Mistletoe

Viscum album

Mistletoe Parts used Uses Habitat and cultivation Research Constituents How much to take

The word "mistletoe" is about as nonspecific a term as you could possibly apply to a plant material. The addition of "American" or "European" helps a little. When properly used, American mistletoe refers to a single one of the more than 200 species of the genus Phoradendron. However, this species has four different scientific names, each of which is used more or less interchangeably. The most acceptable designation, of quite recent coinage, is Phoradendron leucarpum (Raf.) Rev. & M. C. Johnst., synonymous with P. serotinum (Raf.) M. C. Johnst. and P. flavescens (Pursh) Nutt. The nomenclature seems to be evolving more rapidly than the plant group itself. Once considered synonymous with P. tomentosum (DC.) Engelm, subspecies macrophyllum (Cockerell) Wiens, that taxon is now referred to as P. macrophyllum (Engelm.) Cockerell subspecies macrophyllum. At first glance, the nomenclature for European mistletoe seems simpler; it is Viscum album L.. But there are three subspecies commonly recognized: platyspermum Kell., growing on broadleaf trees; abietis Beck, growing on silver fir; and laxum Fiek, growing on various pines, seldom on firs. All of these plants are parasitic shrubs belonging to the family Viscaceae.

Although the berries of both American and European mistletoe have long been considered poisonous, the leaves, in the form of a tea, have a considerable reputation as a home remedy. The reputed uses of the two plants are as different as their names. American mistletoe is believed to stimulate smooth muscles, causing a rise in blood pressure and increased uterine and intestinal contractions. European mistletoe has precisely the opposite reputation of reducing blood pressure and acting as an antispasmodic and calmative agent.

Actually, both kinds of mistletoe contain toxic proteins that are very similar in their chemical composition. These are designated phoratoxin when isolated from Phoradendron species and viscotoxins when obtained from various subspecies of Viscum album. Contrary to the folkloric reputation of the respective plants containing them, phoratoxin and the viscotoxins produced similar effects when injected into test animals. These included hypotension, slowing and weakening of the heartbeat, and constriction of the blood vessels in the skin and skeletal muscles. However, it must be noted that the effects of these toxins following oral administration in human beings have not been studied.

Extracts of European mistletoe are sometimes employed in Germany in the treatment of malignant tumors. A sterile solution, available commercially, is injected either intravenously or into the tumor itself to provide palliative treatment for certain types of cancer. The medication has not been approved for use in the United States. Such use of mistletoe extracts has led to identification in the plant of three lectins, that is, proteins which agglutinate red blood cells. Many plant lectins are highly cytotoxic, and research is currently being conducted to determine their potential in cancer chemotherapy.

Certain Australian species of mistletoe have been shown to extract toxic principles, such as alkaloids and glycosides, from the host plants on which they grow as parasites. Thus, mistletoes grown on Duboisia species contain toxic solanaceous alkaloids and those grown on oleander contain potent cardiac glycosides. The identity of the host plants on which the parasitic mistletoe is found is therefore extremely important if the crude plant material is to be used as a medicine.

Many popular writers on herbs recommend mistletoe tea as a treatment for conditions from anxiety to cancer. Because of the relatively high price of coffee, some persons have even advocated it as a pleasant-tasting substitute. Recent surveys of poisonous plants in the United States continue to emphasize the toxic nature of American mistletoe berries, but German sources now maintain that the berries, but not the leaves, of European mistletoe have only slight toxicity, if any. Until more definitive information is forthcoming, use of either type of mistletoe as a home remedy or as a beverage should definitely be avoided.

For many centuries, herbalists throughout Europe had relied on a tea and tincture of the berries to treat some of the symptoms associated with raised blood pressure: headaches, dizziness, loss of energy, irritability, etc. So from the grave has come one ancient remedy for a very serious medical condition.

European herbalists have a couple of different ways of using mistletoe as a heart sedative and antihypertensive. One way is to take equal parts (about two tablespoons each) of mistletoe and hawthorn berries and lemon balm  leaves and steep them in two pints of boiling water for 25 minutes. One-half cup of the warm tea is taken morning and evening. The other way is to soak 4 teaspoons of chopped mistletoe in 1-1/4 pints of cold water overnight, and take one cup of the cool beverage first thing the next morning.

PARTS USED

Leaves, branches, berries.

USES

European mistletoe is chiefly used to lower blood pressure and heart rate, ease anxiety, and promote sleep. In low doses mistletoe also relieves panic attacks, headaches, and improves concentration. European mistletoe is also prescribed for tinnitus and epilepsy. In anthroposophical medicine, extracts of the berries are injected to treat cancer.
Other medical uses - Breast cancer, Ovarian cancer.

HABITAT AND CULTIVATION

Native to Europe and northern Asia, European mistletoe grows on host trees, especially apple trees. European mistletoe is harvested in autumn.

RESEARCH

European mistletoe's efficacy as an anticancer treatment has been subject to a significant amount of research. There is no doubt that certain constituents, especially the viscotoxins, exhibit an anticancer activity, but the value of the whole plant in cancer treatment is not fully accepted.

CONSTITUENTS

European mistletoe contains glycoproteins, polypeptides (viscotoxins), flavonoids, caffeic and other acids, lignans, acetylcholine, and, in the berries, polysaccharides. Viscotoxins inhibit tumors and stimulate immune resistance.

HOW MUCH TO TAKE

The doses given here are for noncancerous conditions.
Cold infusion: 2.5 g finely chopped leaf (fresh is considered more active than dried) covered in cold water, steeped at room temperature for 10 - 12 hours; 1 - 2 cups daily.
Warm infusion: 2 - 6 g dried leaf, 3 times daily.
Tincture (1:4 in 40% to 50% alcohol): 10 - 60 drops, 3 times daily; 0.5 ml, twice daily.
Fluidextract (1:1 in 25% to 50% alcohol): 25 - 60 drops, 3 times daily; 1 - 3 ml, 3 times daily.
Powder: 10 - 60 grains, 3 or 4 times daily.
Dried herb: 9 - 16 g daily.
For parenteral administration (of a product imported from Europe), the manufacturer's directions should be followed.