The osteoprotective effect of melittin acupoint injection on CIA mice based on the gut-joint axis

Abstract

Abstract Objective The intestinal mucosal barrier and gut microbiota metabolism play an important role in the disease progression and treatment of rheumatoid arthritis. Melittin acupoint injection has been improved and developed from traditional bee needle therapy, and has good anti-RA efficacy. However, its potential therapeutic mechanism is still unclear. We aimed to study the effects of MAI on the efficacy, intestinal mucosal barrier, and gut microbiota metabolism of collagen induced arthritis mice. Methods DBA/1 mice were randomly divided into normal group, model group, methotrexate group, and melittin acupoint injection group. collagen induced arthritis mice were established using enhanced immunotherapy, and melittin acupoint injection intervention was given every 2 days for a total of 28 days of treatment. Closely observe the development of mouse arthritis, detect serum inflammatory factors using ELISA, evaluate the structure of mouse knee and intestinal tissues using histopathological staining, detect the expression of target proteins in bone and intestinal tissues using WB method, and detect differential metabolites in feces using LC-MS technology. Results Compared with the normal group, the arthritis index of the model group mice showed a significant upward trend after strengthened immunization; The pathological staining results of joint tissue showed proliferation of synovium, infiltration of inflammatory cells, significant formation of pannus and erosion of joint cartilage, and a significant increase in osteoclasts; Serum pro-inflammatory factors IL-1β, IL-17 and IL-23 significantly increased, while the anti-inflammatory factor TGF-β1 showed a decreasing trend. The expression of proteins related to OC differentiation was significantly increased. Pathological staining of intestinal tissue showed disruption of the intestinal mucosal barrier, significantly reduced expression of tight junction proteins, and a significant increase in serum intestinal permeability indicators DAO, D-LA, and Zonulin. Fecal metabolomics analysis showed metabolic disorders with a significant decrease in butyrate levels; Compared with the model group, the melittin acupoint injection group showed significant improvement in the above indicators, and the difference was statistically significant. Conclusion melittin acupoint injection had a significant therapeutic effect on Rheumatoid arthritis, improving joint inflammation and joint structural damage. Its mechanism of action may increase fecal butyric acid content by acting on fecal microbial metabolism, regulating butyric acid metabolism pathways, protecting the intestinal mucosal barrier, controlling inflammation, and thus exerting therapeutic effects on Rheumatoid arthritis.