Metabolism of dl-praeruptorin a in rat liver microsomes using HPLC-electrospray ionization tandem mass spectrometry

Abstract

dl-Praeruptorin A (Pd-Ia) is the major active constituent of the traditional Chinese medicine Peucedanum praeruptorum Dunn. Recently it has been identified as a novel agent in the treatment and prevention of cardiovascular diseases. Accordingly, we investigated the metabolism of Pd-Ia in rat liver microsomes. The involvement of cytochrome P450 (CYP) and CYP isoforms were identified using a CYP-specific inhibitor (SKF-525A), CYP-selective inhibitors (α-naphthoflavone, metyrapone, fluvastatin, quinidine, disulfiram, ketoconazole and ticlopidine) and CYP-selective inducers (phenobarbital, dexamethasone and β-naphthoflavone). Residual concentrations of the substrate and metabolites were determined by HPLC, and further identified by their mass spectra and chromatographic behavior. These experiments showed that CYP450 is involved in Pd-Ia metabolism, and that the major CYP isoform responsible is CYP3A1/2, which acts in a concentration-dependent manner. Four Pd-Ia metabolites (M1, M2, M3, and M4) were detected after incubation with rat liver microsomes. Hydroxylation was the primary metabolic pathway of Pd-Ia, and possible chemical structures of the metabolites were identified. Further research is now needed to link the metabolism of Pd-Ia to its drug-drug interactions.

Biological Activities and Pharmacokinetics of Praeruptorins fromPeucedanumSpecies: A Systematic Review

“…The polarity of Pd-la metabolites increased after hydroxylation and therefore the metabolites would be excreted easier than Pd-la from the body. The results confirmed that Pd-la metabolism is mediated by CYP3A1/2 and the metabolic changes in Pd-la may happen with other CYP3A inducers and/or inhibitors (drug-drug interactions) [ 75 ]. In a latest study, the kinetics of enzyme action and the main CYP450 isozyme(s) involved in the metabolism of (+)-praeruptorin A were considered in HLMs by a fast, sensitive, and reproducible UHPLC-QT-MS/MS (ultrahigh-performance liquid chromatography coupled with a hybrid quadruple-linear ion trap mass spectrometry) method.…”

Metabolism of the Hepatotoxic Compound Sophoraflavanone G in Rat Liver Microsomes

“…In this study, chemical inhibition was employed to identify specific CYP isoforms responsible for mono‐hydroxylation of SFG in RLMs. Chemical inhibition is a common and simple method for screening CYP isoforms of RLMs (Ruan and others ; Shi and others ), but chemical inhibition combined with other methods including recombinant CYPs, antibody neutralization, and correlation analysis is required in order to obtain accurate results (Yan and Caldwell ) because most chemical inhibitors inhibit more than one CYP isoforms. However, according to previously published reports, furafylline being a selective inhibitor for rat CYP1A2 (Eagling and others ; Kobayashi and others ) and diethyldithiocarbamate being a selective inhibitor for rat CYP2E1 (Liu and others ; Shi and others ), it can initially be considered that CYP1A2 and CYP2E1 played predominant roles in the mono‐hydroxylation of SFG.…”

Comparative pharmacokinetic study of pyranocoumarins and khellactone in normal and acute lung injury rats after oral administration of Peucedanum praeruptorum Dunn extracts using a rapid and sensitive liquid chromatography–tandem mass spectrometry method

“…Pyranocoumarins could be rapidly transported across the intestine via passive diffusion (Jing et al, ), but underwent cytochrome P450 (CYP450) and carboxylesterase (CES)‐mediated hydrolysis (Jing, Song, Yan, & Wang, ). After absorption into the systemic circulation, the oxidation and hydrolysis were two predominant metabolic pathways of these pyranocoumarins, which were mediated by CYP450 isoenzymes in liver microsomes (Ruan et al, ). Notably, considerable CYP3A4‐, CYP2A1‐ and CYP2C8‐mediated hydrolysis or oxidation of pyranocoumarins occurred during incubation with the liver microsome (Jing et al, ).…”

“…Notably, considerable CYP3A4‐, CYP2A1‐ and CYP2C8‐mediated hydrolysis or oxidation of pyranocoumarins occurred during incubation with the liver microsome (Jing et al, ). Among these metabolites, khellactone was the common hydrolysis metabolite of praeruptorin A (Ruan et al, ), praeruptorin B and praeruptorin E (Song, Yan, Jing, Zhao, & Wang, ). Khellactone has long been used as a synthetic precursor to synthesize khellactone derivatives with antitumor, liver protection and anti‐AIDS activity (Jung et al, ; Liu et al, ).…”

“…Inflammation induced by the intraperitoneal injection of LPS could downregulate the expression and function of CYP450s and CES in mice (Moriya, Kataoka, Fujino, Nishikawa, & Kugawa, ; Zhang et al, ), including CYP3A11, CYP 2C29, CYP 2C55, CYP 1A2, CES1 and CES2 (Theken et al, ), which are responsible for the metabolism of the pyranocoumarins in P. praeruptorum Dunn. Previous work largely dealt with the metabolism (Ruan et al, ) and/or pharmacokinetics of the pyranocoumarins, such as praeruptorin A (Zhang, Liang, et al, ; Zhang, Liu, et al, ), praeruptorin B (Song et al, ) after oral administration of pyranocoumarins or P. praeruptorum Dunn extracts in rats by using high‐performance liquid chromatography (HPLC), LC‐mass spectrometry (LC‐MS) or LC time‐of‐flight MS (Ruan et al, ; Song et al, ; Zhou, Chen, & Liu, ). Considering the popular use of P. praeruptorum Dunn in the treatment of inflammatory disorders, it is important to develop a quantification method for the simultaneous determination of pyranocoumarins and khellactone in biological samples, and apply this method in the pharmacokinetic study of pyranocoumarins and khellactone in rats with inflammatory challenges.…”