Immunostimulating effects of Maitake mushroom [beta]-glucan

Townsend Letter for Doctors and Patients, June, 2006 by Jule Klotter

Supplements derived from the Maitake mushroom (Grifola frondose) can stimulate the immune system, according to a mouse study in the peer-reviewed Journal of the American Nutraceutical Association (2005;8(3)). The study compared Grifton-Pro Maitake D Fraction (MDF), a highly-purified [beta]-glucan; Maitake Gold 404, a [beta]-glucan-protein complex (MTG); and lentinan, a well researched, mushroom-derived glucan that acted as a control. Beta glucans have been isolated from yeast, mushrooms, and seaweed. Their effect on the immune system has been the subject of numerous studies.

In this study, mice received MDF, MTG, or lentinan orally or by injection (intraperitoneal) at different doses. The researchers looked at several markers, including monocyte levels, phagocytosis (the digestion of foreign substances and bacteria by monocytes), T-cells, Interleukin-1 (IL-1), Interleukin-2 (IL-2), tumor necrosis factor-a (TNF-a), and apoptosis. They learned that the Maitake-derived supplements have several effects on the immune system. Oral doses of MDF, MTG, and lentinan (100 [micro]g of glucan/mouse for 14 days) produced "significant stimulation of phagocytosis." Injected delivery of MTG and MDF had a somewhat greater effect. MTG stimulated phagocytosis at injected levels as low as 2.6 [micro]g/mouse. Lentinan required doses of at least 50 [micro]g for a significant effect, and MDF required at least 100 [micro]g before a significant result occurred. IP injections of the Maitake-derived supplements also significantly increased the number of CD4-positive cells. (CD4 cells are T-cells that carry CD4 glycoprotein on their surface. They help produce the antibodies that make IL-2, a protein with several immunologic functions that include increasing activated T-cell levels.) Injected lentinan and injected MDF produced significantly higher levels of IL-2 than the control, Concanavalin A. Concanavalin-A is used in immunology to stimulate T-cell production. MTG was slightly less effective than Concanavalin-A. MTG and MDF, administered by injection, resulted in higher levels of IL-1[beta] secretion than lentinan produced. The elevations appeared within 30 minutes. Interleukin-1[beta] enhances the growth and differentiation of phagocytic [beta] cells. The researchers found little effect on TNF-[alpha] production (tumor necrosis factor-a). They also found no apoptosis (cellular self-destruction) among breast, lung, or prostate cancer cells when exposed to these glucans.

Vetvicka V, Vetvickova J. Immunostimulating properties of two different b-glucans isolated from maitake mushrooms (Grifola frondose). JANA. 2005; 8: 33-39. Available at www.anajana.org/members/journals/JANAVol_91.pdf. Accessed on February 6, 2006.