Four herbal products -- aloe vera, ginseng, kava kava and milk thistle -- and a substance in vegetables thought to inhibit cancer have been recommended by a panel representing the federal health agencies for toxicity testing under the National Toxicology Program at the National Institute of Environmental Health Sciences.
Program officials said today that the National Cancer Institute nominated all five for testing because of their widespread or increasing use by the public. The officials said the substances were then reviewed and approved by the federal Interagency Committee for Chemical Evaluation and Coordination, which advises NTP's testing. Such recommendations are often made when the popularity of a relatively untested substance exposes large numbers of people. No data indicating a known problem is required for a nomination.
Before making a final decision to test the substances, NTP is requesting public comment and any additional scientific information be sent to Dr. William Eastin, NIEHS/NTP, Box 12233, Research Triangle Park, NC 27709, or email him at Eastin@NIEHS.NIH.gov by Sept. 7, 1999.
The four herbs are aloe vera, which is used as a dietary supplement as well as a cosmetic; ginseng, which is promoted for vigor; kava kava is used as a mood elevator, and milk thistle, is considered by some to have anti-cancer and liver-protective properties. The fifth nomination is for indole-3-carbinol, a substance in cruciferous vegetables such as broccoli, and thought to have potential to reduce the risk of cancer.
NTP, which is headquartered at NIEHS in Research Triangle Park, N.C., said that the current toxicity information on the substances is considered "inadequate." NTP also asked for comments on the interagency committee's recommendations to test:
- Ammonium molybdate, one of many soluble molybdenum compounds which workers and the general population may be exposed to.
- 5,6-benzoflavone, also known as Beta-napthaflavone, a synthetic compound similar to compounds naturally occurring in plants, a research substance that lacks drug industry sponsorship but might also have potential for reducing the risk of cancer.
- 1,3-Dichloro-2-butene, a high production industrial chemical with a potential for worker exposure and with a structural similarity to a known carcinogen.
- 3-Picoline, a high production industrial chemical.
Although all nine substances were nominated by health research agencies, nominations may also be made by businesses, unions and the public. A formal announcement of the request for comment is in the Federal Register vol. 64, no. 129, pp. 36704-36707.