Metabonomic study of Wu-tou decoction in adjuvant-induced arthritis rat using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

A urinary metabonomics method based on the ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) had been established to investigate the holistic efficacy of Wu-tou decoction (WTD), a traditional Chinese medicine (TCM) formula used to treat rheumatoid arthritis (RA), in adjuvant-induced arthritis (AIA) rat model. Multivariate statistical approaches, such as principal component analysis (PCA) and orthogonal projection to latent structures squares-discriminant analysis (OPLS-DA) were used to distinguish healthy control group, AIA model group and WTD treated group and find potential biomarkers. There was a clear separation among the three groups in PCA model. Sixteen potential biomarkers had been identified using OPLS-DA, and 11 of them was considered to be in response to therapeutic effects of WTD involved in tryptophan metabolism, phenylalanine metabolism, tricarboxylic acid (TCA) cycle, bile acid biosynthesis, steroid hormone biosynthesis and valine metabolism. In this study, WTD also showed good anti-inflammatory and antioxidant activities in vivo, and it could suppress histopathological changes of AIA rats. There might be a correlation between these results and the regulation of the disturbed metabolites in urine. This study demonstrates that metabonomics is a powerful methodology to gain insight in the mechanism of TCM formula in therapy.