Cia

Not Just a Cosmetic Fix malariaparasiteneedstotakeupfrom its host, but the parasite can be fatally The future weapon against malaria may be a common ingredient found in
shampoo. Fenja Theden reports.
War II. Despite being “malaria-free”, antimalarial drugs, such as chloroquine.
human host and back to the mosquito.
ular stage of the parasite’s life cycle, overuse and indiscriminate treatment.
“The parasite can be fatally tricked into taking up pantothenol instead
of vitamin B5.”
in Africa. Dr Saliba feels that “Australia is essential for the survival of the para- site. The parasite can’t synthesise its own vitamin B5, so it relies on its host’s blood plasma to obtain the nutrient.
most affected by malaria, but also crucial personnel going to malaria-infected areas need to take precautions against malaria, Giemsa-stained malaria parasites (blue/purple) among human red blood cells. (a) Two mature-stage parasites (known as trophozoites)
inside red blood cells. (b) Daughter parasites (known as merozoites) ready to invade new uninfected red blood cells. Three red blood
cells have already been invaded by merozoites, forming a young stage of the parasite known as a “ring”.
human body. The trials indicate that pantothenol lasts long hopeful that the parasite would find it difficult to develop enough in the body to be taken up by the parasite, but not resistance because it “has to obtain this nutrient from the long enough for all parasites to be killed. Thus, says Dr plasma in order to grow. For resistance to develop, the para- Saliba, if an infected person was given a dose of pantothenol, site would need to synthesise vitamin B5 itself in high quan- they would “convert most of it into vitamin B5 by the time tities, and we currently have no evidence that it’s able to do it’s actually had the chance to kill all the parasites”.
so. Alternatively, it needs to come up with a strategy for But with a weakness in the parasite’s life cycle clearly limiting the uptake of the analogues. This will be difficult as identified, Dr Saliba is developing his antimalarial drugs the mechanism would need to discriminate between vitamin further. The research team has discovered that other B5 and the structurally very similar analogues.
analogues of pantothenol, compounds similar to the real “Also, a recent trend has been to combine new vitamin B5, could be even better drugs. Nearly 50 compounds compounds shown to kill the parasite with other compounds have been tested so far, with about 15 of them able to kill that kill the parasite in a completely different way. You essen- tially hit two independent targets. This makes it even more However, Dr Saliba says there are other constraints: “You difficult for the parasite to become resistant to the drug obviously want to find compounds that are able to kill the combination as it would need to develop two separate resist- parasite at low concentrations, so that they won’t be toxic ance mechanisms simultaneously, or one mechanism that to the human host. The concentration with which a couple of our new compounds are able to kill the parasite is encour- Dr Saliba hopes the new drugs will be used either to treat people that have already contracted malaria or to prevent But most drugs developed in the world face the same a malaria episode by being taken during travel to malaria- challenge: harmful organisms adapt and evolve to become resistant to drugs. This has happened to conventional anti- In research facilities around Australia and the world, the malarial drugs. If these new antimalarial compounds were race to save millions of lives from malaria continues every to be used on a large scale, will the malaria parasite even- day. Dr Saliba envisages a world in which people can live and tually develop resistance towards the damage caused by travel without fear of contracting the disease.
Fenja Theden has a background in molecular biology. She is currently undertaking a
Dr Saliba points out that it is very hard to predict whether Graduate Diploma in Science Communication with the Centre for Public Awareness of
resistance to the analogues would develop. However, he is Science at the ANU.

Source: http://www.control.com.au/bi2006/278malaria.pdf