The Anti‐Inflammatory Effect of Yangyin Tongnao Granule on Cerebral Ischemia–Reperfusion Injury in Rats

BACKGROUND: Yangyin Tongnao (YYTN) granule is a classic traditional Chinese medicine (TCM) preparation known for its therapeutic efficacy in promoting blood circulation, resolving stasis, nourishing yin, and reinforcing qi. Its neuroprotective effects have been validated through both clinical and preclinical studies. METHODS: A middle cerebral artery occlusion (MCAO) rat model was established, and rats were randomly assigned to five groups: Sham, MCAO, YYTN, Ag490 (JAK2 inhibitor), and Ag490 + YYTN. YYTN was administered intragastrically at 1.73 g/kg/day, while Ag490 was administered via lateral ventricle injection at a volume of 10 μL per rat. Neurological function was assessed using Garcia scores, and infarct volume was determined by TTC staining. Neuronal integrity and damage were evaluated through HE and Nissl staining. Plasma levels of IL-18 and TNF-α were measured via ELISA, and the mRNA expression of IL-6 and IL-1β was quantified by RT-qPCR. Inflammatory markers, including p-JAK2, p-STAT3, NLRP3, ASC, cl-Caspase-1, and cl-IL-1β, were assessed by Western blotting. The distribution of p-JAK2 and p-STAT3 in brain sections was visualized via immunofluorescence staining. RESULTS: Treatment with YYTN significantly improved neurological function, reduced infarct volumes, and mitigated histopathological damage in the brain. Furthermore, YYTN significantly decreased plasma levels of IL-18 and TNF-α. In brain tissue, YYTN downregulated the mRNA expression of IL-6 and IL-1β and reduced key inflammatory proteins, including p-JAK2, p-STAT3, NLRP3, ASC, cl-Caspase-1, and cl-IL-1β. CONCLUSION: These findings suggest that YYTN mitigates cerebral ischemia-reperfusion injury (CIRI)-induced neuroinflammation by inhibiting the JAK2/STAT3 signaling pathway.