About Arnica Montana

A.montana is endemic to Europe, from southern Iberia to southern Scandinavia and the Carpathians. It is also grown in California and Mexico. A. montana grows in nutrient-poor silcaceous meadows up to nearly 3000 m. It is rare overall, but may be locally abundant. It is becoming rarer, particularly in the north of its distribution, largely due to increasingly intensive agriculture. In more upland regions, it may also be found on nutrient-poor moors and heaths.

Arnica is from an important medicinal plant family, the Compositae family, which includes Chamomile, Calendula, Echinacea, Dandelion, Chicory and Yarrow. They are all known for their anti-inflammatory qualities. Arnica minimizes the immediate effects of damage to tissue and aids the healing of bruises, sprains and injuries.

Form

A. montana has tall stems (20–60 cm), supporting usually a single flower head. Most of the leaves are in a basal rosette, but one or two pairs may be found on the stem. The flower heads are yellow, approximately 5 cm in diameter, and appear from May to August.

Uses and toxicity

Arnica montana is sometimes grown in herb gardens and has long been used medicinally. It contains the toxin helenalin, which can be poisonous if large amounts of the plant are eaten. Contact with the plant can also cause skin irritation. The roots contain derivatives of thymol, which are used as fungicides and preservatives and may have some anti-inflammatory effect. When used topically in a gel, Arnica was found to have the same effect as the use of NSAIDs (ibuprofen) in treating the symptoms of hand osteoarthritis.

The main active components mediating the pharmacological effect of Arnica are sesquiterpene lactones, mainly helenalin and its derivatives. The anti-inflammatory effect is due to several complex molecular mechanisms, a predominant one being the ability of helenalin and its derivatives to inhibit activation of transcription factor NF-KB, a factor involved in the inflammatory process. This mechanism differs from that of conventional non steroidal anti-inflammatory drugs and does not produce the side effects associated with those drugs.

Other pharmacological actions include:
The suppression of inflammatory mediators such as prostaglandins The inhibition of platelet aggregation by the inter action of helenalin and its derivatives with platelet sulfhydryl groups, which supports its use in traditional medicine to improve blood flow and therefore reduce bruising

The plant also possesses counter-irritant properties. Counter-irritation increases local circulation which in turn relieves congestion and inflammation.

Arnica is currently used in liniment and ointment preparations used for strains, sprains, and bruises. Commercial arnica preparations are frequently used by professional athletes. The thymol derivatives concentrated in the plants roots have been clinically shown to be effective vasodilators of subcutaneous blood capillaries. Arnica preparations used topically have been demonstrated to act as an anti-inflammatory and assist normal healing processes by facilitating transport of blood and fluid accumulations through a dilating action of subcutaneous blood capillaries. If ingested internally, the toxin helenalin produces severe gastroenteritis, and internal bleeding of the digestive tract if enough material is ingested.