Inhibitory effects of niclosamide on inflammation and migration of fibroblast-like synoviocytes from patients with rheumatoid arthritis

This study evaluated the anti-inflammatory effect of niclosamide in tumor necrosis factor (TNF)-alpha-stimulated human rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) and inhibitory effects on migration and invasion in RA FLS and investigated the signal mechanism, and further explored the treatment activity of niclosamide on collagen-induced arthritis (CIA). The levels of interleukin (IL)-1 beta, IL-6, IL-8, IL-10,IL-17A and interferon (IFN)-gamma in cultural supernatants were measured by multiplex cytokine assay kits. RA FLS migration and invasion in vitro were measured by the Boyden chamber method and the scratch assay. Signal transduction proteins expression was measured by western blot. The in vivo suppressive effects of niclosamide were elucidated on CIA in a mouse model. Niclosamide reduced the secretion of IL-1 beta, IL-6, IL-8, IL-17A and IFN-gamma from TNF-alpha-induced RA FLS in a dose-dependent manner. Niclosamide inhibits FBS-induced migration and invasion and exhibits F-actin alterations in RA FLS. Niclosamide decreased the phosphorylation of c-Jun N-terminal kinase and ERK in TNF-alpha-stimulated RA FLS and blocked TNF-alpha-induced IKK, I kappa B alpha phosphorylation and translocation of p65. Niclosamide treatments reduced the severity of CIA model. Our data suggest for the first time that niclosamide posses the anti-inflammatory effect in RA both in vitro and in vivo.