Enzyme inhibitor could be key to treating malaria

New research could pave the way for treating malaria, among other serious diseases, by using a method that inhibits a particular calcium-regulated enzyme called calpain.

While the enzyme is essential to many cellular processes, one downside of calpain is that it eases the ability of parasites like Plasmodium falciparum, which causes malaria, to exit their host cells and invade other cells. Calpain is also thought to be a factor in some of the most debilitating diseases, including muscular dystrophy, AIDS, Alzheimer's disease, multiple sclerosis and cancer.

A study published in the latest issue of the Journal of the American Chemical Society highlights a new approach to calpain inhibition, which mimics a natural reaction with a synthesized molecule, stopping this destructive process. A U.S. team led by researchers at the Perelman School of Medicine at the University of Pennsylvania developed the new technique.

The UPenn study is significant because it's thought to be the first to use this kind of inhibitor.

"We found out that parasites like the one that causes malaria use human calpain to allow themselves to get out of the host cell," said study researcher Doron Greenbaum, an assistant professor of pharmacology at UPenn, in an interview with FierceBiotechResearch.

When the malaria parasite enters a cell, calpain essentially chews out the scaffolding of the cell, and once that is dissolved or broken down, the red blood cell falls apart, Greenbaum explained. But if the enzyme is blocked, the parasite becomes trapped within the red blood cell host and dies.

"So that's what led us to become interested in human calpain as a target for therapy for malaria," Greenbaum said.

Malaria, which causes flu-like symptoms and can progress to coma or death, is a major health concern around the world, especially in poor countries. An estimated 655,000 people worldwide died of malaria in 2010, according to the World Health Organization.

- here's UPenn's release