Medicinal uses of Digitalis purpurea

Within the plant kingdom, most medicinal plants are considered small herbaceous, and many of them have spontaneous growth in mountainous areas, meadows and roadsides.

In this case Digitalis purpurea it meets these requirements and we can see it grow in many areas of the European continent. However, this biannual plant produces flowers that come to be valued within the ornamental sector. On the other hand, we must consider the danger of its cultivation since its active ingredients are poisonous and cumulative if they are not known to be used properly.

In this article we are going to know everything it can offer us Digitalis purpurea as a medicinal plant and what advantages (and disadvantages) its use entails.

Features of Digitalis purpurea

Digitalis purpurea It is a herbaceous plant of small size, not exceeding in most cases more than 20 cm in height.  In its morphology, it presents large leaves, with a spectacular pinkish flower in the form of an inflorescence that comes out in summer and the first months of autumn.

Taxonomy

  • Order: Lamiales
  • Family: Plantaginaceae
  • Gender: Digitalis
  • Species: Digitalis purpurea

The history of this plant has passed in Europe, although it can also be seen cultivated in North Africa and even in the American continent (in countries such as Chile, for example), where it was taken there by Europeans.

It usually grows in a wide variety of places, although it prefers mountainous areas, meadows and slopes, where trees such as oaks and fir trees usually grow.

Its leaves are the ones with the highest concentration in active ingredients. These are used today to manufacture various drugs related to the cardiovascular system.

History of medicinal use

Digitalis purpurea it has historically been used as a medicinal plant by the Roman Empire. However, uses to combat heart failure were discovered later, starting in the European tenth century.

With the studies of the British doctor William Withering in the eighteenth century was when it was possible to know what active principles had action to fight against heart failure. In 1957, it was possible to isolate the most important active ingredient from Digitalis purpurea, digoxin considered as a cardiac glycoside.

Active ingredients of Digitalis purpurea

Although the highest concentration of the active substances of pharmacological uses are found in the leaves, the seeds harbor digitalis glycosides, steroid saponins, flavones (chrysoeriol), anthraquinones and organic acids.

  • Cardiotonic heterosides: digitoxin, gitoxin, digitalin
  • Flavonoids
  • Saponosides

The digitalin toxin modifies the behavior of the heart, hence from it several drugs have been synthesized to combat heart failure and arrhythmias.

Both digitoxin and digoxin present in the leaves, flowers and seeds of Digitalis purpurea, are considered as a cumulative poison in the body and are potentially toxic to animals and humans.

These compounds act inhibiting the sodium-potassium ATPase pump, increasing cellular calcium levels. This causes a positive inotropic effect to occur that affects the parasympathetic nervous system.

When there is an overdose, one of the most common phenomena is yellow vision (xanthopsia) and extreme bradycardia.

One of the best known medicines based on the extracts of Digitalis purpurea is Lanoxin, with Digitoxin. This medication works by increasing the strength of the heart’s contractions, altering the heart rate, and increasing blood flow. [More information on cardiac glycosides]

Chemistry of digitalis purpurea

Medicinal properties

Digitalis purpurea, with an exact control of the dosage that today can only be done by pharmacological companies, is indicated for the treatment of different diseases.

As we will see later, it was initially thought that it could have an effect on diseases such as epilepsy, diabetes or even cancer, but currently its uses are limited to controlling arrhythmias and treating heart failure.

Cardiovascular effects

The cardiac glycosides of Digitalis purpurea they have direct effects on the heart muscle, causing it to shrink. This is achieved by facilitating the accumulation of calcium in the myocytes.

Therefore, this medicinal plant has the approval of the scientific community for its antiarrhythmic activity, but the dose must be controlled very well since, an increase in the administration of the active ingredient causes the opposite effect, arrhythmia.

Anti-cancer effects

Trying to dig deeper into the effect of Digitalis purpurea, in vitro studies have been conducted to evaluate the cytotoxic properties of glycosides and flavonoids.

Cell-level activity has been demonstrated in different types of human cancer, including solid tumor lines.

Mechanisms include direct cytotoxicity resulting in apoptosis of cancer cells, inhibition of aflatoxin-induced cytotoxicity, inhibition in nitric oxide synthase induction, and increases in glutathione S-tranferase.

However, it is necessary to delve into the effects applied directly to sick patients, so there is still a long way to go.

Effect on diabetic people

Preliminary studies in hyperglycemic rats have yielded a increased glucose tolerance 2 hours after the rats received a single dose of saponin digitonin.

In addition, related beneficial results on lipid profile and cholesterol were also observed.

However, the conclusions again are insufficient to be able to determine that the same response will occur in humans, so more scientific studies are needed in this regard.

Proven efficacy

  • Irregular heart rhythms (atrial fibrillation): the intake of medicines based on Digitalis purpurea, orally can improve irregular heart rhythms, as well as atrial fibrillation or cardiac flutter.
  • Congestive heart failure (CHF): the intake of medicines based on Digitalis purpurea por orally may improve CHF and CHF-related inflammation.

Contraindications

Toxicology

It must be considered that all parts of Digitalis purpurea they are toxic. In fact, there are cases of toxicity by consumption without medical evaluation in 15% of cases. Ingestion of even extremely low amounts of some part of the plant can lead to severe contraindications, especially in children and animals. The main problem of the toxicology of this plant is that the dose is cumulative.

Pregnancy and lactation

The consumption of any part of the plant or even drugs without medical review is totally discouraged, since there are documented adverse cardiac reactions.

There are interactions with digoxin and digitalis glycosides, which can be life-threatening. Many of the serious interactions occur from elevated serum digoxin levels or electrolyte disorders.