Cytotoxic and antimicrobial effects of lactobacillus sakei on human colorectal adenocarcinoma cell line (HT29) and some pathogenic microorganisms

Even after surgery, as the most effective treatment for colorectal cancer, about 30-40% of cases are recurring. Since growth inhibition is an important strategy in cancer treatment, many attempts are in the program to find new agents, so in this study, the cytotoxic and antimicrobial effects of Lactobacillus sakei on colon cancer cell line (HT-29) and some pathogenic microorganisms have been evaluated. Lactobacillus sakei is a probiotic that, when consumed affects the intestinal flora, causes beneficial effects on host health. Probiotics due to their anti-cancer effects, modulation of the differentiation process in tumor cells, changes in tumor gene expression and lack of immunological responses have attracted a lot of attention as a new and effective treatment for colorectal adenocarcinoma.

In the present study, which was conducted experimentally from May to September 2018 in bacteriology and Cellular and Developmental Research Centers of Islamic Azad University, Shahrekord branch, the antimicrobial activity of supernatant of Lactobacillus sakei was assessed by Well Diffusion Agar (WDA) method against some pathogenic bacteria. HT-29 Colorectal adenocarcinoma cancer cells were cultured in DMEM medium with 10% bovine serum. The cells were treated in 5, 15, 10 and 20 mg/ml concentrations of sakei metabolites and incubated at 24, 48 and 72 hours. Cell growth was analyzed by celltiter 96® aqueous one solution cell proliferation assay kit to the manufacturerchr('39')s protocol in all three incubation times.

The results of this study indicate that sakei was able to produce antimicrobial metabolites against pathogenic bacteria. Besides, the results of the celltiter 96® aqueous one solution cell proliferation assay showed that the bioavailability of HT-29 cell lines decreased at all concentrations of sakei metabolites in a dose and time-dependent manner.

Since lactic acid probiotic bacteria can alter the metabolic activities of the intestinal microflora, attach to carcinogens and destroy them, prevent carcinogenesis such as ammonia and secondary bile acids, producing anti-cancer substances and creating an acidic state to inhibit the growth and proliferation of carcinogenic bacteria, It seems that there is a good research field for the use of bioactive compounds produced by Lactobacillus sakei in the control of bacterial pathogens and treatment of human colorectal adenocarcinoma (HT-29).