Antilipidemic Activity and Phytochemical Properties of Methanol Extract and Fractions of Sphenostylis stenocarpa Seeds

Abstract

Sphenostylis stenocarpa, also known as African yam bean (AYB), has reportedly been used in traditional medicine to manage and control hyperlipidemia, among other health benefits. The aim of this work was to investigate the antilipidemic potentials of methanol crude extract and fractions of Sphenostylis stenocarpa seeds. In this work, pulverized AYB was macerated in absolute methanol for 72 h, filtered, and air-dried to obtain the crude extract. The crude extract was partitioned using n-hexane, ethyl acetate, n-butanol, and distilled water. The n-butanol and aqueous fractions were further fractionated using a vacuum liquid chromatographic technique. The acute toxicity test was conducted using eighteen Wistar rats in a two-phase test, with doses of 10-1000 mg/kg and 1600-5000 mg/kg body weight, respectively. The antilipidemic activity was investigated in Triton-induced adult Wistar rats of either sex for 28 days using L-Livoline and Tween-80 as positive and negative controls, respectively. The phytochemical screening revealed that the methanol extract, aqueous fraction, and the ethyl acetate fraction contained terpenoids d saponins, while the n-butanol fraction contained only terpenoids. The methanol extract, ethyl acetate-, n-butanol-, and aqueous fractions, and the n-butanol- and aqueous sub-fractions showed antilipidemic activity in the rat model, with the aqueous sub-fraction showing better antilipidemic activity (27.21 ± 1.43 mg/dL) in the low-density lipoprotein assay when compared with the standard livoline (33.24 ± 3.43 mg/dL). There was a significant difference in the antilipidemic activity as measured by total cholesterol, low-density lipoprotein, and phospholipid levels (p < 0.05).