OBJECTIVESince human mast cell is an important source of cytokines, it is of importance to understand the effects of anti-allergic drugs on cytokines modulation in mast cells. In the present study, we aimed at observing whether IL-4 could be released from human mast cell line (HMC-1) after the stimulation of PMA + A23187, and the effects of systemic glucocorticosteroid, dexamethasone, topical glucocorticosteroid, budesonide and H1 antagonist, desloratadine on IL-4 release and mRNA expression.

METHODSHMC-1 was stimulated with 25 ng/ml phorbol 12-myristate 13-acetate (PMA) and 2.5 x 10(-7) mol/L ionomycin (A23187) and cultured for 6 hours, 12 hours and 24 hours respectively in the presence or absence of 10(-6)-10(-10) mol/L concentrations of test drugs. Culture supernatants were collected and the levels of IL-4 were assayed by enzyme-linked immunosorbent assays (ELISA). The mRNA expression of IL-4 was measured by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSHMC-1 expressed IL-4 mRNA and the resulting protein production of IL-4 released after being stimulated with PMA plus A23187. Dexamethasone, budesonide and desloratadine had potent inhibitory effect on IL-4 release at any concentrations and time points, with significant deference (P < 0.05) compared to the control cells. The inhibitory effect did not show time-dependent and concentration-dependent manner. Desloratadine and budesonide showed neither up-regulatory nor down-regulatory effects on IL-4 mRNA expression at the test concentrations, however, desloratadine could down-regulate IL-4 mRNA expression.

CONCLUSIONSHMC-1 could express and produce IL4 after stimulation. Dexamethasone, budesonide and desloratadine all had inhibitory effects on IL-4 release from HMC-1. In addition, desloratadine could also inhibit the IL-4 mRNA expression.