Related Experiment Video
Updated: Mar 20, 2026

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures
Published on: March 28, 2017
Interaction effects on cytochrome P450 both in vitro and in vivo studies by two major bioactive xanthones from
Ru Feng1, Xiang-Shan Tan1, Bao-Ying Wen1
1State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing, China.
Abstract:
The major components, 1-hydroxy-2,3,5-trimethoxy-xanthone (HM-1) and 1,5-dihydroxy-2,3-dimethoxy-xanthone (HM-5) isolated from Halenia elliptica D. Don (Gentianaceae), could cause vasodilatation in rat coronary artery with different mechanisms. In this work, high-performance liquid chromatography coupled to ion trap time-of-flight mass spectrometry (LCMS-IT-TOF) was used to clarify the metabolic pathways, and CYP450 isoform involvement of HM-1 and HM-5 were also studied in rat. At the same time, in vivo inhibition effects of HM-1 and ethyl acetate extracts from origin herb were studied. Three metabolites of HM-5 were found in rat liver microsomes (RLMs); demethylation and hydroxylation were the major phase I metabolic reactions for HM-5. Multiple CYP450s were involved in metabolism of HM-1 and HM-5. The inhibition study showed that HM-5 inhibited Cyp1a2, 2c6 and 2d2 in RLMs. HM-1 inhibited activities of Cyp1a2, Cyp2c6 and Cyp3a2. In vivo experiment demonstrated that both HM-1 and ethyl acetate extracts could inhibit Cyp3a2 in rats. In conclusion, the metabolism of xanthones from the origin herb involved multiple CYP450 isoforms; in vitro, metabolism of HM-5 was similar to that of its parent drug HM-1, but their inhibition effects upon CYP450s were different; in vivo, Cyp3a2 could be inhibited by HM-1 and ethyl acetate extracts.
More Related Videos
08:03Unveiling Xenobiotic Transport and Effects in Isolated Mitochondria: Insights from Respirometric and Enzymatic Assays
Published on: March 7, 2025
09:33Formation of Covalent DNA Adducts by Enzymatically Activated Carcinogens and Drugs In Vitro and Their Determination by 32P-postlabeling
Published on: March 20, 2018
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Drug Metabolism: Phase I Reactions
Pharmacokinetics: Drug–Drug Interactions
Factors Affecting Drug Biotransformation: Biological
Species differences: Variations in enzyme systems across species can cause disparities in drug metabolism. For instance, humans may metabolize certain drugs faster than rodents, altering therapeutic effects.
Strain differences: Genetic variations within a species can result in differing enzyme activity, impacting drug response and toxicity. For example, some mouse strains may...
Drug toxicity: Idiosyncratic Reactions
Bioactivation and Tissue Toxicity