Antiproliferative effect of Lactobacillus casei and Lactobacillus fermentum cell-free supernatants on colonic cancer cell line

Cell-free supernatants of two probiotics namely Lactobacillus casei and Lactobacillus fermentum were assessed for their antiproliferative and antitumor activity on human colon cancer CaCo2 and normal NCM425 cell lines. MTT 3-(4,5- Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay was used to detect cytotoxic activity and cell viability. Our results indicated that both supernatants exhibited cytotoxic activities and their impact was in a dose-dependent manner. The results also showed that the supernatants were less toxic to normal cells. Lactobacillus casei cell-free supernatant (LcCFS) was more cytotoxic on cancer cells than Lactobacillus fermentum cell-free supernatant (LfCFS) at higher concentrations. However, no significant differences were observed between the impact of LcCFS and LfCFS on the NCM425 cell line. In conclusion, cell-free supernatants of Lactobacillus casei and Lactobacillus fermentum could be good candidates for cancer treatment and control.