Antibacterial and In vivo Cytotoxic Activities of the Leaves of Leucas aspera

Antimicrobial and cytotoxic activities of the leaves of Leucas aspera, a medicinal plant found in Bangladesh, were evaluated. In vitro bactericidal activity was screened against ten pathogenic or food poisoning bacteria using the disc diffusion method. In vivo cytotoxicity was examined against Anemia sauna (brine shrimp nauplii). The dichloromethane fraction of the methanol extract of the leaves of Leucas aspera had strong antibacterial and cytotoxic effects, whereas the ethyl acetate fraction exhibited significant bactericidal activity against only Gram-positive bacterial strains. The active constituents, a-amyrin and a-tocopherol, were isolated for the first time from the dichloromethane fraction and their cytotoxic effects against A. sauna were significant with LC50 values of 241 and 195 ppm, respectively.