Nature's Pharmacy: Ancient Knowledge, Modern Medicine

Foxglove purpurea
(Digitalis)

Name, Habitat and Appearance
Foxglove is the common name for about 20 to 30 species of summer-flowering biennials or short-lived perennial herbs of the family Scrophulariaceae. The earliest known name for this plant is the Anglo-Saxon "foxes glofa" (the glove of the fox). Its name may be derived from the large tubular flowers which resemble the fingers of a glove. Many varieties have been obtained through breeding plants with flowers varying from white to a deep rose color. They are widely cultivated as ornamentals for gardens.

Foxglove is native to western and central Europe, the British Isles, northwest Africa, central Asia and naturalized in the United States Pacific Northwest. Foxglove is naturally found in clearings, dry hilly pastures, along roadsides, in burned areas and rocky places. It thrives in siliceous or loamy soil, growing to a height of five feet; however, it needs very little soil to survive.

Legends and Folklore
According to a Northern European legend, bad fairies gave these blossoms to the foxes to put on their toes to soften their footsteps so that they could prowl around the chicken coop with impunity. Folksglove is one of its oldest names, and refers to the "good folk" or fairies, whose favorite haunts were said to be in the deep hollows and woody dells where foxglove thrives.

History
The dried leaves of Foxglove have been used medicinally since the 13th century. Historically, Foxglove was employed by herbalists as an ointment for cleansing wounds and reducing swelling, and as a tea for use as an expectorant. Native Americans brewed the plant to treat swelling in the legs caused by heart problems.

Digitalis was the most important drug introduced during the 18th century. William Withering began collecting detailed case histories in 1775 which were the impetus for his publication, Account of the Foxglove. The classic study included 163 cases that either he or one of his trained disciples had handled. Ultimately, scientists determined that Foxglove contained the active ingredient, Digitalis, now the drug of choice for treating patients with congestive heart failure (once known as Dropsy).

By the early nineteenth century, digitalis was commonly used in the treatment of heart problems. Evidence of this is seen in a poem written in 1818 by a woman whose father had been given digitalis for congestive heart failure:

The Foxglove's leaves, with caution given,
Another proof of favouring Heav'n,
Will happily display;
The rapid pulse it can abate;
The hectic pulse it can moderate;
And blest by Him whose will is fate,
May give a lengthened day.

By the beginning of this century, digitalis became the primary drug in the treatment of heart failure, and is still used for this and other cardiovascular problems. No synthetic drugs can duplicate the action of the naturally occurring glycosides in the treatment of heart failure.

Warnings
The whole plant is poisonous! It contains various cardiac glycosides that are toxic to a wide range of animals, including humans. Many of Foxglove's other common names pertain to its toxic nature. Although ingestion of this plant can be fatal at any time during the life of the plant, it is most poisonous just before the seeds ripen. The upper leaves of the stem are more toxic than the lower leaves. Symptoms include dizziness, vomiting, irregular heart beat, and delirium or hallucinations.

Modern Medicinal Uses
Digitalis increases the activity of all muscle tissue, but most importantly that of the heart, the arterioles, and its affect on the circulatory system. It is commonly prescribed to stimulate a weakened heart, regulate its beat and elevate blood pressure. Digitalis lowers venous pressure in hypersensitive heart ailments. It also causes an irregular pulse to become regular and improves the nutrition of the heart by increasing the flow of blood.

In small or moderate doses, Digitalis acts as a powerful diuretic and reduces swelling. It is also used in treating internal hemorrhaging, inflammatory diseases, delirium tremens, acute mania, epilepsy and various other conditions. Vincent van Gogh took digitalis for epilepsy and some historians suggest that the yellow vision this drug creates may have influenced his art.