[Metabolomics study on anti-inflammatory effects of Guanjie Zhentong Babu plaster in collagen-induced arthritis rats].

OBJECTIVES

To investigate the anti-inflammatory effects of Guanjie Zhentong Babu plaster on collagen-induced arthritis (CIA) rats and its potential mechanisms.

METHODS

Rats were randomly divided into normal control group and experimental group. The experimental group was immunized with bovine type Ⅱ collagen emulsion to establish the CIA rat model, and then subdivided into the following groups: cold syndrome model group, heat syndrome model group, high-dose cold syndrome group, high-dose heat syndrome group, low-dose cold syndrome group, positive control cold syndrome group, positive control heat syndrome group, and blank plaster cold syndrome group, with eight rats in each group. Arthritis index (AI) scores of paw joints were evaluated on day 0, day 4, day 7, and day 14 after drug administration. A plethysmometer was used to assess hind paw joint swelling. After completion of the pharmacodynamic evaluation, the rats were sacrificed, and hematoxylin and eosin staining was performed to observe histopathological changes in ankle joint tissues. Serum metabolite profiles were analyzed using ultra performance liquid chromatography coupled with linear ion trap quadrupole-Orbitrap mass spectrometry, and metabolic pathway enrichment analysis was conducted to explore the potential mechanisms of drug intervention. In addition, immunohistochemistry and enzyme-linked immunosorbent assay were performed to investigate the levels of tumor necrosis factor-α (TNF-α), IL-17, and IL-10.

RESULTS

Compared with the cold syndrome model group, the high-dose cold syndrome group showed a significant improvement in AI scores on day 14 (P<0.05) and a significant reduction in hind paw joint swelling (P<0.01), accompanied by markedly alleviated histopathological damage in the ankle joint. In contrast, no significant changes were observed in the high-dose heat syndrome group compared with the heat syndrome model group. Metabolomics analysis revealed that arginine biosynthesis and purine metabolism pathways were markedly disrupted in the cold-syndrome model group, and compared with the cold syndrome model group, the contents of L-citrulline were significantly increased, whereas the contents of uric acid and xanthine were significantly decreased in the high-dose cold syndrome group (all P<0.05). Immunohistochemistry and enzyme-linked immunosorbent assay results indicated that, compared with the cold syndrome model group, TNF-α and IL-17 levels in synovial tissue and serum were significantly decreased (all P<0.05), whereas IL-10 levels were significantly increased (all P<0.01) in the high-dose cold syndrome group.

CONCLUSIONS

Guanjie Zhentong Babu plaster alleviates joint injury in CIA rats with cold syndrome by regulating arginine and purine metabolism-related pathways to restore inflammatory balance.