Abstract
The Simiao pill (SMP) is a classic prescription that has shown anti-inflammatory, analgesic, and immunomodulatory effects and is clinically used to treat inflammatory diseases, such as rheumatoid arthritis (RA) and gouty arthritis, for which the effects and mechanism of action remain largely unknown. In this study, serum samples from RA rats were analyzed using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry based metabolomics technology and liquid chromatography with tandem mass spectrometry proteomics technology together with network pharmacology to explore the pharmacodynamic substances of SMP. To further verify the above results, we constructed a fibroblast-like synoviocyte (FLS) cell model and administered phellodendrine for the test. All these clues suggested that SMP can significantly reduce the level of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in complete Freund's adjuvant rat serum and improve the degree of foot swelling; combined with metabolomics, proteomics, and network pharmacological technology, it is determined that SMP plays a therapeutic role through the inflammatory pathway, and phellodendrine is found to be one of the pharmacodynamic substances. By constructing an FLS model, it is further determined that phellodendrine could effectively inhibit the activity of synovial cells and reduce the expression level of inflammatory factors by downregulating the expression level of related proteins in the TLR4-MyD88-IRAK4-MAPK signal pathway to alleviate joint inflammation and cartilage injury. Overall, these findings suggested that phellodendrine is an effective component of SMP in the treatment of RA.