Suppression by azelastine hydrochloride of NF-kappa B activation involved in generation of cytokines and nitric oxide. 
The influence of the anti-allergy agent azelastine hydrochloride (Azeptin) on NF-kappa B activation associated with the generation of cytokines and nitric oxide (NO) was investigated in various kinds of human and mouse cells. Azeptin dose-dependently suppressed both DNA and protein synthesis in human gingival fibroblasts (HF) and also suppressed blastogenesis of human peripheral blood lymphocytes (PBL). Generation of tumor necrosis factor-alpha, interleukin 1-beta, granulocyte-macrophage colony-stimulating factor and interleukin-6 from 10(-5) M Azeptin-treated PBL and human monocytes (HM) was decreased to approximately 1/3 to 2/3 of the control levels. In parallel with the decreased cytokine generation, each cytokine mRNA was less expressed in the presence of 10(-5) M Azeptin. In addition, both inducible nitric oxide synthase-mRNA level and NO generation in mouse peritoneal macrophages were suppressed by 10(-5) M Azeptin. Being compatible with those results, Azeptin (10(-5) M) suppressed activation of NF-kappa B in PBL, HM and HF. These results appear to indicate that suppression of cytokine and NO generation by Azeptin results at least partially from the inhibition of NF-kappa B activation.