HCRT and ulcerative colitis: Of interest, in vitro, as well as, animal studies have shown the anti-inflammatory effects of orexin-A on cells and tissues involved in various diseases, such as multiple sclerosis, ulcerative colitis etc.; these effects are exerted via either inhibiting the synthesis and secretion of pro-inflammatory cytokines, or inducing the synthesis of anti-inflammatory cytokines and mediated via orexin receptors orexin-A receptor 1 (OX1R) and orexin-A receptor 2 (OX2R) [8,9,10].