albino rats as drinking water, caused significant declines in the blood levels of triglycerides [TG] [30%], total cholesterol [TC] [10.3%], LDL-C [45%] and increase of HDL-C [81%] and tibial calcium [20%]. This study demonstrates one possible mechanism by which sage leaves aqueous extract which rich in phenolic substances can improve the bone calcification, and acting as hypocholesterolemic agent