ARNICA FLOWERS, ARNICA ROOT, COMMON ARNICA, LEOPARD'S BANE, MEXICAN ARNICA, MOUNTAIN ARNICA, MOUNTAIN DAISY, MOUNTAIN TOBACCO, SNEEZEWORT, WOLF'S BANE

Taxonomic Class

Asteraceae

Common Trade Names

Arnicaid, Arnica Spray, Arniflora (Gel), Traumeel-S (homeopathic formulation of arnica and other plant extracts manufactured in Italy)

Common Forms

Available as a spray for topical application and in creams (preferred in Europe), gels, ointments, sublingual preparations, tablets, teas, and tinctures. Creams typically contain 15% arnica oil; salves should contain 20% to 25% arnica oil.

Source

Active components are usually extracted from the flowers and root­stocks of Arnica montana, A. fulgens, A. sororia, and A. cordofolia. Mexican arnica is derived from Heterotheca inuloides. Certain species of Arnica are native from Alaska to the Western United States and Mexico. Others are native to Europe and Siberia.

Chemical Components

Arnica's active ingredients are thought to be flavonoid glycosides and sesquiterpenoid lactones, including anthoxanthine, arnisterol (arnidiol), choline, dihydrohelenalin, faradiol, and helenalin. Arnica also contains a group of polysaccharides with a content of 65% to 100% galacturonic acid and 0.5% to 1 % resins, tannins, and volatile oils.

Actions

Four sesquiterpenoids isolated from H. inuloides in one study demonstrated antibacterial activity in vitro. One compound exhibited gram­positive antibacterial activity and minimal bactericidal concentrations of 12.5 mcg/ml against methicillin-resistant Staphylococcus aureus . Another in vitro study supported arnica's inhibitory effect against a few gram-positive organisms, but the effect was considered minor.

An A. montana extract has been shown to increase phagocytosis in mice .

In a Dutch study, most arnica flavonoids demonstrated moderate to low cytotoxicity in vitro when compared with cisplatin. Helenalin, a sesquiterpene lactone, displayed the strongest cytotoxicity . Another study apparently found a quicker recovery from carbon tetrachloride-induced hepatic injury in rats when the rats were given a preparation of phenolic compounds of A. montana. Other studies in rats have also supported a role of arnica extracts in reducing lipid peroxidation and restoration of glutathione activity in the carbon tetrachloride-induced hepatic injury.