Subarachnoid Hemorrhage (SAH), a devastating form of stroke, is associated with high mortality and disability rates due to complex secondary brain injuries-including neuroinflammation, oxidative stress, and blood-brain barrier disruption-for which effective neuroprotective treatments remain scarce. Inspired by the neuroprotective properties of the traditional Chinese herb Gastrodia elata, this study identifies a novel bioactive mechanism: its extracellular vesicles (G-EVs) are naturally enriched with β-Sitosterol, a plant sterol with proven anti-inflammatory, antioxidant, and endothelial-protective effects.

This project represents the first clinical investigation into the therapeutic potential of β-Sitosterol for patients with aneurysmal SAH. Given the excellent safety profile of β-Sitosterol as a widely used dietary supplement, this study aims to evaluate its safety and tolerability in SAH patients while preliminarily exploring its efficacy in improving neurological outcomes. By analyzing key biomarkers of inflammation and oxidative stress, this research seeks to bridge the gap between traditional medicine and modern nanomedicine, offering a novel, safe, and accessible adjunct therapy for SAH and paving the way for plant-derived compounds in acute neurocritical care.

Inclusion Criteria:

• Aged 18 to 75 years, regardless of gender.
• Confirmed diagnosis of spontaneous aneurysmal subarachnoid hemorrhage (aSAH) by head CT or cerebral angiography (DSA/CTA).
• Time from symptom onset to planned first dose administration within 48 hours.
• Aneurysm successfully secured by surgical clipping or endovascular intervention.
• World Federation of Neurosurgical Societies (WFNS) grade I-III.
• Written informed consent signed by the patient or their legal representative.

Exclusion Criteria:

• Non-aneurysmal SAH (e.g., caused by trauma, arteriovenous malformation, etc.).
• Secondary to other severe intracranial diseases (e.g., large intracerebral hematoma, severe brain herniation).
• Complicated with severe cardiac, hepatic, renal, or hematopoietic system dysfunction (as defined by specific laboratory criteria).
• Known allergy to Gastrodia elata or any of its components.
• Pregnancy or breastfeeding.
• Participation in another interventional clinical trial within 30 days prior to enrollment.
• Any other condition that, in the judgment of the investigator, makes the patient unsuitable for participation in this study.