ORAL TOXICITY AND CARCINOGENICITY STUDIES OF SUCROSE ACETATE ISOBUTYRATE (SAIB) IN THE FISCHER-344 RAT AND B6C3F(1) MOUSE

Sucrose acetate isobutyrate (SAIB), a food additive used as a flavour emulsion stabilizer in citrus-based soft drinks, was evaluated,for chr onic toxicity in B6C3F(1) mice and Fischer 344 rats. SAIB dissolved in acetone was blended into NIH07 rodent diet at concentrations that wer e adjusted weekly during the first 12 to 18 months of the studies so t hat ingested dose levels per kg body weight were constant. Groups of 2 0 rats per sex were given dose levels of 0.0, 0.0, 0.5, 1.0 and 2.0 g SAIB/kg body weight for 1 yr, and groups of 50 rats per sex were given dose levels of 0.0, 0.0, 0.5, 1.0 and 2.0 g SAIB/kg body weight for 2 yr. Mice were fed dose levels of 0.0, 0.0, 1.25, 2.5 and 5.0 g SAIB/k g body weight for 2 yr. The highest doses fed, equivalent to dietary c oncentrations of approximately 5%, were considered to be the maximum c oncentrations that could be fed without risk of nutritional deficienci es. Depressions in body weight gain were noted, particularly in female rats during the first 12 to 18 months of the studies. Recovery during the last quarter of the 2-yr study suggests that the reduced body wei ght gain was nutritional rather than SAIB-related. There were no diffe rences in survival between SAIB-treated rats or mice and controls. Dec reased body weight gains, primarily in females, but less consistent th an those in the rat, were noted in the 2-yr mouse study. No signs of t oxicity were observed in clinical chemistry, haematology, organ weight s, gross necropsy findings or light microscopy studies in the 1- or 2- yr rat studies. Electron microscopic examinations of liver sections fr om high dose level rats from the l-yr study also revealed no effects o f SAIB treatment. There were no significant increases in benign or mal ignant tumours in the long-term rat or mouse carcinogenicity studies. The lowest no-observed-adverse-effect level (NOAEL) was 2 g SAIB/kg bo dy weight derived from the 1- and 2-yr chronic toxicity studies in the rat. (C) 1998 Elsevier Science Ltd. All rights reserved.