Anti-Proliferative Effects of Two New Lactobacillus Strains of Human Origin on Caco-2 Cell Line

Abstract

Background: Anti-proliferative effects of probiotics are considerable in the treatment of various cancers, including colon cancer. In the present study, two new Lactobacillus strains as probiotics were isolated from stool samples at a clinical lab. Objectives: The aim of this study was to evaluate the effects of the cell-free lyophilized filtrate of two new strains of Lactobacillus, isolated on viability on Caco-2 cells. Methods: Two new strains of Lactobacillus were isolated from 1 gr of each infant stool specimens from a total of fifty volunteers, according to the principles of a scientific questionnaire. The anti-proliferative effects of the strains were investigated using the MTT assay with Caco-2 cell lines. Results: Out of 50 samples, seven isolates were lactic acid bacteria, two strains of which were probiotics related to L. fermentum (E) and L. rhamnosus (G). The results showed that the two Lactobacillus strains had good anti-proliferative effects against the cancer cell lines tested. These strains were resistant to low pH and 0.3% bile salt. Cytotoxicity assay revealed that the most effective concentration of strains E (~55% to~72%) and G (~60% to~80%) on Caco-2 cells was 10000 µg/mL after 24 to72 hours. Conclusions: Cytotoxicity effect of the cell-free lyophilized filtrate of bacteria on Caco-2 cells in a dose-and time-dependent manner suggested that these strains might be used in colon cancer therapy.

Chitosan–Sodium Caseinate Composite Edible Film Incorporated with Probiotic Limosilactobacillus fermentum: Physical Properties, Viability, and Antibacterial Properties

“…fermentum for use as probiotics and in the medical field because of their health-promoting effects, such as preventing alcoholic disease and reducing gastrointestinal and upper respiratory tract infections. Its anti-proliferative, immunomodulatory, anti-inflammatory, and antioxidant activities were also reported [ 31 , 32 , 33 ]. Interestingly, the antimicrobial activity of Lb.…”

Anticancer Potential of Post-Fermentation Media and Cell Extracts of Probiotic Strains: An In Vitro Study

“…From the literature data, it is evident that intestinal cells are the most common research model on this topic, due to the fact that probiotics and the products of their metabolism (postbiotics) interact with the intestinal epithelium after reaching the intestines. Many authors have investigated the antiproliferative and cytotoxic activity of LAB postbiotics against colon adenocarcinoma cell lines, such as Caco-2, SW-480, CT26, HRT-18, or HT-29 [ 9 , 10 , 11 , 29 , 30 , 31 , 32 , 33 , 34 ]. The concentrations of the PFM are the most often given as a percentage or mg/mL, less often in µg/mL.…”

“…The concentrations of the PFM are the most often given as a percentage or mg/mL, less often in µg/mL. The range of the tested concentrations is from 0.47% to 100% [ 11 , 35 , 36 , 37 , 38 , 39 ] or from 0.0001 to 1000 mg/mL [ 18 , 29 , 31 , 34 , 40 , 41 ]. In all of the above-mentioned studies, the MTT assay dominates as a tool of antiproliferative activity testing for cancerous cell lines and cytotoxicity assayed to normal cells.…”

“…The antiproliferative effect of PFM of L. casei was at a level ranging from 19% (for a concentration of 5%) to 45% (for a concentration of 20%), according to Soltan Dallal et al [ 43 ], which was similar to our strains of L. casei tested (i.e., 0903, 0924). Two out of seven isolates of LAB had a good antiproliferative effect against Caco-2 cells after 24 h exposure [ 31 ]. For 10% concentration of the PFM of Limosilactobacillus fermentum , the viability of cells decreased by 62.8% after 24 h exposition.…”