Effect of polysaccharides from Aconitum pendulum Bush on rheumatoid arthritis

The Tibetan people of China have used the roots of Aconitum pendulum Bush as a folk remedy for rheumatoid arthritis (RA). In this study, we investigated the effects of A. pendulum polysaccharides (APPs) on RA. Chemical analysis revealed that APPs were mostly composed of galacturonic acid, glucose, and glucuronic acid. Structural characterization showed that it is an α-glucan with (1 → 4) and (1 → 3,6) glycosidic linkages. Furthermore, we examined the therapeutic potential of APPs (100 and 400 mg/kg) in a rat model of bovine collagen-induced arthritis (CIA). Results indicated that APP administration markedly reduced the critical characteristics of CIA, including foot swelling, thymic and splenic indices, and serum concentrations of pro-inflammatory cytokines. Histopathological analysis further validated that APPs mitigated vascular opacities and synovial inflammation in the ankle joints. Moreover, initial analysis of fecal samples revealed changes in the abundance of specific intestinal microbial taxa after APP treatment. These findings collectively establish an experimental basis for the potential of APPs as adjunctive therapeutic agents for RA. However, additional research, encompassing fecal microbiota transplantation and studies in germ-free models, is essential to clarify the potential causal relationship between the observed alterations in gut microbiota and the anti-arthritic effects of APPs.