Study

SUMMARY OF DATA FOR CHEMICAL SELECTION MYRISTICIN CAS NO. 607-91-0 BASIS OF NOMINATION TO THE CSWG Myristicin is presented to the CSWG for review because of its potential for widespread human exposure through foods and beverages and the possibility of adverse effects in diverse populations. Information available on myristicin suggests a range of effects, some beneficial and others harmful. Myristicin is the hallucinogenic agent in nutmeg and mace. In quantities readily obtained from the local market, these spices have, at times, been drugs of abuse. On the other hand, nutmeg and mace are used as traditional medicines in Asia to treat stomach cramps, diarrhea, and rheumatism. Myristicin is presented, rather than one of 20 spices, oleoresins, and oils containing myristicin, to permit exploration of its potential to be both a carcinogen and an anticarcinogen. Limited in vivo and in vitro studies suggest myristicin could inhibit tumor formation; in this regard its ability to prevent carbon tetrachloride liver toxicity in mice is interesting. On the other hand, the probability that myristicin will be a liver carcinogen in experimental animals is extremely high. Myristicin is closely related to safrole, a liver carcinogen in mice and rats. Myristicin not only induces liver enzymes often associated with carcinogens, but also the corresponding mRNA. Like safrole, myristicin forms DNA adducts in mouse liver, although at a somewhat lower level. Experimental data on safrole suggest that myristicin may cause tumors from in utero exposure and through nursing. The increased incidence of liver tumors in mice given phenobarbital and safrole, if repeated for myristicin, is also of concern since this suggests an increased risk to certain vulnerable populations.

SELECTION STATUS ACTION BY CSWG: 7/16/97 Studies requested: Carcinogenicity Mutagenicity assays Metabolism studies In vitro cytogenic analysis In vivo micronucleus assay Priority: High Rationale/Remarks: Lack of