Mistletoe (Viscum album)

Description

Viscum album, commonly known as European mistletoe, is an evergreen hemiparasitic plant belonging to the family Santalaceae. It lives anchored to the branches of host trees (broadleaf and conifer species), from which it absorbs water and part of its nutrients through specialized structures called haustoria. It can colonize species such as poplar, oak, linden, apple, pine, and fir.

Its morphology is distinctive: globular, bushy clumps, articulated and bifurcated branches, opposite elliptic leaves that are leathery and persistent, and white, translucent berries rich in mucopolysaccharides that ripen between autumn and winter. The berries contain sticky seeds, dispersed mainly by birds that feed on them and thus contribute to natural spread.

For centuries, mistletoe has held a strong symbolic and ritual value in European cultures: a symbol of peace, rebirth, protection, and good fortune. However, from a direct food perspective it is not considered a common edible plant, as several fractions contain bioactive and potentially toxic substances that must be handled with care.

Botanical classification
Common name: mistletoe
Clade: Angiosperms
Order: Santalales
Family: Santalaceae
Genus: Viscum
Species: Viscum album L.

Cultivation and growth conditions

Climate
Mistletoe is typical of temperate regions, with cold winters and fairly regular rainfall. It grows naturally across Europe and parts of Asia and tolerates frost and even severe cold. It is hemiparasitic, obtaining water and minerals from the host tree, so climatic balance and water availability influence both the host and the mistletoe.

Exposure
The plant prefers full light or sunny to partially sunny positions, ensuring efficient photosynthesis in its evergreen leaves. In deep shade, growth slows and berry formation decreases. Open, luminous conditions—such as isolated trees or woodland edges—promote better development.

Soil
Mistletoe does not root in the soil, anchoring itself through specialized haustoria that penetrate branches. Soil characteristics therefore concern the host: fresh, moderately fertile and moist soils promote its vigor, indirectly supporting mistletoe growth. Very poor or overly chalky soils may weaken the host, limiting mistletoe development.

Irrigation
No direct irrigation is needed since water is absorbed from the vascular system of the branch. However, regions with regular rainfall and adequate humidity benefit both the host and the mistletoe. Extended drought may stress the host, reducing shoot production and mistletoe vigor.

Temperature
Optimal temperatures range from about 8–22 °C. The plant is highly frost-resistant and tolerates harsh winters. Very hot and dry conditions may slow photosynthesis and growth.

Fertilization
Mistletoe requires no specific fertilization. Nutrients are taken from the host through the haustorial connection. Improving the organic matter and mineral balance of the soil can, indirectly, support the host’s health. Excessive fertilization is not necessary.

Crop care
Cultivation is essentially the management of its spread. On fruit trees and ornamentals, excess growth may weaken branches by competing for water and nutrients. The most common actions are pruning and selective removal of infested branches. In ornamental or ecological contexts, mistletoe may be left, provided the balance between host vitality and mistletoe density is maintained.

Harvesting
Harvesting is carried out in winter, when white berries are ripe. Sprigs are cut manually, avoiding excessive damage to the host. Once collected, branches are cleaned and used for traditional or decorative purposes. In nature, birds disperse seeds while feeding on the berries.

Propagation
Propagation occurs by seed. The berry pulp is sticky and helps seeds adhere to bark. Under controlled conditions, seeds are manually applied to small bark incisions in well-lit areas. Germination is slow: the young plant develops haustoria that connect to host tissues. Full berry production usually requires a few years.

Indicative nutritional values per 100 g

(dried plant – approximate values, variable according to host tree and origin)

• Energy: ~ 250–300 kcal

• Water: ~ 5–10 g

• Total carbohydrates: ~ 40–50 g

• Dietary fibre: present in significant amount

• Protein: ~ 15–20 g

• Total fat: ~ 3–5 g

• First occurrence SFA (Saturated Fatty Acids): present in small amounts – excessive intake may contribute to higher LDL cholesterol

• MUFA (MonoUnsaturated Fatty Acids): minor fraction, potentially neutral or slightly favourable to lipid profile

• PUFA (PolyUnsaturated Fatty Acids): prevalent in the lipid fraction, generally associated with more favourable cardiovascular profiles

• Minerals: potassium, calcium, magnesium, iron, zinc, manganese

• Vitamins: traces of B-group compounds and minor antioxidants

Note: direct food use is not recommended for berries or crude, unprocessed plant material due to the presence of lectins and viscotoxins.

