Investigation of antioxidant activity and immunological properties of promising probiotic cultures in the presence of inuline

Gastrointestinal system (GIS) epitelium cells secrete cytokines which play an important role in systemic and mucosal immunity. Chronic and excess secretion of proinflammatory cytokines leads to oxidative damage related to inflammation that causes inflammatory bowel disease and/or colon cancer. In this study, it has been targeted to determine the relationship between the exopolysaccharide production and antioxidant activity, effect on interleukin (IL)-6 and IL-8 secretion on Caco-2 and CCL-221 cells of 5 strains with the origin of human and food origin those selected from Lactobacillus and Bifidobacterium cultures according to EPS production. It was aimed to select new probiotic strains for clinical and food industry. Of the strains EPS production was observed between 28 ±0,7 mg/L and 155±0,4 mg/L and Lactobacillus delbrueckii subsp. bulgaricus B3 (155±0.4 mg/L) and Bifidobacterium breve A28 (122±0.7 mg/L) has showed the highest EPS production capacity. Inulin effect on viability, EPS and autoaggregation ability has been investigated and determined the inulin has improved these properties. Antioxidant activity has been observed by both spectrophotometric method and using fibroblast cell cultures. All strains showed antioxidant activity with varying values with in relation with the EPS production (p<0,05). Adhesion ability, the prerequisite criteria for selecting new probiotic strains, has been examined in two different colon cancer cell lines and L. delbrueckii subsp. bulgaricus B3 and L. rhamnosus GD11 strains those have high EPS production capacity were found as high adhesive ability. Anticancerogeneic activity was determined with trypan blue exclusion assay. We have found apoptotic like cells in SEM analysis. Immunological properties of strains were examined by determining proinflammatory cytokine levels in Caco-2 and CCl-221 cells stimulated with TNF-alpha. According to datas obtained from this study B3 and A28 strains were stand out with high EPS production capacity, strong autoaggregation ability and antioxidant activity, having anticancerogeneic property and inflammatory suppressive strains.