Analysis of Antigenotoxicity of Lactobacillus Salivarius by High Performance Liquid Chromatography

High performance liquid chromatography (HPLC) was used to determine the antigenotoxic activity of Lactobacillus salivarius (L. salivarius) and was compared with the traditional SOS-chromotest assay. After co-incubation of L. salivarius FDB89 with 4-Nitroquinoline-N-oxide (4-NQO) (20 mg l−1) for 3 hours, SOS-chromotest assay was carried out to test the antigenotoxicity of L. salivarius FDB89. Simultaneously HPLC assay was used to determine the quantitative change of 4-NQO before and after co-incubation with L. salivarius FDB89. HPLC assay was performed on a reversed phase C18 column with UV detection at 365 nm and the flow rate was 1.0 ml min−1. HPLC results clearly show that the toxic 4-NQO is converted to less toxic compounds and therefore its genotoxicity is inhibited. The genotoxicity measured by SOS-chromotest and HPLC methods were positively correlated, with a square correlation coefficient (R2) of 0.991. Under the above conditions, instrument detection limits were 1.2 ng. The recovery of 4-NQO was 85%–98% when the cell densities were in the range of 106–109 cfu ml−1. The results suggest that the HPLC method can be a useful alternative to SOS-chromotest assay in detecting the antigenotoxicity of lactobacillus, in being more sensitive and accurate than the latter.