New Tools Examined to Combat Anthrax, Bioterrorism

UNIVERSITY, Miss. - New drugs to combat the world's most feared diseases - including the weapons of bioterrorism - may be found at the ocean bottom in sea sponges.  But few scientists have the expertise to locate and identify sponge species, a necessary first step to unlocking the medical potential of these primitive creatures.

At The University of Mississippi this week, scientists at UM's Center for Water and Wetland Resources are developing skills that organizers hope will lead to an international network of specialists.  Scientists include 20 faculty members, graduate students and post-doctoral
fellows from Ole Miss and the University of Alabama at Birmingham, said Dr. Mark Hamann, a UM pharmacognosist who seeks to develop novel drugs from marine organisms. "Hopefully, they will go back to their institutions and collaborate with us on drug discovery projects," Hamann said. "We have students and post-doctoral fellows in this workshop from India, Venezuela, Pakistan,
Egypt, Indonesia, China and Korea, and we're hoping that when they finish their tour here at The University of Mississippi, they'll be able to help us set up collaborative projects there."
In lab tests, one of Hamann's projects yielded a compound - alkaloids called manzamines - effective against malaria, tuberculosis and other diseases. His team extracted the compound from sponges harvested near Indonesia, and he is working with scientists there, as well as in Singapore
and the U.S., to determine if it is safe and effective for humans.Hamann also has shipped sponge extracts, including the manzamines, to the National Institutes for Health where researchers are particularly interested in testing the samples against the smallpox virus and the Bacillus anthracis bacteria, which causes anthrax.

Several letters containing Bacillis anthracis have been found in New York, Washington, Florida and Nevada, and officials suspect terrorism. They also fear that terrorists could use smallpox virus to infect large numbers of people. This UM session is led by Dr. Michelle Kelly, a National Institute of Water and Atmospheric Research specialist from New Zealand. One of the few scientists with a broad knowledge of the world's sponges, Kelly has studied them for 25 years and has helped Hamann identify and harvest them. "It's because of people like Mark that we've been able to amass this knowledge of sponges from all around the world," she said.

"They go out and collect sponges and send samples to me and to scientists throughout the world, and that helps us learn how different species are distributed." Kelly uses lectures with practical lab exercises to help the workshop participants learn to recognize characteristics that help identify sponge species. She also stresses the importance of conserving the world's sponges because the creatures can be killed through overharvesting, pollution or other factors. Sponges and other marine organisms represent thousands or even millions of possibilities for developing new drugs, she said. "Theoretically, the potential is huge. These marine organisms, because they don't move, are able to use their own metabolites to create some amazing compounds. They have to be able to synthesize compounds to fend off fungal infections, predators and bacterial invaders."  In reality, that potential is only as good as the number of sponge varieties scientists can study.

Only about 1 percent of sponge drugs have pharmaceutical use because they are toxic to living cells and the difficult discover and testing process is so lengthy, Kelly said.But insights gained from studying sponge compounds - even when those compounds do not yield a clinically usable drug - can help scientists design better drug molecules to target specific diseases.  "Ultimately, one of these compounds could provide the key to developing important new drugs," she said. Meanwhile, Hamann and his fellow investigators continue to probe the possibility of using manzamines to fight malaria and other diseases. They have collected enough of the compounds to start pre-clinical trials, which they hope to begin later this year at Tulane University.  "It's exciting work, and we're ready to get on with the next phase," he said.

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