A novel anti-allergic drug, betotastine besilate, suppresses interleukin-5 production by human peripheral blood mononuclear cells.

The effect of a novel anti-allergic drug, betotastine besilate (betotastine) on interleukin (IL)-5 production by human peripheral blood mononuclear cells (PBMC) was investigated. PBMC of Dermatophagoides farinae extract (Df)-sensitive donors produced IL-5 and showed a proliferative response upon stimulation with relevant antigen (10 microg/ml). Df-induced IL-5 production by PBMC was significantly inhibited by betotastine at 10 and 100 microM. Betotastine also suppressed proliferation of PBMC with less potency. The effect of betotastine on IL-5 production was enhanced and significant even at 0.1 microM when the drug was added 120 min before antigen stimulation. Ketotifen and cetirizine also inhibited IL-5 production, but the effects of these drugs were significant only at 100 microM. These findings indicate that the suppression of IL-5 production may be involved in the anti-allergic effect of betotastine.