Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Newly developed anti-malarial medicine treats toxoplasmosis

05.03.2008
A new drug that will soon enter clinical trials for treatment of malaria also appears to be 10 times more effective than the key medicine in the current gold-standard treatment for toxoplasmosis, a disease caused by a related parasite that infects nearly one-third of all humans—more than two billion people worldwide.

In the March issue of PLoS Neglected Tropical Diseases, a research team based at the University of Chicago Medical Center shows that the drug, known as JPC-2056, is extremely effective against Toxoplasma gondii, the parasite that causes toxoplasmosis, without toxicity.

"JPC-2056 has the potential to replace the standard treatment of pyrimethamine and sulfadiazine," said infectious disease specialist Rima McLeod, professor of ophthalmology at the University of Chicago and senior author of the study. "The drug, taken by mouth, is easily absorbed, bioavailable, and relatively nontoxic. In tissue culture and in mice, it was rapidly effective, markedly reducing numbers of parasites within just a few days."

Untreated mice injected with the parasite "appeared ill," four days after the injection, the authors note, "with ruffled fur and hunched shoulders." Treated mice remained well.

"Studies in tissue culture found no evidence of the parasite or the plaques they produce 52 days after four days of treatment," said co-author Ernest Mui, a researcher in McLeod's laboratory.

"The absence of growth," the authors write, "indicates that this compound is 'cidal' and not merely 'static' for the active form of T. gondii.

The drug inhibits the action of an enzyme, dihydrofolate reductase (DHFR), produced by the family of parasites that includes those that cause toxoplasmosis and malaria. It is structurally distinct from the human DHFR.

"The drug's effect on the malaria and Toxoplasma enzymes is robust," said McLeod. "It has much less effect on the human enzyme."

The new drug was effective against all malaria parasites, even those with multiple mutations that make them resistant to other anti-folate medicines, suggesting that "this family of parasites, including not just Toxoplasma but also various malaria parasites, will not easily develop resistance," she said.

Toxoplasma infection is "probably the most common parasitic infection in the world, causing very significant disease in those who have immature immune systems or who are immune-compromised," McLeod said. "New medications are urgently needed."

The standard medicines to treat the infection can cause severe side effects and many patients become hypersensitive to them. There are no medicines that can eliminate certain latent stages of the parasite's life cycle. There is no vaccine.

T. gondii infects humans through three principal routes: a newly infected pregnant woman passing the infection to her fetus; consumption of undercooked, infected meat; and ingestion of T. gondii oocysts in food, through accidental contamination from cat litter.

"An infected cat can excrete up to 20 million oocysts over two weeks," McLeod said. "Even a single oocyst is infectious and they can remain infectious in water for up to six months and in warm moist soil for up to a year."

Congenital toxoplasmosis, which occurs in an estimated 1 per 5,000 births a year in the United States, can cause severe vision loss, brain damage and even death. The annual cost of caring for these children may exceed $1 billion.

Also at increased risk are people with compromised immune systems, such as those with cancer, autoimmune disease, AIDS or transplant recipients. Even people with normal immune systems can suffer major organ damage from chronic infections. Eye disease leading to loss of sight is caused both during the primary infection and as a result of infection transmitted from mother to child. Recent epidemics in Surinam and French Guiana have been lethal even for young healthy victims. Studies have also found an association between chronic brain infection with Toxoplasma and diseases such as schizophrenia and epilepsy, although cause-and-effect relationships have not been proven.

JPC-2056 was developed in the late 1980s by teams led by Wilbur Milhous and Dennis Kyle of the Walter Reed Army Institute for Research in Silver Spring Maryland (both now at the University of South Florida), and David Jacobus of Jacobus Pharmaceutical Company. The original version was quite toxic, but the researchers found ways to reduce the toxicity and developed an oral version of the drug. Clinical trials using JPC-2056 to treat malaria are scheduled to begin later this year.

This new class of medicine holds "considerable promise for significant advances in the treatment of toxoplasmosis, which damages the eye and the brain," said McLeod, "as well as malaria, which kills one million children each year."

John Easton | EurekAlert!
Further information:
http://www.uchospitals.edu

More articles from Health and Medicine:

nachricht Team discovers how bacteria exploit a chink in the body's armor
20.01.2017 | University of Illinois at Urbana-Champaign

nachricht Rabies viruses reveal wiring in transparent brains
19.01.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Bodyguards in the gut have a chemical weapon

20.01.2017 | Life Sciences

SF State astronomer searches for signs of life on Wolf 1061 exoplanet

20.01.2017 | Physics and Astronomy

Treated carbon pulls radioactive elements from water

20.01.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>