Lactiplantibacillus plantarum exerts anticancer effects and increase the chemosensitivity of 5-fluorouracil against oral cancer cells in vitro.

Introduction: Probiotics are used to provide health benefits and can improve the immune response. They can also target cancer cells directly with anticancer effects through various mechanisms. In this study, Lactiplantibacillus plantarum (basonym: Lactobacillus plantarum) strain MCC 3016 and its postbiotic metabolites/cell free supernatant (CFS) were used against Cal27 oral cancer cells in vitro.

Methods: Standard assays were employed to investigate the effect of Lpb. plantarum on cell viability, proliferation, migration, and clonogenicity of Cal27 cells. The mechanism of action was assessed by measuring the levels of reactive oxygen species (ROS), interleukins (IL)-6 and IL-8, tumor necrosis factor-α (TNF-α), as well as the expression of Ki67, vascular endothelial growth factor (VEGF), p53 and caspase-3. Further, the effect of Lpb. plantarum and its CFS on the cytotoxicity of chemotherapy drug 5-fluorouracil (5-FU) was evaluated using cell viability assays.

Results: Cal27 cells treated with Lpb. plantarum and its CFS showed a significant decrease (P < 0.01) in cell viability, proliferation, migration, and clonogenicity, along with increased levels of ROS and induced apoptosis. It significantly reduced IL-6, IL-8, TNF-α, and VEGF levels and upregulated p53 and caspase-3 expression. The postbiotic metabolites also showed similar effects on Cal27 cells. Furthermore, the cytotoxic effect of 5-FU on Cal27 cells was enhanced by Lpb. plantarum and its CFS treatment.

Conclusion: Lpb. plantarum MCC 3016 and its postbiotic metabolites exhibited promising anticancer effects on oral cancer cells and improved drug efficacy, demonstrating their potential therapeutic value in oral cancer therapy.