Interaction between 3,4‑dichlorophenyl‑propenoyl‑sec.‑butylamine (3,4‑DCPB), an antiepileptic drug, and cytochrome P450 in rat liver microsomes and recombinant human enzymes in vitro

Mitochondrial Lipid Peroxidation and Microsomal Drug-metabolizing Enzyme Activity of Rat Hepatotoxicity under Heavy Metals from Slag Waste Exposure

Heavy metals from slag waste (HMSWs) have attracted much attention because of their serious toxicity to the environment and human organs, especially hepatotoxicity. The aim of this study was to explore the effects of different HMSWs exposure on mitochondrial lipid peroxidation, microsomal drug metabolizing enzyme activities as well as their relationship in the rat liver injury. Based on toxicogenomic analysis, heavy metals including iron, copper, cobalt, nickel and manganese, might interfere with pathophysiological processes such as oxidative stress, cell death, and energy metabolism regulation in vivo, and participate in the regulation of HIF-1 signaling pathway, peroxisomes, drug metabolism-cytochrome P450, ferroptosis, and other signaling pathways. HMSWs exposure caused weight loss, and significantly increased lactate dehydrogenase (LDH), malondialdehyde (MDA), alanine transaminase (ALT), and aspartate transaminase (AST) in different groups of rat liver, suggesting the presence of mitochondrial lipid peroxidation damage. In addition, the ratios of AST/ALT and ALT/LDH were down-regulated, especially the ALT/LDH ratios were less than 1, indicating that hepatic ischemic injury occurred in the process of liver injury. The superoxide dismutase (SOD) and mitochondrial membrane potential (MMP) activities in rats also showed significant decreases, indicating the occurrence of hepatic oxidative/antioxidant dysfunction imbalance. Further decision tree analysis of live biochemical abnormalities suggested that AST > 58.78 U/gprot and MDA > 173.2 nmol/mgprot could be used for hepatotoxicity warning. Liver microsomal cytochrome P4501A2 (CYP1A2) and 3A1 (CYP3A1) enzymes were also involved in the hepatotoxic process of heavy metals. These results suggest that lipid peroxidation damage and metabolic damage in liver mitochondria and peroxisomes, may be one of the key events in heavy metal-induced liver injury.

A Novel System for Evaluating the Inhibition Effect of Drugs on Cytochrome P450 Enzymes in vitro Based on Human-Induced Hepatocytes (hiHeps)

Cytochrome P450 (CYP) is the most important phase I drug-metabolizing enzyme, and the effect of drugs on CYP enzymes can lead to decreased pharmacological efficacy or enhanced toxicity of drugs, but there are many deficiencies in the evaluation models of CYP enzymes in vitro. Human-induced hepatocytes (hiHeps) derived from human fibroblasts by transdifferentiation have mature hepatocyte characteristics. The aim was to establish a novel evaluation system for the effect of drugs on CYP3A4, 1A2, 2B6, 2C9, and 2C19 in vitro based on hiHeps. Curcumin can inhibit many CYP enzymes in vitro, and so the inhibition of curcumin on CYP enzymes was compared by human liver microsomes, human hepatocytes, and hiHeps using UPLC-MS and the cocktail method. The results showed that the IC₅₀ values of CYP enzymes in the hiHeps group were similar to those in the hepatocytes group, which proved the effectiveness and stability of the novel evaluation system in vitro. Subsequently, the evaluation system was applied to study the inhibitory activity of notoginseng total saponins (NS), safflower total flavonoids (SF), and the herb pair of NS–SF on five CYP enzymes. The mechanism of improving efficacy after NS and SF combined based on CYP enzymes was elucidated in vitro. The established evaluation system will become a powerful tool for the research of the effect of drugs on the activity of CYP enzymes in vitro, which has broad application prospects in drug research.

Evaluation of the effects of notoginseng total saponins (NS), safflower total flavonoids (SF), and the combination of NS and SF (CNS) on the activities of cytochrome P450 enzymes using a cocktail method in rats

Notoginseng total saponins (NS), safflower total flavonoids (SF), and the combination of NS and SF, namely CNS, are used for the treatment of cardiovascular diseases in clinic. This study developed a cocktail assay involving seven cytochrome P450 (CYP) enzymes to elucidate the effect of NS, SF, and CNS on CYP enzymes and to explore the synergistic effect of CNS in terms of CYP enzymes. Ultra-performance liquid chromatography-MS and reverse-transcription polymerase chain reaction were applied to detect the activities and mRNA expression levels of CYP enzymes. SF exhibited inhibitory effects on CYP1A2, 2B1, 2E1, and 2C11 and induction effects on CYP2C19 and 2D4. NS exhibited induction effects on CYP1A2, 2B1, 2E1, 2C11, 2C19, and 2D4. CNS exhibited induction effects on CYP1A2, 2B1, 2E1, 2C19, and 2D4 and inhibitory effects on CYP3A1 in vivo. Moreover, mRNA expression results were consistent with pharmacokinetic results. Potential herb-drug interactions should be studied closely when SF, NS, or CNS with clinical drugs are metabolized by CYP1A2, 2B1, 2E1, 2C11, 2C19, 2D4, and 3A1. CNS could change the inhibition or induction effects of CYP compared to the NS group, which might be one of the causes for the synergistic effects of the combination of NS and SF.