International Agency for Research on Cancer (IARC) - Summaries & Evaluations
CYCASIN
VOL.: 10 (1976) (p. 121)
CAS No.: 14901-08-7
Chem. Abstr. Name: (Methyl-ONN)azoxymethyl-b-D-glucopyranoside
5. Summary of Data Reported and Evaluation
5.1 Animal carcinogenicity data
Cycasin is carcinogenic in mice, rats, hamsters, guinea-pigs, rabbits
and fish; it produced a variety of malignant tumours, mainly in the
liver, kidney and intestine. It is carcinogenic in rats, hamsters,
guinea-pigs, rabbits and fish following its oral administration. It is
active in newborn and suckling mice and newborn rats and hamsters
after its subcutaneous injection both in single doses and following
prenatal exposure. The carcinogenicity of its aglycone,
methylazoxymethanol, has been demonstrated in rats following its
intraperitoneal administration and in hamsters following its
intraperitoneal or intravenous administration. The closely-related
synthetic substance, methylazoxymethanol acetate, is carcinogenic in
rats by various routes of administration (see Appendix).
5.2 Human carcinogenicity data
The one epidemiological study reported showed no appreciable increase
in cancer mortality 2 to 7 years after heavy intake of cycads. This
negative result is insufficient to exclude a possible carcinogenic
effect of cycasin in man. No case reports or other epidemiological
studies of cancer in relation to exposure to cycasin or
methylazoxymethanol were available to the Working Group.
Previous evaluation: Vol. 1 (1972)
Subsequent evaluation: Suppl. 7 (1987) (p. 61: Group 2B)
For definition of Groups, see Preamble Evaluation.
Synonyms for Cycasin
- b-D-Glucosyloxyazoxymethane
- Methylazoxymethanol-b-D-glucoside
Last updated: 22 March 1998