Quercetin alleviates high fluoride-induced hepatocyte ferroptosis via regulating the ROS/PERK signaling pathway

Ferroptosis is closely associated with fluoride-induced liver injury. As a natural flavonoid with potent anti-ferroptotic activity, quercetin (Que) could mitigate fluoride-triggered hepatotoxicity. Therefore, the aim of this study was to investigate the protective effects of Que against sodium fluoride (NaF)-induced ferroptosis and to elucidate its molecular mechanisms. In vivo data demonstrated that Que restored liver function, ameliorated hepatic pathological lesions, and alleviated mitochondrial damage in NaF-exposed mice. Additionally, Que suppressed NaF-induced apoptosis and inflammation. Both in mouse liver tissues and AML-12 cells, Que exerted anti-ferroptotic actions via restraining reactive oxygen species (ROS) and lipid peroxidation, alleviating iron overload, increasing reduced to oxidized glutathione (GSH/GSSG) ratio and GSH content, altering the expression of ferroptosis-related proteins including glutathione peroxidase 4, Acyl-CoA synthetase long-chain family member 4, transferrin receptor, and ferritin heavy chain 1. Mechanistically, molecular docking combined with molecular dynamics simulations indicated the high reliability and stability of Que binding to Protein kinase R-like ER kinase (PERK). Que inhibited the activation of PERK signaling pathway. Pharmacological intervention assays verified that PERK inhibitor GSK2606414 mimicked Que's anti-ferroptotic effects, whereas PERK agonist CCT abolished Que-mediated protection against NaF-induced ferroptosis. Importantly, ROS elimination by N-acetylcysteine suppressed PERK activation and subsequent ferroptosis triggered by NaF. Overall, Que mitigates NaF-induced hepatic ferroptosis via inhibiting the ROS/PERK signaling pathway, highlighting its potential therapeutic application against high fluoride-induced hepatotoxicity.