Limonoids (pronounced lye-muh-noids) are compounds in citrus fruits, generally found in the peels, that produce the familiar bitter taste. More importantly, limonoids have been shown to produce anticancer activities in animals and inhibit the spread of human breast cancer cells in culture. Other studies indicate limonoids could help lower LDL cholesterol, often called Abad cholesterol, and help plants ward off insects. More than a dozen research papers related to these compounds are being presented during the national meeting of the American Chemical Society, the world=s largest scientific society, in Anaheim, Calif., March 21 - 25. Selected samples of the research being discussed are included below. All papers are embargoed until the time of presentation, unless otherwise noted.
Clinical Trials Needed to Substantiate Health Benefit Claims - Based on observations of limonoids= anticancer activities in animals, new foods rich in limonoid glucosides are under development. But, the researchers say, clinical trails are needed to substantiate the claims in humans. Research on antitumor activity of twelve citrus limonoids will be reviewed. (Baylor College of Dentistry, Dallas, Texas; USDA, Albany, Calif.; AGFD paper 54; Tuesday, March 23, 9:30 a.m.; Hilton, Palos Verdes A/B.)
Human Breast Cancer Cell Proliferation Inhibition - Tests with a mixture of various limonoids show they are Apotent inhibitors of proliferation of human breast cancer cells in culture, according to this paper. Tests with mice are currently underway. (University of Western Ontario, London, Ontario; USDA, Albany, Calif.; AGFD paper 55; Tuesday, March 23, 10:00 a.m.; Hilton, Palos Verdes A/B.)
LDL Cholesterol Reduction in Tests with Rabbits - A reduction of low-density cholesterol in rabbits was observed after substituting orange juice and grapefruit juice for water. Testing of the limonoids in the juices suggests the compounds Acould contribute to cholesterol-lowering action of citrus juices. (University of Western Ontario, London, Ontario; USDA, Albany, Calif.; AGFD paper 57; Tuesday, March 23, 10:40 a.m.; Hilton, Palos Verdes A/B.)
Insect Pest Management Prospects - Limonoids were effective in field tests against Colorado potato beetles in levels not poisonous to the plants, according to the researchers. (University of Maine, Orono, Maine; AGFD paper 58; Tuesday, March 23, 11:00 a.m.; Hilton, Palos Verdes A/B.)
A nonprofit organization with a membership of nearly 159,000 chemists and chemical engineers, the American Chemical Society publishes scientific journals and databases, convenes major research conferences, and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.