The carcinogenicity of beta-cyclodextrin, a cyclic, water-soluble carb
ohydrate comprising seven glucose units, was examined in Fischer 344 (
F344) rats. Groups of 50 males and 50 females were given the compound
in their diet at concentrations of 0 (control), 2.5 or 5% for 104 wk.
Surviving rats were then given a basal diet for a further 5 wk and kil
led at 109 wk. The dose levels were selected from the results of a 13-
wk subchronic toxicity study. Dose-dependent inhibitory effects of bet
a-cyclodextrin on growth were observed in both sexes of the treated gr
oups. The survival rates, mean survival times and range, however, demo
nstrated no significant differences between the control and treated gr
oups. A variety of tumours developed in all groups, including the cont
rol group, but all the neoplastic lesions were histologically similar
to those known to occur spontaneously in this strain of rat, and no st
atistically significant increase in the incidence of any tumour was fo
und for either sex of the treated groups. Thus, it is concluded that u
nder the present experimental conditions, the high dose, about 340-400
times higher than the current daily human intake from ingestion as a
food additive and from pharmaceutical use, does not have any carcinoge
nic potential in F344 rats. (C) 1997 Elsevier Science Ltd.