Plant Profiler

Arnica (Arnica montana)


Arnica (Arnica montana) Image
Synonyms / Common Names / Related Terms
6-methoxykaempferol, Aconitum napellus, alisma, American arnica, Arnica augustifolia, Arnica chamissonis, Arnica cordifolia, arnica da serra, arnica flower, Arnica fulgens, Arnica latifolia, Arnica lonchophylla, Arnica montana, arnica root, Arnica sororia, arnica spray, Arnicae flos, arnicaid, arniflora, arnika, Arnikablüten, Asteraceae (family), bergwohlverleih, bétoine des montagnes, betuletol, bilmes herb, Caltha alpina, chamissonolid, common arnica, Compositae (family), donnerblume, engel trank, European arnica, fallherb, fallkraut, flavonoids, fleurs d'arnica, guldblomme, helenalin, herbe aux chutes, hispidulin, jaceosidin, kraftwurz, leopard's bane, lignans, monkshood, mountain arnica, mountain daisy, mountain snuff, mountain tobacco, pectolinarigenin, polmonaria di montagna, prickherb, sesquiterpene lactones, SinEcch™, smokeherb, sneezewort, snuffplant, souci des alpes, Spanish flower heads, St. John's strength flower, strengthwort, tabac des Vosges, tabaco de montana, thunderwort, waldblume, wellbestow, wolfesgelega, wolf's bane, wolf's eye, wolf's yellow, wolfsbane, wolfsblume, wolfstoterin, woundherb, wundkraut.

Mechanism of Action

Pharmacology:

  • Constituents: The active ingredients of arnica are sesquiterpene lactones, such as helenalin and 11,13- dihydrohelenaline and chamissonolid.7,8,4,5,9,10,1 Sesquiterpene lactone levels in arnica are found in higher concentrations in the disk flowers and lower concentrations in the stem of the plant.11 Arnica species (including A. angustifolia, A. lonchophylla, A. chamissonis, and A. montana) also contain lignans of the furofuran, dibenzylbutyrolactone, and dibenzylbutyrolactol types.12 Besides pinoresinol, epipinoresinol, phillygenin, matairesinol, nortrachelogenin, and nortracheloside, six dibenzylbutyrolactol derivatives with different stereochemistry and substitution at C-9 have been isolated. Other constituents include flavonoids13, caffeic acid derivatives (including 1-methoxyoxaloyl-3,5-dicaffeoylquinic acid13, 11alpha,13-dihydro-2-O-tigloylflorilenalin and the respective 2-O-isovaleryl derivative14), 6-acetoxy-2,2-dimethylchroman-4-one, and 10-acetoxy-8,9-epoxythymol isobutyrate14. Additionally, 2beta-ethoxy-2,3-dihydrohelenalin esters have been isolated. Studies of the extract after a two-year storage at 4 degrees C demonstrated that the latter were artifacts that had been formed by addition of ethanol to the cyclopentenone structure of helenalin.14
  • Analgesic effects: In a study investigating transcutaneous electrostimulation to measure analgesic effects, Kucera et al. compared topical spray applications of arnica, hydroxyethyl salicylate, and a combination of arnica and hydroxyethyl salicylate in a randomized, controlled, single-blind trial.6 The authors concluded that the combination is more effective than either ingredient alone.
  • Anticoagulation effects: Two sesquiterpene lactones of Arnica montana, helenalin and 11,13-dihydrohelenal have been shown to inhibit collagen-induced platelet aggregation, thromboxane formation, and 5-hydroxytryptamine secretion in a dose-dependent manner at 3-300mcM. Helenalin was more potent in terms of both the inhibition of platelet aggregation and thromboxane formation.1
  • Anti-inflammatory effects: The sesquiterpene lactones of arnica, helenalin and dihydrohelenalin, may be responsible for anti-inflammatory and analgesic activity.7,8 Anti-inflammatory effects of arnica have been tested in acute and chronic inflammatory models in rats. It was shown that pretreatment with A. montana 6CH blocked the action of histamine in increasing vascular permeability.15 The sesquiterpene lactones in arnica have also been shown to attack inflammatory processes by inhibiting NF-KappaB and NF-AT at micromolar concentrations7 and by inhibiting neutrophil migration, lysosomal rupture, enzymatic activity, and prostaglandin synthesis16. In human cell lines, the active ingredients of arnica, sesquiterpene lactones such as helenalin and 11,13- dihydrohelenaline and chamissonolid, inhibit activation of transcription factor NF-kB, which correlates with the drug's anti-inflammatory property.8
  • Dermatological effects: Helenalin and its derivatives found in arnica may lead to Contact Dermatitis.4,5,9,10
  • Lipid-lowering effects: Sesquiterpene lactones block lipogenesis, resulting in lowering of serum lipids in mice.2

Pharmacodynamics/Kinetics:

  • Topical absorption: In a study using the stripped layers of stratum corneum in pig skin, penetration of arnica sesquiterpene lactones into the stratum corneum has been found to be greater when the herbal is applied topically as a tincture.17 Using a modified Franz diffusion cell and human stratum corneum and epidermis as an experimental membrane, another study has shown that oleic acid and dimethylsulfoxide enhanced cutaneous absorption.18 Based on in vitro study, bioactive constituents such as sesquiterpene lactones from commercially available Arnica montana preparations can be detected within three hours of topical application when applied on the skin.19 The individual sesquiterpene lactones bind serum proteins with different affinities, which has been suggested affects their biological activities.3

