Anti-allergic effects of Rosae multiflorae fructus via inhibition of T cell proliferation and the mast cell function

Anti-allergic effects of the hot water extract of Rosae multiflorae fructus (Rosae extract), which has long been used in oriental medicine for treatment of various diseases, were explored with a chicken ovalbumin (cOVA)-induced mouse model of food allergy. Compared to the sham mice to show severe allergic symptoms (i.e., anaphylaxis, diarrhea and decrease in the body temperature) following oral cOVA challenge, the Rosae extract-treated mice showed a marked improvement in those symptoms. Histology data demonstrated that Rosae extract treatment resulted in a amelioration in the intestinal inflammatory lesion and a reduction in the numbers of mast cells and eosinophils in the small intestine. Studies using DO11.10 TCR transgenic T cells indicated that Rosae extract had an activity to subdue the antigen-specific T cell activation/proliferation in vivo and thereby to lower the level of Th2 cytokine production by T cells during the antigen-specific immune response. Moreover, passive systemic anaphylaxis study showed that the extract also had an activity to inhibit the mast cells function in vivo, i.e., release of granules triggered by specific IgE-antigen interaction. Altogether, the results from this study not only imply a potential clinical application of Rosae extract in prevention and treatment of food allergy but also clearly elucidate the immunoregulatory mechanisms of Rosae extract underlying its anti-allergic effect.