Immunomodulatory effect of Eriobotrya japonica seed extract on allergic dermatitis rats.

We examined the immunomodulatory effect of Eriobotrya japonica seed extract (ESE) on rat allergic dermatitis elicited by repeated dinitrofluorobenzene (DNFB) application on the ear. Oral administration of ESE significantly inhibited development of allergic dermatitis based on lower ear thickness and serum immunoglobulin E (IgE) levels. Th1 cytokine interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), Th2 cytokine interleukin-4 (IL-4) and interleukin-10 (IL-10) in the lesional skin were determined. Oral administration of ESE significantly decreased IL-4 while significantly increasing IL-10 in lesional skin, and the lower levels of IFN-gamma and IL-2 were reversed by oral administration of ESE. The infiltration of eosinophils in the lesional skin was decreased by oral administration of ESE. These results suggested that ESE exerts anti-allergic actions by improving the balance of Th1/Th2 in allergic dermatitis.