Abstract

Crude extracts from the leaves of kaffir lime (Citrus hystrix, DC.) were extracted using hexane, ethanol, ethyl acetate, butanol and methanol. The fractions were investigated in vitro for their potential cytotoxic activity on HL60, K562, Molt4, U937 cell lines, and normalhuman peripheral blood mononuclear cells (PBMCs) using the MTT assay. The in vitrocytotoxicity bioassays on 4 leukemic cell lines showed that the ethyl acetate fraction exhibited the highest cytotoxicity, with IC₅₀ values of 19.0±0.6, 35.3±1.4, 21.8±0.4, and 19.8±1.0 µg/ml, in response to HL60, K562, Molt4, and U937 cell lines, respectively. These were higher than those of fractions from hexane, ethanol, and butanol. The methanol fraction had no cytotoxic activity (IC₅₀ value > 100 µg/ml). None of the fractions had cytotoxic effects on PBMCs. The active compound in the ethyl acetate fraction should be investigated for possible use in chemotherapy.

Key words: Kaffir lime, Citrus hystrix, DC., cytotoxicity, leukemic cell line.