Schisandrin A alleviates neuronal ferroptosis in mice with hypoxic-ischemic brain injury by inhibiting the ACSL4/TFRC/PTGS2 signaling pathway

To investigate the inhibitory effect of schisandrin A (Sch A) on neuronal ferroptosis following hypoxic ischemic brain damage (HIBD) and the underlying mechanism.

Thirty-six neonatal C57BL/6J mice (7-10 days old) underwent sham operation (n=6) or permanent left carotid ligation followed by 40 min of hypoxic exposure and daily treatment with Sch A at 10, 30, or 90 mg/kg or with Fer 1 (5 mg/kg) for 3 consecutive days (n=6). Western blotting was used to detect protein expressions of ACSL4, TFRC, and PTGS2 in the cortical ischemic penumbra of the mice; ACSL4/4 HNE co localization in the neurons was detected by immunofluorescence staining, and the levels of ROS, MDA, GSH, and Fe²⁺ were quantified. In cultured HT22 hippocampal neurons with oxygen glucose deprivation (OGD), the effects of pretreatment (1 h prior to OGD) with Sch A (10 μmol/L) and PRGL493 (10 μmol/L), alone or in combination, were assessed by detecting expressions of ferroptosis related proteins, ROS production, lipid peroxidation, cell viability, mitochondrial membrane potential, and the levels of MDA, GSH, and Fe²⁺.

In the neonatal mice, HIBD significantly upregulated ACSL4/TFRC/PTGS2, increased ACSL4/4 HNE co-localization and ROS, MDA, and Fe²⁺ levels, and decreased GSH in the cortical ischemic penumbra. Sch A dose-dependently reversed these changes with effects comparable to that of Fer-1. In cultured HT22 cells, OGD similarly upregulated these proteins, enhanced ACSL4/NeuN co-localization, increased ROS, lipid peroxidation, MDA, and Fe²⁺ levels, and reduced GSH, cell viability, and mitochondrial potential. Both Sch A and PRGL493 alone significantly ameliorated these changes, and their combined treatment further downregulated ACSL4, TFRC and PTGS2 expressions, more effectively alleviated oxidative stress and lipid peroxidation, restored cell viability and mitochondrial function, and reduced Fe²⁺ accumulation.

Sch A protects against HIBD in mice by inhibiting the ACSL4/TFRC/PTGS2 pathway and alleviating neuronal ferroptosis and produces synergistic effects with PRGL493.