Abstract:Objective To systematically compare the chemical compositional differences between Puerariae Thomsonii stem base（PTSB） and Puerariae Thomsonii Radix（PTR）， and to explore the potential hepatoprotective effects of PTSB by liver metabolomics.Method Ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS/MS） was used to analyze the chemical compositions of PTSB and PTR. Twenty Kunming mice aged 6-8 weeks， half male and half female， were randomly divided into the blank group（sterile water） and PTSB group（1.95 g·kg-1）， with 10 mice in each group， and the drug was administered by gavage for 14 d， and the body mass was weighed once a day. After the last administration， mice were anesthetized， organs such as heart， liver， spleen， lungs and kidneys were collected， and the organ index was calculated. Enzyme-linked immunosorbent assay（ELISA） was used to measure the levels of aspartate aminotransferase（AST）， alanine aminotransferase（ALT）， total cholesterol（TC） and triglyceride（TG） in the serum of mice from each group， the morphological changes of heart， liver， spleen， lung and kidney tissues were observed by hematoxylin-eosin（HE） staining， and the regulation of PTSB for the hepatic metabolic profiles of mice was analyzed by UPLC-Q-TOF-MS/MS， then the differential metabolites between the blank group and PTSB group were designated， and the metabolic pathways was enriched by Kyoto Encyclopedia of Genes and Genomes（KEGG）.Result A total of 19 common chemical constituents were identified from PTSB and PTR， all of which were the main pharmacodynamic substances of PTR. The pharmacodynamic results showed that PTSB could control the growth of body mass of mice and reduce the contents of TC， TG， ALT and AST in serum of mice. HE staining observations and organ indexes showed that there was no significant effect of PTSB on all major organs at the highest clinically equivalent dose. A total of 38 differential metabolites were identified by metabolomics， of which 35 were up-regulated and 3 were down-regulated. These differential metabolites were mainly compounds such as amino acids， fatty acids， vitamins， steroids， nucleosides， pyrimidines and alkaloids. Three key metabolic pathways， including tyrosine metabolism， vitamin B6 metabolism and tryptophan metabolism， were screened by metabolic pathway analysis.Conclusion PTSB has a similar chemical composition to that of PTR， and it may regulate the metabolism of amino acids and vitamins through the flavonoids and isoflavonoids， thus exerting a potential hepatoprotective effect. This study provides an experimental reference for the clinical application and product development of PTSB.
