Biological activity and food analysis of Cyttaria spp. (Discomycetes)

The biological activity and nutritional composition of Chilean collections of Cyttaria berteroi C, darwinii, C, espinosae, C. harioti and C. johowii h ave been determined. The crude protein, lipid, ash, and carbohydrate conten t of the samples examined were similar to that of other edible fungi. Amino acid analysis of Chilean Cyttaria showed that proteins of no species are d eficient in methionine and cysteine and excepting one C. espinosae collecti on, all samples proven to be below the WHO values for the essential amino a cids valine, isoleucine, leucine, and lysine. The acute oral toxicity rest of C, espinosae in mts showed that doses up to 2.5 g extract/kg body weight (corresponding to 25.7-38.7 g fresh weight/kg) did nor produce mortality o r microscopic damage in the organs examined of the test animals. Cyttaria e xtracts assayed at 50 mu g/ml were inactive or moderately active as inhibit ors towards the enzymes xanthine oxidase (0-31%) and beta-glucuronidase (0- 65%), and lacked antifungal and antibacterial effects in a battery of antim icrobial assays. When administered intravenously at 2.5 mg/kg, the water-so luble extract of Cyttaria produced a hypotensive response in rats (-16 to - 21%). Furthermore, most of the aqueous extracts of C. espinosae and C. hari oti showed DNA binding activity. The main sterols from Cyttaria espinosae a nd C. berteroi were identified as dihydrobrassicasterol derivatives. Our st udy suggests that edible Cyttaria species no not represent an acute toxicit y risk for consumers and that their nutritional value is similar to that of other edible, cultivated mushrooms, The preservation of Cyttaria spp. as f ood resource is linked to the protection of the temperature Nothofagus fore sts.