Suppression

Arnica montana (leopard's bane, mountain tobacco, mountain arnica)

Category: Medicines - plant based

Type

Voluntary

Introduction and description

 

Arnica montana, commonly called leopard's bane, mountain tobacco and mountain arnica, is a European flowering plant in the sunflower - Asteraceae – family.  Botanical synonyms include:

  • Doronicum montanum Lam.
  • Doronicum oppositifolium Lam.
  • Arnica helvetica Loudon
  • Arnica petiolata Schur
  • Arnica plantaginifolia Gilib.
  • Arnica lowii Holm
  • Cineraria cernua Thore

Arnica contains a number of chemicals that are chelating agents – of the soil.  Thus potentially Arnica may be a very useful bioremedial plant.

Distribution

 

Arnica montana is widespread across most of Europe, although it is absent from the British Isles and the Italian and Balkan Peninsulas. It grows in nutrient-poor siliceous meadows up to nearly 3,000 metres (9,800 ft). 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.

It is a wild perennial, but can be and is cultivated.  Arnica thrives in a mixture of loam, peat, and sand. It may be propagated by root division or from seed.

Description

The leaves of Arnica montana form a flat rosette, from the centre of which rises a flower stalk, 1 to 2 feet high, bearing the flowers.

Most of the leaves are in a basal rosette, but one or two pairs may be found on the stem and are, unusually for composites, opposite.

The flower heads are yellow, approximately 5 cm (2.0 in) in diameter, and appear from May to August.

The rhizome is dark brown, cylindrical, usually curved, and bears brittle wiry rootlets on the under surface.

Medicinal Uses

Arnica montana has historically been used as medicine, but traditionally it has always been used externally or in extremely tiny homeopathic doses of a carefully prepared tincture of only some parts of the plant. 

Mrs Grieve
The tincture is used for external application to sprains, bruises, and wounds, and as a paint for chilblains when the skin is unbroken. Repeated applications may produce severe inflammation. It is seldom used internally, because of its irritant effect on the stomach.

Mrs Grieve mentions one very intriguing use:

A homoeopathic tincture, X6, has been used successfully in the treatment of epilepsy; also for seasickness, 3 X before sailing, and every hour on board till comfortable.

we assume here that Mrs Grieve is referring to the flower extract, although it is not that clear in her explanation.

Clinical trials

 

Clinical trials on Arnica have been very unsatisfactorily handled in the main, meaning the results tend to be meaningless. 

In the olden days, as Mrs Grieve says, it was used to ‘bring out a bruise’.  It probably did this via its effect on the immune system as at low doses it is an immunostimulant.  But all sorts of uses are being tested. 

It has been tested for treating osteoarthritis. It predictably failed.  Predictably, because in the first place osteoarthritis is caused by a pathogen, as such external remedies will have no healing effect, and secondly Arnica was not traditionally used for skeletal pain relief. 

Arnica is used homeopathically internally, but homeopathy requires considerable dilution of a tincture prepared from only some of the plant.  There is [or should be] a choice of two -  the British Pharmacopoeia Tincture of the root, and the United States Pharmacopoeia Tincture of the flowers.  Each does different things.

It appears that in the USA, where one such trial was conducted, that not only is the concept of homeopathy not understood, or the idea that different parts of the plant can do different things,  but the tincture was not used – I quote “three pills of Arnica were taken per day”.  The result, as you can imagine, was not a great success.

Given that Arnica montana contains helenalin, which can be poisonous, this was an unnecessarily risky experiment with people’s lives. Helenalin produces severe gastroenteritis and internal bleeding of the digestive tract if enough material is ingested.  We quote from the analysis of Dr Duke:

HELENALIN Plant:

Allergenic; Cardiotoxic; Cytotoxic ED50=0.1 ug/ml; Degranulant; Dermatitigenic; Fungicide; Inotropic EC50=14; Insecticide; Insectifuge; Irritant; Paralytic; Pesticide; Piscicide; Respiroanaleptic; Sympathomimetic; Vermifuge

 

 

  • An inotrope is an agent that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions. Positively inotropic agents increase the strength of muscular contraction.  The heart is a muscle, hence there is the potential here – at the wrong doses to cause arrhythmias or even heart attacks.
  • A Sympathomimetic is an agent that causes a 'flight and fight' response, - adrenaline, perspiration, heart racing –this can happen when we are being poisoned, as such this is simply confirmation that this plant is not exactly safe.  Quotes such as these “used as a decoction or tincture it stimulates the circulation and is valuable in the treatment of angina and a weak or failing heart” [Chevallier. A. The Encyclopedia of Medicinal Plants] are downright dangerous as the only reason the circulation is racing is because we are not well. The word Cardiotoxic should be born in mind here.
  • Paralytic, is self explanatory.

