An extract of the medicinal mushroom Agaricus blazei Murill can protect against allergy

Since according to the Th1/Th2 paradigm an increased Th1 response may promote a reduced Th2 response, the aim was to examine whether AbM had anti-allergy effects.A mouse model for allergy was employed, in which the mice were immunized s.c. with the model allergen ovalbumin (OVA). Additionally, the animals were given a mushroom extract, AndoSan？, mainly (82%) containing AbM, but also Hericium erinaceum (15%) and Grifola frondosa (3%), or PBS p.o. either a day before or 19 days after the immunization. The mice were sacrificed on day 26, and anti-OVA IgE (Th2 response) and IgG2a (Th1 response) antibodies were examined in serum and Th1, Th2 and Treg cytokines in spleen cells cultures.It was found that the AndoSan？ extract both when given either before or after OVA immunization reduced the levels of anti-OVA IgE, but not IgG2a, in the mice. There was a tendency to reduced Th2 relative to Th1 cytokine levels in the AndoSan？ groups.This particular AbM extract may both prevent allergy development and be used as a therapeutical substance against established allergy.Agaricus blazei Murill (AbM) of the family Basidiomycetes is a popular edible medicinal mushroom, originally native to a small village, Piedade, in the highland areas of Atlantic forest near S？o Paulo, Brazil. It has traditionally been used for the prevention of a range of diseases, including cancer, hepatitis, atherosclerosis, hypercholesterolemia, diabetes and dermatitis [1,2]. Because of its alleged health effects, the mushroom was brought to Japan in the mid-60-ies and subjected to biomedical research. AbM was found to be rich in immuno-modulating substances such as β-glucans [3,4] and proteoglycans [5], and it had anti-infection [6,7] and anti-tumor [4,5] effects in mice.Anti-tumor and anti-infection immunity are both due to Th1 responses, which also do promote autoimmune disease when overshooting. On the other hand, anti-helminth and anti-rejection immunity are due to Th2 responses, which may also induce IgE