Abstract: Objective To investigate the effects of Sidaxue (SX), a recipe in Miao ethnomedicine, on apoptosis and pyrolysis of human fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS). Methods The target proteins related with RA and those involved in cell apoptosis and pyroptosis were searched in different online databases, and Venny software was used to obtain apoptosis- and pyroptosis-related proteins in RA. RA-apoptosis-pyroptosis protein interaction (PPI) network was constructed to identity the key target proteins related with apoptosis and pyroptosis in RA. Autodock vina software was used to perform molecular docking to verify the binding ability of the main active ingredients in SX with the apoptosis- and pyroptosis-related proteins. In the cell experiment, MH7A cells were treated with 5 mg/L TGT (positive control) or 5, 10, 20, and 40 mg/L SX, and the changes in cell migration and invasion abilities and expressions of apoptosis- and pyroptosis-related proteins were examined using wound healing assay, Transwell assay, ELISA and Western blotting. Results We identified 9 RA-related apoptotic target proteins, 15 RA-related pyroptosis target proteins, and 4 overlapping target proteins related with RA, apoptosis and pyroptosis. The main active ingredients in SX had a high affinity with the target proteins including TNF-α, Fas, and Bax. In MH7A cells, SX treatment concentration-dependently increased the cell inhibition rate at 24, 48 and 72 h (P<0.05), and significantly lowered the cell migration ability at 6, 12 and 24 h (P<0.05); treatment with 20 and 40 mg/L SX for 24 h obviously suppressed MH7A cell invasion (P<0.05). SX treatment (20 and 40 mg/L) and TGT treatment both significantly lowered the expression levels of TNF-α, IL-1β, and IL-18 in the cells (P<0.05). The Bax/Bcl-2 ratio and Fas and FasL expressions were increased significantly in cells treated with 20 and 40 mg/L SX (P<0.05), and caspase-1 expression was decreased significantly in cells treated with 5 and 40 mg/L SX (P<0.05). Conclusion SX can induce apoptosis and pyroptosison in RA-FLSs possibly by down-regulating the expressions of TNF-α, IL-1β and IL-18, up-regulating the expressions of Bax, Fas, and FasL, and inhibiting Bcl-2 and caspase-1 protein expressions.

Key words: Miao ehtnomedicine recipe Sidaxue; rheumatoid arthritis; apoptosis; pyroptosis; data mining; molecular docking