At homeopathically low doses Helenalin, according to Dr Duke, is an Immunostimulant [ED42=1 uM], in effect it kick starts the immune system.

Rhizome

The rhizome of Arnica contains Formic acid and according to Dr Duke

FORMIC-ACID Rhizome:

Acaricide; Antiseptic; Antisyncopic; Astringent; Corrosive; Counterirritant; FLavor FEMA 500-2,500; Fungistat; Fungitoxic; Irritant; Pesticide; Preservative; Toxic

 

So toxic if ingested, which is why the tincture containing the root is not ingested.  Note that this analysis shows the antiseptic, and counterirritant [irritant at high doses] nature of formic acid, and shows why its external use has some benefits.

Flower

 

The flower has some extremely interesting activities, - antiviral, antibacterial and antiparasitic.  As Mrs Grieve says “In the North American colonies the flowers are used in preference to the rhizome”.

Having said this, the ingestion of the flowers in any quantity would also be very unwise – the flowers not only contain the aforementioned Helenalin, but also Gallic acid which can damage the kidneys at high doses; and thymol which is ‘Enterotoxic’, again at the wrong doses - the prefix entero- refers to the intestine (from Greek ἔντερον, enteron). However it can also be used for cells not found in the intestine like Gastric enteroendocrine cells and Pancreatic enteroendocrine cells.

Before we get too worked up about the presence of thymol etc, the key is the dose.  Thymol is in thyme and does us no harm, but if we start to make pills of the flowers or use essential oils or high concentration extracts, we are heading for trouble.  As Mrs Grieve says

Great care must be exercised, as some people are particularly sensitive to the plant and many severe cases of poisoning have resulted from its use, especially if taken internally.

The old Eastern bloc countries are making a new and vital contribution to the study of plants like Arnica and are interestingly carrying out more research on some of the little studied activities of the plant.  For example

Polyphenolic compounds of plant origin are well known to be beneficial to human health: they exert protective effects on haemostasis and have a particular influence on blood platelets. However, the anti-platelet properties of polyphenolic compounds observed so far have not been weighed against their potential cytotoxic action against platelets.
The aim of this study was to demonstrate that anti-platelet and cytotoxic effects on blood platelets may interfere and therefore, may often lead to confusion when evaluating the properties of plant extracts or other agents towards blood platelets.
The anti-platelet and cytotoxic in vitro effects of plant extracts obtained from the husks of walnuts (J. regia) and flowers of arnica (A. montana) on platelet reactivity and viability were examined. …… The results reveal that none of the studied plant extracts demonstrated cytotoxicity towards blood platelets.
 The phenolic acid-rich extract of A. montana (7.5 and 15 µg/ml) significantly reduced the ADP-induced aggregation in both whole blood and PRP, and decreased the platelet reactivity index (PRI; VASP phosphorylation) in whole blood, while showing excellent antioxidant capacity………... Thus, its high polyphenol content, excellent antioxidant capacity and distinct anti-platelet properties, in combination with its lack of toxicity, make the extract of A. montana flowers a possible candidate as an anti-platelet agent.  PMID:  24679412

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References and further reading

  • Platelets. 2015;26(2):168-76. doi: 10.3109/09537104.2014.894970. Epub 2014 Mar 28.  Comparison of cytotoxic and anti-platelet activities of polyphenolic extracts from Arnica montana flowers and Juglans regia husks.  Rywaniak J1, Luzak B, Podsedek A, Dudzinska D, Rozalski M, Watala C.  1Department of Haemostasis and Haemostatic Disorders, Central Veterans' Hospital, Medical University of Lodz , Lodz , Poland

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