Since the 13th century, the herb and poisonous plant Foxglove has been used to cleanse wounds and its dried leaves were carefully brewed by Native Americans to treat leg swelling caused by heart problems. Digoxin (see structure), the active ingredient in digitalis, or the poisonous plant Foxglove, can enhance the body's own protective mechanism against high blood pressure and heart failure.
High blood pressure can be prevented by reducing salt intake, being active and keeping a healthy weight, but about 1 in 3 Americans has high blood pressure, also called hypertension, which can damage the body in many ways. 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.
Ref; http://www.uofmhealth.org/news/digoxin-0613