Abstract
Context: Cinnamomi ramulus, the dry twig of Cinnamomum cassia Presl. (Lauraceae), has been reported to exert several activities such as antitumor, anti-inflammatory, and analgesic effects. Objective: This study investigates the effects of an aqueous extract of Cinnamomi ramulus (ACR) on rheumatoid arthritis (RA). Materials and methods: TNF-α-induced RA-derived fibroblast-like synoviocyte MH7A cells were incubated with ACR (0.1-2 mg/mL) for 24 h. The proliferation was tested using CCK-8 and colony formation assays. The migration and invasion abilities were measured using transwell tests and wound healing assays. Apoptosis and cell cycle were examined by flow cytometry. The potential mechanisms were determined by western blotting and quantitative real-time PCR. UPLC-QE-MS/MS was used for chromatographic analysis of ACR and its compounds were identified. Molecular docking strategy was used to screen the potential anti-RA active compounds of ACR. Results: We found that ACR induced apoptosis in MH7A cells at concentrations of 0.4, 0.8, and 1.2 mg/mL. The proliferation of MH7A cells was reduced and the cell cycle was blocked in the G2/M phase at concentrations of 0.2, 0.4, 0.6 mg/mL. Migration and invasion of MH7A cells were reduced through inhibiting the expression of MMP-1, MMP-2, and MMP-3. The molecular docking strategy results showed that 9 compounds in ACR have good affinity with protein crystal, and benzyl cinnamate (10-100 µg/mL) could inhibit cell migration and induce apoptosis. Conclusions: The anti-RA effect of ACR may be attributed to its anti-proliferative and anti-migration effects on synovial fibroblasts. These data suggest that Cinnamomi ramulus may have therapeutic value for the treatment of RA.