Key constituents

• Lectins (mistletoe lectins)

• Viscotoxins (bioactive polypeptides)

• Flavonoids: quercetin, rutin, and derivatives

• Complex polysaccharides

• Triterpenes: oleanolic acid, betulinic acid

• Phytosterols

• Essential oil traces

• Minerals: calcium, magnesium, iron, zinc, potassium

• Structural dietary fibre

Production process

(for dry extracts, powders, or functional ingredients)

1. Harvesting of leaves and twigs

   • Manual collection in winter, when the plant is relatively richer in active compounds

   • Selection of healthy, uncontaminated aerial parts

2. Preliminary cleaning

   • Removal of berries (which contain higher levels of potentially toxic compounds)

   • Discarding damaged or mouldy fractions

3. Controlled drying

   • Indirect warm air or low-temperature dryers to preserve phytochemicals

   • Moisture reduction to ensure microbiological stability

4. Cutting and milling

   • Preparation of powdered material or fine cuts suited for extraction

5. Extraction (where applicable)

   • Aqueous or hydroalcoholic methods

   • Concentration and purification to obtain standardized extracts

6. Storage and packaging

   • Protection from moisture, light, and heat

   • Microbiological control and declaration of active compound titration

Physical properties

• Globular, bushy growth on the host tree

• Leathery leaves, uniform olive-green colour

• Spherical, white berries with a sticky consistency due to high polysaccharide content

• Fibrous, resistant internal structure

• Dried plant material: light, friable, and hygroscopic

Sensory and technological properties

• Mild, herbaceous, slightly balsamic aroma

• Resinous, woodland-like notes

• Gentle vegetable bitterness in leaves, more intense in concentrated extracts

• Good solubility for fluid extracts

• In dried form, may be incorporated in herbal blends or infusions (in controlled amounts and only when raw materials are approved for such use)

Food applications

(very limited and subject to specific rules)

• Herbal teas and mixtures containing selected, controlled plant parts

• Functional ingredients in small amounts in complex plant-based formulations

• Historical local traditions using thermally treated leaves

• Current uses: mainly herbal extracts and supplements, NOT fresh berries and NOT home-prepared raw material for food

Important note: berries and crude extracts must not be consumed as household food.

Nutrition and health

Use of mistletoe in the health field is centred on controlled extracts, not on direct food consumption. Its bioactive substances (lectins, flavonoids, polysaccharides, triterpenes) are the subject of research in phytotherapy and complementary applications.

Key nutritional and physiological points

• phytochemical component rich in polyphenols and polysaccharides

• structural fibre with potential effects on digestion and intestinal transit

• mineral content contributing to cellular and enzymatic functions

Warnings

• presence of lectins and viscotoxins requires specific extraction, titration, and safety evaluation

• NOT a common food ingredient

• applications are mainly herbal and complementary, not culinary

Portion note

There is no standard “food portion” because mistletoe is not used as a direct food.
In phytopreparations, any dosage must be defined by qualified professionals and according to the applicable regulatory framework.

Allergens and intolerances

• not classified as a primary food allergen

• possible individual sensitivity to protein compounds (lectins)

• berries may have irritant/toxic effects

• crude, home-prepared material can pose toxicity risks

Storage and shelf-life

• Store at room temperature, protected from moisture and light

• Dry extracts: shelf-life typically between 12–36 months, depending on the formulation

• Avoid containers permeable to water vapour

• Close tightly after use to limit oxidation and degradation of phytochemicals

Safety and regulatory aspects

• NOT considered a common food ingredient

• Regulated use in herbal products and food supplements

• Compliance required for: purity, microbiological limits, titration, labelling, notifications where applicable

• Berries can contain potentially toxic actives: home use as food is strongly discouraged

Labelling

For approved products (teas, extracts, supplements):

