Toxicology studies of indole-3-carbinol in F344/N rats and B6C3F1/N mice and toxicology and carcinogenesis studies of indole-3-carbinol in Harlan Sprague Dawley rats and B6C3F1/N mice (gavage studies).

Indole-3-carbinol is sold as a sole ingredient in dietary supplements or as a combination nutraceutical along with a variety of herbs and/or vitamins. It is marketed for its potential ability to prevent cancer and provide other health benefits, such as detoxifying the liver and boosting the immune system. Indole-3-carbinol is a naturally formed breakdown product of glucosinolate glucobrassicin, a component found in cruciferous vegetables of the Brassica genus, including broccoli, brussels sprouts, cauliflower, cabbage, kale, kohlrabi, and turnips. Exposure to indole-3-carbinol occurs through the oral route through the ingestion of Brassica vegetables or dietary supplements. Indole-3-carbinol was nominated by the National Cancer Institute for toxicity and carcinogenicity testing because of its occurrence in natural products and for its potential use as a breast cancer chemopreventive agent. Male and female F344/N rats and Harlan Sprague Dawley rats received indole-3-carbinol in corn oil by gavage for 3 months or 2 years, respectively. Male and female B6C3F1/N mice received indole-3-carbinol in corn oil gavage for 3 months or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Escherichia coli, rat bone marrow cells, and mouse peripheral blood erythrocytes. (Abstract Abridged).