Evaluation of in vitro Antibacterial and Antioxidant Activity of Aqueous Extracts of Olax psittacorum

Abstract

Present study aimed to evaluate the phytoconstituents of the aqueous extracts of stem and fruits of Olax psittacorum as well as the free radical scavenging and the antibacterial activity of the extracts. Free radical scavenging activities were evaluated through DPPH radical scavenging assay, ABTS radical scavenging assay, phosphomolybdate radical scavenging assay, hydrogen peroxide assay and reducing power assay using ascorbic acid as the standard. Well diffusion method was adopted for antibacterial activity evaluation of the aqueous extract of fruits and stem against Staphylococcus aureus, Bacillus stereothermophillus, Pseudomonas aeruginosa, Vibrio cholera, Escherichia coli and Acinetobacter baumanii. Positive response to phytochemical screening of tannin, saponin, steroids and terpenoids showed in both aqueous extract of stem and fruit where as positive response to the presence of glycoside, flavonoids, carbohydrate and reducing sugar showed only by the aqueous extract of fruit. Total phenolic, tannin and saponin content in aqueous extract of fruit was more than that of aqueous extract of stem. Total flavonoid content of aqueous extract of fruit was found to be 279.33 mg quercetin equivalent per gram of dry extract. Variations in phytoconstituents and in vitro experimental data obtained through antioxidant as well as antimicrobial assay method indicates the existence of significant difference (p<0.05) between the antioxidant potency and zone of inhibition with S. aureus, V. cholerae, A. baumanii, which aqueous extract of stem failed to show at the same concentration (100 mg/ml), respectively and thus provided valid reasons to give superiority to aqueous extract of fruit as compared to aqueous extract of stem.