Azelastine Inhibits Secretion of IL-6, TNF-α and IL-8 as well as NF-κB Activation and Intracellular Calcium Ion Levels in Normal Human Mast Cells

Abstract

Background: Mast cells are involved in allergic inflammation by secreting histamine, proteases and several cytokines, including interleukin (IL)-6, tumor necrosis factor-α (TNF-α) and IL-8. Certain histamine-1 receptor antagonists, such as azelastine present in the ophthalmic solution Optivar^®, have been reported to inhibit histamine and tryptase secretion, but its effect on inflammatory cytokine release from normal human umbilical cord blood-derived cultured mast cells (hCBMC) are not well known. Methods: We investigated the effect of azelastine on the secretion of IL-6, TNF-α and IL-8 from hCBMC, as well as its possible mechanism of action. hCBMC sensitized with IgE were pretreated for 5 min with azelastine at 0.01, 0.1, 1, 3, 6, 12, 24, or 60 µM of Optivar^®, before stimulation with anti-IgE for 6 h. Optivar^® vehicle without azelastine was used as control. Cytokines were measured by ELISA, intracellular calcium levels by calcium indicators confocal, and nuclear factor-ĸB (NF-ĸB) by electromobility shift assay. Results: Stimulation with anti-IgE led to substantial secretion of IL-6, TNF-α and IL-8. Preincubation for 5 min resulted in almost maximal inhibition with 6 µM azelastine for TNF-α (80%), with 24 µM for IL-6 (83%) and 60 µM for IL-8 (99%); the vehicle solution at the same concentrations as Optivar^® had no effect. Stimulation with anti-IgE increased intracellular Ca²⁺ level and induced NF-ĸB expression in hCBMC, which was inhibited by 24 µM azelastine. Conclusion: Azelastine inhibited hCBMC secretion of IL-6, TNF-α and IL-8, possibly by inhibiting intracellular Ca²⁺ ions and NF-ĸB activation. Azelastine may, therefore, be helpful in treating allergic inflammation.

Rupatadine Inhibits Proinflammatory Mediator Secretion from Human Mast Cells Triggered by Different Stimuli

“…Moreover, pretreatment of mast cells with diphenhydramine (50 µ M ), which totally blocks the H 1 receptor, could not prevent the ability of rupatadine to inhibit mast cells (results not shown). Rupatadine may inhibit intracellular calcium ion elevations and/or nuclear factor-ĸB activation, as previously shown for azelastine [29]. The ability of rupatadine to antagonize PAF may also somehow contribute to mast cell inhibition, especially if PAF is secreted from mast cells and has an autocrine stimulatory action.…”

“…For instance, azelastine resulted in a maximal inhibition of tryptase (55%) and histamine (41%) release [28], as well as of IL-6 (83%) release from hCBMCs at 24 µ M [25]. Azelastine also inhibited IL-6, IL-8 and TNF release from hCBMCs stimulated by IgE/anti-IgE [29]. More recently, the H 1 receptor antagonists [30] epinastine (40 µ M ) and azelastine (200 µ M ) reduced IL-8 release by almost 30%, epinastine and olopatadine reduced IL-10 release by 30–50%, while epinastine and olopatadine reduced TNF release by about 30% [30].…”

Effect of Histamine H₁ Receptor Antagonists on TARC/CCL17 and MDC/CCL22 Production from CD14+ Cells Induced by Antigenic Stimulation in vitro

“…We also demonstrated that FEX is the most effective agent in terms of the suppression of TARC and MDC production from CD14+ cells after Cry j 1 stimulation. This conclusion may be supported by the observation that FEX exerted a significant suppressive effect at a concentration of 250 ng/ml, which is almost equal to therapeutic blood levels [18], but other agents, AZE, KET and OXA, required higher concentrations (approximately 1.5–2 times higher) than their therapeutic blood levels [19,20,21]. …”

Mast cell stabilisers

“…Many observations were reported upon evaluation of azelastine, including superior inhibition of IL6, tryptase and histamine secretion from mast cells over olopatadine (Kempuraj et al, 2002;Kempuraj et al, 2003). Azelastine is commonly formulated in combination with a corticosteroid; novel non aqueous formulations based on hydrofluoroalkane propellants offer promise in control of allergic rhinitis (Meltzer et al, 2014).…”