Extracts of Chuanxiong and Baizhi Attenuate Neuroinflammation in Chronic Migraine Rats by Inhibiting TLR4/MyD88/Nuclear Factor Kappa B Signal Pathway

Abstract This study investigates the mechanism by which a compound mixture of Chuanxiong and Baizhi (CMCB) modulates the TLR4/MyD88/nuclear factor kappa B (NF-κB) pathway to alleviate neuroinflammation in nitroglycerin (NTG)-induced chronic migraine (CM) rat models. In vivo CM rat models were induced with 10 mg/kg NTG, while in vitro models utilized BV2 cells stimulated with lipopolysaccharide. Toxicity of CMCB extracts was assessed through CCK8 assay and lactate dehydrogenase detection. Protein and messenger RNA expression levels were analyzed by quantitative real-time polymerase chain reaction and western blotting. Immunofluorescence was employed to evaluate the nucleoplasmic distribution of NF-κB p65. Inflammatory status and cell apoptosis were evaluated through enzyme-linked immunosorbent assay, flow cytometry, and immunohistochemistry. Results showed that CMCB concentrations below 16 μM were nontoxic to BV2 cells and effectively reduced cell apoptosis and inflammation, akin to the effects of a TLR4 pathway inhibitor, TAK-242. CMCB extracts decreased protein expression of TLR4 and MyD88, phosphorylation of NF-κB p65, and limited NF-κB p65 nuclear translocation. In vivo experiments demonstrated that both zolmitriptan and CMCB treatment ameliorated symptoms like red ear, head scratching, and cage climbing in CM rat models. High dosages of CMCB exhibited comparable efficacy to zolmitriptan in reducing inflammatory responses, indicating that CMCB alleviates neuroinflammation in CM rat models through the inhibition of the TLR4/MyD88/NF-κB signaling pathway.