The concentration of total

phenols obtained in this study might be due to the polarity of ethanol. The total phenolic contents in plant extracts depend on the type of extract, i.e. the polarity of solvent used in extraction. High solubility of phenols in polar learn more solvents provides high concentration of these compounds in the extracts obtained using polar solvents for the extraction.14 The extract demonstrated varied DPPH radical scavenging-effect. DPPH is a very stable free radical. Unlike the in vivo-generated free radicals such as the hydroxyl radical and superoxide anion, DPPH has the advantage of being unaffected by certain side reactions, such as metal ion chelation and enzyme inhibition. selleck A freshly prepared DPPH solution exhibits a deep purple colour with an absorption maximum at 517 nm. This purple colour generally fades when anti-oxidant molecules quench DPPH free radicals (i.e. by providing hydrogen atoms or by electron donation, conceivably via a free radical attack on the DPPH molecule) and convert them into a colourless and or/bleached product (i.e. 1,1-diphenyl-2-hydrazine, or a substituted analogous hydrazine), resulting in a decrease in absorbance at 517 nm band. 9 The effect of anti-oxidants on DPPH radical is thought

to be due to their hydrogen-donating ability. The result of this investigation demonstrates that the extract possesses strong scavenging effect on DPPH radical. This may be as a result of the concentration of total phenols in the extract. Phenols are very important plant constituents because of their scavenging ability on free radicals due to their hydroxyl groups. Therefore, the phenolic content of plants may contribute directly to their antioxidant action. 15 The extract showed a strong capability of iron (II) chelation in a manner that is comparable to that of a standard anti-oxidant (ascorbic

acid). This may be attributable to the anti-oxidant effect of total phenols. It is known that several mechanisms contribute to the anti-oxidant effect of phenolics in lipid system. These mechanisms are: suppression of the formation of reactive oxygen species (ROS) by those inhibiting some enzymes, up-regulating or protecting anti-oxidant defence, scavenging free radicals especially ROS and capacity to chelate divalent metal ion involved in free radical production.16 That the extract exhibited a nitric oxide (NO)-scavenging activity implies an anti-oxidant activity. The contribution of NO to oxidative damage is increasingly becoming evident even though it has some beneficial effects. Excess production of NO has been associated with several ailments such as carcinomas, juvenile diabetes, multiple sclerosis, arthritis and ulcerative colitis.