Subchronic toxicity and genotoxicity studies of Antrodia mushroom β-glucan preparation.

Antrodia cinnamomea is one of the most highly valued mushrooms utilized in traditional Taiwanese therapeutic practices. Its neutral monosaccharides (mannose, glucose and xylose) linked by a β-D-glucan chain have been claimed to be responsible for its health benefits. The objective of the present study was to investigate adverse effects, if any, of β-glucan (∼65% pure) from A. cinnamomea in subchronic toxicity and mutagenicity studies. In the subchronic toxicity study, Sprague Dawley rats (12/sex/group) were followed Organization for Economic Cooperation and Development (OECD) test guideline with Good Laboratory Practice (GLP) application, and were administered (gavage) Antrodia mushroom β-glucan preparation at dose levels of 0, 500, 1000 and 2000 mg/kg body weight (bw)/day for 90 days. Treatment with β-glucan preparation did not result in any toxicologically significant treatment-related changes in clinical observations, ophthalmic examinations, body weights, body weight gains, feed consumption, and organ weights. The clinical pathology as studied by hematology, serum chemistry, urinalysis or terminal necropsy (gross or histopathology findings) did not reveal any treatment-related adverse effects. The results of mutagenicity studies as evaluated by gene mutations in Salmonella typhimurium, in vitro chromosome aberrations and in vivo micronucleus test in mice did not reveal any genotoxicity of β-glucan preparation. Based on the subchronic study, the no observed-adverse-effect level (NOAEL) for β-glucan preparation from Antrodia mushroom was determined as 2000 mg/kg bw/day, the highest dose tested.