Investigating the effects of Lactobacillus acidophilus and Lactobacillus paracasei supernatant on cervical cancer cells

Lactic acid bacteria, recognized as probiotics, have garnered significant attention as potential adjuvants in chemotherapy for various cancer types, including cervical cancer. In this study, we investigated the anti-cancer properties of two indigenous Iranian strains, Lactobacillus acidophilus and Lactobacillus paracasei, individually and in combination, targeting human cervical cancer cell lines compared to normal control cells.

The cytotoxic effect of Lactobacillus acidophilus and Lactobacillus paracasei supernatants, as well as their 1:1 mixture, on CaSki and HNCF PI 52 cell lines, was evaluated using the MTT assay. The apoptotic and anti-metastatic effects of these supernatants were assessed by analyzing the gene expression of BAX/BCL2 ratio, Caspase-3, and MMP2/ MMP9 using Real-Time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR).

Significant cytotoxicity was observed in Ca Ski cells attributed to the low pH of the supernatants. The increase in the BAX/BCL2 ratio, leading to an up-regulation of Caspase-3, indicated the induction of apoptosis (P<0.001). In addition, the expression of MMP9 significantly deceased in Ca Ski cells treated with Lactobacillus acidophilus (P<0.001) and Lactobacillus paracasei (P<0.05), while no significant difference in MMP2 expression was observed in all samples compared to the control groups.

while further validation is needed, the heightened expression of apoptotic genes suggests a potential induction of apoptosis in cancer cells in response to Lactobacillus toxicity. The significant down-regulation of the MMP9 gene emphasizes the need for comparative analyses across different cervical cancer cell lines to establish the anti-metastatic potential of these local probiotic supernatants.