A slightly sweet fragrance lingers in the humid air of Mahtab Jafari's UC Irvine laboratory, where she and a dozen researchers, graduate students and undergrads from the Department of Pharmaceutical Sciences are hard at work to find a compound that can prolong life and health.
The whirring sound of a blender makes the aroma's source suddenly clear: a banana smoothie, but not for the humans. The puree, spiked with the essence of the plant Rhodiola rosea, is for the tens of thousands of fruit flies in the lab's sponge-topped test tubes.
A nearly pure extract of Rhodiola rosea not only extends the lives of fruit flies an average of 24%, it also protects cultured human cells against the damaging effects of ultraviolet light and the herbicide paraquat, Jafari and her team report in the journals Free Radical Biology & Medicine and Free Radical Research. The two newly published papers, available on line in June 2009, also show that the plant decreases the production of superoxides in flies.
What makes the chemist in Jafari really curious, though, is how the botanical works. It protects cells from the harmful effects of oxidation, but not in the same way as other promising anti-aging compounds such as resveratrol. Nor does it neutralize the destructive oxygen molecules produced by the cellular furnaces known as mitochondria.
It's the kind of puzzle that has entranced her since she was a fifth grader in Iran, when she finished a textbook describing photosynthesis and the molecular mechanisms of plants and animals in the first weeks of class and demanded another.
"I always thought science was fascinating and very cool," says Jafari, who first came to UC Irvine in 1997 as a clinical pharmacologist and began directing the university's cholesterol clinic the following year.
Jafari recalls that her elementary school science teacher soon had her tutoring classmates. Teaching is a job she still relishes, and one that has earned her the Academic Senate's Distinguished Assistant Professor Award for Teaching.
It was the chance to guide budding scientists as a founding faculty member of the university's new Department of Pharmaceutical Sciences that helped lure her back to UC Irvine in 2005 after a three-year stint in private industry. The other draw was the opportunity to launch her own research on aging.
"After working for almost 10 years in the pharmacotherapy of many diseases such as cardiovascular and neurodegenerative problems, finally the apple fell from the tree," the associate professor of pharmaceutical science explains. "I realized it all falls under the umbrella of aging."
If the aging process could be slowed down at the molecular level, so too could the progression of such diseases, she theorized. "I screened 75 possible anti-aging compounds, botanicals and pharmaceuticals, but my best results were with plants," she says. "The most striking was Rhodiola rosea."
The flowering plant has long been a folk remedy in the harsh, cold and mountainous regions in Europe and Asia where it is found, Jafari knew. In the 1940s, Russian scientists began studying it to enhance endurance, memory and mood. Research has since shown that it can reduce blood glucose levels in diabetic mice, slow the growth of tumors in rat models and protect snail larvae from certain environmental threats.
To see if Rhodiola rosea also prolongs the span and quality of life, Jafari began testing it on fruit flies, which live a matter of weeks, not decades. She and her project scientist Samuel E. Schriner are beginning a study of its effects on mice. "As you know, you can't study lifespan extension in humans, we just live too long," she says.
The puzzle of how the plant works is beginning to take shape, Jafari says, adding, "The data is so exciting that some nights I just want to wake up at 4 a.m. and start writing."
Jafari wants her students to find similar inspiration. "I tell them, ‘You have to get up every morning being excited about your work, even as an undergraduate student."