OBJECTIVETo evaluate the immunoregulatory effects of the Lonicera water extract in the ovalbulmin (OVA)-sensitized BALB/c mice and to explore feasibility of treating food allergy with the traditional Chinese medicine (TCM).

METHODSForty female BALB/c mice aged 6 weeks fed with ovalbulmin-free feed, were randomly divided into 5 groups with 8 mice in each. Four groups were sensitized with OVA intraperitoneally two times and challenged intragastrically four times. Groups H, M and L were treated respectively with high (100 mg/100 ml), medium (50 mg/100ml) and low (25 mg/100 ml) concentration of the Lonicera water extract at a dose of 0.3 ml/10 g body weight just 4 hours after the first challenge and then twice daily for 10 consecutive days. The mice in group Ch were used as positive control and were sensitized intraperitoneally and treated with normal saline solution intragastrically daily. The mice in NS group were used as negative control without sensitization and challenge. Just 1 hour after the last challenge, the mice in each group were sacrificed and specimens of jejunum were taken. Histological examinations on the jejunum specimens were performed after either HE or toluidine blue staining, the levels of histamine in gut of the mice were assayed with a fluorescent method; the IFN-gamma and IL-4 production in peripheral lymph node mononuclear cell (PLNMC) and the OVA-specific IgE levels in serum were measured by using ELISA; the mRNA expression of IL-12p40 in PLNMC of the mice was evaluated by RT-PCR; the footpad swelling reactions were assessed for the OVA-induced delayed hypersensitivity.

RESULTS(1) The inflammatory reactions were significantly inhibited in the mice of group H and M; the accumulated and degranulated mast cells in lamina propria were significantly reduced in the mice by gavage with 100% or 50% of the Lonicera extract, concomitant with the increased percentage of the intact mast cells. (2) The release of histamine in gut in the mice of group H and M was significantly reduced. (3) Either the IL-4 production and the ratio of IL-4/IFN-gamma in PLNMC or the IFN-gamma generation was significantly reduced in group H and M. (4) IL-12p40 mRNA expression in PLNMC was significantly reduced in group H and M. (5) The levels of OVA-specific IgE in serum were reduced in the mice of group H and M. (6) The footpad swelling reactions induced in the allergic mice were significantly inhibited after giving the Lonicera extract of the three different concentrations.

CONCLUSIONThe Lonicera extract showed significant immunoregulatory effects in OVA-induced allergic mice model in this study. Lonicera extract may be of potential research value in treatment of both IgE and none IgE mediated food allergy.