London, Jan 28 (IANS): Chickens that are genetically modified to produce human proteins in their eggs can offer a cost-effective method of producing certain types of drugs, a new research suggests.

The study -- which has initially focused on producing high quality proteins for use in scientific research -- found the drugs working just as well as the same proteins produced using existing methods.

High quantities of the proteins can be recovered from each egg using a simple purification system and there are no adverse effects on the chickens themselves, which lay eggs as normal, suggests the study published in the journal BMC Biotechnology.

"We are not yet producing medicines for people, but this study shows that chickens are commercially viable for producing proteins suitable for drug discovery studies and other applications in biotechnology," said co-author Helen Sang, Professor at the University of Edinburgh.

Eggs are already used for growing viruses that are used as vaccines, such as the flu jab.

This new approach is different because the therapeutic proteins are encoded in the chicken's DNA and produced as part of the egg white.

For the study, the team initially focused on two proteins that are essential to the immune system and have therapeutic potential -- a human protein called IFNalpha2a, which has powerful antiviral and anti-cancer effects, and the human and pig versions of a protein called macrophage-CSF, which is being developed as a therapy that stimulates damaged tissues to repair themselves.

Just three eggs were enough to produce a clinically relevant dose of the drug. As chickens can lay up to 300 eggs per year, researchers say their approach could be more cost-effective than other production methods for some important drugs.

Protein-based drugs, which include antibody therapies such as Avastin and Herceptin, are widely used for treating cancer and other diseases, according to the researchers

"We are excited to develop this technology to its full potential, not just for human therapeutics in the future but also in the fields of research and animal health," said co-author Lissa Herron from the varsity.

The team noted that the findings provide sound evidence for using chickens as a cheap method of producing high quality drugs for use in research studies and, potentially one day, in patients.