The Protective Effects of the Ethyl Acetate Part of Er Miao San on Adjuvant Arthritis Rats by Regulating the Function of Bone Marrow-Derived Dendritic Cells
Aims. /e aim of this study was to evaluate the protective effects of Er Miao San (EMS) and the regulative function of bone marrow-derived dendritic cells (BMDCs) on adjuvant arthritis (AA) in rats. Methods. /e ethyl acetate part of EMS (3 g/kg, 1.5 g/kg, and 0.75 g/kg) was orally administered from day 15 after immunization to day 29. /e polyarthritis index and paw swelling were measured, the ankle joint pathological changes were observed using hematoxylin-eosin (HE) staining, and the spleen and thymus index were determined. Moreover, T and B cell proliferation were determined using the CCK-8 assay. /e expression of BMDC surface costimulatory molecules and inflammatory factors were determined using flow cytometry and ELISA kits, respectively. Results. Compared with the AA model rats, the ethyl acetate fraction of EMS obviously reduced paw swelling (from 1.0 to 0.7) and the polyarthritis index (from 12 to 9) (P < 0.01) and improved the severity of histopathology (P < 0.01). /e treatment using ethyl acetate fraction of EMS significantly reduced the spleen and thymus index (P < 0.01) and inhibited T and B cell proliferation (P < 0.01). Moreover, EMS significantly modulated the expression of surface costimulatory molecules in BMDCs, including CD40, CD80, CD86, and major histocompatibility complex class II (MHC-II) (P < 0.01). /e results also showed that the ethyl acetate part of EMS significant inhibited the levels of proinflammatory cytokines interleukin- (IL-) 23 tumor necrosis factor- (TNF-) {\alpha} and inflammatory factor prostaglandin (PG) E2 in the supernatant of BMDCs. However, the level of antiinflammatory cytokine IL-10 was significantly increased (P < 0.01). Conclusion. /ese results suggest that the ethyl acetate part of EMS has better protective effects on AA rats, probably by regulating the function of BMDCs and modulating the balance of cytokines.