Assessing Drug-Induced Mitochondrial Toxicity in Cardiomyocytes: Implications for Preclinical Cardiac Safety Evaluation

Drug-induced cardiotoxicity not only leads to the attrition of drugs during development, but also contributes to the high morbidity and mortality rates of cardiovascular diseases. Comprehensive testing for proarrhythmic risks of drugs has been applied in preclinical cardiac safety assessment for over 15 years. However, other mechanisms of cardiac toxicity have not received such attention. Of them, mitochondrial impairment is a common form of cardiotoxicity and is known to account for over half of cardiovascular adverse-event-related black box warnings imposed by the U.S. Food and Drug Administration. Although it has been studied in great depth, mitochondrial toxicity assessment has not yet been incorporated into routine safety tests for cardiotoxicity at the preclinical stage. This review discusses the main characteristics of mitochondria in cardiomyocytes, drug-induced mitochondrial toxicities, and high-throughput screening strategies for cardiomyocytes, as well as their proposed integration into preclinical safety pharmacology. We emphasize the advantages of using adult human primary cardiomyocytes for the evaluation of mitochondrial morphology and function, and the need for a novel cardiac safety testing platform integrating mitochondrial toxicity and proarrhythmic risk assessments in cardiac safety evaluation.

Synthesis, 3D-pharmacophore modelling and 2D-QSAR study of new pyridine-3-carbonitriles as vasorelaxant active agents

A new set of pyridine-3-carbonitriles (3a–v) conjugated with various five-membered ring systems at pyridinyl C-6 were designed and synthesized as vasorelaxant active agents.

An HPLC method for the determination of a novel anti-hypertension agent 6,7-dimethoxy-3-(4-(4-fluorobenzyloxy)-3-methoxyphenylmethyl)quinazolin-4(3H)-one in rat plasma: application to pharmacokinetic study

6,7-dimethoxy-3-(4-(4-fluorobenzyloxy)-3-methoxyphenylmethyl) quinazolin-4(3H)-one (DFMQ-19), a novel analogue of 3-benzylquinazolin-4(3H)-ones, may be considered as a drug candidate for the treatment of hypertension. The aim of this study was to develop and validate a reverse-phase high-performance liquid chromatography to determine the DFMQ-19 in plasma and demonstrate its application in pharmacokinetic study. Separation of DFMQ-19 and I.S (structural analog of DFMQ-19) was performed using Shim-Pack VP-ODS column and a mixture of acetonitrile and water as mobile phase. The HPLC method was validated according to the ICH guidelines. The limit of detection and lower limit of quantitation were 0.05 µg/ml and 0.1 µg/ml respectively. The recovery rate of DFMQ-19 from blood samples was >81% of the spiked amount. The RSD of the intra- and inter-day precisions was within 7.5%, and RE of accuracy was between -14.4% and 4.5%. This method was successfully applied to the pharmacokinetic study after administration of DFMQ-19. The pharmacokinetic parameters, such as half-life (t_1/2 ), mean residence time (MRT), maximum concentration (C_max ) were determined. Based on these pharmacokinetic parameters, the oral bioavailability of DFMQ-19 was calculated to be 13.42% in rat. This article is protected by copyright. All rights reserved.

HIGHLIGHTS

HPLC method was validated to quantify DFMQ-19 in rat plasma I.S is one of the structural analogs of the analyte The HPLC method was validated according to the ICH guidelines The oral bioavailability of DFMQ-19 was 13.42% in rat.