Chunghyul-dan, a multi-botanical ethanol extract, improves collateral perfusion and neurovascular stability in permanent focal cerebral ischemia

Background Collateral perfusion and neurovascular stability critically influence outcomes after ischemic stroke; however, no pharmacological agent is currently approved to enhance these processes. Objectives Chunghyul-dan (CHD), a standardized multi-botanical ethanol extract with reported vascular and anti-inflammatory properties, was evaluated for its neurovascular protective effects in a permanent middle cerebral artery occlusion (pMCAO) mouse model. The Process and Methods Male ICR mice subjected to pMCAO received oral Chunghyul-dan (30–120 mg/kg). Cortical infarct volume, anterior cerebral artery perfusion, angiogenesis-related signaling, neuroinflammation, and endothelial barrier integrity were assessed using histological analysis, laser Doppler flowmetry, immunohistochemistry, and complementary in vitro studies in BV2 microglia and bEND.3 endothelial cells. Results CHD significantly reduced cortical infarct volume, with maximal protection observed at 60 mg/kg. Laser Doppler analysis demonstrated enhanced ACA perfusion at 30 mg/kg during early ischemia. CHD upregulated VEGF expression in ischemic cortex and endothelial cells, supporting vascular remodeling. Neuroinflammation was attenuated, as CHD reduced Iba-1–positive microglial activation and suppressed iNOS, IL-6, and TNF-α expression. Endothelial barrier integrity was preserved through reduced PECAM-1 expression, restoration of claudin-5 and occludin, and selective inhibition of STAT3 phosphorylation, whereas TLR4/MAPK signaling remained unchanged. Conclusion CHD confers multi-level neurovascular protection by promoting collateral perfusion, facilitating VEGF-associated vascular adaptation, suppressing neuroinflammation, and stabilizing endothelial junctional architecture. These findings support further translational evaluation of CHD as a pharmacological modulator of collateral circulation in ischemic stroke.