New Test Measures Anti-Malarial Drugs
July 26, 2011 –A faster, highly effective and less expensive test that checks the potency of potential anti-malarial drugs has been created by the co-director of the Georgetown Center for Infectious Disease.
Paul Roepe,an internationally recognized expert in drug-resistant malaria, is also a professor of biochemistry and cellular & molecular biology at Georgetown University Medical Center.
His test uses a fluorescent dye to quantify parasitic DNA in human red blood cells, measuring the ability of a drug to shut down growth of the protozoa.
“For malaria, you could argue that the cell-killing effects of the drug are more important than the growth inhibitory effects,” says Roepe, also a professor in the Main Campus chemistry department. “Even though the distinction between growth inhibitory and cell-killing effects for an antimicrobial drug is actually a straightforward concept in microbiology and infectious disease, no one had designed a test to look at how well a drug can kill malarial parasites.”
Earlier tests used expensive radioactive elements to measure the incorporation of radioactivity in parasitic DNA.
Recently adopted by the U.S. military as well as by malaria research labs around the world, Roepe’s test rapidly measures whether a new formula will effectively slow the growth of malarial parasites.
Designing new therapies to treat the infection is vital, he says.
While fewer than a dozen anti-malarial drugs are now used around the world, most cannot efficiently and effectively treat the 500 million people who are infected annually with the parasite, the professor explains.
Roepe says nearly 2 million of them die from the disease, and most of these victims are children.
Infections by some strains of the mosquito-borne disease are never cured, according to Roepe, and resistance to drugs designed to treat them is growing at an alarming rate.
“A good malaria drug has to be cytocidal – it has to be able to kill the bugs – as well as being growth inhibitory,” Roepe says.
Roepe’s new – and inexpensive – test can now be used to test how effective investigational drugs now in the drug development pipeline will be.
“It will provide a critical filter that should speed up this pipeline,” Roepe says. “With it, you will know an essential fact about the drug – how well it kills malaria – and may not need to launch expensive animal studies.”