Danhong Injection Alleviates Blood-Brain Barrier Disruption Caused by Cerebral Ischemia-Reperfusion Injury in 5Hyperlipidemia Rats by Regulating the Wnt/β-Catenin Pathway

Background: Danhong injection (DHI), a standardized traditional Chinese medicine formulation, has shown clinical benefits in treating cerebrovascular diseases. Blood–brain barrier (BBB) disruption is a key pathological feature of ischemic stroke, but its modulation by DHI under hyperlipidemic conditions remains unclear. This study aimed to investigate the protective effects and mechanisms of DHI in cerebral ischemia/reperfusion injury (CI/RI) under hyperlipidemia, focusing on BBB integrity and the Wnt/β-catenin signaling pathway. Methods: Rats were divided into control, ischemic, hyperlipidemic, and treatment subgroups to evaluate DHI’s dose-dependent effects and pathway specificity using DKK1 inhibition. Assessments included neurological scores, TTC and Nissl staining, TEM, and molecular analyses (qRT-PCR/Western blot/immunofluorescence/immunohistochemistry). Results: DHI significantly improved neurological function, reduced cerebral infarct size, and alleviated cortical damage. DHI treatment upregulated the expression of tight junction proteins (Claudin-5, Occludin, ZO-1) and downregulated MMP-9 expression. Mechanistically, DHI promoted the nuclear translocation of β-catenin and increased the expression of Wnt3α, p-GSK-3β, and Cyclin D1, thereby activating the Wnt/β-catenin pathway. Additionally, DHI treatment increased the count of NeuN-positive neurons, suppressed astrocyte activation, and markedly reduced IgG infiltration in the ischemic cerebral cortex. These effects were reversed by DKK1. Conclusions: The results indicate that DHI protects BBB integrity and alleviates CI/RI in hyperlipidemic rats independently of direct lipid-lowering activity. Specifically, DHI activates the Wnt/β-catenin pathway by enhancing β-catenin nuclear translocation, which in turn mediates the upregulation of tight junction proteins and suppression of MMP-9, ultimately preserving BBB integrity. These findings support its therapeutic potential in ischemic stroke with comorbid hyperlipidemia.