Combinational therapy of cervical cancer consisting of probiotic particles and vincristine: a molecular in vitro study.

Cervical cancer remains a major global health concern and ranks among the leading causes of cancer-related mortality in women. Although Vincristine Sulfate is a clinically established chemotherapeutic agent with potent anti-mitotic activity, its therapeutic utility is often restricted by dose-dependent toxicities and off-target effects. Recent evidence suggests that probiotics such as Lactobacillus fermentum may possess anti-tumor properties and could enhance the efficacy of conventional therapies. This study was designed to investigate whether co-administration of Lactobacillus fermentum could potentiate the anti-cancer effects of Vincristine Sulfate in HeLa cervical cancer cells, potentially allowing for a reduction in the effective chemotherapeutic dose. Lactobacillus fermentum was isolated from traditional dairy products and identified via molecular techniques. HeLa cells were treated with L. fermentum, Vincristine Sulfate, or a combination of both. Cell viability was assessed using the MTT assay, while apoptosis was quantified through Annexin V-FITC/PI staining and flow cytometry. Quantitative real-time PCR was employed to evaluate the expression of genes involved in apoptosis and the PI3K/AKT/mTOR signaling pathway. To evaluate the safety of bacterial treatment, L. fermentum was also tested on normal human umbilical vein endothelial cells (HUVECs) using the MTT assay. The half-maximal inhibitory concentrations (IC₅₀) were established at OD₆₀₀ = 0.5 (10 µL/mL) for L. fermentum and 10 µg/mL for Vincristine Sulfate in HeLa cells. Monotherapy with either agent led to a moderate reduction in cancer cell viability. However, the combination treatment (1 µg/mL Vincristine Sulfate + 10 µL/mL L. fermentum) significantly enhanced cytotoxicity, inducing a more profound decrease in cell viability and a marked increase in apoptotic cell populations. Gene expression analysis revealed upregulation of pro-apoptotic genes (PTEN, BAX, Caspase-3, -8, -9, Fas, IκB) and downregulation of survival-related genes (AKT, Bcl-2, mTOR) in the combination group compared to monotherapies. Importantly, L. fermentum had no significant cytotoxic effects on HUVECs, indicating selective targeting of cancer cells. Co-treatment with Lactobacillus fermentum and Vincristine Sulfate demonstrated a synergistic effect in HeLa cells, enhancing apoptosis and suppressing oncogenic signaling pathways, while enabling a tenfold reduction in Vincristine dosage. The lack of cytotoxicity in normal endothelial cells further underscores the therapeutic potential of this approach. These findings support the incorporation of probiotic-based adjuvants in cancer therapy to improve efficacy and reduce adverse effects. Future in vivo studies and clinical trials are warranted to validate the translational potential of this combinatorial strategy in cervical cancer management.