Flavonoids protect plants from sunlight and sunlight damage, help defend against pathogens and are responsible for producing the colors of fruits and flowers.
"There has not been definitive research on plant flavonoids that the Food and Drug Administration says makes them proven to help human health, but research has shown there is a direct correlation between people that have a lot of flavonoids in their diets and lower instances of cancer, heart disease, dementia, improved blood circulation and slower aging," said Smalle, an associate professor in the Department of Plant and Soil Sciences.
Interest is increasing among food scientists in using flavonoids to color food instead of the current coloring processes, which often rely on synthesized fossil fuel-derived compounds. Flavonoids also have potential for the paint industry as they could lead to more environmentally friendly paint production and reduce the industry’s dependence on fossil fuels.
Smalle and fellow UKAg research scientist Jasmina Kurepa developed nanoharvesting, which involves inserting titanium dioxide nanoparticles into a plant. Inside the plant, the nanoparticles bind with flavonoids in cells. Plants then secrete the nanoparticles coated with flavonoids.
Until this discovery, conducting research on flavonoids was difficult, as many flavonoid species are unstable and degrade or become modified during the classical isolation procedures. It was also hard for scientists to deliver them to human cells for pharmaceutical research.
"We now have an extremely simple way to isolate these compounds," he said. "It has the added advantage that this type of nanoparticle is known to be taken up by human cells. We may now be able use these particles coated with flavonoids directly in drug discovery."
These same nanoparticles are also potentially useful for the paint industry. Theoretically, the flavonoid-coated nanoparticles could be placed directly into paint to provide color. An additional benefit is that flavonoids have antimicrobial properties which may help exterior paint last longer. Current exterior paints are often degraded over time by microbes.
Using the model plant Arabidopsis, Smalle will look at the plant mechanisms and pathways involved in taking up nanoparticles and then secreting them coated with flavonoids. His research will also explore whether similar pathways exist and are as efficient in other plants, especially agricultural plants that farmers are already able to successfully produce.
"Flavonoids in green tea are supposed to help us live longer, but those are different flavonoids than the ones in blueberries that provide us with other health benefits, and those are different from the ones in chocolate," Kurepa said. "So if there is a simple and unified system to get flavonoid-coated nanoparticles from everything, then that’s brilliant."