A polysaccharide-rich fraction (ATF) of medicinal mushroom
Agaricus brasiliensis
was evaluated on the candidacidal activity, H
2O
2 and nitric oxide (NO) production, and expression of mannose receptors by murine peritoneal macrophages. Mice received three intraperitoneal (i.p.) injections of ATF and after 48 h their peritoneal resident macrophages were assayed against
Candida albicans
yeast forms. The treatment increased fungicidal activity and it was associated with higher levels of H
2O
2, whereas NO production was not affected. We also found that the treatment enhances mannose receptor expression by peritoneal macrophages, which are involved in the attachment and phagocytosis of non-opsonized microorganisms. Treatment of animals with ATF was able to enhance the clearance of
C. albicans during the first 6 h after the experimental i.p. infection. Our results suggest that this extract can increase host resistance against some infectious agents through the stimulation of microbicidal activity of macrophages.
