Salvianolic acid B mitigates neuronal ferroptosis after intracerebral hemorrhage in rats through a Piezo1-associated AMPK-mTOR pathway.

Secondary brain injury (SBI) after intracerebral hemorrhage (ICH) is driven in part by iron-dependent oxidative damage and neuronal ferroptosis, but the molecular signals associated with ferroptotic vulnerability in the hemorrhagic brain remain incompletely defined. Here, we investigated whether the mechanosensitive channel Piezo1 contributes to neuronal ferroptosis after ICH and whether Salvianolic acid B (Sal B) confers protection through a Piezo1-associated mechanism. In an autologous blood-induced rat ICH model and hemin-treated HT-22 cells, Piezo1 expression was increased after ICH and was associated with indices of injury severity. Pharmacological activation of Piezo1 aggravated neurological deficits, lipid peroxidation, iron dysregulation, ferroptosis-related mitochondrial damage, and ferroptosis-associated protein changes, whereas Piezo1 inhibition produced the opposite effects. Sal B improved acute and long-term neurological outcomes, reduced brain edema and neuronal degeneration, and attenuated multiple hallmarks of ferroptosis. Combined in silico analysis and surface plasmon resonance (SPR) supported a direct interaction between Sal B and Piezo1. Mechanistically, the Piezo1 agonist Yoda1 largely abolished Sal B-mediated protection in vivo, while AMPK inhibition partly reversed the protective effects of Sal B in vivo and in vitro. Together, these findings suggest that Piezo1 is associated with ferroptosis-related oxidative injury after ICH and that Sal B mitigates SBI, at least in part, through a Piezo1-associated mechanism involving AMPK-mTOR signaling.