April 21, 2005

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COLLEGE STATION - Limonoids, a compound found exclusively in citrus, have been shown to target and, in some cases, kill neuroblastoma. Neuroblastomas are malignant tumors composed of embryonic nerve cells, and occur mainly in infants and young children

Results of the study by Texas Agricultural Experiment Station scientists is featured this month in the Journal of Nutrition, where it is the lead cover article.

Studies were done on neuroblastoma cells in labs on the Texas A&M University campus after the limonoids had been extracted from citrus at the Texas A&M University-Kingsville Citrus Center in Weslaco. The work is a collaboration between Dr. Ed Harris, Experiment Station biochemist, and Dr. Bhimu Patil, a horticulturist and director of the Texas A&M University Vegetable and Fruit Improvement Center. Their findings on the antioxidant work of several compounds, including limonoids, also appears this month in the Journal of Agriculture and Food Chemistry.

Neuroblastomas account for about 10 percent of all cancer in children, Harris noted. They are usually solid tumors in the neck, chest, spinal cord or adrenal gland.

Patil calls citrus fruit "a vast reservoir of anti-carcinogens" and a storehouse of health-promoting properties.

"We have these results from the lab, but it is too early to say what the results will be when trials are conducted with humans," Patil said.

The research found that the citrus compound is promising not only for its potential to arrest cancer but also because limonoids induce no side effects.

"Limonoids are naturally occurring compounds," Harris said, in earlier reports about the study. "Unlike other anti-cancer drugs that are toxic, limonoids apparently do not hurt a person. That's the beautiful potential."

Their work emphasized the compounds' ability to kill existing the neuroblastoma cells with the rationale that if the method and time limonoids take to obliterate the cancer could be found, perhaps scientists could exploit it to help cure the disease.

The duo said that limonoids may work against cancer in any of three ways: prevent it from forming, slow the growth of existing cancer, or kill cancer cells. In the lab, relatively small amounts of extracted limonoid caused death to neuroblastoma cells in 48 hours or less.

Patil and Harris have proposed that studies be funded for the next phase, which would include trials on the purification of limonoids, bioactivity studies in neuroblastoma in animals and then humans.

Full information, a photo and a video about the study can be found at http://agnews.tamu.edu/dailynews/stories/BICH/Nov3004a.htm The complete article from the Journal of Nutrition can be found at http://www.nutrition.org/