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In this study, we investigated whether rutaecarpine could aggravate acetaminophen-induced acute liver damage in vivo and in vitro. CCK-8 and apoptosis assays were performed to verify the cytotoxicity of acetaminophen to L02 cells with or without rutaecarpine. The expression levels of the target proteins and genes were determined using Western blotting and qRT-PCR. The liver pathological changes were evaluated with hematoxylin and eosin staining, while the aspartate aminotransferase (AST) and alanine aminotransferase (AST) levels in plasma were measured to assess the liver damage. Our results revealed that pretreatment of the cell and mice with rutaecarpine significantly aggravated the acetaminophen-induced liver damage. Mechanistically, rutaecarpine induces the CYP1A2 protein, which accelerates the metabolism of acetaminophen to produce a toxic intermediate, N-acetyl-p-benzoquinone imine (NAPQI), leading to severe liver inflammation. Rutaecarpine exacerbated the liver damage by upregulating CYP1A2 and proinflammatory factors. These findings highlight the importance of carefully considering the dosage of rutaecarpine when combined with acetaminophen in drug design and preclinical trials. [ABSTRACT FROM AUTHOR]

Although the functions of metabolic enzymes and nuclear receptors in controlling physiological homeostasis have been established, their crosstalk in modulating metabolic disease has not been explored. Genetic ablation of the xenobiotic-metabolizing cytochrome P450 enzyme CYP2E1 in mice markedly induced adipose browning and increased energy expenditure to improve obesity. CYP2E1 deficiency activated the expression of hepatic peroxisome proliferator-activated receptor alpha (PPAR α ) target genes, including fibroblast growth factor (FGF) 21, that upon release from the liver, enhanced adipose browning and energy expenditure to decrease obesity. Nineteen metabolites were increased in Cyp2e1 -null mice as revealed by global untargeted metabolomics, among which four compounds, lysophosphatidylcholine and three polyunsaturated fatty acids were found to be directly metabolized by CYP2E1 and to serve as PPAR α agonists, thus explaining how CYP2E1 deficiency causes hepatic PPAR α activation through increasing cellular levels of endogenous PPAR α agonists. Translationally, a CYP2E1 inhibitor was found to activate the PPAR α -FGF21-beige adipose axis and decrease obesity in wild-type mice, but not in liver-specific Ppara -null mice. The present results establish a metabolic crosstalk between PPAR α and CYP2E1 that supports the potential for a novel anti-obesity strategy of activating adipose tissue browning by targeting the CYP2E1 to modulate endogenous metabolites beyond its canonical role in xenobiotic-metabolism., (© 2022 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.)

PT2385 is a first-in-class, selective small-molecule inhibitor of hypoxia-inducible factor-2 α (HIF-2 α ) developed for the treatment of advanced clear cell renal cell carcinoma. Preclinical results demonstrated that PT2385 has potent antitumor efficacy in mouse xenograft models of kidney cancer. It also has activity toward metabolic disease in a mouse model. However, no metabolism data are currently publically available. It is of great importance to characterize the metabolism of PT2385 and identify its effect on systemic homeostasis in mice. High-resolution mass spectrometry-based metabolomics was performed to profile the biotransformation of PT2385 and PT2385-induced changes in endogenous metabolites. Liver microsomes and recombinant drug-metabolizing enzymes were used to determine the mechanism of PT2385 metabolism. Real-time polymerase chain reaction analysis was employed to investigate the reason for the PT2385-induced bile acid dysregulation. A total of 12 metabolites of PT2385 was characterized, generated from hydroxylation (M1, M2), dihydroxylation and desaturation (M3, M4), oxidative-defluorination (M7), glucuronidation (M8), N -acetylcysteine conjugation (M9), and secondary methylation (M5, M6) and glucuronidation (M10, M11, and M12). CYP2C19 was the major contributor to the formation of M1, M2, and M7, UGT2B17 to M8, and UGT1A1/3 to M10-M12. The bile acid metabolites taurocholic acid and tauro- β -muricholic acid were elevated in serum and liver of mice after PT2385 treatment. Gene expression analysis further revealed that intestinal HIF-2 α inhibition by PT2385 treatment upregulated the hepatic expression of CYP7A1, the rate-limiting enzyme in bile acid synthesis. This study provides metabolic data and an important reference basis for the safety evaluation and rational clinical application of PT2385., (U.S. Government work not protected by U.S. copyright.)

Objective: To study the chemical constituents of ethyl acetate-soluble fraction from methanolic extract of the roots and rhizomes of Notopterygium incisum ., Method: The chemical constituents were isolated and purified by various chromatographic methods, and their structures were identified by NMR and MS data analysis., Result: Five compounds were obtained and identified as falcarindiol (1), 8-hydroxy-l-methoxy-( Z) -9-heptadecene-4, 6-diyn-3-one (2) angenomalin (3), scopoletin (4), O-methylnotopterol (5)., Conclusion: Compound 5 was a new natural product and compounds 2-4 were isolated from the roots and rhizomes of N. incisum for the first time.