Troxerutin mitigates ferroptosis-related neuroinflammation by regulating the microglial NOX4/Nrf2 axis in Parkinson's disease.

Parkinson's disease (PD) is characterized by progressive dopaminergic neurodegeneration and chronic neuroinflammation. Increasing evidence suggests that microglial ferroptosis plays a critical role in the pathogenesis of PD. Troxerutin (TRX), a natural flavonoid derivative with potent antioxidant and anti-inflammatory activities, has shown neuroprotective potential; however, its effects on microglial ferroptosis and the underlying mechanisms in PD remain unclear. Here, we investigated the effects of TRX in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD and MPP+-stimulated BV2 cells. TRX improves motor performance, preserves nigrostriatal dopaminergic neurons, and attenuates microglial activation and pro-inflammatory cytokine expression in vivo. In BV2 cells, TRX attenuated ferroptosis-related changes, reduced lipid reactive oxygen species accumulation, and restored GPX4 and SLC7A11 expression. Furthermore, treatment with erastin, a classical ferroptosis inducer, reactivates ferroptosis-related responses and reverses the anti-inflammatory effects of TRX, linking ferroptotic stress to microglial inflammatory activation. Mechanistically, the cellular thermal shift assay supported target engagement between TRX and NOX4. TRX enhances K48-linked polyubiquitination of NOX4 and promotes its proteasomal degradation, which restores Nrf2 nuclear accumulation and activates downstream antioxidant responses. These results reveal that TRX alleviates ferroptosis-related neuroinflammation by modulating the microglial NOX4/Nrf2 axis in PD.