Antioxidant and anti infective potential of Oleanolic acid acetate vis-à-vis Vitex negundo Linn. and Oroxylum indicum Vent. against human pathogens causing infections of UT, GIT and skin

Abstract

The present investigation was undertaken to evaluate the in-vitro antioxidant and antimicrobial potential of extracts of Vitex negundo (VN) root, Oroxylum indicum (OI) whole plant and Oleanolic acid acetate (OAA), an isolated phyto-constituent from VN root extracts against some selected human pathogens causing infections of UT, GIT and skin. Methanol : dichloromethane (1:1) was used as solvent for extraction. The antioxidant potential of VN, OI and OAA was evaluated by DPPH method. Agar well diffusion and Poison food method (mycelial fungi) were employed for evaluating antibiogram pattern. The minimum inhibitory (MIC) concentration of the test agents was determined. VN, OI and OAA scavenged the DPPH free radical with an IC50 value of 35.11, 42.71 and 24.17 μg/ml respectively. OAA exhibited comparative higher inhibitory zones and broader spectrum followed by VN and OI. OI, VN and OAA inhibited S. flexneri 1457, E. coli 118 and S. enterica typhimurium 98 at 39.06, 39.06 and 19.53 μg/ml respectively. OAA inhibited the growth of both yeast and mycelial fungi at a comparative lower concentration (μg/ml) as compared to VN and OI, justifying OAA to be a potential antimicrobial candidate. OAA registered potent antioxidant activity followed by VN and OI which might be attributed to its triterpenoid chemical moiety. OAA registered higher zone of inhibition and restriction with lowest MIC values against the tested bacterial and fungal pathogens of UT, RT and skin followed by VN and OI, comparable with reference antibiotics, claiming it to be a potential antimicrobial agent.