Hypolipidemic Potentials of Methanolic Extract of Rauvolfia vomitoria Leaves in Rats Fed with High Cholesterol

Abstract
The study was aimed to investigate the hypolipidemic potential of methanolic extract Rauvolfia vomitoria leaves in high cholesterol-fed rats. The preliminary study showed that R. vomitoria leaves were able to scavenge the 2,2-azino-bis (3-ethylbenzthiazoline-6-sufonic acid) (ABTS) and 2-Diphenyl-1- picrylhydrazyl (DPPH) radicals and these radicals scavenging abilities were found to be dose-dependent. Administration of cholesterol to rats for 45 days induced a significant increase in the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and increase lipids levels in the plasma and tissues while HDL cholesterol was decreased. It also elevated the levels of malondialdehyde (MDA) and decreased superoxide dismutase (SOD) activities in the tissues. However, co-administration of high cholesterol-fed rats with R. vomitoria extract at doses of 100 and 200 mg/kg significantly reversed lipids levels to near normal with cholesterol in the plasma, liver, heart, kidney and lung reduced by (23.13% and 56.43%), (30.09% and 20.90%), (38.21% and 74.53%), (12.61% and 32.49%) and (37.11% and 29.90%) respectively while HDL cholesterol level was increased by (225.44% and 110.39%). The levels of AST, ALT and ALP in the plasma and MDA in the tissues were also decreased while SOD activities in the liver, heart, kidney and lung were elevated by (89.35% and 149.21%), (74.91% and 68.35%), (56.76% and 114.77%), and (204.91% and 274.62%) respectively. The extract of R. vomitoria was found to be rich in phenolic content and was proved to have no toxic effects on rats when administered alone to normal rats at a dose level of 200mg/kg/day. The results obtained in this study demonstrated the antioxidant and lipid-lowering effects of R. vomitoria and, suggests that the plant could serve as a new potential natural product for the treatment of hyperlipidemia.