Mistletoe

Scientific Name(s): Phoradendron tomentosum (DC.) Engelm. ex A. Gray (Christmas mistletoe), Viscum album L. (European mistletoe)
Common Name(s): All heal, Bird lime, Devil's fuge, Golden bough, Iscador, Mistel, Mistletoe

Medically reviewed by Drugs.com. Last updated on Sep 13, 2021.

Clinical Overview

Use

Mistletoe has been used to treat cancer, although there is a lack of quality clinical trials and little evidence of an effect. Further study is needed. In folk medicine, it has been used for its cardiovascular properties. Clinical efficacy has not been established. Injectable mistletoe extract is widely used in Europe but is not licensed for use in the United States.

Dosing

Crude mistletoe fruit or herb is used to make a tea to treat hypertension at a dosage of 10 g/day. There are a number of proprietary extracts containing low levels of mistletoe lectin-Ι (ML-Ι) used as adjuvant cancer therapies. These extracts usually are given by intravenous (IV) or subcutaneous injection at dosages of 0.01 to 30 mg several times per week. Mistletoe preparations, produced according to anthroposophical methods, are given in incrementally increasing dosages depending on the patient's general condition and response to the injection. Use in pediatric patients has been reported. The pharmacokinetics in healthy adults has been determined.

Contraindications

Data are limited. Use of mistletoe extracts in patients with primary or secondary brain tumors, leukemia, or malignant lymphoma is contraindicated.

Pregnancy/Lactation

Mistletoe contains toxic constituents. Avoid use during pregnancy or lactation.

Interactions

None well documented.

Adverse Reactions

Local reactions following injection include redness, itching, inflammation, and induration at the injection site. Systemic reactions include mild fever or flu-like symptoms. Anaphylaxis has been reported.

Toxicology

Poison centers report toxicity of the whole plant, but especially mistletoe berries. The use of preparations standardized to small doses of ML-Ι or depleted of lectins may reduce toxicity.

Botany

The family Viscaceae (Christmas Mistletoe family) contains 5 genera and more than 50 different mistletoe species. Synonyms include Phoradendron flavescens, Phoradendron serotinum, and Viscum coloratum. Mistletoe is a hemiparasitic plant that grows on a wide variety of host trees such as pine, oak, birch, and apple. The term hemiparasitic indicates that the mistletoe plant carries out photosynthesis independently but obtains its water and minerals from the host. There are several subspecies and varieties of mistletoe, which are defined by the host that they parasitize. European mistletoe is dioecious, with male and female flowers on separate plants. They are pollinated by insects and bear small white berries on evergreen foliage. Other varieties bear red berries.1, 2

History

Mistletoe preparations have been used medicinally in Europe for centuries to treat epilepsy, infertility, hypertension, and arthritis. The Celtic priests, known as Druids, revered the oak tree and the mistletoe that grew upon it, according to Roman author and naturalist Gaius Plinius Secundus (also known as Pliny the Elder). At the winter celebration of Samhain, the sacred oaks were bare except for the green boughs of mistletoe. This was taken as a sign of eternal fertility. The Celts placed a sprig of mistletoe above the door of their houses. Its sacred nature prohibited fighting beneath it. This evolved over centuries into the custom of kissing underneath mistletoe at Christmas.3 In 1921, the Austrian anthroposophical spiritu...