Objective. Oxidative stress leads to numerous physiological disorders including infectious diseases, inflammation, and cancer. The present study was carried out to investigate antioxidant, antibacterial, and cytotoxic activity of methanol crude extract of leaves and fruits of the Ficus racemosa (LCME and FCME, resp.) and to analyse its major bioactive polyphenols by HPLC-DAD. Methods. Antioxidant capacity of the extracts was evaluated by DPPH free radical scavenging, reducing power, total phenolic, total flavonoid, total tannin content assay, superoxide radical, hydroxyl radical, and hydrogen peroxide scavenging assay. Identification and quantification of bioactive polyphenols were done by HPLC-DAD method. Antibacterial activity was tested by “disc diffusion” method. Brine shrimp lethality assay was carried out to check the cytotoxic potential. Result. Both LCME and FCME showed DPPH scavenging ability and concentration dependent reducing power activity. They had phenolic content, flavonoid content, and tannin content. Both the extracts showed superoxide radical scavenging ability, hydroxyl radical scavenging ability, and hydrogen peroxide scavenging ability. HPLC analysis of LCME and FCME indicated the presence of significant amount of gallic acid along with other phenolic constituents. Conclusion. Significant amount of gallic acid along with other phenolic constituents might have played an important role in the observed antioxidant, antibacterial, and cytotoxic activity.

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The crude methanolic extract of the root bark of Pongamia pinnata was taken into consideration to isolate secondary metabolites. A total six known natural compounds were separated and purified by various chromatographic techniques and five isolates were identified as flavonoid derivatives such as pongachromene (1), kanugin (2), karanjin (3), demethoxykanugin (4), dimethoxypongapine (5) and the other is a triterpenoid (6). The pure compounds as well as petroleum ether, dichloromethane and ethyl acetate soluble fractions of crude methanolic extract were evaluated for bioactivities using established methods. In vitro antioxidant activity was studied by DPPH radical scavenging method using butylated hydroxyl anisole as standard. Among the pure compounds, kanugin and pongachromene showed significant antioxidant activity with the IC50 values of 27.20 ± 0.39 μg/mL and 43.53 ± 0.63 μg/ml, respectively as compared to the standard (23.87 ± 0.09 μg/ml), whereas karanjin, demethoxykanugin and dimethoxypongapine demonstrated moderate antioxidant activity. Mild thrombolytic activity was observed by different fractions with clot lysis ranging from 18.49 to 29.35% as compared to standard streptokinase (79.12%). The different solvent fractions and pure isolates showed very mild antimicrobial activity with zone of inhibition of 7.5 - 10.0 mm against the tested microorganisms using azithromycin and ketoconazole as standards. In the brine shrimp lethality bioassay, the dichloromethane, ethyl acetate, and methanol soluble fractions revealed significant lethality with LC50 values of 0.67 ± 0.05, 0.61 ± 0.13 and 0.56 ± 0.10 μg/ml, respectively as compared to standard tamoxifen (LC50 value 0.34 ± 0.09 μg/ml). Dhaka Univ. J. Pharm. Sci. 19(1): 1-8, 2020 (June)