The biological properties of Agaricus brasiliensis mainly include immunostimulating and antitumour activities. This study evaluated the immunomodulating effect of A. brasiliensis mycelium (LPB) and its exopolysaccharides (EPS) on immunological parameters, such as phagocytosis of Candida albicans and nitric oxide (NO) production by infected macrophages, splenocytes proliferation in response to C. albicans. It also assessed the effects of the intake of LPB on the number of lymphocytes in the lymph node and spleen of treated animals and the TNF-a production. It was showed that the LPB and EPS had opposite effects; LPB had antiproliferative action and also reduced the NO levels produced by macrophages. However, the EPS showed an immune-stimulating effect potentiating the splenocytes proliferation and NO production from macrophages after stimulation with C. albicans. In addition, it also protected the macrophages from death induced by yeast. These data confirmed the immunomodulatory properties of LPB and its polysaccharides.

The biological properties of Agaricus brasiliensis mycelium, including their immuno-stimulating and anti-tumour activities, have previously been investigated. The aim of this study was to evaluate the effects of long-term intake of A. brasiliensis mycelium cultivated on wheat grains by solid-state culture on tumour growth and immune response in Sarcoma 180 tumour-bearing mice. Mice received dietary supplementation with 100% or 50% Agaricus mycelium cultivated on wheat grains for 14 weeks and were inoculated with Sarcoma 180 tumours. We found that A. brasiliensis had anti-tumour activity, and that dietary supplementation with a 50% concentration (A50S) prevented loss of body weight, inhibited tumour growth, induced the increase of CD4 ' T cells and CD25 ' CD4 ' T subsets in peripheral organs and downregulated Tumor necrosis factor alpha production in plasma. Our results confirm that dietary supplementation with Agaricus may offer immunomodulatory activity and protection against tumour growth.