ABSTRACT:
Natural products are considered as a symbol of protection when compared to modern synthetic drugs due to its adverse effects associated with the treatment of diseases like leukemia. Hence, there is a need to develop alternative anti-leukemic agent with minimal side effects. Objective: The objective of the present study was to evaluate the cytotoxicity and apoptotic activities of Morinda pubescens leaves on human leukemic cells. Methodology: In vitro cytotoxic potential of Morinda pubescens leaf extracts was evaluated against human promyelocytic leukemic cell line (HL-60) using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide [MTT] assay. The treated cell morphology of various extracts was observed by light microscope. The apoptotic mechanism of the effective extract was determined by analysis of DNA fragmentation through Agarose gel electrophoresis technique. Results: The plant extracts inhibited proliferation of HL-60 cells in a concentration dependent manner. The IC50 values of various extracts such as petroleum ether, ethyl acetate and methanol was found to be 315.44µg/ml, 265.36µg/ml, 213.09µg/ml for 24 hrs, respectively and the standard drug, cyclophosphamide was found to be 155.65µg/ml. Among these different extracts, the methanolic extract was found to be more cytotoxic with lower inhibitory concentration (IC50). Apoptosis assay of the effective extract reveals, that there is a cleavage of DNA by nucleases at proper sites which leads to a ladder formation. Conclusion: Morinda pubescens leaf extract induces cell death in HL-60 cell line. Further, in vivo studies and identification of active constituents from Morinda pubescens leaf extract, and their exact mechanism of action could be valuable in designing novel anti-cancer agents.