Credit: Brian Douglass
Ralph Waldo Emerson described flowers as a "proud assertion that a ray of beauty outvalues all the utilities of the world." Perhaps this is so, but recent research shows that sunflowers may have value outside of beauty. The flower that starred in Van Gogh's paintings can do more than looking good and providing us with yummy seeds—it may be a source of an affordable drug to fight AIDS.
In his doctoral thesis at the Bonn Centre of Molecular Biotechnology (CEMBIO) Claudio Cerboncini studied the sunflower's response to "white stem rot"—an infection caused by the fungus Sclerotina sclerotiorum. During his work, he isolated compounds the flowers produce to fight off the invasive mould. One of them, dicaffeoyl quinic acid (DCQA), is a substance that AIDS researchers have identified as showing great promise as a new treatment for the disease.
"Dicaffeoyl quinic acid can prevent the HIV virus from reproducing, at least in cell cultures," Cerboncini said in a press statement released by the University of Bonn.
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AIDS drugs typically work by achieving a stable immune defense condition—slowing the rate at which the virs replicates until it is equal to, or slower than, the rate at which infected cells die. Three enzymes—reverse transcriptase, protease and integrase—are required for virus replication. Unlike most existing AIDS drugs, which inhibit reverse-transcriptase or protease, DCQA inhibits integrase. Because integrase is not normally active in human cells, drugs targeting integrase may have fewer side effects—anorexia, fatigue, fevers and nausea to name a few—than the current crop of drugs.
The catch is that it's very expensive to manufacture DCQA. The few known natural sources of the substance, such as artichoke and wild chicory, yield only miniscule amounts of the compound. As a result, the current market price for DCQA is about $1,200 (or €1,000) per mg.
Ralf Theisen, a plant biotechnology researcher at CEMBIO, has patented a method to produce DCQA more efficiently, using sunflowers and bacteria. By comparing genes from infected and non-infected plants, Theisen plans to identify the sunflower gene responsible for production of DCQA.
"We can use isolated enzymes—use the DNA or RNA to transform bacteria so that they can produce it," Theisen said. "That is most likely a cheaper way than the chemical synthesis."
With this method, DCQA could be produced on an industrial basis.
Theisen and his colleagues at the Julich Research Center are looking for partners in industry to help them produce the compound on a large scale. An affordable source of DCQA would make further clinical tests of the integrase inhibitor feasible.
If DCQA turns out to be as effective a treatment as is hoped, sunflowers could add more than color to the lives of over 40-million people living with HIV/AIDS worldwide.