Strawberries, grapes, blueberries and some familiar seasonings like rosemary contain compounds that can--in test tubes--kill cells of a childhood cancer. Nutrition-focused research by molecular biologist Susan J. Zunino of the Agricultural Research Service (ARS) Western Human Nutrition Research Center (WHNRC), Davis, Calif., may reveal exactly how the powerful plant chemicals fight the disease known as acute lymphoblastic leukemia.

Zunino's current studies build upon her 2006 findings about the ability of carnosol from rosemary; curcumin from turmeric; resveratrol from grapes; and ellagic acid, kaempferol and quercetin from strawberries to kill the leukemia cells. She did the work using laboratory cultures of both healthy human blood cells and cancerous ones as her model.

Her studies are of interest not only to cancer researchers, but also to nutrition scientists exploring the health benefits of natural compounds in the world's fruits, vegetables, herbs and spices.

For the most part, scientists don't yet have all the details about how plant chemicals, or phytochemicals, bolster healthy cells and battle harmful ones. That's true even for better-known phytochemicals such as the resveratrol in grapes, blueberries and some other fruits, according to Zunino.

Her investigations provide some new clues about how phytochemicals attack cancer cells. For example, she found that the phytochemicals interfere with the orderly operations of mitochondria, the miniature energy-producing power plants inside cells. Without energy, cells die.

Mitochondria exposed to resveratrol and the other phytochemicals that Zunino tested couldn't function properly. But more work is needed, to fully understand how the phytochemicals achieved that.

And, Zunino and colleagues want to know more about the phytochemicals' other modes of action that result in cell death.

She's collaborating in the investigations with molecular biologist David Storms, at WHNRC; Jonathan Ducore at the University of California-Davis Cancer Center; and Navindra Seeram, formerly with the University of California-Los Angeles and now at the University of Rhode Island-Kingston.