Promising anti-malaria compound destroys parasite quickly
Date: Dec-08-2014 One of the challenges in the fight against malaria - a disease that threatens
half the world's population and kills a child in Africa every minute - is that it
rapidly becomes resistant to new drugs. To sustain their effectiveness, new drugs
need to act fast and eliminate the parasite before it has a chance to develop
resistance. Now, a new study offers such a compound - in mice it removed all traces of
malaria parasite within 48 hours.
Within 48 hours of receiving a new compound that tricks
the immune system into destroying only infected red blood cells, malaria-infected
mice showed no traces of the parasite.
The study, which was conducted by an international team led by researchers at St.
Jude Children's Research Hospital in Memphis, TN, is published in the Proceedings
of the National Academy of Sciences.
Malaria is a disease that develops when a mosquito infected with a
Plasmodium parasite bites a person. Once it gets into the bloodstream, the
parasite invades and lives in the new host's red blood cells.
According to the World Health Organization (WHO), malaria killed an estimated
627,000 people in 2012, the majority of them sub-Saharan African children under the
age of 5.
(+)-SJ733 - the compound tested in the new study - tricks the host immune
system into destroying only infected red blood cells while leaving healthy ones
alone.
The new compound is a derivative of one identified in a previous St. Jude-led
study that helped spur worldwide anti-malaria drug development projects.
New compound disrupts malaria parasite's internal sodium balance
The researchers found (+)-SJ733 uses a previously unknown mechanism to kill the
parasite.
After whole genome sequencing the deadliest malaria parasite species -
Plasmodium falciparum - the international team discovered that (+)-SJ733
disrupts activity of the ATP4 protein in the parasite.
ATP4 is a sodium-removing pump that the parasite relies on to maintain sodium
balance in its single, protozoan cell.
In their study, the team showed that giving a single dose of (+)-SJ733 to
malaria-infected mice killed 80% of the parasites within 24 hours. Furthermore, the
parasite was undetectable after 48 hours.
Results suggests new compound suppresses malaria drug-resistance
The researchers suggest their lab results show (+)-SJ733 both slows and suppresses the development of drug-resistant malaria
parasites.
Corresponding author Dr. R. Kiplin Guy, chair of the St. Jude Department of
Chemical Biology and Therapeutics, says, "Our goal is to develop an affordable,
fast-acting combination therapy that cures malaria with a single dose."
The team now plans to carry out safety trials of the compound in healthy human
adults.
Grants from various bodies, including the National Institutes of Health,
Medicines for Malaria Venture, Australian National Health and Medical Research
Council, and the Howard Hughes Medical Institute helped fund the study.
Meanwhile, Medical News Today recently learned of another breakthrough in
the fight against malaria, where researchers found good gut bacteria to be highly effective against malaria.
In that study, the team discovered certain bacteria in the gut may induce a natural
antibody defense against the infection. They also found children tend not to have
enough of the antibodies to stave off malaria.
Written by Catharine Paddock PhD
Not to be reproduced without permission.
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Courtesy: Medical News Today
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