The Mushroom Agaricus blazei Murill Elicits Medicinal Effects on Tumor, Infection, Allergy, and Inflammation through Its Modulation of Innate Immunity and Amelioration of Th1/Th2 Imbalance and Inflammation

Abstract

The medicinal mushroom Agaricus blazei Murill from the Brazilian rain forest has been used in traditional medicine and as health food for the prevention of a range of diseases, including infection, allergy, and cancer. Other scientists and we have examined whether there is scientific evidence behind such postulations. Agaricus blazei M is rich in the immunomodulating polysaccharides, β-glucans, and has been shown to have antitumor, anti-infection, and antiallergic/-asthmatic properties in mouse models, in addition to anti-inflammatory effects in inflammatory bowel disease patients. These effects are mediated through the mushroom's stimulation of innate immune cells, such as monocytes, NK cells, and dendritic cells, and the amelioration of a skewed Th1/Th2 balance and inflammation.

Figures

Figure 1

Agaricus blazei Murill. Photo NutriCon. The mushroom is cultivated commercially for the health food market in Japan, China, and Brazil. The AbM-based AndoSan extract is produced in Japan and developed and distributed by ImmunoPharma AS, Oslo, Norway.

Figure 2

5-6-week-old female inbred NIH/Ola mice were given either 200 μL of AndoSan AbM extract or phosphate-buffered saline (PBS) intragastrically a day before i.p. injection of 1 million colony-forming units of Streptococcus pneumoniae serotype 6B. There was a significant difference (P < 0.05) between survival after treatment with AndoSan (red line) and PBS (black line). From [14], permission granted for republication by Scand J Immunol, where the figure was originally published.

Figure 3

Female NIH/Ola mice were given either 200 μl of the AndoSan AbM-based extract or PBS intragastrically on day 1 and 10 μg of ovalbumin s.c. on day 0 and again on day 20, before exsanguination for serum on day 26. IgE antiovalbumin levels were lower in the AbM- than in the PBS-treated groups (P = 0.002). Similar results were found if AbM extract or PBS was given 3 weeks after the allergen immunization (not shown, please see [16]). IgG2a antiovalbumin levels (Th1 response) tended to show the opposite result (not shown). From [16], previously published by a BMC journal, which allows reuse.

Figure 4

Bar graphs (mean and standard error the mean (SEM)) with levels of cytokines (pg/mL) MIP-1β, IL-6, IL-8, and MCP-1 (a) and IL-1β, G-CSF, and GM-CSF (b) in stimulated (LPS 1 ng/mL) whole blood ex vivo from eleven patients (unless otherwise stated) with ulcerative colitis prior to (day 0) and after AndoSan consumption for 12 days. Days 0 and 12 after stimulation are depicted by the first and second bars from the left, respectively. For MIP-1β and IL-8, measurements in nine out of ten patients were available. Corresponding measurements from eleven patients with Crohn's disease (unless otherwise stated) were significantly reduced for cytokines MIP-1β, MCP-1, IL-8, and IL-1β (c) and G-CSF, IL-17, GM-CSF, and IL-2 (d). For MIP-1β and IL-8, measurements in ten out of eleven patients were available. Despite remeasurement of MIP-1β after dilution of plasma 1/10, high out of range values still occurred. Accordingly, the true concentrations of MIP-1β were even higher. The P values between the bar graphs compare with the cytokine levels at day 0 prior to the intake of AndoSan. From [24] where the data was part of scatter plots in Scand J Immunol.

Figure 5

Role of the mushroom Agaricus blazei Murill in immune system modulation and disease control. It is assumed that besides β-glucans also other, yet unknown substances in the mushroom, probably of low molecular weight, do parttake in the action. IL-12 is the cytokine from the monocyte/dendritic cell that stimulates Th0.

Figure 6

The Ying and Yang of adaptive immunity. There is a balance between the Th responses in such a way that Th1 inhibits Th2, which inhibits Th17 and which again inhibits the Treg response. “Over-shoot” of Th1 and Th17 responses in susceptible individuals can result in autoimmune disorders. The regulation by T reg cells results in immunosuppression and tolerance. The Agaricus mushroom shifts the Th1/Th2 balance towards increased Th1 response, which in addition to intracellular pathogens also fights cancer.