Panaxadiol Attenuates Brain Damage by Inhibiting Ferroptosis in a Rat Model of Cerebral Hemorrhage

Intracerebral hemorrhage (ICH) is the most common subtype of hemorrhage stroke, with a high disability, morbidity and mortality rate globally. Panaxadiol (PD), a triterpenoid sapogenin monomer, is isolated from the roots of ginseng, which has shown a variety of biological properties, such as anti-inflammation, anti-cancer, and neuroprotection. However, its effect and mechanism on ICH were still unknown. Thirty-six rats were randomly divided into six group (n = 6), namely, sham, ICH, ICH + 5 mg/kg PD, ICH + 10 mg/kg PD, ICH + 20 mg/kg PD, and ICH + 10 mg/kg PD + 50 mg/kg vismodegib. Rats were treated with type IV collagenase to induce an in vivo model of ICH, and then intraperitoneally injected with PD (5, 10 and 20 mg/kg) and 50 mg/kg vismodegib (an inhibitor of hedgehog signal). The effect and potential mechanism of PD on ICH were explored by behavioral test, brain water content measurement, Evans blue detection, hematoxylin-eosin (HE) staining, iron level examination, Prussian blue staining, western blot and immunohistochemistry, respectively. An increase in the mNSS (13.17 ± 1.17), and a decrease in the rotarod latency (40.67 ± 9.31), modified Garcia score (9.83 ± 1.47), forelimb use times (3.33 ± 0.82), left forepaw placements (29.90 ± 4.38) and left turns (17.34 ± 3.55) in ICH rats were reversed with the PD treatment (6.83 ± 0.75, 113.5 ± 11.95, 17.50 ± 1.87, 8.17 ± 0.98, 63.56 ± 9.84, and 42.13 ± 4.52 respectively). PD treatment reduced the brain water content (73.13 ± 3.16 vs. 86.82 ± 4.74), the level of Evans blue (2.14 ± 0.25 vs. 4.03 ± 0.20) and cerebral hemorrhage in ICH rats. Also, PD injection decreased the iron level (0.06 ± 0.005 vs. 0.17 ± 0.02) and the expression of ACSL4 (0.56 ± 0.07 vs. 1.23 ± 0.16), with the increased expression of GPX4 (1.14 ± 0.08 vs. 0.21 ± 0.03) in ICH rats. Mechanically, PD treatment restored the decreased expression of SHH (0.96 ± 0.13 vs. 0.20 ± 0.03), GLI1 (0.89 ± 0.13 vs. 0.06 ± 0.007) and PTCH (0.75 ± 0.05 vs. 0.10 ± 0.01) in ICH rats. Inhibition of SHH signaling by vismodegib reversed the ameliorative effect of PD on ICH rats. PD improved brain damage by suppressing ferroptosis via the activation of the SHH/GLI signaling pathway, which could lay a theoretical foundation for the treatment of ICH.