Identification of cryptolepine metabolites in rat and human hepatocytes and metabolism and pharmacokinetics of cryptolepine in Sprague Dawley rats

BMC Pharmacology and Toxicology

Werner Gertsch¹  Amanda Cirello¹  Arnold Donkor Forkuo²  Charles Ansah²  David Pearson³  Caroline Rynn⁴  Adam Amaral⁵  Jaimie Spear⁵  Colin W. Wright⁶ 

[1] Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research;Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Science, College of Health Sciences Kwame Nkrumah University of Science and Technology;Drug Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research;Metabolism and Pharmacokinetics, Novartis Institute for BioMedical Research;Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research;School of Pharmacy, University of Bradford;

关键词: Cryptolepine;    Cryptolepis sanguinolenta;    Metabolism;    Pharmacokinetics;    Metabolite identification;   

DOI  :  10.1186/s40360-017-0188-8

来源: DOAJ

【 摘 要 】

Abstract Background This study aims at characterizing the in vitro metabolism of cryptolepine using human and rat hepatocytes, identifying metabolites in rat plasma and urine after a single cryptolepine dose, and evaluating the single-dose oral and intravenous pharmacokinetics of cryptolepine in male Sprague Dawley (SD) rats. Methods The in vitro metabolic profiles of cryptolepine were determined by LC-MS/MS following incubation with rat and human hepatocytes. The in vivo metabolic profile of cryptolepine was determined in plasma and urine samples from Sprague Dawley rats following single-dose oral administration of cryptolepine. Pharmacokinetic parameters of cryptolepine were determined in plasma and urine from Sprague Dawley rats after single-dose intravenous and oral administration. Results Nine metabolites were identified in human and rat hepatocytes, resulting from metabolic pathways involving oxidation (M2-M9) and glucuronidation (M1, M2, M4, M8, M9). All human metabolites were found in rat hepatocyte incubations except glucuronide M1. Several metabolites (M2, M6, M9) were also identified in the urine and plasma of rats following oral administration of cryptolepine. Unchanged cryptolepine detected in urine was negligible. The Pharmacokinetic profile of cryptolepine showed a very high plasma clearance and volume of distribution (Vss) resulting in a moderate average plasma half-life of 4.5 h. Oral absorption was fast and plasma exposure and oral bioavailability were low. Conclusions Cryptolepine metabolism is similar in rat and human in vitro with the exception of direct glucuronidation in human. Clearance in rat and human is likely to include a significant metabolic contribution, with proposed primary human metabolism pathways hydroxylation, dihydrodiol formation and glucuronidation. Cryptolepine showed extensive distribution with a moderate half-life.

【 授权许可】

Unknown