A Comprehensive Strategy for Characterizing Metabolites and Metabolic Profile in Rat Urine and Feces Following Oral...

Huachansu (HCS) tablets, prepared from dried toad skin through water decoction and ethanol extraction, possess detoxifying and analgesic effects and are clinically used in the treatment of advanced tumors. However, the in vivo metabolism of HCS tablets has not been systematically investigated. In this study, a comprehensive analysis strategy based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF/MS^E) was established for screening and identifying the prototype components and metabolites of HCS tablets in rat urine and feces. A total of 28 prototype components (16 bufadienolides, six alkaloids, four amino acids and peptides, two nucleosides) and 64 metabolites (44 bufadienolide-related metabolites and 20 alkaloid-related metabolites) were identified in the urine and feces of rats treated with HCS tablets. Based on the analysis of 64 metabolites, the metabolic processes of HCS tablets in rats mainly include desaturation, reduction, dehydroxylation, hydroxylation, hydration, dehydration, glucuronidation, methylation, acetylcysteine conjugation, acetylcysteine-S conjugation, and other related conjugation reactions. This approach enabled the rapid identification of HCS-related exogenous components in rat urine and feces, helping to elucidate the active substances and facilitate mechanistic research.