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
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

US Imposes Sanctions on Alleged Honduran Drug Gang

Treasury department alleges Los Valles group is responsible for smuggling tens of thousands of kilograms of cocaine into US each month More

At 91, Marvel Creator Stan Lee Continues to Expand his Universe

Company's chief emeritus hopes to interest new generation of children in superheroes of all shapes and sizes by publishing content across multiple media platforms More

Photogallery New Drug Protects Against Virus in Ebola Family

Study by researchers at University of Texas Medical Branch, Tekmira Pharmaceuticals is first looking at drug's effectiveness after onset of symptoms 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.
African Media Tries to Educate Public About Ebolai
X
George Putic
August 20, 2014 8:57 PM
While the Ebola epidemic continues to claim lives in West Africa, information technology specialists, together with radio and TV reporters, are battling misinformation and prejudice about the disease - using social media to educate the public about the deadly virus. VOA’s George Putic has more.
Video

Video African Media Tries to Educate Public About Ebola

While the Ebola epidemic continues to claim lives in West Africa, information technology specialists, together with radio and TV reporters, are battling misinformation and prejudice about the disease - using social media to educate the public about the deadly virus. VOA’s George Putic has more.
Video

Video Ferguson Calls For Justice as Anger, Violence Grips Community

Violence, anger and frustration continue to grip the small St. Louis suburb of Ferguson, Missouri. Protests broke out after a white police officer fatally shot an unarmed black teenager on August 9. The case has sparked outrage around the nation and prompted the White House to send U.S. Attorney Eric Holder to the small community of just over 20,000 people. VOA’s Mary Alice Salinas has more from Ferguson.
Video

Video Beheading Of US Journalist Breeds Outrage

U.S. and British authorities have launched an investigation into an Islamic State video showing the beheading of kidnapped American journalist James Foley by a militant with a British accent. The extremist group, which posted the video on the Internet Tuesday, said the murder was revenge for U.S. airstrikes on militant positions in Iraq - and has threatened to execute another American journalist it is holding. Henry Ridgwell has more from London.
Video

Video Family Robots - The Next Big Thing?

Robots that can help us with daily chores like cooking and cleaning are a long way off, but automatons that serve as family companions may be much closer. Researchers in the United States, France, Japan and other countries are racing to build robots that can entertain and perform some simpler tasks for us. VOA’s George Putic reports.
Video

Video In Ukraine, Fear and Distrust Remain Where Fighting has Stopped

As the Ukrainian military reclaims control of eastern cities from pro-Russian separatists, residents are getting a chance to rebuild their lives. VOA's Gabe Joselow reports from the town of Kramatorsk in Donetsk province, where a sense of fear is still in the air, and distrust of the government in Kyiv still runs deep.
Video

Video Five Patients Given Experimental Ebola Drug Said to Be Improving

The World Health Organization has approved the use of experimental treatments for Ebola patients in West Africa. The Ebola outbreak there is unprecedented, the disease deadly. The number of people who have died from Ebola has surpassed 1,200. VOA's Carol Pearson reports on the ethical considerations of allowing experimental drugs to be used.
Video

Video China Targets Overseas Assets of Corrupt Officials

As China presses forward with its anti-graft effort, authorities are targeting corrupt officials who have sent family members and assets overseas. The efforts have stirred up a debate at home on exactly how many officials take that route and how likely it is they will be caught. Rebecca Valli has this report.
Video

Video Leading The Fight Against Islamic State, Kurds Question Iraqi Future

Western countries including the United States have begun arming the Kurdish Peshmerga forces in northern Iraq to aid their battle against extremist Sunni militants from the Islamic State. But there are concerns that a heavily-armed Kurdistan Regional Government, or KRG, might seek to declare independence and cause the break-up of the Iraqi state. As Henry Ridgwell reports from London, the KRG says it will only seek greater autonomy from Baghdad.
Video

Video In Rural Kenya, Pressure Builds Against Female Circumcision

In some Kenyan communities, female genital mutilation remains a rite of passage. But activists are pushing back, with education for girls and with threats of punishment those who perform the circumcision. Mohammed Yusuf looks at the practice in the rural eastern community of Tharaka-Nithi.

AppleAndroid