21 June 1999

Drug that could beat HIV

Researchers in Canberra, Australia, have discovered a new drug that stops viruses in their tracks. The new type of dug has the potential to offer a side-effect-free treatment for HIV and mosquito-borne diseases such as Ross River Fever.

The approach could also pave the way for the development of a host of new pharmaceuticals including anaesthetics, tranquilisers and anti-epileptics, as well as drugs to prevent strokes and congestive heart failure.

The potential HIV drug, known as C9, has been developed by researchers at the John Curtin School of Medical Research, based at the Australian National University in Canberra.

Independent laboratory tests, conducted on mammalian cells in test-tubes, has shown the drug stopped the AIDS virus replicating. But its effectiveness remains to be proven in humans, as the compound has not yet been put through clinical trial.

The drug was discovered through basic research work conducted during 1993 and 1994 into ion channels - pathways found in cell membranes that allow positive and negatively-charged particles, or ions, into and out off cells.

Ions convey messages between cells that enable them to function and human cells have many different kinds of channels through which the ions pass.

Lead researcher Peter Gage says the team was surprised to find viruses also made ion channels - which the C9 compound was able to block during the laboratory tests.

This meant that the virus could enter cells and replicate, but could not then escape the cells, thus preventing the infection from spreading.

"By finding the precise location and form of a disorder at the molecular level, it is possible to identify or design a drug to lock onto the site and interact with the ion flow to stop the condition," Professor Gage said.

"The benefit of this targeted approach is that the effect of the disorder is arrested, and there are no - or minimal - side-effects."

Using the same approach to target other ion channels could provide better anaesthetics, tranquillisers, and even a people and environmentally friendly insecticide, he said.