News / Health

New Malaria Drugs Stop Parasite Early

Animal tests promising, but human trials still ahead

US scientists are experimenting with a compound of anti-malaria drugs that kill the parasite in its dormant liver stage.
US scientists are experimenting with a compound of anti-malaria drugs that kill the parasite in its dormant liver stage.

Multimedia

Audio
TEXT SIZE - +
Art Chimes

U.S. medical researchers report a possible breakthrough that might prevent infection by one of the two most widespread varieties of malaria.

A new class of anti-malaria compounds kills the parasites in the developmental stages in the liver, before they get into the bloodstream.

The compounds proved highly successful in animal tests, according to a study published in Science, but their effectiveness in humans is still unproven.

Plasmodium vivax is the dominant strain of the malaria parasite outside Africa. Unlike the more deadly Plasmodium falciparum, vivax can infect a person but stay dormant in the liver for months or even years, before emerging to cause disease.

Scientists at the Scripps Research Institute in California and other institutions evaluated chemical compounds that were known to kill the malaria parasite in the blood. They were looking for ones that also might kill the parasite in its dormant liver stage.

In this study, the researchers mixed each one of the compounds with malaria parasites taken from live mosquitoes. Each combination was put with liver cells into individual compartments, called wells, on a microscope slide. Author Elizabeth Winzeler explains that to screen thousands of chemicals as potential malaria drugs required some sophisticated technology.

"We used an automated microscope to go and take about 100 images of each of the wells, and then we used computer scripts to analyze the images and identify those wells that had compounds that appeared to affect the development of the parasites."

To test potential drugs developed from the chemicals that looked promising, Winzeler and her colleagues infected laboratory mice with the malaria parasite. Left alone, the mice died within 10 days.  But "if you give the mice the same treatment, and you give them a small oral dose of the compounds that we made, the mice are cured or they never develop malaria in the first place."

These new substances, called IZPs, are effective in mice, Winzeler says, "but there's always a big step between going from something that works in a mouse model and actually going into something that's safe and efficacious in humans."

Researchers at Scripps, backed by the pharmaceutical company Novartis, are now considering that next step, safety testing in humans.

If successful, this work could lead to a malaria drug that attacks the dormant stage of the parasite, which occurs only in the Plasmodium vivax form of the disease. Scientists theorize that this period of dormancy was an evolutionary strategy to keep infection active through the cold winter months.

"For example, vivax malaria was found in places like Finland and England, up until about 100 years ago. And clearly, there weren't mosquitoes out biting people in December."

Vivax now occurs mainly in Asia and Latin America.

You May Like

Algerians Vote in Presidential Election

There were few media reports of protests and clashes around the country, but so far no significant violence More

Sharks More Evolved than Previously Thought

The discovery could “profoundly affect our understanding of evolutionary history” More

Pakistan Military Asked to Protect Polio Workers

Request comes as authorities say a Taliban ban on vaccinations in 2012 and deadly attacks on anti-polio teams have prevented thousands of children from getting inoculated More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Google Buys Drone Companyi
|| 0:00:00
...
 
🔇
X
George Putic
April 15, 2014
In its latest purchase of high-tech companies, Google has acquired a manufacturer of solar-powered drones that can stay in the air almost indefinitely, relaying broadband Internet connection to remote areas. It is seen as yet another step in the U.S. based Web giant’s bid to bring Internet to the whole world. VOA’s George Putic reports.
Video

Video Google Buys Drone Company

In its latest purchase of high-tech companies, Google has acquired a manufacturer of solar-powered drones that can stay in the air almost indefinitely, relaying broadband Internet connection to remote areas. It is seen as yet another step in the U.S. based Web giant’s bid to bring Internet to the whole world. VOA’s George Putic reports.
Video

Video Ray Bonneville Sings the Blues and More on New CD

Singer/songwriter Ray Bonneville has released a new CD called “Easy Gone” with music that reflects his musical and personal journey from French-speaking Canada to his current home in Austin,Texas. The eclectic artist’s fan base extends from Texas to various parts of North America and Europe. VOA’s Greg Flakus reports from Austin.
Video

Video Millions Labor in Pakistan's Informal Economy

The World Bank says that in Pakistan, roughly 70 percent work in the so-called informal sector, a part of the economy that is unregulated and untaxed. VOA's Sharon Behn reports from Islamabad on how the informal sector impact's the Pakistani economy.
Video

Video Passover Celebrates Liberation from Bondage

Jewish people around the world are celebrating Passover, a commemoration of their liberation from slavery in Egypt more than 3,300 years ago. According to scripture, God helped the Jews, led by Moses, escape bondage in Egypt and cross the Red Sea into the desert. Zlatica Hoke reports that the story of the Jewish Exodus resonates with other people trying to escape slave-like conditions.
Video

Video Police Pursue Hate Crime Charges Against Kansas Shooting Suspect

Prosecutors are sifting through the evidence in the wake of Sunday’s shootings in a suburb of Kansas City, Missouri that left three people dead. A suspect in the shootings taken into custody is a white supremacist. As VOA’s Kane Farabaugh reports, he was well-known to law enforcement agencies and human rights groups alike.
Video

Video In Eastern Ukraine, Pro-unity Activists Emerge from Shadows

Amid the pro-Russian uprisings in eastern Ukraine, there is a large body of activists who support Ukrainian unity and reject Russian intervention. Their activities have remained largely underground, but they are preparing to take on their pro-Moscow opponents, as Henry Ridgwell reports from the eastern city of Donetsk.
Video

Video Basket Maker’s Skills Have World Reach

A prestigious craft show in the U.S. capital offers one-of-a-kind creations by more than 120 artists working in a variety of media. As VOA’s Julie Taboh reports from Washington, one artist lucky enough to be selected says sharing her skills with women overseas is just as significant.
Video

Video UN Report Urges Speedier Action to Avoid Climate Disaster

A new United Nations report says the world must switch from fossil fuels to cleaner energy sources to control the effects of climate change. The Intergovernmental Panel on Climate Change released the report (Sunday) following a meeting of scientists and government representatives in Berlin. The comprehensive review follows two recent IPCC reports that detail the certainty of climate change, its impacts and in this most recent report what to do about it. VOA’s Rosanne Skirble has the details.
AppleAndroid