Toxicological Evaluation of Neosugar: Genotoxicity, Carcinogenicity, and Chronic Toxicity

Neosugar, a fructooligosaccharide mixture, was tested for genotoxicity in three assays: (1) microbial reverse mutation assays in Salmonella typhimurium (Ames assay) and Escherichia coli WP2 uvr A, (2) the L5178Y mouse lymphoma TK ± mammalian cell mutation assay, and (3) an assay for the induction of unscheduled DNA synthesis (UDS) in human epithelioid cells (HeLa S3). Each assay was conducted at a wide range of dose levels, both with and without metabolic activation. Test results gave no indication that neosugar possessed any genotoxic potential. The carcinogenicity and chronic toxicity of neosugar were examined in Fischer 344 rats. Rats were fed diets containing 0, 8000, 20,000, or 50,000 ppm neosugar for 104 weeks. No dose-related effects on survival, growth, hematology, blood chemistry, organ weights, or nonneoplastic lesions were observed. The incidence of rare and spontaneous tumors was comparable between control and neosugar treatment groups, with the exception of pituitary adenomas in male rats. In light of the background incidence of this tumor and an equivocal dose-response trend, it is unlikely that neosugar treatment is related to the incidence of pituitary adenomas in male rats. The results of this study indicate that neosugar is nonmutagenic and that rats are not adversely affected by chronic neosugar exposure.