FREE RADICAL SCAVENGING AND ANTIOXIDANT CAPACITY OF LEAF OF Combretum platypterum (Welw) Hutch and Dalziel

Abstract

An antioxidant is a molecule capable of preventing or inhibiting the oxidation of other molecules. It ends these reactions by removing free radical intermediates and inhibiting other oxidation reactions. Combretum platypterum is a plant that belongs to the family Combretaceae. Despite being used in ethnomedicine, there is no report of the in vitro antioxidant and free radical scavenging activities of its leaves. This study is aimed at testing the in vitro antioxidant and free radical scavenging activities of Combretum platypterum leaves. In vitro antioxidants such as ascorbic acid, carotenoids, and lycopene, and free radical scavenging activities such as 2,2-diphenyl-1-picrylhydrazyl, superoxide radicals, hydroxyl radicals, hydrogen peroxide, nitric oxide, and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) were analyzed using well-established methods. DNA protective assay was analyzed using DNA unwinding wheat germ plasm topoisomerase with supercoiled pBR322 plasmid. The vitamin C content in the aqueous extract was significantly higher compared to ethanol, methanol, and chloroform leaf extracts (p < 0.05). The carotenoid content in the methanol extract was higher compared to ethanol, methanol, and chloroform leaf extracts (p < 0.05). Lycopene content in the methanol extract was higher compared to water, ethanol, and chloroform leaf extracts (p < 0.05). DPPH, superoxide radicals, hydroxyl radicals, hydrogen peroxide, nitric oxide, and ABTS are just some of the radicals that the leaves of Combretum platypterum can scavenge. Methanol and aqueous extracts of Combretum platypterum protected the DNA from damage compared to the effect of dimethyl sulfoxide on DNA. Combretum platypterum leaves have antioxidant, scavenging, free radical, and DNA protection potential.