How extract from poisonous Foxglove can PROTECT against high blood pressure and heart failure
Plant has been used to cleanse wounds since the 13th century



16:03 GMT, 15 June 2012

Deadly: Foxgloves are poisonous if eaten

Deadly: Foxgloves are poisonous if eaten. But an extract could prove beneficial to heart patients

A lethal poison made from a toxic plant once used as a Victorian murder weapon could help treat millions of people with high blood pressure.

Since the 13th century, the herb Foxglove has been used to cleanse wounds and its dried leaves were brewed by Native Americans to treat leg swelling caused by heart problems.

Researchers at the University of Michigan reveal that digoxin, the active ingredient in digitalis, or Foxglove, can enhance the body's own protective mechanism against high blood pressure and heart failure.

Around one in three people in Britain and the U.S have high blood pressure, also known as hypertension.

The condition is linked to obesity and can be prevented by reducing salt intake, being active and keeping a healthy weight.

Most current treatments prevent excess hormone and stress signals that can lead to high blood pressure and heart failure.

But recent studies have found that the body has the ability to keep excess stimulation in check through production of a family of inhibitors called RGS proteins.

Researchers looked for ways to 're-purpose' old drugs to tap into this protective mechanism which is lost among some individuals with high blood pressure and heart failure.

Study author Dr Benita Sjogren, said: 'We tested several thousand known drugs and bioactive molecules for a potential role in enhancing RGS2 and/or RGS4 expression and function and have identified a novel mechanism for digoxin.'

Case histories collected by Dr William Withering in 1775 determined that Foxglove contained the active ingredient, digoxin, now an important drug for treating patients with congestive heart failure.

This new action of digoxin was found by treating engineered human kidney cells with thousands of known drugs in a high-throughput screen at the U-M Center for Chemical Genomics. Digoxin was then shown to have similar actions in isolated mouse blood vessel cells.

Dr Rick Neubig said: 'Low dose digoxin, the active ingredient of digitalis, was able to increase RGS2 levels in the heart and kidney.

'This new action of digoxin could help explain the fact that low doses seem to improve the survival of heart failure patients.'

The article was published online in Molecular Pharmacology.