Abstract:Aim To investigate the effect of dendrobium officinale polysaccharide (DOP) on Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in brain tissue of ischemic stroke rats. Methods The rat model of middle cerebral artery occlusion was established by thread embolism. SD rats were randomly divided into model group, DOP low dose (25 μg/g) group, DOP medium dose (50 μg/g) group, DOP high dose (100 μg/g) group and edaravone group, with 12 rats in each group; Another 12 SD rats were set as sham operation group. After drug intervention, the neurological deficit of rats in each group was scored by Longa grading method. The cerebral infarction in rats was detected by triphenyltetrazolium chloride staining. Hematoxylin-eosin staining was used to observe the pathological changes of hippocampal nerve tissue in rats. Enzyme-linked immunosorbent assay was used to detect the levels of inflammatory cytokines interferon-γ (IFN-γ), cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) in rat brain. Western blot was used to detect the expression level of JAK/STAT3 signaling pathway related proteins in rat brain. Results Compared with the sham operation group, the hippocampal neurons in the model group were shriveled, smaller, degenerated and necrotic, damaged in structure and disordered in arrangement, and the number of them decreased obviously. The whole hippocampal nerve tissue showed obvious pathological damage, and the neurological deficit score, cerebral infarction area, levels of IFN-γ, COX-2 and IL-6 in brain tissue, p-JAK/JAK, p-STAT3/STAT3 increased obviously (P<0.05). Compared with the model group, the pathological damage of hippocampal nerve tissue in the drug treatment group was reduced, the neurological deficit score, cerebral infarction area, the levels of IFN-γ, COX-2 and IL-6 in brain tissue, p-JAK/JAK, p-STAT3/STAT3 were all decreased, and there was a dose-dependent relationship among DOP groups (P<0.05). Compared with edaravone group, there was no significant change in all indexes of rats in DOP high dose group (P>0.05). Conclusion DOP can inhibit the activation of JAK/STAT3 signaling pathway in ischemic stroke rats, reduce the synthesis and secretion of inflammatory cytokines, relieve brain inflammation and repair nerve function.