It is of great concern that recent allergic diseases-including atopic dermatitis, allergic rhinitis, asthma, allergic conjunctivitis, contact dermatitis, occupational allergies, and drug allergy have become prevalent over the last few decades, especially in infants and young children in developing countries.1) These kinds of allergic symptoms may result from increasing industrial pollutants and environmental risk factors like antigens, endocrine disruptors, artificial foodstuffs, etc. Over the last several decades, the incidence of allergic diseases-especially atopic dermatitis-in developed countries has been constantly increasing 3-5 times; however, the treatment for such allergic diseases and their frequently-recurring symptoms are limited.
2)On the other hand, inflammation-related diseases-such as atopic dermatitis, allergic rhinitis and asthma-are considered chronic diseases caused by severe immune imbalances between Th1 and Th2 cell subsets.3) It has now been revealed that some of all cytokines 10,13,25, 31, 32, 33) and chemokine receptors are associated with the balance of these two subsets of T cell lineage in atopic dermatitis.4) The activation of mast cells during immune stimulation requires several kinds of events, most of which happen successively in mast cells: 1) Fc receptor-mediated triggering, 2) an increase in intracellular calcium concentration and decreased levels of cAMP signaling via a process of degranulation of mast cells, and 3) histamine or mediator release.5) A variety of signs and symptoms-vascular permeability, edema, itching, allergies, bronchial smooth muscle contraction-caused by the mediators released from mast cells then appear.6,7) If we can estimate the expression profiles between the cells, this will result in a preventive remedy against atopic dermatitis that will be especially rewarding because at present there are few potent natural agents or other non-steroidal drugs.The underlying mechanism for atopic dermatitis is still not clearly known. Temporary treatment with steroids and antihistamines relieves the symptoms, but the possibility of side effects still remains with these kinds of drugs. 8) Nevertheless, there are under researching on clinical efficacy test of chemicals or natural products. This research is guided by the activation of mast cells on atopic dermatitis-induced mast cells using a compound 48/80-induced mouse model in order to verify whether ovalicin has potential in ameliorating atopic dermatitis symptoms.In the course of screening anti-allergic agents, we found that a culture broth from Metarhizium anisopliae var. anisopliae has potential activity against atopic dermatitis-related symptoms when we used a compound 48/80-induced animal model. We isolated and purified the active constituent and finally identified the compound as ovalicin. In this report, we investigate whether ovalicin ameliorates atopic dermatitis symptoms in vivo. To further confirm the decrease of atopic dermatitis symptoms, we isolated the mast cells from mice, and examined whether the gr...