| Objective To investigate the therapeutic effect of siegesbeckia orientalis on the collagen induced arthritis (CIA) rat model based on interleukin-23 (IL-23)/T helper cell 17 (Th17) inflammatory axis. Methods The CIA rat model was established. The rats successfully modeled were randomly divided into model group, siegesbeckia orientalis group, siegesbeckia orientalis + IL-23 group, 10 in each group, and the other 10 rats in negative control group were treated as control. The morphology and weight of rats were observed, the swelling degree of toes was measured by water volume method, and the arthritis index was measured by 5-grade scoring method; hematoxylin eosin staining (HE) was used to detect the morphology of synovial membrane; the contents and mRNA levels of IL-23, IL-17, IL-6, IL-22, IL-21 in abdominal aortic blood and synovial tissue were detected by enzyme-linked immunosorbent assay (ELISA) and real-time fluorescence quantitative PCR (RT-qPCR); the percentage of Th17 cells in abdominal aortic blood and synovial tissue was detected by flow cytometry. Results Compared with those in the negative control group, the body weight of rats in the model group was lower, the swelling degree of toe, arthritis index, contents and mRNA levels of IL-23, IL-17, IL-6, IL-22, IL-21 in abdominal aortic blood and synovial tissue, and percentage of Th17 cells were higher (P<0.05); compared with those in the model group, the body weight of rats in the siegesbeckia orientalis group was higher, the swelling degree of toe, arthritis index, contents and mRNA levels of IL-23, IL-17, IL-6, IL-22, IL-21 in abdominal aortic blood and synovial tissue, and percentage of Th17 cells were lower (P<0.05); compared with the siegesbeckia orientalis group, the body weight of rats in the siegesbeckia orientalis + IL-23 group was lower, the swelling degree of toe, arthritis index, contents and mRNA levels of IL-23, IL-17, IL-6, IL-22, IL-21 in abdominal aortic blood and synovial tissue, and percentage of Th17 cells were higher (P<0.05). Conclusion Siegesbeckia orientalis can reduce the level of inflammation by inhibiting the inflammatory axis of IL-23/Th17, thus realize the treatment of CIA rats. |