In vitro genotoxic and antigenotoxic effects of an exopolysaccharide isolated from Lactobacillus salivarius KC27l strain

Exopolysaccharides are macromolecules produced by eukaryotes and prokaryotes. Exopolysaccharide isolated from Lactobacillus salivarius (Ligilactobacillus salivarius) KC27L strain (EPSKC27L) demonstrates antioxidant properties including 1,1-diphenyl-2-picrylhydrazase (DPPH) radical and superoxide anion radical (O2-.) scavenging activity, and iron ion (Fe2+) chelating activity. This is the first study to investigate in vitro genotoxic and antigenotoxic effects of EPSKC27L. EPSKC27L (12.50; 25.00; 50.00 ve 100.00 μg/mL) was applied alone for genotoxicity and simultaneously in combination with mitomycin C (MMC; 0.20 μg/mL), methyl methanesulfonate (MMS; 5.00 μg/mL) and hydrogen peroxide (H2O2; 100 µM) for antigenotoxicity. For this purpose, chromosome aberration (CA), sister chromatid exchange (SCE), micronucleus (MN), and comet assays were performed in human peripheral lymphocytes. The structure of EPSKC27L and changes in cells after EPSKC27L and EPSKC27L + MMC treatments were studied using scanning electron microscopy (SEM). EPSKC27L alone did not cause a significant genotoxic effect in CA, SCE, MN, and comet tests. Treatment of EPSKC27L alone significantly reduced mitotic ındex (MI) at the highest concentration (100 µg/mL) in all treatments, compared to the negative control (distilled water). Treatment of EPSKC27L + MMC significantly decreased CA, SCE, and MN (except 12.50 μg/mL) at all concentrations, compared to positive control (MMC). EPSKC27L, also significantly decreased the frequency of CA, SCE and MN induced by MMS. EPSKC27L, EPSKC27L + MMC ve EPSKC27L + MMS treatments did not significantly affect the replication index (RI) and nuclear division index (NDI). EPSKC27L also significantly reduced DNA damage induced by H2O2. The results of this study show that exopolysaccharide EPSKC27L has no genotoxic activity, but it has antigenotoxic activity against MMC, MMS, and H2O2 mutagens. EPSKC27L and EPSKC27L + MMC treatments did not cause significant changes in lymphocytes and erythrocytes in SEM observations. Consequently, EPS was found to exhibit chemopreventive activity against genotoxic agents. This effect is considered to be due to the strong antioxidant properties of EPS.