title: Carcinogenesis Bioassay of Locust Bean Gum (CAS No. 9000-40-2) in F344 Rats and B6C3F1 Mice (Feed Study).
abstract: A carcinogenesis bioassay of locust bean gum, a widely used food stabilizer, was conducted by feeding diets containing 25,000 or 50,000 ppm of the test substance to 50 F344 rats and 50 B6C3F1 mice of either sex for 103 weeks. Groups of 50 untreated rats and mice of either sex served as controls. Mean body weights of high-and low-dose rats of either sex, of low-dose male mice, and of high-and low-dose female mice were comparable with those of the controls; mean body weights of high-dose male mice were slightly lower than those of controls. No other compound-related clinical signs or effects on survival were observed. Although the rats and mice might have been able to tolerate higher doses, 50,000 ppm (5%) is the recommended maximum concentration of a test chemical mixed in feed according to the guidelines of the Bioassay Program. Although alveolar/bronchiolar adenomas occurred in low-dose male mice at a significantly (P=0.017) higher incidence than that in the controls (7/50, 17/50, 11/50), no significant statistical results were obtained when the combined incidence of animals with either alveolar/bronchiolar adenomas or carcinomas was analyzed (14/50, 21/50, 14/50). Cortical adenomas in the adrenal gland of female rats occurred with a statistically significant (P=0.042) positive trend (1/50, 4/50, 6/50), but comparisons between test groups and the control group were not statistically different. Under the conditions of this bioassay, locust bean gum was not carcinogenic for male or female F344 rats or B6C3F1 mice. Levels of Evidence of Carcinogenicity: Male Rats: Negative Female Rats: Negative Male Mice: Negative Female Mice: Negative