A drug used to treat backpain may also prevent patients with diabetes from going blind or having limbs amputated, a study suggests.

Scientists in the United States have found evidence to indicate that benfotiamine may be able to keep blood vessels healthy.

Damaged blood vessels can trigger serious complications in patients with diabetes, adversely affecting the eyes, kidneys and heart.

This is very interesting work and these are very promising results Dr Paul Thornalley, Essex University

But tests on animals have suggested this drug, which is a derivative of vitamin B1, could prevent this from happening.

Dr Michael Brownlee and colleagues at the Albert Einstein College of Medicine in New York tested benfotiamine on diabetic rats.

Cell damage

They found that the drug stopped cells from being damaged, preventing complications like blindness or kidney disease.

In people with diabetes, all cells are bathed in blood that contains high levels of glucose.

Most cells are unaffected by this and have normal levels of glucose inside.

However, some cells are affected and have high levels of glucose inside.

These cells are often unable to get rid of this excess glucose.

As a result, they become damaged and activate what scientists refer to as pathways of cellular damage - damaging other cells and triggering complications like kidney disease and blindness.

Previous research has suggested that four biochemical pathways are responsible for most complications in patients with diabetes.

This latest study suggests that benfotiamine can block three of these pathways.

The scientists said the discovery could pave the way for new treatments for people with diabetes.

Dr Michael Brownlee, who headed the study, said his team were now applying to US regulators for permission to carry out further tests on the drug, possibly in humans.

German tests

Benfotiamine has been licensed for use in Germany for the past 10 years. It is prescribed there for treating sciatica and other painful nerve conditions.

Dr Brownlee said he was confident they would be given permission to carry out further studies on the drug.

He added: "Benfotiamine has been used extensively in Germany for many years and to my knowledge there are no reported side effects."

Dr Paul Thornalley of Essex University who has carried out similar studies in this area welcomed the research.

"This is very interesting work and these are very promising results," he told BBC News Online.

"Thiamine supplementation will probably offer prospects for treatment in the future. It would also be a very economical therapy."

The study is published in the journal Nature Medicine.