Hepatoprotective effects of oridonin against bisphenol A induced liver injury in rats via inhibiting the activity of xanthione oxidase.

Bisphenol A (BPA) is widely used to manufacture packaging materials for various daily necessities and causes harmful effects in organs, especially liver injury, by generating oxidative stress. Oridonin, an active diterpenoid isolated from Rabdosia rubescens (Hemsl.) Hara, has been reported to possess a wide range of pharmacological activities including anti-inflammatory, antioxidative and antiapoptotic effects. However, the role of oridonin in BPA--induced liver injury and its potential protective mechanism have not been well characterized. In this research, we explored the metabolic alterations in the liver tissue of rats after exposure to BPA with or without pretreatment with oridonin for 14 days by metabolomics analysis based on UPLC-MS/MS. Rats were randomly divided into groups as follows: Control, Vehicle, Oridonin (10 mg/kg), Bisphenol A (500 mg/kg), bisphenol A + Oridonin (500 + 10 mg/kg), Bisphenol A + Diammonium glycyrrhizinate (500 + 40 mg/kg). The biochemical results showed that oridonin significantly reduced the levels of AST and ALT (P < 0.05), ameliorated the abnormal histopathological changes and reduced hepatic apoptosis compared with the BPA group. Furthermore, metabolomics results revealed that purine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis and phenylalanine metabolism were reprogrammed, based on 28 identified significant differential metabolites among the Vehicle, BPA and BPA + oridonin groups. In-depth studies demonstrated that pretreatment with oridonin may play a protective role by restoring BPA-induced changes in oxidative stress and the activity of oxidase (XOD) (P < 0.05). Additionally, oridonin could inhibit the activity of XOD by binding to it, therefore decreasing the reactive oxygen species (ROS) level, upregulating the content of hypoxanthine and xanthine, and reducing the level of uric acid in the liver (P < 0.05). This research presents the potential protective mechanisms of oridonin on BPA-induced liver injury at the metabolic level, which might be used to identify new protective agents that prevent BPA-induced liver injury.