New perspective: the multi-targets mechanism of hydroxychloroquine in the treatment of rheumatoid arthritis based on network pharmacology

Background Network pharmacology is a new method of bioinformatics in exploring drug targets in recent 3 years. Hydroxychloroquine (HCQ) is a multi-targets drug that are clinically effective in rheumatoid arthritis (RA) but whose mechanism is not well understood. Methods The predicted targets of HCQ and the proteins related to RA were returned from databases. Followed by protein-protein interaction (PPI) network, the intersection of the two group of proteins was conducted. Furthermore, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment was used to analyse these proteins in a macro perspective. Finally, the candidate targets were verified by molecular docking. Results The results suggest that the efficacy of HCQ against RA is mainly associated with 4 targets of smoothened homolog (SMO), sphingosine kinase (SPHK) 1, SPHK2 and gatty-acid amide hydrolase (FAAH), with their related 3316 proteins’ network which regulate ErbB, HIF-1, NF-κB, FoxO, Chemokine, MAPK, PI3K/Akt pathways and so forth. Biological process are mainly concentrated in the regulation of cell activation, myeloid leukocyte activation, regulated exocytosis and so forth. Molecular docking analysis shows that hydrogen bonding and π-π stacking are the main forms of chemical force. Conclusions Our research provides protein targets affected by HCQ in the treatment of RA. SMO, SPHK1, SPHK2 and FAAH involving 3316 proteins become the multi-targets mechanism of HCQ in the treatment of RA. As well, the research also provides a new idea for introducing network pharmacology into the evaluation of the multi-target drugs in internal medicine.