Abstract:Objective To investigate the effect of Huayu Zhitong Plaster on inflammatory response in rats with acute soft tissue injury (ASTI) by regulating the interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signal pathway. Methods SPF grade SD rats were randomly grouped into control group, model group, low, medium and high dose Huayu Zhitong plaster groups, and Goupigao group. ASTI animal model was established by mechanical impact contusion method. After successful modeling, each group applied corresponding drugs once a day for 8 hours each time for 7 days. The rats were scored with ASTI damage; the hemorheology indexes were measured by hemorheology detector; the pathological changes of muscle tissue at the injured site were observed by hematoxylin and eosin (HE) staining; enzyme-linked immunosorbent assay (ELISA) was applied to detect the levels of interleukin (IL)-6, IL-β and tumor necrosis factor-α (TNF-α) in the muscle tissue of the injured rats in each group; the expression of IL-6 and STAT3 mRNA in muscle tissue of the injured site was detected by real-time fluorescence quantitative PCR (qRT-PCR); Western blot was applied to detect the expression of IL-6/STAT3 signal pathway protein in the injured muscle tissue of rats. Results Compared with the control group, the soft tissue injury score, whole blood viscosity, plasma viscosity, hematocrit, muscle histopathological score, the IL-6, IL-β, TNF-α levels, the IL-6 and STAT3 mRNA expression levels, and the IL-6 and p-STAT3/STAT3 protein expression levels in the model group were increased (P<0.05); compared with the model group, the soft tissue injury score, whole blood viscosity, plasma viscosity, hematocrit, muscle histopathological score, the IL-6, IL-β, TNF-α levels, the IL-6 and STAT3 mRNA expression levels, and the IL-6 and p-STAT3/STAT3 protein expression levels in the low, medium and high dose Huayu Zhitong Plaster groups and the Goupigao group were decreased (P<0.05); there was no obvious difference in the above indexes between the high dose Huayu Zhitong Plaster groups and the Goupigao group (P>0.05) Conclusion Huayu Zhitong Plaster may alleviate the inflammatory reaction of ASTI rats by down-regulating IL-6/STAT3 signal pathway