In vitro studies on antibacterial, antifungal, and cytotoxic properties of Leucas aspera

The leaves of the plant Leucas aspera belonging to the family Lamiaceae was studied to determine the in vitro antibacterial, antifungal, and cytotoxic properties. All extracts showed remarkable antibacterial activity against all of the studied organisms except Escherichia coli. Methanol extract showed stronger activity compared to ethyl acetate and petroleum ether extracts. It showed highest activity against Pseudomonas aeruginosa with zone of inhibition of 15 mm. The standard chloramphenicol did not show any activity against Shigella sonnei. But all the extracts showed moderate activity against this pathogen with zone of inhibition ranging from 10 to 13 mm. None of the extracts has shown any significant antifungal activity against the fungi. Incase of brine shrimp lethality bioassay, methanol extract showed the strongest cytotoxic effect with LC50 value of 4.28 μg/ml which is followed by ethyl acetate extract with LC50 value of 5.36 μg/ml. Thus it can be inferred that this plant may be a potential source of novel bioactive compounds.