Phytochemical screening, antioxidant and antimicrobial activities of leaf extracts of Randia uliginosa

Abstract

Phytochemical consisting of phenols and flavonoid possess antioxidant properties, which are useful to scavenge reactive oxygen species (ROS).The present study was conducted to evaluate antioxidant and antimicrobial activities of leaf extracts of roots of Randia uliginosa, using DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging assay, cupric reducing antioxidant capacity, nitric oxide scavenging assay, ferric reducing antioxidant power, total antioxidant capacity, determination of total phenol and flavonoid contents and disc diffusion technique. Preliminary phytochemical study revealed the presence of alkaloid in the extracts. The tested fraction showed significant antioxidant activities in the assay compared to the reference ascorbic acid in a dose dependent manner. In DPPH radical scavenging assay, the IC50 value of the crude chloroform extract was 399.12 μg/mL, whereas IC50 value for the reference ascorbic acid was 8.77 μg/mL. In case of nitric oxide scavenging assay, the IC50 value of the crude chloroform extract was 58.27 μg/mL, whereas IC50 value for the reference ascorbic acid was 51.07 μg/mL. Moreover, at 200 μg/mL extract concentration, lower grade total antioxidant activity (36.27±1.39 mg/g equivalent to ascorbic acid) was observed. Furthermore, extract showed good cupric reducing power and reducing power capability. In addition, significant amount of flavonoids and low phenols content were obtained from the extract. In case of antimicrobial activity studied using different solvent like methanol, chloroform, petroleum ether against bacterial strains like Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, P.aeruginosa, E.coli, S.typhi, Serratia spp. and P.mirrabilis. Varying concentration of each extracts 100 mg/ml, 50 mg/ml, 25 mg/ml prepared by using disc diffusion method. Among all the extracts used, methanol extract was found to be highly active against the entire organism when compared with amoxicillin 25 mg/ml. The results suggest that Randia uliginosa can be used as a medicament for various infections.