Antioxidant and antimicrobial activities of stem bark extracts of Oroxylum indicum Vent. (Bignoniaceae) ‐ A medicinal plant of northeastern India

Abstract

The antioxidant activity of extracts of Oroxylum indicum stem bark wasevaluated using different methods. The ethyl acetate extract (EAE) showedthe lowest IC50 value (0.76 mg/ml) with the highest inhibition of DPPH. In theFRAP assay, the hexane extract (HE) showed the highest ferric reducing abilitywhereas the EAE showed better antioxidant ability with lowest IC50 value(0.80mg/ml) in βCL assay. The EAE and HE showed highest ascorbic acidequivalent (6.60 ± 0.22) and trolox equivalent (2.04 ± 0.07) values in antioxidativecapacity of ACW and ACL in PCL assay. During antimicrobial evaluationHE, Chloroform extract (CE) and EAE were found effective against thetested bacteria while the water extract (WE) showed better activity (14.25 ±0.478) against yeast.