Ethyl Acetate Extract of Senna alata (L) Roxb Increases Cytotoxicity in the Human Breast, Prostate and Colorectal Cancer Cells

Abstract

The objective of this study is to evaluate the effects of ethyl acetate extract of Senna alata (L) Roxb on some human carcinomas-MCF 7 (human breast), C4-2WT (prostate), HT 29 and HTC 116 (colorectal) cell lines. Screening assays carried out to determine cytotoxicity include:-MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), clonogenic cell survival, Trypan Blue exclusion and methylene blue assays. Evaluation of the results showed that the extract strongly decreased the proliferation of the carcinoma cells in a dose-dependent manner. The minimum concentration of the extract required for 50% inhibition (GI 50) of the different cell lines calculated after MTT test were as follows: MCF-7 = 5.90 µg/ml, HCT 29 = 4.97 µg/ml, HCT 116 =11.86 µg/ml and C4-2WT = 9.48 µg/ml. Trypan Blue exclusion assay showed a decrease in the number of viable cells and an increase in the number of non-viable cells over 72 hrs post-treatment with the extract. Methylene blue assay showed that the number of viable cells, when their optical densities were measured over 72 hrs post-treatment, was reduced compared with the control. For clonogenic cell survival, there was an increase in cell proliferation and colony formation in the control cultures. However, cells treated with GI 50 and 2X (twice) GI 50 concentration of the extract showed a decrease in the number of colonies formed. The results indicate the cytotoxic potentials of the extract and therefore, suggests the use of ethyl acetate leaf extract of Senna alata (L) Roxb in preparing recipes for the management of cancer-related ailments.