Reducing Arsenic in Rice

Arsenic – the name is nearly synonymous with poison. 

It is a chemical element naturally found in many soils. Because of its toxicity, it was also used for decades in agricultural pesticides and defoliants that persist in soil. Unfortunately, rice plants grown in arsenic-containing soil accumulate the toxin in the grains that people eat, potentially increasing the risk for cancer. 

FIU biochemist Barry Rosen’s decades of research on how organisms handle arsenic at the molecular level is now pointing to strategies that may reduce the amount of arsenic that ends up in rice. His work also has implications for toxic waste cleanup and for optimizing drugs that use arsenic compounds to treat disease.

“That’s what basic research is,” explains Rosen, professor in the Department of Cellular Biology and Pharmacology in the Herbert Wertheim College of Medicine and the college’s associate dean for basic research and graduate studies. “Most of my work is studying the mechanisms of enzymes and transport systems for arsenic within organisms. It’s research that is designed to find out how things work, and down the road you find ways to use that knowledge.”

Reducing the amount of arsenic in rice, a food staple for billions of people around the world, would have tremendous benefits, says Bala Rathinasabapathi, an associate professor of horticultural sciences at the University of Florida.

“A lot of land in Bangladesh, India, and China where rice is cultivated is contaminated with arsenic from natural sources,” he says. “It’s very important to understand how plants deal with arsenic, and Barry Rosen’s work is very significant in that regard. He discovered that cyanobacteria, which usually grow in rice paddies, are important in detoxifying arsenic. Not only may we be able to use those bacteria to reduce the arsenic available to rice, we may be able to engineer rice plants to detoxify arsenic.”

Rosen also studies how arsenic-containing drugs get inside the patient’s cells when used to treat conditions such as leukemia.

“Paracelsus, the father of modern pharmacology said, ‘The poison is in the dose,’ ” Rosen says. “If you get the dose too low, it doesn’t work; too high, the patient dies. It has to get inside the cell and interact with specific proteins. With my collaborators Rita Mukhopadhyay and Hiranmoy Bhattacharjee, we have been able to show what the transport systems are that take the drug into the cell. When you know that, you might make a drug more effective at lower doses,” reducing side effects. 

Rosen has been awarded a $5 million MERIT grant from the National Institutes of Health, a  distinction  given to fewer than 1 percent of grant recipients. Former FIU President Modesto Maidique cited Rosen’s decision to come to FIU in 2009 after 22 years at Wayne State University in Detroit as an example of FIU’s rising stature as a research university.

“He came with his life’s work – research that could improve the safety of food supplies around the world,” Maidique noted. “He is proof that despite difficult times, we continue to attract outstanding senior faculty and extraordinary research talent to our university.”