To reveal the toxic mechanism of Kansui stir-baked with vinegar(VEK), conducta comparative study on the metabolites of fecal samples of rats before and after being treated with chemical constituents group B and C(VEKB/VEKC) extracted from VEK by metabolomics approach. The fecal samples of each group were analyzed using ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry(UFLC-Q-TOF-MS). Then the data was processed by principal component analysis(PCA) and partial least square discriminant analysis(OPLS-DA) to screen and identify biomarkers relating to the toxicity of VEK. Besides, t-test was adopted for univariate statistical analysis, so as to study the changes of these biomarkers in drug groups before and after being treated with VEKB/VEKC and explore the effect of VEKB/VEKC on the metabolism of rat feces. Furthermore, the toxic mechanism of VEKB/VEKC was explored based on the results of the metabolic pathway analysis. The results displayed that compared with control group, the metabolism of fecal samples of VEKB and VEKC treated groups show obvious changes, and the VEKB treated group show more significant changes. A total of 16 potential biomarkers and 5 metabolic pathways relating to the toxicity of VEK were found and identified. And the toxicity of VEK might be associated with the disorder of such metabolic pathways as tryptophan metabolism, primary bile acid biosynthesis, amino sugar and nucleotide sugar metabolism, purine metabolism, and degradation of valine, leucine and isoleucine. This study provides a scientific basis for the clinical safety application of VEK.
Keywords: Kansui stir-baked with vinegar; OPLS-DA; chemical constituents group; fecal metabolomics; metabolic pathway analysis.