ABSTRACT
We studied antitumor activity in vitro and in vivo and partial chemical characterization of exobiopolymers (EBPs) of Agaricus brasiliensis produced by submerged cultivation. The EBPs comprised 61.2% total sugar and 22.3% total protein, and the chromatographic profile mainly identified mannose (65.5%), galactose (17.5%), and glucose (13.1%). In vitro analysis revealed a dose with antitumor effectiveness, time-dependent treatment, and 46% inhibition of solid Walker 256 tumors in rats. Metabolic changes were significant in the spleens of the animals; this is possibly related to higher immune activity triggered by the presence of EBPs in the treated group. The increase of nitric oxide production by peritoneal macrophages from animals may be related to the tumor reduction observed, because nitric oxide acts as an important effector pathway in the defense of the organism.