Metabolomics analysis of the effects of quercetin on Cd-induced hepatotoxicityin rats

Cadmium (Cd) is known to cause damage to the liver. In this study, metabolomics technology was used to investigate the effect of quercetin (QE) on Cd-induced hepatotoxicity. A total of 60 male SD rats were randomly divided into the following six groups: control group (C), low and high-dose QE group (Q1: 10 mg/kg·bw, Q2: 50 mg/kg·bw), Cd group (D), low and high-dose QE and Cd combined intervention group (DQ1, DQ2). The rats were given Cd chloride (CdCl₂) at a concentration of 40 mg/L through free drinking water. After 12 weeks of treatment, liver samples of rats were collected for metabonlomic analysis. A total of 12 metabolites were identified, the intensities of PC (18:0/14:1(9Z)) and arachidonate acid were decreased in the Cd-treated group (p < 0.01), whereas the intensities of chenodeoxyglycocholic acid, cholic acid, taurochenodesoxycholic acid, glycocholic acid, prostaglandin D2, 15-deoxy-d-12,14-PGJ2, oxidized glutathione, cholesterol, protoporphyrin IX, bilirubin were increased significantly in the Cd-treated group compared with group C (p < 0.01). When rats were given high doses of QE and Cd at the same time, the intensity of the above metabolites was significantly restored in group DQ2. Results suggest that the protective effect of QE on Cd-induced liver injury is associated with antioxidant activity of QE, as well as QE can regulates hepatic bile acid metabolism by affecting FXR and BSEP, and regulates AA metabolism by inhibiting Cd-induced activities of COX-2 and PLA2.