Metabolomics analysis of Danggui Sini decoction on treatment of collagen-induced arthritis in rats

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by persistent joint inflammation leading to bone and cartilage damage and even disability. However, the pathogenesis of RA is multi-factorial and to a large degree, remains unknown. Danggui Sini decoction (DSD), a traditional Chinese medicine (TCM) formula, has been widely used as a remedy for rheumatoid arthritis (RA) in recent years. In our study, ¹H-nuclear magnetic resonance (¹H NMR) based metabolomics analysis of 7 potential biomarkers, including taurine (1), urea (2), betaine (3), pyruvate (4), hippurate (5), succinate (6) and acetone (7) was performed to investigate the progression of RA and assess the efficacy of DSD in collagen-induced arthritis (CIA) rats. According to pathway analysis using identified metabolites and correlation construction, taurine and hypotaurine metabolism, gut microbiota metabolism, pyruvate metabolism, glycolysis/gluconeogenesis, the citrate cycle (TCA cycle) and lipid metabolism were recognized as being the most influenced metabolic pathways associated with RA. As a result, deviations of metabolites 1, 3, 4, 5, 6 and 7 in CIA rats were improved by DSD, which suggested that DSD mediated the abnormal metabolic pathways synergistically. In summary, the efficacy and its underlying therapeutic mechanisms of DSD on RA were systematically investigated and expect to provide a new insight in relevant studies of other TCM formulas.