Yangyin Yiqi Huoxue Decoction improves the mechanism of microglia activation against CIS-induced neuroinflammatory injury by regulating the Wnt signaling pathway

Background

Ischemic stroke is a predominant cause of neurological disability, characterized by neuroinflammation and neuronal apoptosis. The Wnt signaling pathway plays a critical role in brain repair. Yangyin Yiqi Huoxue Decoction, a traditional Chinese herbal formula, has shown potential in alleviating neuroinflammatory injury, yet, the precise mechanism underlying its effects remains unclear.

Purpose

This study aims to explore the therapeutic efficacy of Yangyin Yiqi Huoxue Decoction on ischemic stroke and its potential mechanism of action, particularly focusing on its modulation of the Wnt signaling pathway and impact on neuroinflammation and neural stem cells activity.

Study Design and Methods

The middle cerebral artery occlusion (MCAO) rat model and an Oxygen glucose deprivation/re-oxygenation (OGD/R) cell model were employed. In vivo experiments were conducted to investigate the therapeutic effects of the Yangyin Yiqi Huoxue Decoction at high, medium, and low dosages (3.3, 1.65, and 0.83 g/kg). The effects of Yangyin Yiqi Huoxue Decoction on neuroinflammatory cytokine levels, microglial activation, and neural stem cells proliferation and differentiation were assessed in vivo experiments. Wnt signaling components were evaluated through Quantitative Real-Time PCR and Western blot in both vivo and vitro. Additionaly, the Wnt inhibitor Dickkopf-related protein 1(DKK1) was used to confirm the pathway's involvement.

Results

The high-dose group(3.3 g/kg) of the Yangyin Yiqi Huoxue Decoction exhibited the most pronounced therapeutic effects. Yangyin Yiqi Huoxue Decoction significantly reduced pro-inflammatory cytokine levels, inhibited microglial overactivation, and enhanced neural stem cells proliferation and differentiation. It also modulated the Wnt pathway by upregulating Wnt Family Member 3A(Wnt3a) and β-catenin, while downregulating Wnt Family Member 5A(Wnt5a) and glycogen synthase kinase-3β(GSK-3β). The inhibition of Wnt signaling by Dickkopf-related protein 1(DKK1) reversed these beneficial effects, confirming Yangyin Yiqi Huoxue Decoction 's mechanism.

Conclusions

Yangyin Yiqi Huoxue Decoction exerts neuroprotective effects by suppressing neuroinflammation and promoting neural-stem-cell-mediated brain repair through the Wnt signaling pathway, positioning it as a potential candidate for ischemic stroke treatment.