Probiotics have been evaluated as therapeutic agents for cancer treatment in an increasing number of studies. This study investigated the inhibitory and cytotoxic effects of specific Lactobacillus strains on a human colorectal adenocarcinoma cell line (HT-29). The strains assessed were Limosilactobacillus (L.) reuteri VA 102, Ligilactobacillus (L.) animalis VA 105, and Limosilactobacillus (L.) reuteri KCTC 3594 (ATCC 23272). The viability of HT-29 cells was evaluated using the MTT assay. The findings revealed that cell-free supernatants (CFS) exhibited significant anticancer effects. Heat-inactivated L. reuteri VA 105 and L. reuteri KCTC 3594 induced a pronounced reduction in cell viability. Furthermore, live cultures of L. reuteri VA 105 and L. reuteri VA 102 also showed reduced cell viability compared to the control group. These results suggest that CFS and heat-inactivated cells may be more suitable for therapeutic applications than live bacteria owing to their improved safety profiles and reduced potential for adverse effects. Our findings also emphasize the potential anticancer benefits of these LAB strains.

Backgrounds : The action mechanisms of several chemopreventive agents derived from herbal medicine and edible plants have become attractive issues in cancer research. Tea is the most widely consumed beverage worldwide. It have been demonstrated that the active principles of tea sources such as flower extract Camellia sinensis (CSF) and Camellia japonica (CJF)were attributed to their tea polyphenols. We focused on investigating CSF, CJF, mixtures of CSF and CJF has been proven to suppress colonic tumorigenesis. Methods and Results : In this study, human colorectal carcinoma HT-29 cells were treated with CSF, CJF, mixture of CSF and CJF to examine the anti-proliferative and pro-apoptotic effects of mixture of CSF and CJF (3 : 1), as well as the molecular mechanism underlying these effects. Cell viability assay, nuclear staining, DNA fragmentation, caspase assay, cytochrome c release, were utilized to dissect the signaling pathways. In mixture of CSF and CJF (3 : 1), CSF appeared most anticancer effect by both MTT assays and the cleavage analysis of apoptosis-related molecules and PARP. Interestingly, we found that CJF make it possible to express the apotosis inducing by CSF in a short time and apoptosis effect of CSF maintained sustainable. Conclusion : In summary, our results from this study suggest that in HT-29 human colon cancer cells (i) CSF treatment causes damage to mitochondria, and (ii) CJF contributed CSF induced apoptotic cell death mediates cytochrome C release, (ⅲ) mixture of CSF and CJF (3 : 1) the potential to function as a chemopreventive agent against colon cancer.