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

ObjectiveTo investigate the anti-inflammatory effects of Guanjie Zhentong Babu Plaster on collagen-induced arthritis (CIA) rats and its potential mechanisms.MethodsRats were randomly divided into a normal control group and a experimental group. The experimental group was immunized with type II collagen emulsion to establish a collagen-induced arthritis (CIA) model. After modeling, the animals were further divided 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 8 rats in each group. Arthritis index (AI) scores were evaluated on day 0 (D0), day 4 (D4), day 7 (D7), and day 14 (D14) after drug administration. A plethysmometer was used to measure hind paw toe volume to assess ankle joint swelling. After completion of the pharmacodynamic evaluation, rats were sacrificed, and hematoxylin–eosin (HE) staining was performed to observe histopathological changes in ankle joint tissues. Serum metabolite profiles were analyzed using ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (LC-LTQ Orbitrap MS), 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 changes in tumor necrosis factor (TNF)-α, IL-17, and IL-10.ResultsCompared with the cold syndrome model group, the high-dose cold syndrome group showed a significant improvement in AI scores at day 14 (P < 0.05) and a significant reduction in ankle joint swelling (P < 0.01), accompanied by markedly alleviated histopathological damage of the ankle joint. In contrast, no significant changes were observed in the high-dose heat syndrome group compared with the heat syndrome model group. Metabolomic analysis revealed that arginine metabolism and purine metabolism pathways were markedly disrupted in the cold-syndrome model group, and after treatment, the levels of citrulline, uric acid, and xanthine were significantly restored (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 < 0.01), whereas IL-10 levels were significantly increased (all P < 0.01) in the high-dose cold syndrome group.ConclusionGuanjie Zhentong Babu Plaster can improve inflammatory responses and joint damage in CIA rats with cold syndrome. Its mechanism may be related to the regulation of the arginine metabolic pathway, modulation of inflammatory factors, and restoration of inflammatory balance.