Xyloketal B, a marine compound, acts on a network of molecular proteins and regulates the activity and expression of rat cytochrome P450 3a: a bioinformatic and animal study

Abstract

Junhui Su,1–3,* Cui Chang,3,* Qi Xiang,1,2 Zhi-Wei Zhou,4 Rong Luo,5 Lun Yang,6 Zhi-Xu He,7 Hongtu Yang,2,3 Jianan Li,1 Yu Bei,1 Jinmei Xu,1,2 Minjing Zhang,1 Qihao Zhang,1 Zhijian Su,1 Yadong Huang,1 Jiyan Pang,5 Shu-Feng Zhou4,7 1Institute of Biomedicine and Guangdong Provincial Key Laboratory of Bioengineering Medicine, 2Department of Pharmacy, Jinan University, Guangzhou, 3The People’s Hospital of Shenzhen City, Shenzhen, People’s Republic of China; 4Department of Pharmaceutical Science, College of Pharmacy, University of South Florida, Tampa, FL, USA; 5School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 6Bio-X Institutes, Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 7Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guiyang Medical University, Guiyang, People’s Republic of China *These two authors contributed equally to this work Abstract: Natural compounds are becoming popular for the treatment of illnesses and health promotion, but the mechanisms of action and safety profiles are often unknown. Xyloketal B (XKB) is a novel marine compound isolated from the mangrove fungus Xylaria sp., with potent antioxidative, neuroprotective, and cardioprotective effects. However, its molecular targets and effects on drug-metabolizing enzymes are unknown. This study aimed to investigate the potential molecular targets of XKB using bioinformatic approaches and to examine the effect of XKB on the expression and activity of rat cytochrome P450 3a (Cyp3a) subfamily members using midazolam as a model probe. DDI-CPI, a server that can predict drug–drug interactions via the chemical–protein interactome, was employed to predict the targets of XKB, and the Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to analyze the pathways of the predicted targets of XKB. Homology modeling was performed using the Discovery Studio program 3.1. The activity and expression of rat hepatic Cyp3a were examined after the rats were treated with XKB at 7 and 14 mg/kg for 8 consecutive days. Rat plasma concentrations of midazolam and its metabolite 1'-OH-midazolam were determined using a validated high-performance liquid chromatographic method. Bioinformatic analysis showed that there were over 324 functional proteins and 61 related signaling pathways that were potentially regulated by XKB. A molecular docking study showed that XKB bound to the active site of human cytochrome P450 3A4 and rat Cyp3a2 homology model via the formation of hydrogen bonds. The in vivo study showed that oral administration of XKB at 14 mg/kg to rats for 8 days significantly increased the area under the plasma concentration-time curve (AUC) of midazolam, with a concomitant decrease in the plasma clearance and AUC ratio of 1'-OH-midazolam over midazolam. Further, oral administration of 14 mg/kg XKB for 8 days markedly reduced the activity and expression of hepatic Cyp3a in rats. Taken together, the results show that XKB could regulate networks of molecular proteins and related signaling pathways and that XKB downregulated hepatic Cyp3a in rats. XKB might cause drug interactions through modulation of the activity and expression of Cyp3a members. More studies are warranted to confirm the mechanisms of action of XKB and to investigate the underlying mechanism for the regulating effect of XKB on Cyp3a subfamily members. Keywords: Xyloketal B, molecular target, cytochrome P450 3A, DDI-CPI tool, DAVID, midazolam, pharmacokinetics, rat, bioinformatics