Mallow
Scientific Name(s): Althaea officinalis L., Malva neglecta Wallr., Malva sylvestris L.
Common Name(s): Common mallow, Common marshmallow, Malva
Medically reviewed by Drugs.com. Last updated on Jul 1, 2022.
Clinical Overview
Use
Limited clinical trial data consist mostly of studies on the anti-inflammatory properties of the plant for skin, oral, and pharyngeal conditions. Despite the lack of clinical data, the German Commission E approved mallow for treating irritation of oral and pharyngeal mucosa, as well as for dry cough.
Dosing
Commercial tea products are the primary dosage forms of mallow.
Contraindications
Avoid use if allergic or hypersensitive to any components of the plant species. Animal studies document that the plant may lower blood sugar levels; thus, use with caution in patients with diabetes or in those sensitive to changes in blood glucose levels.
Pregnancy/Lactation
Information regarding safety and efficacy in pregnancy and lactation is lacking.
Interactions
None well documented.
Adverse Reactions
No serious adverse reactions were reported in 2 clinical trials.
Toxicology
No toxicity studies could be found.
Scientific Family
- Malvaceae (mallow)
Botany
The Malvaceae family is represented by the genera Althaea, Malva, and Lavatiera, and the mallow plants are members of this family.1 Mallows are perennial plants native to Europe, North Africa, and southwestern Asia. The plants have been naturalized in North America and are cultivated from western Europe to Russia. They prefer damp areas, such as the ocean, salt marshes, meadows, sides of ditches, and banks of tidal rivers. They grow from 1 to 2 m tall, and the leaves, flowers, and roots have been used for medicinal purposes. The flowers bloom in late spring, and the roots must be at least 2 years old before harvesting.2, 3, 4, 5
History
Mallow has a rich ethnomedicinal history and has been used since ancient Greece and Roman times. The leaves and shoots of common mallow have been used as food sources since the 8th century BC.3 The aboveground portions of the plant have been used in pancakes and salads, cooked as greens, and used as stuffing.6 The immature fruits may be consumed raw as a snack.7
Ethnomedicinal references document the plant's efficacy as an anti-inflammatory for the respiratory tract, GI tract, and the skin.8, 9, 10, 11, 12, 13 The plant can be used topically or in a bath to treat abscesses, bruises, burns, dermatitis, swellings, and varicose ulcers.5, 8 A decoction may be chewed, gargled, or used as a wash to treat sore throat as well as mouth, throat, and gingival inflammations.10, 13 Respiratory conditions, such as bronchitis and whooping cough, can also be treated with a decoction.4, 11 It may be used as a compress on the stomach to help heal abdominal pains.12 Mallow may be taken as food to treat constipation or similar GI discomfort.5, 13 Other uses have been documented.5
The mucous compounds in the plant species are of commercial interest, particularly in dermatology and cosmetic preparations. The plant species has been used to treat acne.5, 10, 13, 14
Chemistry
The active components of the plant species are found in the leaves, flowers, and roots. Several studies document the mucilaginous polysaccharide content in the plant; the primary components are composed of rhamnose, galactose, galacturonic acid, and glucuronic acid.15, 16, 17, 18 Flavonoids, phenolic acids, tannins, and volatile oils have also been isolated.4, 19, 20, 21 Malonated anthycyanins have been isolated from the flowers.22, 23, 24
Pharmaceutical-grade marshmallow leaf must have a swelling index of at least 12 and pass macroscopic and microscopic authentication for botanical identification. The British Herbal Pharmacopoeia requires marshmallow leaf to be harvested before the flowering period and identified by thin-layer chromatography (TLC). The water-soluble extract must be at least 15%. Pharmaceutical-grade marshmallow root also must pass macroscopic and microscopic authentication tests and have a swelling index of at least 10 with the pulverized root. The British Herbal Pharmacopoeia requires botanical identification by TLC and additional quantitative standards for marshmallow root. A swelling index of at least 15 is required by The Swiss Pharmacopoeia.4, 25, 26
Uses and Pharmacology
Limited clinical trial data mainly focuses on the anti-inflammatory properties of the plant for dermal, oral, and pharyngeal conditions. Commission E approves mallow for treating irritation of oral and pharyngeal mucosa, as well as dry cough.
Antitussive activity
Animal data
A 100 mg/kg complex extract and 50 mg/kg polysaccharide dosage form isolated from the roots of A. officinalis were effective as antitussive agents in cats. The cough suppressant activity of the polysaccharide was more effective than prenoxidiazine but not dropropizine.27 Tracheobronchial smooth muscle contractility was inhibited by extracts of Althaea root in studies in rats, suggesting a potential role in asthma.28, 29
Clinical data
A multi-ingredient preparation, which included marshmallow root (A. officinalis), was evaluated for effect versus placebo in a clinical study of acute pharyngitis (n=60). Although reported findings were positive, attribution of effect to A. officinalis is not possible.30 Similarly, other clinical studies have evaluated multi-ingredient preparations as a cough expectorant.31, 32
Efficacy of oral preparations of A. officinalis are considered to be due to observed bioadhesive properties, thereby acting to relieve mucosal irritation and hyposalivation.33, 34
Other uses
In vitro studies document antioxidant properties in the plant.35, 36, 37 A. officinalis has antibacterial activity and may be useful in periodontal prophylaxis.20, 38, 39 Histopathological results document that M. neglecta extracts protected rats from gastric lesions induced by ethanol.40 Antiulcerogenic activity may be associated with the high mucilage content from the plant species.
A. officinalis inhibited intracellular calcium mobilization in normal human melanocytes (NHMC) activated by endothelin-1 (ET-1). ET-1 expression increased in the epidermis after ultraviolet (light) B (UVB) irradiation, which is likely to contribute to UVB-induced pigmentation. ET-1 also is involved with inducing NHMC. The results of the study suggest the extracts from A. officinalis inhibit the physiological effect of ET-1 on NHMC after UVB irradiation and may be useful when used in combination with other preparations in treating hyperpigmentary conditions or disorders.41
Root extracts were shown to reduce UVA-induced DNA damage in cultured human lung and skin fibroblasts.42
One study in rats investigated the effects of anthocyanin from M. sylvestris on plasma lipids. Decreases in total cholesterol (20%) and triglycerides (34%) were found.43
A carbohydrate in mallow has anticomplementary activity on the immune system. In vitro analysis of an acidic polysaccharride from the seeds of a related mallow stimulated the reticuloendothelial system. In vitro analysis of a crude powder from another mallow species showed antitumor activity.17, 44, 45
Dosing
Commercial tea products are the primary dosage forms of mallow.4, 32
Pregnancy / Lactation
There is no clinical evidence to support the safe use of the herb during pregnancy and lactation.
Interactions
None well documented.
Adverse Reactions
No serious adverse reactions were reported in 2 clinical trials.
Toxicology
No toxicity studies could be found.
References
Disclaimer
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This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.
Further information
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