Cytotoxic Effect and Cell Death Mechanism of Salmonella Typhimurium Protein Fractions on Breast Cancer Cells In Vitro

Background and purpose: Cancer is the second leading cause of death in the world after cardiovascular disease. In relation to cancerous diseases in developed countries, the prevalence of breast cancer is increasing. Treatment in early stages is of great importance in the recovery of patients. The purpose of this study was to investigate the cytotoxic effect of bacterial fractions of Salmonella typhimurium on growth and proliferation of breast cancer cells in vitro. Materials and methods: In this experimental study, the breast cancer cell line MCF7 was used. Different bacterial fractions were prepared by ammonium sulfate method. Interactions between cancer cells and different concentrations of Salmonella typhimurium fractions were studied at 24 and 48 hours. Cell proliferation was assessed by MTT assay. Results: According to MTT test, bacterial fractions and 80% protein deposition at 24 and 48 hours showed the highest cytotoxicity effect at 24 hours and in 100 μg/ml bacterial lysates and 40 μg/ml of 80% protein deposition. Following the treatment of cancer cells with bacterial lysate, the rate of induction of apoptosis was 67% and necrosis was 7%. Conclusion: Bacterial fractions of Salmonella typhimurium have high toxicity and lethal effect on breast cancer cells and induce apoptosis. Purification of these compounds could reveal new information on the mechanisms of cell death and cell signaling that could be suggested in the future as a basis to develop alternative cancer treatments