Bioactivities of selected Sutherlandia frutescens (L.) R. Br. leaf extracts

Abstract

Sutherlandia frutescens (L.) R. Br. (family: Fabaceae) is a medicinal plant widely used by traditional healers in South Africa for treating various human ailments. In this study, the Sutherlandia frutescens leaf powder was extracted with methanol and further subsequently fractionated with chloroform, ethyl acetate, and 1-butanol for investigating total phenolic content, L-canavanine content, DPPH free radical scavenging activity and anti-tumor activities on PC-3 and LNCaP prostate tumor cell lines of obtained extracts. According to the results, all Sutherlandia frutescens extracts contained phenolic compounds and L-canavanine, and exhibited DPPH radical scavenging activity and anti-tumor activity (growth inhibition effect on human prostate tumor cell lines) at different levels. While DPPH scavenging activity was generally associated with total phenolic content, anti-tumor activity could not be linked closely to L-canavanine content. These findings provide a starting point and warrant further research to investigate the mechanisms for the health claims of Sutherlandia frutescens.