A protein extracted from caterpillars has proven effective against the viruses that cause measles and the AH1N1 strain of flu, Brazilian scientists said.

The discovery was made by scientists at the Butantan Institute as part of a project funded by the Sao Paulo State Support for Research Foundation.

"We still don't know the exact chemical composition of that substance, but it's already demonstrated great potential: it reduces replication of the picornavirus (related to poliomyelitis) by 2,000 times and that of the measles virus by 750 times, as well as having neutralized the H1N1 flu virus," virologist Ronaldo Zucatelli Mendonça said.

Last year, researchers at Butantan reported the discovery of a caterpillar protein capable of reducing replication of the herpes virus by a factor of 1 million.

Both proteins have the ability to promote apoptosis, or programmed death, of invasive or damaged cells, a characteristic that has the potential to make them useful in cancer treatment, the foundation said.

Butantan has already developed ways of obtaining large quantities of the proteins in the lab.

The substances must still undergo clinical trials in animals and humans, Mendonça said. EFE