Diets of mice containing 0.5% turmeric or 0.015% curcumin did not show significant increases in the incidences of micronucleated polychromatic erythrocytes, aberrations of bone marrow chromosomes, alter¬ations of pregnancy rate or embryo survival, among others. At LOAEL values of 400 mg/kg bw/day or higher (2000 mg/kg bw/day), enlargement of the liver, ulcers, and hyperplasia in the gastrointestinal tract have been observed. Toxic activity is related to inhibition of the cytochrome P-450 enzymes.