Free radical scavenging activity of two edible vegetables from the Niger delta region of Nigeria

Oxidative stress and diseases that have their aetiology and pathophysiology in reactive oxygen species can be prevented by medicinal plants and herbs. We undertook in this study, to investigate the free radical scavenging activity of dichloromethane (DCM) and ethanol (ETOH) extracts of Lasianthera africana and Gongronema latifolium in vitro using 2, 2, diphenyl-1-picrylhydrazine (DPPH). The leaves of both plants were obtained locally, washed, dried and pulverized using mechanical grinder. The powdered materials were defatted using n-hexane and subsequently extracted with DCM and thereafter with ETOH. The DPPH scavenging potentials of the extracts were then evaluated. The percentage inhibition of the DCM and ETOH extracts were; 46.2 and 80% respectively for L. africana and 37.2 and 82.6 respectively for G. latifolium. The standard substance (quercetin) produced 98.4 per cent inhibition at 1 mg/mL. The IC₅₀ for the L. africana were; 2.017 and 3.256 mg/mL; DCM and ETOH extracts respectively. While that of G. latifolium were 1.495 and 1.116 mg/mL respectively for DCM and ETOH extracts. The standard substance produced IC₅₀ of 0.55 mg/mL. The DPPH inhibitory activity was found to be prominent with the ETOH extracts of both plants. The result from this study validates the use of the leaves of both plants as supplements to improve health conditions and quality of life in general.