Plumbagin inhibits CYP2J/EETs metabolic pathway and leads to heart injury in cardiac organoids and rats

Cytochrome P450 2J (CYP2J) enzymes are critical in synthesizing cardioprotective epoxyeicosatrienoic acids (EETs), which help reduce oxidative stress, inflammation, and apoptosis. Plumbagin, a natural antitumor agent, induces cardiac injury, although its mechanism remains uncharacterized. This study systematically evaluated the mechanism behind plumbagin-induced heart injury. In vitro rat microsomal experiments demonstrated that plumbagin inhibited CYP2J activity in a dose-dependent manner and reduced the biosynthesis of EETs. Meanwhile, human cardiac organoids exposed to plumbagin exhibited mitochondrial dysfunction, apoptosis, and exacerbated inflammation. Further in vivo experiments in rats showed that plumbagin downregulated cardiac CYP2J expression, reduced EETs, prolonged the QT interval of the heart, caused cardiomyocyte atrophy, and elevated serum injury biomarkers, similar to the results of CYP2J knockout. Importantly, the suppression of the CYP2J/EETs metabolic pathway by plumbagin resulted in mitochondrial damage, inflammatory cascades, and apoptotic signaling, directly linking EETs depletion to structural and functional heart injury. These findings confirm that the interruption of the CYP2J/EETs metabolic pathway is the primary mechanism of plumbagin-induced cardiotoxicity, emphasizing the necessity of cardiovascular safety assessment for CYP2J inhibitors.