• Name: “Mistletoe” or “Viscum album”

• Indication of parts used (leaves/twigs, standardized extract)

• Country of origin

• Batch and date

• Directions for use and warnings

• Indication of titration/standardization of active components

Troubleshooting

In herbal use

• overly bitter, harsh taste → reduce concentration or infusion time, or combine with milder herbs

• strong loss of aroma → possible excessive exposure to heat or light during storage or processing

• precipitation in solutions → filtration or carefully adjusted hydroalcoholic ratio

In storage

• earthy, musty odour → likely excessive humidity or poor drying

• marked discolouration → photodegradation of phenolic compounds

Sustainability and supply chain

Viscum album grows spontaneously on host trees and does not require intensive cultivation. Key aspects include:

• respectful harvesting that follows the plant’s seasonal cycle

• maintaining host tree vitality (partial, controlled removal of clumps)

• traceability of origin and harvesting area

• monitoring of environmental contaminants in collection zones

Main INCI functions (cosmetics)

In cosmetics, Viscum album Extract is used primarily as:

• skin conditioning agent (improved softness and skin comfort)

• mild skin toning component

• functional fraction in botanical, plant-based, or “natural concept” formulations

Cosmetic use is more common than direct nutritional use.

Conclusion

Viscum album is an evergreen plant with a strong historical, symbolic, and cultural relevance. From a technical point of view, it represents a vegetal matrix rich in bioactive compounds, fibre, polyphenols, minerals, and distinctive protein fractions.

Despite a potentially interesting nutrient profile on paper, it is not used as a direct food because of the presence of lectins and viscotoxins, which require specific processing and strict safety control. Its modern role is therefore mainly linked to herbal extracts and cosmetics, where it is valued for its functional components and botanical identity.

When used correctly, according to safety and standardization criteria, mistletoe remains a peculiar botanical resource, a bridge between ancient traditions and modern technical applications.

Mini-glossary

Lectins: carbohydrate-binding proteins with specific biological actions, potentially toxic at high doses.
Viscotoxins: short polypeptides characteristic of mistletoe, with marked bioactivity and toxicity risks if misused.
Skin conditioning: cosmetic function related to improved skin feel, softness, and comfort.
SFA: Saturated Fatty Acids – fats that tend to raise LDL cholesterol when consumed in excess.
MUFA: MonoUnsaturated Fatty Acids – fats generally considered neutral or beneficial for cardiovascular health.
PUFA: PolyUnsaturated Fatty Acids – fats frequently associated with more favourable blood lipid profiles and cardiovascular protection.

Studies

Mistletoe: its antioxidant components include viscotoxins, small proteins capable of counteracting cancer cells, oligosaccharides, polysaccharides, triterpene acids, phenylpropanoids, alkaloids and flavonoid.

Chemical analysis performed with high resolution chromatography equipped with high resolution mass spectrometer has identified the following main components: caffeic acid, chlorogenic acid, sakuranetin, isosakuranetin, syringenin 4-O-glucoside, syringenin 4-O-apiosyl-glucoside, alangilignoside C and ligalbumoside A (1).

Mistletoe extracts have been used as adjuvants in cancer therapy for decades. The main component of the mistletoe is a protein called Mistletoe lectin 1, which stimulates the immune system and influences the proliferation and motility of cancer cells (1).

This study shows the first evidence that an extract of mistletoe leaves produced interesting cardioprotective effect in rats (3).

Mistletoe studies

References____________________________________________

(1) Melo MNO, Oliveira AP, Wiecikowski AF, Carvalho RS, Castro JL, de Oliveira FAG, Pereira HMG, da Veiga VF, Capella MMA, Rocha L, Holandino C. Phenolic compounds from Viscum album tinctures enhanced antitumor activity in melanoma murine cancer cells.    Saudi Pharm J. 2018 Mar;26(3):311-322. doi: 10.1016/j.jsps.2018.01.011

