Biological Activity and Food Analysis ofCyttaria spp. (Discomycetes)

The biological activity and nutritional composition of Chilean collections ofCyttaria berteroi C. darwinii, C. espinosae, C. harioti andC. johowii have been determined. The crude protein, lipid, ash, and carbohydrate content of the samples examined were similar to that of other edible fungi. Amino acid analysis of ChileanCyttaria showed that proteins of all species are deficient in methionine and cysteine and excepting oneC. espinosae collection, all samples proved to be below the WHO values for the essential amino acids valine, isoleucine, leucine, and lysine. The acute oral toxicity test ofC. espinosae in rats showed that doses up to 2.5 g extract/kg body weight (corresponding to 25.7–38.7 g fresh weight/kg) did not produce mortality or macroscopic damage in the organs examined of the test animals. Cyttaria extracts assayed at 50 fig/ml were inactive or moderately active as inhibitors towards the enzymes xanthine oxidase (0-31%) and β-glucuronidase (0-65%), and lacked antifungal and antibacterial effects in a battery of antimicrobial assays. When administered intravenously at 2.5 mg/kg, the water-soluble extract ofCyttaria produced a hypotensive response in rats (-16 to -21%). Furthermore, most of the aqueous extracts ofC. espinosae andC. harioti showed DNA binding activity. The main sterols fromCyttaria espinosae andC. berteroi were identified as dihydrobrassicasterol derivatives. Our study suggests that edibleCyttaria species do not represent an acute toxicity risk for consumers and that their nutritional value is similar to that of other edible, cultivated mushrooms. The preservation ofCyttaria spp. as a food resource is linked to the protection of the temperateNothofagus forests.