Apoptosis of Leukemia Cells by Ocimum basilicumFractions Following TNF alpha Induced Activation of JNK and Caspase 3

Purpose: Leukemia, one of the major cancers, affects a large proportion of people around the world. Better treatment options for leukemia are required due to a large number of side effects associated with current therapeutic regimens. In the present study, we sought to determine the pathway of triggering apoptosis of leukemic cells by Ocimum basilicum (O. basilicum) plant extract. Materials/Methods: Methanolic extract of the O. basilicum plant material was prepared. The crude extract was fractionated into several fractions through column chromatography using ethyl acetate and n-hexane as eluting solvents. Cell viability of leukemic cells was assessed via Cell titer GLO assay and apoptosis was measured through Annexin V/PI staining. Two apoptotic molecules JNK and caspases were analyzed through western blotting while pro-inflammatory cytokines TNFα, CCL2 and CXCL8 using qPCR. Fractions were characterized through LC-MS. Results: The most potent with lowest IC50 values among the fractions were BF2 (2:8 n-hexane:ethyl acetate) and BF3 (3:7 n-hexane:ethyl acetate). Cytotoxicity was associated with apoptosis. Apoptosis was found caspasedependent and P-JNK activation was detected sustained. A significant increase in the level of TNF α and a decrease in the level of CXCL8 were observed in BF2 and BF3 treated cells. Conclusion: The fractions of O. basilicum extract were found to kill cells following JNK pathway activation. Excellent results were obtained with BF2 and BF3 probably due to predominant Epicatechin and Cinnamic acid derivatives in these fractions.