Isolation of probiotic bacteria from the vagina and invsetigation of their anticarcinogenic effects

In healthy women, the vaginal microbiota is dominated by lactobacilli and these bacteria provide balance of vaginal microbiota. Recently, studies on the anticancer activity of lactic acid bacteria have been focused. In this study, examining probiotic properties of lactic acid bacteria isolated from vagina of healthy woman, aims to investigate the anticancer activity of selected lactic acid bacteria. Microorganisms (326 bacteria and 18 yeast) were isolated from vagina of healthy women (20-40 ages). Lactic acid bacteria, other bacteria and yeast isolated from vagina were identified with API CHL-50, VITEK II, 16s rRNA seguence analysis and MALDI-TOF Mass Spectrometry Techniques. Performing antibiotic susceptibilities, antimicrobial activities, autoaggregation, coaggregation, hydrofobicity assays, acid and bile salt resistivity, hydrogen peroxide, lactic acid and proteolytic quantitations of identified lactic acid bacteria have been determined probiotic properties of these bacteria. Two isolates were choosen from identified bacteria that have high production rate of hydrogen peroxide and lactic acid. Exopolysaccharides were obtained from these bacteria. Afterwards, cytotoxic effects of exopolysaccharides of two lactic acid bacteria (Enterococcus faecalis 3M2 and Enterococcus faecalis 8M10) were studied on HeLa cells (servix carcinoma cells) and HUVEC cells (human umbilical vein endothelial cells) by MTT Assay (tetrazolium assay). To determine this cytotoxic effect, exopolysaccharides of these bacteria were applied on HeLa cells and HUVEC cells at different concentrations (20mg/mL, 15mg/mL, 10mg/mL, 7,5mg/mL, 5mg/mL and 2,5mg/mL). In this study, we determined these exopolysaccharides of two bacteria exerted different effects on cell viability depending on dose. Data from obtained statistical results revealed that maximum dose of exopolysaccharide of Enterococcus faecalis 3M2 (20mg/mL) were the most efficient bacteria on HeLa cell viability at 24h incubation. Keywords: Exopolysaccharide, HeLa cells, lactic acid bacteria, MTT assay, vaginal flora.