Digitalis

From ArticleWorld

The genus of Digitalis is composed of approximately 20 species of herbaceous or non-woody biennials, perennial and shrubs. This group has in the past been placed in the grouping of the figwort family however due to new available research this set of plants has now been assigned to the family Plantaginaceae. This genus is composed of species native to three major continents, namely, Europe, Africa and Asia.

Description

The flowers of digitalis are tubular in structure and vary in color according to the species. They are found on a tall spike and flower colors may be purple, pink, yellow and white. A common name for digitalis is foxgloves and the scientific name is translated as finger-like. One common member of this species and perhaps the most well-known is the common foxglove or digitalis purpurea. This plant is a biennial and is utilized as an ornamental plant due to its flowers which are violet in color. In the first year of growth only the long, basal leaves are produced but in the second year of growth the erect leafy stem is produced. This stem normally grows to about 0.5-2.5 m.

Medical use

A chemical that is extracted from digitalis plants is digoxin which is used in preparations with cardiac glycosides. This chemical is used in the treatment of heart conditions such as heart failure as it is seen to strengthen cardiac contractility and as an anti-arrhythmic agent to regulate the heart beat. The digoxin is extracted mainly from the leaves produced in the second year of growth. The chemical extracted works by inhibiting the sodium-potassium ATPase thereby increasing intracellular calcium. This increase in intracellular calcium is the cause of the strengthening of cardiac contractility. Overdoses of digitalis may result in jaundiced or yellow vision and in the appearance of blurred outlines. A side effect is the reduction in appetite and due to this digitalis has been used as a weight loss drug.