Anticancer and cytotoxic effects for Agave americana versus Agave micrantha extracts on human colon cancer cells in vitro

Colon cancer represents a huge health problem to the patients due to the high incidence and mortality rates. This study was focused on investigating the anticancer effects of methanolic extracts of the aerial parts of Agave americana and Agave micrantha. Then, the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay was done to study the cytotoxic activities of these extracts in vitro on cell line HCT 116 that is of a human colon cancer origin. In addition, cytotoxicity was studied in the normal human epithelial cell line RPE1. Additionally, the morphological changes of HCT 116 cells upon exposure to these plant extracts were studied using the inverted microscope. Results showed a significant antiproliferative and anticancer activities of Agave Americana extract at concentrations 12.5, 25 and 50 and 100 µg/ml with IC50 of 73.7 µg/ml. Exposure of HCT 116 cells to this plant extract resulted in more altered cell shapes from polygonal to circular with cell shrinkage. Conversely, the extract of Agave micrantha did not exert any significant cytotoxic effects or morphological changes on HCT 116 cells. In addition, both extracts did not show cytotoxicity in normal RPE1 cells. Extract of Agave Americana is recommended for further anticancer investigations that might result in isolation and development of effective anticancer drug.