Effects of Postbiotics from Food Probiotic and Protective Cultures on Proliferation and Apoptosis in HCT-116 Colorectal Cancer Cells

Background and Objective: Postbiotics are microbial-derived soluble products, which are released during the growth and fermentation process of beneficial microorganisms in gastrointestinal tract, food and complex microbiological culture systems (cell-free supernatant or extracellular extract) or after cell lysis (intracellular extract). Colorectal cancer is one of the most common cancers within the leading causes of cancer mortality worldwide, which can be associated with a defeated gastrointestinal barrier. In this study, potential functionality of the extracellular and intracellular extracts of probiotics (Latilactobacillus sakei, LS) and protective culture (FreshQ6®, FQ) on proliferation and cell survival of HCT-116 colon cancer epithelial cells was investigated. Material and Methods: Probiotic bacteria were cultivated in de Man, Rogosa and Sharpe broth and then postbiotics was isolated by centrifugation and sonication. The achieved solutions were lyophilized and stored until use. Moreover, HCT-116 cells were exposed to various concentrations of Latilactobacillus sakei and FreshQ6® extracts (1.25-40 mg ml-1) for 24 h and then effects of these products on cell cytotoxicity, proliferation and apoptosis were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound healing and AO/EB assays. Results and Conclusion: Extracellular and intracellular extracts of Latilactobacillus sakei and FreshQ the decreased in cell viability based on the postbiotic concentrations (p≤0.05), while cell proliferation was inhibited by extracellular and intracellular extracts of Latilactobacillus sakei and FreshQ6® in wound healing assay. Results showed that postbiotics could induce apoptosis evidenced by acridine orange/ethidium bromide staining. In summary, Latilactobacillus sakei and FreshQ6® postbiotics are able to decrease cell viability and proliferation and enhance apoptosis in HCT-116 colorectal cancer cells. In addition, FreshQ^® postbiotics seemed more potent than that Latilactobacillus sakei postbiotics did.