Plant extract 'protects chickens from bird flu'
[BEIJING] A Chinese scientist claims that he has developed a plant extract that can effectively treat poultry infected with the bird flu virus, H5N1.
The product totally eliminates H5N1 from infected chickens, says Liang Jianping, director of the Laboratory of New Veterinary Drugs at the Lanzhou Institute of Animal Husbandry and Veterinary Drugs, part of the Chinese Academy of Agricultural Sciences.
Liang extracted his product — named hypercine — from a plant in the Hypericaceae family. He is keeping its identity secret. Unlike most veterinary drugs, hypercine was developed with techniques used in traditional Chinese medicine.
On 30 October, the Key Lab of Poultry Disease at the Guangzhou-based South China Agricultural University (SCAU) reported that it had independently tested hypercine and confirmed its effectiveness.
Liang says that in the SCAU study, 16 chicken infected with H5N1 were fed hypercine every 12 hours. The virus normally kills birds within a day or two of infection, but three days after the experiment began, all of the chickens were still alive and the researchers could find no trace of H5N1 in them.
The university confirmed that the study had taken place, but refused to let SciDev.Net see the results.
Liang says he was invited to Vietnam earlier this year to help fight bird flu there, and that hypercine had proved effective in several poultry farms near the capital, Hanoi.
He added that hypercine passed the Chinese Ministry of Science's evaluation process last year. The extract has not been licensed as a drug, however, because official policy now is to cull infected birds rather than treat them.
Liang is investigating whether hypercine could work in rats in preparation for testing it in people.
"In principle, traditional Chinese medicine can play a role in fighting the H5N1 virus," says Wei Yanming, a senior researcher of veterinary drugs at Gansu Agricultural University in Lanzhou. He points out that the flu drug Tamiflu contains an extract of the star anise plant, which has long been used as a traditional remedy in China.
Wei, who formerly studied hypercine with Liang, says that because the plant extract is a complex mixture of chemicals rather than a single molecule, it would struggle to meet strict standards of agencies such as the US Food and Drug Administration.