UA researchers are growing withania plants using an "aeroponic" system to improve their growth rate. LESLIE GUNATILAKA, UNIVERSITY OF ARIZONA

Drug-discovery research points to a leafy plant growing in a south-side greenhouse as a possible treatment for tumors and other medical conditions.

A compound from withania plants - grown to big bushes in an old University of Arizona greenhouse - is showing promise for treating cancer, eye disorders and neurological diseases.

Growing a better withania plant is the work of professor Leslie Gunatilaka and his team at the UA's Natural Products Center.

The compound, called withaferin A, shrinks some tumors by preventing the growth of blood vessels that make a tumor malignant, and it helps protect healthy cells.

Gunatilaka's plants are "a unique resource here in Arizona," said Haiyong Han, an investigator with the Translational Genomics Research Institute in Phoenix.

He is testing the compound in mice as a possible treatment for deadly pancreatic cancer.


Gunatilaka grew up in Sri Lanka wondering about the scientific validity of the traditional medicine practiced there. When he came to Arizona in 1997, he wondered how plants survive in the desert.

A conversation with a cancer biologist about how plants handle heat stress led them to study withania, which is used in traditional medicine in India.

The researchers thought they might be able to use it to produce large amounts of withaferin A, the potential anti-cancer drug, Gunatilaka said.


You have to grow a lot of plants to get the compound, and that makes it very expensive. At the time, just 10 milligrams cost about $195. (A baby aspirin is 81 mg.)


Gunatilaka decided to grow his own withania plants - faster and five times bigger. He and his team built an "aeroponic" system that sprays a nutrient solution onto the plants' roots every few minutes.

His low-water, low-energy method produces up to 20 grams of the compound in an old UA greenhouse. Ladybugs keep the plants pest-free.


While trying to make withaferin A, Gunatilaka and his team found withaferin A sulfate - a new compound. It is water-soluble and converts to the active compound inside cells, making it an ideal candidate for a drug.

It was "a chance discovery," Gunatilaka said.

His team worked out a way to get only the withaferin A sulfate from the plant. The team, including collaborators from the Whitehead Institute in Boston, holds a patent on the production of the new compound.


Gunatilaka is supplying the withaferin compounds - for free - to other researchers he works with.

"When people approach me for research, I give it to them" in the name of collaboration, he said.

He gave 10 grams to a Dartmouth College researcher. That amount would have cost as much as $390,000 from a commercial provider.

Shalesh Kaushal, who chairs the ophthalmology department at the University of Massachusetts Medical School, contacted Gunatilaka about the compound after hearing about it from Massachusetts Institute of Technology researchers who are using it. Kaushal is studying it as a potential treatment for macular degeneration, and "we've had some wonderful results already," he said.

Other research using Gunatilaka's withaferin A is going on at the University of Michigan and the Burke Medical Research Institute in New York. The team also is applying the growing method to other plants with cancer-fighting potential, and more compounds are coming, he said.

Contact reporter Becky Pallack at or 807-8012.