Antigenotoxicity and Cytotoxic Potentials of Metabiotics Extracted from Isolated Probiotic, Lactobacillus rhamnosus MD 14 on Caco-2 and HT-29 Human Colon Cancer Cells.

Probiotics, the beneficial bacteria produce active metabolites which could probably mimic their anticancer effect and prevent the risk associated with live bacteria. Thus, the study was designed to isolate effective lactic acid bacteria (LAB) and monitor anticancerous potential of their metabiotic extracts. Probiotics were isolated from different sources and their cell free supernatants (CFS) were screened for antigenotoxic and cytotoxic potentials using SOS Chromo Test and MTT assay on Caco-2 and HT-29 cells. Organic extracts of CFS were prepared and dissolved in different solvents. The isolate with most effective metabiotic extract in terms of cytotoxicity was classified for probiotic and phylogenetic characters and the metabiotic extract was characterized physiochemically. Among 60 isolated LAB, CFS of only 10 isolates showed antigenotoxicity more than 30% and four exhibited 70-80% cytotoxicity. Further, organic extracts of these four CFS dissolved in carboxymethyl cellulose showed 80-90% cytotoxicity. Interestingly, the most effective isolate was found to possess probiotic attributes and phylogenetic characterization revealed it to be Lactobacillus rhamnosus MD 14. Physiochemical characterization of its metabiotic extract indicated the presence of heat sensitive organic acids and proteins. To conclude, metabiotics produced by isolated probiotic L. rhamnosus MD 14 exhibited both antigenotoxic and cytotoxic potential against colon cancer.