Toxicity comparison of raw and vinegar-processed Bupleuri Radix based on ~1H-NMR metabolomics

Abstract

This study compared the toxicity of raw Bupleuri Radix(BR) and vinegar-processed Bupleuri Radix(VPBR) based on proton nuclear magnetic resonance(~1H-NMR), and explored the mechanism of toxicity. Thirty-two male Sprague-Dawley(SD) rats were randomly divided into four groups: a control group(distilled water), a raw BR group(15 g·kg~(-1)·d~(-1)), a rice VPBR(R-VPBR) group(15 g·kg~(-1)·d~(-1)), and a shanxi VPBR(S-VPBR) group(15 g·kg~(-1)·d~(-1)). After administration for 30 d, pathological sections were treated and observed, and biochemical indexes related to liver and renal function were determined. The serum, liver, and kidney of rats were collected and analyzed by ~1H-NMR. The principal component analysis(PCA) and orthogonal partial least squares-discrimination analysis(OPLS-DA) were performed. The results showed that, as compared with the control group, alanine aminotransferase(ALT), aspartate aminotransferase(AST), and alkaline phosphatase(ALP) in the raw BR group were increased significantly, while ALT and ALP in the R-VPBR and S-VPBR groups were significantly decreased(P<0.05), which indicated that BR showed certain hepatotoxicity, and vinegar processing reduced its hepatotoxicity. No significant difference of blood urea nitrogen(BUN) and creatinine(CREA), the biochemical indexes related to renal function, was observed in the control group and administration groups, indicating that BR had less effect on the renal function. The results of multivariate statistical analysis showed that the biomarkers of BR affecting liver metabolism were methionine, glutamine, and glutamic acid, and affecting kidney metabolism were taurine, ornithine, and inosine. These biomarkers were mainly involved in amino acid metabolism, energy metabolism, lipid metabolism, and taurine metabolism. VPBR alleviated the effect on the biomarkers, and S-VPBR had smaller effect than R-VPBR. Combining the results of biochemical indexes and metabolomics analysis, both raw BR and VPBR showed toxic effect on rats, whereas vinegar processing reduced its toxicity. S-VPBR has smaller effect on kidney and liver metabolism than R-VPBR, which indicates that the vinegar used for processing has certain effect on the toxicity of BR.