title: Safety evaluation of an enzymatically-synthesized glycogen (ESG).
abstract: An enzymatically-synthesized glycogen (ESG), intended for use as a food ingredient, was investigated for potential toxicity. ESG is synthesized in vitro from short-chain amylose by the co-operative action of branching enzyme and amylomaltase. In an acute toxicity study, oral administration of ESG to Sprague-Dawley rats at a dose of 2000 mg/kg body weight did not result in any signs of toxicity. ESG did not exhibit mutagenic activity in an in vitro bacterial reverse mutation assay. In a subchronic toxicity study, increased cecal weights noted in the mid- (10%) and high-dose (30%) animals are common findings in rodents fed excess amounts of carbohydrates that increase osmotic value of the cecal contents, and thus were considered a physiological rather than toxicological response. The hematological and histopathological effects observed in the high-dose groups were of no toxicological concern as they were secondary to the physiological responses resulting from the high carbohydrate levels in the test diets. The no-observed-adverse-effect level for ESG in rats was therefore established to be 30% in the diet (equivalent to approximately 18 and 21 g/kg body weight/day for male and female rats, respectively). These results support the safety of ESG as a food ingredient for human consumption.
authors.affiliation: Cantox Health Sciences International, Mississauga, Ontario, Canada. stafazoli@cantox.com
authors.forename: Shahrzad
authors.initials: S
authors.lastname: Tafazoli
authors.forename: Andrea W
authors.initials: AW
authors.lastname: Wong
authors.forename: Hideki
authors.initials: H
authors.lastname: Kajiura
authors.forename: Ryo
authors.initials: R
authors.lastname: Kakutani
authors.forename: Takashi
authors.initials: T
authors.lastname: Furuyashiki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takata
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuriki
mesh_terms: D000688:Amylose / Q000737:chemistry*; D000818:Animals; D003257:Consumer Product Safety; D003912:Dextrins / Q000737:chemistry*; D004040:Dietary Carbohydrates / Q000032:analysis / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D005260:Female; D006003:Glycogen / Q000138:chemical synthesis / Q000737:chemistry / Q000633:toxicity*; D006004:Glycogen Debranching Enzyme System / Q000737:chemistry*; D006801:Humans; D007517:Isoamylase / Q000737:chemistry*; D008297:Male; D009152:Mutagenicity Tests; D051381:Rats; D017207:Rats, Sprague-Dawley; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D023382:Toxicity Tests, Acute; D036401:Toxicity Tests, Chronic
chemical_list: D003912:Dextrins; D004040:Dietary Carbohydrates; D006004:Glycogen Debranching Enzyme System; D006003:Glycogen; D000688:Amylose; C020569:4 alpha-glucanotransferase; D007517:Isoamylase