Free radical scavenging activity of Telfairia occidentalis extracts and their effects on iron-sulphate induced lipid per oxidation.

Non-enzymic natural antioxidants of plant origin are known to play a key role in inflammation linked with free radicals and oxidative stress. This study investigates the free radical scavenging activity of various Telfairia occidentalis leaves extracts in relation to their inhibitory effects on lipid peroxidation. The extracts markedly exhibited antioxidants activity especially the ethyl acetate (EE) and chloroform (CE) extract which scavenged 1,1-diphenyl-2-picryhydraxyl (DPPH) radicals significantly (p<0.05) by 76.34 and 76.62% respectively at 600μ/ml with minimum effects (53.34%) obtained with the methanol (ME) extract. Similarly the extracts scavenged iron/EDTA/H2O2 induced hydroxyl radical formation in a dose-dependent manner as the ME, EE and CE extracts scavenged the radicals at 300µg/ml by 40.55, 24.23 and 19.64% respectively. Interestingly, ME, EE and CE extracts inhibited iron-induced lipid per oxidation significantly (P<0.05) by 93.56, 76.24 and 70.54% respectively at 300µg/ml. Phytochemical analysis showed the presence of phenols and flavonoids at 2.58, 1.98, 3.24 and 0.840, 0.300, 0.400mg/g garlic acid and quercetin equivalence at 300 μg/ml concentrations respectively. Bioactive constituents of the leaves extracts shows antioxidants potentials, radical scavenging and inhibitory effects on lipid per oxidation which were highly expressed in methanol extract and may be a template for drug discovery.