Molecular mechanisms of hepatotoxicity induced by compounds occurring in Evodiae Fructus

Evodiae Fructus (EF) is a common herbal medicine with thousands of years of medicinal history in China, which has been demonstrated with many promising pharmacological effects on cancer, cardiovascular diseases and Alzheimer's disease. However, there have been increasing reports of hepatotoxicity associated with EF consumption. Unfortunately, in a long term, many implicit constituents of EF as well as their toxic mechanisms remain poorly understood. Recently, metabolic activation of hepatotoxic compounds of EF to generate reactive metabolites (RMs) has been implicated. Herein, we capture metabolic reactions relevant to hepatotoxicity of these compounds. Initially, catalyzed by the hepatic cytochrome P450 enzymes (CYP450s), the hepatotoxic compounds of EF are oxidized to generate RMs. Subsequently, the highly electrophilic RMs could react with nucleophilic groups contained in biomolecules, such as hepatic proteins, enzymes, and nucleic acids to form conjugates and/or adducts, leading to a sequence of toxicological consequences. In addition, currently proposed biological pathogenesis, including oxidative stress, mitochondrial damage and dysfunction, endoplasmic reticulum (ER) stress, hepatic metabolism disorder, and cell apoptosis are represented. In short, this review updates the knowledge on the pathways of metabolic activation of seven hepatotoxic compounds of EF and provides considerable insights into the relevance of proposed molecular hepatotoxicity mechanisms from a biochemical standpoint, for the purpose of providing a theoretical guideline for the rational application of EF in clinics.