Gentiopicroside Attenuates Renal Ischemia-Reperfusion Injury through Suppression of JNK/MAPK Signaling.

BACKGROUND: Renal ischemia-reperfusion injury (IRI) is a major cause of acute kidney injury (AKI) with significant clinical impact. Gentiopicroside (GPS), a natural secoiridoid glycoside isolated from traditional medicinal plants, has been reported to exert anti-inflammatory and cytoprotective activities, yet its potential role in renal IRI has not been fully explored. METHODS: Mice underwent bilateral renal ischemia with oral GPS pretreatment. Renal function, histological injury, apoptosis, and inflammation were evaluated. Primary mouse renal tubular epithelial cells (mRTECs) and BUMPT cells were subjected to oxygen-glucose deprivation/reperfusion (OGD/R). Network pharmacology, molecular docking and cellular thermal shift assay (CETSA) were performed to identify potential GPS-associated pathways and targets. JNK signaling was further examined using JNK1-specific siRNA and anisomycin. RESULTS: GPS improved renal function, reduced tubular injury, apoptosis, and inflammation in IRI mice, and increased viability while reducing apoptosis in OGD/R-treated mRTECs and BUMPT cells. Network pharmacology highlighted MAPK signaling, and docking identified MAPK8 (JNK1) as a candidate GPS target. CETSA showed increased JNK1 thermal stability after GPS treatment. JNK1 silencing phenocopied the anti-apoptotic effects of GPS, with no significant additional reduction in JNK phosphorylation or caspase-3 cleavage after GPS treatment. Conversely, anisomycin partially reversed GPS-mediated protection. GPS also attenuated oxidative stress and modulated ferroptosis- and autophagy-associated molecular changes during OGD/R injury. CONCLUSION: GPS protects against renal IRI and OGD/R-induced tubular injury, with JNK/MAPK signaling serving as an important, but not exclusive, mediator of its anti-apoptotic effects. These findings support further investigation of oral GPS as a potential therapy for AKI.