Objective To observe the effect of several antihistamines,including epinastine,on the release of leukotriene B4(LTB4),interleukin 4(IL-4)and interleukin 5(IL-5)from spleen lymphocytes of allergic mice challenged by ovalbumin(OVA).Methods OVA-sensitized BALB/c mice were used as animal model of allergy.Spleen lymphocytes isolated from these mice were treated with epinastine(0.1,1.0,10 μmol/L),ebastine(10 μmol/L),cetirizine(10 μmol/L),and dexamethasone(1.0 μmol/L),respectively,followed by incubation with OVA.Those cells without pretreatment with antihistamines served as the control.One hour after the challenge,enzyme-linked immunosorbent assay(ELISA)was applied to measure the level of LTB4,IL-4 and IL-5 in the cell culture supernates.Results Following the incubation with OVA,the levels of LTB4,IL-4 and IL-5 increased significantly in culture supernates of control spleen lymphocytes.Epinastine significantly inhibited the release of LTB4,IL-4 and IL-5 in a dose-dependent manner.At the concentration of 10 μmol/L,the inhibitory effect of epinastine was more potent than that of ebastine and cetirizine for IL-5 and LTB4 release(all P＜0.05):for IL-4,the efrect of epinastine was similar to that of ebastine (P＞0.05)but more potent than that of cetirizine(P＜0.05).Conclusion Epinastine has a potent anti-inflammatory effect.