Lack of chronic toxicity or carcinogenicity of dietary N-acetylglucosamine in F344 rats

Chronic toxicity and carcinogenicity of N-acetylglucosamine (GlcNAc) were examined in male and female F344 rats. GlcNAc was given in the diet at levels of 0%, 1.25%, 2.5% or 5% to groups of 10 rats of each sex for 52 weeks in the chronic toxicity study and 0%, 2.5% or 5% to groups of 50 rats of each sex for 104 weeks in the carcinogenicity study. GlcNAc exerted no toxic effects with regard to clinical signs, mortality, hematology, serum biochemistry and histopathological assessment. Slight suppression of body weight gain was observed at more than 2.5%, but this appeared to be due to slight reduction of caloric intake with the high concentration of test compound, rather than any toxicity. Thus, it was concluded that GlcNAc has neither toxic nor carcinogenic effects in F344 rats, the no observed adverse effect levels (NOAEL) estimated from the chronic toxicity study being 5% in both sexes, equivalent to 2323 and 2545 mg/kg/day in males and females, respectively.