Abstract. Cancer is one of the biggest problems in public health worldwide. Plants have been shown important role in anticancer research. Viscum album L. (Santalaceae), commonly known as mistletoe, is a semi-parasitic plant that grows on different host trees. In complementary medicine, extracts from European mistletoe (Viscum album L.) have been used in the treatment of cancer. The study was conducted to identify chemical composition and antitumor potential of Viscum album tinctures. Chemical analysis performed by high resolution chromatography equipped with high resolution mass spectrometer identified caffeic acid, chlorogenic acid, sakuranetin, isosakuranetin, syringenin 4-O-glucoside, syringenin 4-O-apiosyl-glucoside, alangilignoside C and ligalbumoside A compounds. Some of these compounds are probably responsible for the reduction of tumoral cellular growth in a dose-dependent manner. It was observed that melanoma murine cells (B16F10) were more sensitive to V. album tinctures than human leukaemic cells (K562), besides non-tumoral cells (MA-104) had a much lower cytotoxicity to them. Apoptotic-like cells were observed under light microscopy and were confirmed by a typical DNA fragmentation pattern. Additionally, flow cytometry results using Annexin-V/FITC permitted to quantify increased expression of early and late apoptotic markers on tumoral cells, confirming augmented Sub G0 population, which was probably associated with a consistent decrease in G1, and an increase in S or G2/M populations. Results indicate the chemical composition of V. album tinctures influences the mechanisms of in vitro tumoral cell death, suggesting a potential use in cancer pharmacotherapy research.

(2) Schötterl S, Miemietz JT, Ilina EI, Wirsik NM, Ehrlich I, Gall A, Huber SM, Lentzen H, Mittelbronn M, Naumann U. Mistletoe-Based Drugs Work in Synergy with Radio-Chemotherapy in the Treatment of Glioma In Vitro and In Vivo in Glioblastoma Bearing Mice.   Evid Based Complement Alternat Med. 2019 Jul 3;2019:1376140. doi: 10.1155/2019/1376140.

Abstract. Background: Extracts from Viscum album L. (VE) are used in the complementary cancer therapy in Europe for decades. VE contain several compounds like the mistletoe lectins (MLs) 1-3 and viscotoxins and also several minor ingredients. Since mistletoe lectin 1 (ML-1) has been described as the main component of VE harboring antitumor activity, purified native or recombinant ML-1 has been recently used in clinical trials. MLs stimulate the immune system, induce cytotoxicity, are able to modify the expression of cancer-associated genes, and influence the proliferation and motility of tumor cells. Objective: In this study our goal was to determine anticancer effects of the VE ISCADOR Qu, of recombinant ML-1 (Aviscumine), and of native ML-1 in the treatment of glioblastoma (GBM), the most common and highly malignant brain tumor in adults. Additionally we were interested whether these drugs, used in combination with a temozolomide-(TMZ)-based radio-chemotherapy, provide synergistic effects. Methods: Cell culture assays, ex vivo murine hippocampal brain slice cultures, human GBM cryosections, and a xenograft orthotopic glioblastoma mouse model were used. Results: In cells, the expression of the ML receptor CD75s, which is also expressed in GBM specimen, but not in normal brain, correlates with the drug-induced cytotoxicity. In GBM cells, the drugs induce cell death in a concentration-dependent manner and reduce cell growth by inducing cell cycle arrest in the G2/M phase. The cell cycle arrest was paralleled by modifications in the expression of cell cycle regulating genes. ML containing drugs, if combined with glioma standard therapy, provide synergistic and additive anticancer effects. Despite not reaching statistical significance, a single intratumoral application of Aviscumine prolonged the median survival of GBM mice longer than tumor irradiation. Moreover, intratumorally applied Aviscumine prolonged the survival of GBM-bearing mice if used in combination with irradiation and TMZ for further 6.5 days compared to the radio-chemotherapy. Conclusion: Our results suggest that an adjuvant treatment of glioma patients with ML-containing drugs might be beneficial.

(3) Suveren E, Baxter GF, Iskit AB, Turker AU. Cardioprotective effects of Viscum album L. subsp. album (European misletoe) leaf extracts in myocardial ischemia and reperfusion.   J Ethnopharmacol. 2017 Sep 14;209:203-209. doi: 10.1016/j.jep.2017.07.010.