Induction of apoptosis in myelogenous leukemic K562 cells by ethanolic leaf extract of Annona muricata

Prevalence of cancer, especially in Nigeria, is silently growing at exponential rates due to its nature and numerous risk factors as-sociated with its development. Most chemotherapeutic drugs used today are expensive and toxic to normal cells, hence the need for alternative treatment options. In this present study, the efficacy of ethanolic extracts of Annona muricata leaves for its cytotoxicity potential and induction of apoptosis in K562 cancer cells, was investigated. Phytochemical screening verified presence of alkaloids, tannins, flavonoids, saponins, anthraquinones and cardiac glycosides. Using Neutral red uptake assay, the ethanolic extract showed peak cytotoxicity levels (P<0.001) at 2.5mg/ml which decreased with increased concentrations. Caspase-3 activity was significantly enhanced (P<0.001) during apoptosis induced by the extract at low quantities, with the peak activity shown at 50µg/ml. Apoptosis was confirmed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay. Caspase-3 activity and TUNEL results suggested that the ethanolic extract of Annona muricata induced apoptosis in the myelogenous leukemic K562 cell line. This supports the therapeutic application of Annona muricata to be considered as a natural product source for the development of pro-apoptotic drugs