Cytotoxic activity and apoptosis induction by supernatant of Lentilactobacillus buchneri on HT-29 colon cancer cells

Colorectal cancer (CRC) is the fourth most commonly diagnosed cancer and the third most deadly cancer in the world. According to recent experimental reports, probiotics and their derivatives protect CRC patients from treatment-related side effects. Therefore, the present study aimed to investigate the cytotoxic impact of the cell-free supernatant (CFS) of Lentilactobacillus buchneri on the HT-29 cancer cell line.

In the current study, we used the L. buchneri CFS, which was well isolated and identified in our previous investigation from traditional yogurt in the Arak region of Iran. The apoptosis induction in HT-29 cancer cells was assessed by cell cytotoxicity, flow cytometry, and qRT-PCR.

L. buchneri CFS inhibited the proliferation of HT-29 cancer cells in a time- and dose-dependent manner. The apoptotic effect of CFS was further supported by the flow cytometry data, which showed that the maximum incidence of apoptosis was observed in HT-29 cancer cells treated with the IC50 concentration of CFS after 72 hours. CFS of L. buchneri also exerted the up-regulating effect on the expression of pro-apoptotic genes including BAX, CASP9, and CASP3. L. buchneri CFS at an IC50 dose induced cell cycle arrest in the G0/G1 phase in HT-29 cells.

This study indicates that L. buchneri CFS can prevent colorectal cancer (CRC) development in patients by inducing cancer cell apoptosis. This finding suggests that the CFS of L. buchneri could be used as a therapeutic agent for the control of CRC.