Chemical composition and in vitro antiobesity and in vivo anti-hyperlipidemic effects of Ceratotheca sesamoides, Jatropha tanjorensis, Mucuna flagellipes, Pterocarpus mildbraedii and Piper guineense

Abstract

Ceratotheca sesamoides, Jatropha tanjorensis, Mucuna flagellipes, Pterocarpus mildbraedii and Piper guineense are all medicinal plants found in West Africa and used traditionally for the treatment of various ailments such as; hypertension, arteriosclerosis, anemia, malaria and flatulence. The purpose of this study is to ascertain the in vitro anti-obesity and in vivo anti-hyperlipidemic activity of extracts and fractions of selected plants. The ethanolic extract of the aforementioned five plants were tested in vitro for their activity against porcine pancreatic lipase and alpha-amylase at a concentration of 1mg/ml. Thereafter, the IC50 values of the plants active against alpha-amylase were determined. The ethanolic extract of P. mildbraedii and M. flagellipes were fractionated using n-hexane, n-butanol, ethyl acetate and water, thus the four fractions each obtained were used for further in vitro and in vivo studies. Thirty-five male rats were divided into seven groups out of which groups 2–7 were made hyperlipidemic using poloxamer 407 (1.0 g/kg body weight) intraperitoneally. Groups 1, 2 and 3 were the normal, hyperlipidemic and standard drug control groups respectively, whereas groups 4–7 were the test groups. C. sesamoides, M. flagellipes and P. mildbraedii inhibited alpha-amylase activity, while M. flagellipes and P. mildbraedii had activity against pancreatic lipase. The n-hexane fraction of P. mildbraedii and M. flagellipes inhibited both lipase and amylase enzyme activities among the four fractions of each plant tested. The GCMS analysis of n-hexane fractions revealed the presence of two major compounds in each plant which were 9-octadecenoic acid and hexadecanoic acid in P. mildbraedii, and hexadecanoic acid and 9,12-octadecadienoic acid in M. flagellipes. The in vivo studies revealed that the n-hexane fraction of P. mildbraedii and M. flagellipes significantly decreased (p < 0.05) total triglycerides, total cholesterol, and low density lipoprotein cholesterols when compared to the hyperlipidemic control rats. P. mildbraedii and M. flagellipes have the potency to act as antiobesity and anti-hyperlipidemic agents.