Seaweed defense offers clues against malaria

Seaweed sends off a natural chemical response to ward off fungi that would otherwise colonize an injured plant, a process that could help the search for anti-malaria drugs, a US scientist said Monday.

Malaria, caused by the parasite Plasmodium falciparum, kills more than a million people worldwide each year, and new drugs are needed because the parasite is developing resistance to popular pharmaceuticals.

"There are only a couple of drugs left that are effective against malaria in all areas of the world, so we are hopeful that these molecules will continue to show promise as we develop them further as pharmaceutical leads," said scientist Julia Kubanek, an associate professor at Georgia Tech.

Researchers discovered the class of seaweed defense compounds, known as bromophycolides, by studying 800 species of seaweed off Fiji Island.

One type in particular caught their attention, Callophycus serratus, "because it seemed particularly adept at fighting off microbial infections," said the study presented Monday at an international science conference in Washington.

The molecules appeared in light-colored blotches on certain parts of the seaweed, and were visible with the help of a new technique known as desorption electrospray ionization mass spectrometry developed at the Georgia Tech's School of Chemistry and Biochemistry.

"The alga is marshaling its defenses and displaying them in a way that blocks the entry points for microbes that might invade and cause disease," said Kubanek.

"Seaweeds don't have immune responses like humans do. But instead, they have some chemical compounds in their tissues to protect them," she said.

"We can co-opt these chemical processes for human benefit in the form of new treatments for diseases that affect us."

However, more research needs to be done before the process can be turned into a drug for humans, and studies on mice are planned next.

"As with other potential drug compounds, however, the likelihood that this molecule will have just the right chemistry to be useful in humans is relatively small," said the study.

The research was funded by the National Institutes of Health as part of a long-term study of chemical signaling among organisms in coral reefs.