Antibacterial and Cytotoxic Activities of the Fruit Extract of Averrhoa carambola

The investigation was conducted with methanolic fruit extract of Averrhoa carambola for its antibacterial and cytotoxic activities. Antibacterial activity of the extract was evaluated against various Gram-positive and Gram-negative bacteria using disk diffusion technique. For cytotoxic activity, brine shrimp lethality bioassay was performed to estimate LC50 values. In our preliminary screening, the n-hexane, water and dichloromethane soluble fractions of the crude methanolic extract of Averrhoa carambola were subjected to antibacterial activity and brine shrimp lethality bioassay. The water and dichloromethane soluble partitionate of the methanol extract of Averrhoa carambola exhibited mild to moderate antibacterial activity. Water extract of the said plant showed antibacterial activity against Staphylococcus aureus and Bacillus cereus (Gram positive) while dichloromethane its extract showed antibacterial activity against Escherichia coli and Salmonella typhi (Gram-negative). Dichloromethane soluble partitionate exhibited strong cytotoxicity against the brine shrimp, Artemia salina having LC50 of 1.180 μg/mL.