Antioxidant activity and total flavonoids content of different parts of Azadirachta indica A. Juss

Abstract

Reactive oxygen species are known to play a key role in many pathological conditions, and antioxidants from plant sources have been of great contribution in modulating this effect. Different parts of Azadirachta indica (AI) A. Juss were studied for their antioxidant capacity. We investigated antioxidant properties and total flavonoid contents of successive solvent extracts of different parts of AI. Total antioxidant assay was performed using the 2,2’-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and ferric reducing antioxidant potential (FRAP) methods. Total flavonoid contents were measured using colourimetric method. Root bark methanolic extract was also subjected to lipid peroxidation inhibitory activity. Methanolic extract of root bark was found to exhibit highest IC50 value of 13.83 g/ml by ABTS total antioxidant assay, 420.04 g/ml by lipid peroxidation inhibition and EC1 value of 503.53 g/ml by FRAP assay. Content of total flavonoids were expressed in quercetin equivalents ranging from 65.06 to 72.96 g/ml in the leaf, 18.99 to 93.03 g/ml in the seed and 55.70 to 98.00 g/ml in the root bark. The present study evaluated the antioxidant activities and total flavonoids content of different parts of Azadirachta indica A. Juss, and root bark methanolic extract showed significant antioxidant activities due to free radical scavenging potential, which was comparable with its total flavonoids content in Azadirachta indica A. Juss.