LONDON (Reuters) – An experimental drug that boosts the body's ability to exercise may one day help people recover from heart failure, researchers said this week.

A study of mice showed the drug, derived from wheat, spurred red blood cells to strengthen surrounding tissue by releasing more oxygen, they reported in the Proceedings of the National Academy of Sciences.

The researchers said they hoped clinical trials in humans could begin in the middle of the year although it would be several years before a drug was available for widespread use.

"With this compound, more oxygen is released than under normal conditions," said Jean-Marie Lehn, a Nobel Prize-winning researcher at Universite Louis Pasteur-ISIS in Strasbourg, France, who co-led the study.

"The sick mice were running as well as the normal ones, and the normal ones were running better than normal," he told Reuters.

Heart failure, in which the heart is unable to supply enough blood to the body's organs, affects 23 million people worldwide and kills 600,000 each year.

Exercise helps recovery by making the heart pump more efficiently.

Lehn, who won the Nobel Prize for Chemistry in 1987, and his team showed how a compound known as myo-inositol trispyrophosphate (ITPP) binds to haemoglobin in the blood and spurs the release of oxygen, making muscle and other tissue stronger.

"(The compound) is thus an attractive candidate for the therapy of patients with reduced exercise capacity caused by heart failure,"

The researchers, who injected the mice with the drug and administered it in drinking water, reported none of the animals showed side effects, Lehn said in a telephone interview.

Because the drug appeared to be as potent when taken orally, it could one day offer an easy way to treat people with heart failure, he added.

Boston-based NormOxys, a venture capital-funded drug development company founded in 2004 by Lehn and others, holds the patents for uses of the drug.