Targets of hydroxychloroquine in the treatment of rheumatoid arthritis. A network pharmacology study

•Four targets play a key role in the treatment of rheumatoid arthritis with hydroxychloroquine: smoothened homolog (SMO), sphingosine kinase (SPHK) 1, SPHK2 and gatty-acid amide hydrolase (FAAH).•The related 3316 proteins’ network which regulate ErbB, HIF-1, NF-κB, FoxO, chemokines, MAPK, PI3K/Akt pathways participate in the multi-targets mechanism of hydroxychloroquine.•Molecular docking analysis demonstrated that hydrogen bonding and π-π stacking are the main forms of chemical force of hydroxychloroquine and the targets.