EDN1 and rheumatoid arthritis: A recent study conducted by Abbasifard et al32 was based on the development of bee venom nanoemulsion which was evaluated for its penetration and activity to modulate serum levels of endothelin-1 (which is a pro-inflammatory factor that participates in RA pathogenesis) in collagen-induced RA model and found to have good skin permeation and showed a decrease in serum level of endothelin-1, because of anti-oxidant, anti-inflammatory and immunomodulatory effect of bee venom.