Abstract
Medicinal plants are a rich source of active phytochemicals and have been in use in ethnomedicine. This study investigates the anti-proliferative activity of ethyl acetate leaf extract of Annona muricata L. on selected carcinoma human cell lines of MCF 7, HT 29, HT 116 and C4-2WT. MTT (3- (4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, methylene blue, Trypan Blue exclusion assay and wound or scratch assays were carried out to evaluate, in vitro, the cytotoxicity potential of the ethyl acetate leaf extract of Annona muricata L. Results showed that anti-proliferation activity increased with increase in the concentration of the extract used. The minimum concentration of the extract required for 50% inhibition (GI50) of the different cell lines calculated after MTT test were as follows: MCF-7 = 2.61 ?æg/ml, C4-2WT = 9.33 ?æg/ml, HCT 29 = 4.97 ?æg/ml and HCT 116 =2.13 ?æg/ml. There was a significant reduction (p<0.05), using the methylene blue assay, in the total number of viable cells when their optical densities were measured at 24 hrs, 48 hrs and 72 hrs. Trypan Blue exclusion assay showed a significant reduction (p<0.05) in the total count of viable cells and a significant increase (p<0.05) in the total count of non-viable cells over 72 h post-treatment with the extract. Photomicrographs of scratch assay obtained after 48 h using MCF 7 as the experimental model showed an increase in cell proliferation and wound healing up to approximately 100% confluence in control cultures not treated with the extract. However, cells treated with GI50 of the extract showed non-proliferation, expansion and deterioration of the wound or gap created by the scratch. Conclusively, there was linearity in the relationship between different concentrations of the extract used and the anti-proliferative activity of the extract.
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