The effect of Colchicum pusillum in human colon cancer cells via Wnt/β-catenin pathway.

Colchicum pusillum belongs to the family Colchicaceae that particularly rich in tropolonic alkaloids. The aim of this study was to investigate the cytotoxicity and in vitro anticancer activity of Colchicum pusillum ethanolic extract on Colo-320 primer and Colo-741 metastatic colon adenocarcinoma cell lines. Colchicum pusillum was collected and extracted with ethanol. Different concentrations of Colchicum pusillum extract were incubated for 24 h and 48 h with Colo-320 and Colo-741 cells. Cell growth and cytotoxicity were measured by 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT) assays. Anticancer and antiproliferative activities of Colchicum pusillum were investigated by immunocytochemistry using antibodies directed against to β-catenin, Ki-67, LGR-5 Ki-67, DKK1, Frizzled-4, Wnt4, Wnt7a and caspase3 in Colo-741 cells. All concentrations of Colchicum pusillum extract had toxic effect in Colo-320 cells. Because of this, we used Colchicum pusillum extract at 20 μg/ml for evaluate anticancer activities only in Colo-741 cells. As a result of immunohistochemical staining, β-catenin, LGR-5 and caspase-3 immunoreactivities were significantly increased while Wnt7a immunostaining intensity was decreased in Colo-741 cells. Conclusion We conclude that Colchicum pusillum extract increased β-catenin and LGR-5 via Wnt/β-catenin pathway in colon cancer cells. Interestingly, it decreased other signaling molecule, Wnt7a which is assumed to play protective role during carcinogenesis. Also, it increased significantly caspase-3 immunoreactivity showing that apoptotic pathways were triggered.