References

  1. Schroder, H., Losche, W., Strobach, H., Leven, W., Willuhn, G., Till, U., and Schror, K. Helenalin and 11 alpha,13-dihydrohelenalin, two constituents from Arnica montana L., inhibit human platelet function via thiol-dependent pathways. Thromb Res 3-15-1990;57(6):839-845. 2116680
  2. Hall, I. H., Lee, K. H., Starnes, C. O., Muraoka, O., Sumida, Y., and Waddell, T. G. Antihyperlipidemic activity of sesquiterpene lactones and related compounds. J Pharm Sci 1980;69(6):694-697. 7205585
  3. Wagner, S., Kratz, F., and Merfort, I. In vitro behaviour of sesquiterpene lactones and sesquiterpene lactone-containing plant preparations in human blood, plasma and human serum albumin solutions. Planta Med 2004;70(3):227-233. 15114499
  4. Hausen, B. M., Herrmann, H. D., and Willuhn, G. The sensitizing capacity of Compositae plants. I. Occupational Contact Dermatitis from Arnica longifolia Eaton. Contact Dermatitis 1978;4(1):3-10. 148995
  5. Hausen, B. M. Identification of the allergens of Arnica montana L. Contact Dermatitis 1978;4(5):308. 154377
  6. Kucera, M., Horacek, O., Kalal, J., Kolar, P., Korbelar, P., and Polesna, Z. Synergetic analgesic effect of the combination of arnica and hydroxyethyl salicylate in ethanolic solution following cutaneous application by transcutaneous electrostimulation. Arzneimittelforschung 2003;53(12):850-856. 14732966
  7. Merfort, I. [Arnica: new insights on the molecular mode of action of a traditional medicinal plant]. Forsch Komplementarmed Klass Naturheilkd 2003;10 Suppl 1:45-48. 12808362
  8. Lyss, G., Schmidt, T. J., Merfort, I., and Pahl, H. L. Helenalin, an anti-inflammatory sesquiterpene lactone from Arnica, selectively inhibits transcription factor NF-kappaB. Biol Chem 1997;378(9):951-961. 9348104
  9. Herrmann, H. D., Willuhn, G., and Hausen, B. M. Helenalinmethacrylate, a new pseudoguaianolide from the flowers of Arnica montana L. and the sensitizing capacity of their sesquiterpene lactones. Planta Med 1978;34(3):299-304. 704699
  10. Schmidt, T. J., von Raison, J., and Willuhn, G. New triterpene esters from flowerheads of Arnica lonchophylla. Planta Med 2004;70(10):967-977. 15490326
  11. Douglas, J. A., Smallfield, B. M., Burgess, E. J., Perry, N. B., Anderson, R. E., Douglas, M. H., and Glennie, V. L. Sesquiterpene lactones in Arnica montana: a rapid analytical method and the effects of flower maturity and simulated mechanical harvesting on quality and yield. Planta Med 2004;70(2):166-170. 14994196
  12. Schmidt, T. J., Stausberg, S., Raison, J. V., Berner, M., and Willuhn, G. Lignans from Arnica species. Nat Prod Res 5-10-2006;20(5):443-453. 16644542
  13. Spitaler, R., Schlorhaufer, P. D., Ellmerer, E. P., Merfort, I., Bortenschlager, S., Stuppner, H., and Zidorn, C. Altitudinal variation of secondary metabolite profiles in flowering heads of Arnica montana cv. ARBO. Phytochemistry 2006;67(4):409-417. 16405933
  14. Kos, O., Lindenmeyer, M. T., Tubaro, A., Sosa, S., and Merfort, I. New sesquiterpene lactones from Arnica tincture prepared from fresh flowerheads of Arnica montana. Planta Med 2005;71(11):1044-1052. 16320207
  15. Macedo, S. B., Ferreira, L. R., Perazzo, F. F., and Carvalho, J. C. Anti-inflammatory activity of Arnica montana 6cH: preclinical study in animals. Homeopathy 2004;93(2):84-87. 15139092
  16. Hall, I. H., Starnes, C. O., Jr., Lee, K. H., and Waddell, T. G. Mode of action of sesquiterpene lactones as anti-inflammatory agents. J Pharm Sci 1980;69(5):537-543. 6247478
  17. Wagner, S., Suter, A., and Merfort, I. Skin penetration studies of Arnica preparations and of their sesquiterpene lactones. Planta Med 2004;70(10):897-903. 15490315
  18. Bergonzi, M. C., Bilia, A. R., Casiraghi, A., Cilurzo, F., Minghetti, P., Montanari, L., and Vincieri, F. F. Evaluation of skin permeability of sesquiterpenes of an innovative supercritical carbon dioxide Arnica extract by HPLC/DAD/MS. Pharmazie 2005;60(1):36-38. 15700776
  19. Tekko, I. A., Bonner, M. C., Bowen, R. D., and Williams, A. C. Permeation of bioactive constituents from Arnica montana preparations through human skin in-vitro. J Pharm Pharmacol 2006;58(9):1167-1176. 16945174




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