Piperine Improves Hyperuricemic Nephropathy by Inhibiting URAT1/GLUT9 and the AKT-mTOR Pathway.

Uncontrolled hyperuricemia often leads to the development of hyperuricemic nephropathy (HN), characterized by excessive inflammation and oxidative stress. Piperine, a cinnamic acid alkaloid, possesses various pharmacological activities, such as antioxidant and anti-inflammatory effects. In this study, we intended to investigate the protective effects of piperine on adenine and potassium oxonate-induced HN mice and a uric-acid-induced injury model in renal tubular epithelial cells (mRTECs). We observed that treatment with piperine for 3 weeks significantly reduced serum uric acid levels and reversed kidney function impairment in mice with HN. Piperine (5 µM) alleviated uric acid-induced damage in mRTECs. Moreover, piperine inhibited transporter expression and dose-dependently inhibited the activity of both transporters. The results revealed that piperine regulated the AKT/mTOR signaling pathway both in vivo and in vitro. Overall, piperine inhibits URAT1/GLUT9 and ameliorates HN by inhibiting the AKT/mTOR pathway, making it a promising candidate for patients with HN.

Febuxostat ameliorates APAP-induced acute liver injury by activating Keap1/Nrf2 and inhibiting TLR4/NF-κB p65 pathways.

Excessive acetaminophen (APAP) application is a major cause of drug-induced liver injury (DILI). Febuxostat (Feb), a drug for reducing uric acid (UA) levels, was demonstrated to relieve hepatic inflammation and reverse organ functions. However, the effect of Feb on APAP-induced DILI and its mechanisms have not been fully explored. In this study, Feb (10 mg/kg) was given to mice by gavage 1 h after APAP (300 mg/kg, i.g.) induction. Serum and liver samples were collected 12 or 3 h after APAP challenge. Feb treatment was found to remarkably improve APAP-induced DILI, as evidenced by reduced serum ALT, AST and UA levels, pathomorphology, inflammatory, and oxidative responses. Consistently, treatment with Feb also reduced the cell injury induced by APAP in LO2 cells. Mechanistically, Feb induced GPX4 expression, activated the Keap1/Nrf2 pathway, and inhibited the TLR4/NF-κB p65 pathway. Feb also inhibited glutathione (GSH) depletion and Jun N-terminal kinase (JNK) activation in the early injury phase. Notably, pretreatment with Feb for 3 days also revealed preventive effects against APAP-induced DILI in mice. Overall, our data revealed a potential health impact of Feb on APAP-mediated DILI in vivo and in vitro, suggesting that Feb might be a potential candidate for treating DILI.