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WHO Monographs on Selected Medicinal Plants - Volume 2
(2004; 358 pages) View the PDF document
Table of Contents
View the documentIntroduction
View the documentGeneral technical notices
View the documentRadix Althaeae
View the documentHerba Andrographidis
View the documentRadix Angelicae Sinensis
View the documentFlos Calendulae
View the documentFlos Caryophylli
View the documentRhizoma Cimicifugae Racemosae
View the documentFolium cum Flore Crataegi
View the documentRadix Eleutherococci
View the documentAetheroleum Eucalypti
View the documentFolium Eucalypti
View the documentCortex Frangulae
View the documentFolium et Cortex Hamamelidis
View the documentSemen Hippocastani
View the documentHerba Hyperici
View the documentAetheroleum Melaleucae Alternifoliae
View the documentFolium Melissae
View the documentAetheroleum Menthae Piperitae
View the documentFolium Menthae Piperitae
View the documentFolium Ocimi Sancti
View the documentOleum Oenotherae Biennis
View the documentRhizoma Piperis Methystici
View the documentCortex Pruni Africanae
View the documentCortex Rhamni Purshianae
View the documentFlos Sambuci
View the documentRadix Senegae
View the documentFructus Serenoae Repentis
View the documentFructus Silybi Mariae
View the documentHerba Tanaceti Parthenii
View the documentRadix Urticae
View the documentFolium Uvae Ursi
View the documentAnnex: Participants in the Second WHO Consultation on Selected Medicinal Plants
 

Radix Althaeae

Definition

Radix Althaeae consists of the dried roots of Althaea officinalis L. (Malvaceae) (1-4).

Synonym

Malva officinalis L. (5).

Selected vernacular names

Altea, altee, althea, bardul khatmi, benefischi, bismalva-hibiscus, blanca malva, bon visclo, bourdon de St Jacques, Eibisch, Eibischwurzel, erva molle, guimauve, Heilwurz, hobbiza, Ibischwurz, khairi, khatmi, korzén prawóslazu, marshmallow, marshmallow root, malvaccioniu, malvavisco, marmolone, molotta, Moorish mallow, orvosiziliz gyökér, racine d’althée, racine de guimauve, Sammetpappel, sauvage, Schleimwurzel, suzmool, sweet weed, white mallow, wymote (3, 6-8).

Geographical distribution

Indigenous to western Asia and Europe, and is naturalized in the United States of America (9, 10). Roots are obtained from commercially cultivated plants that are at least 2 years old and harvested in the autumn (6, 10).

Description

A perennial herb with erect, woody stems, 60-120 cm high. Leaves alternate, ovate to slightly cordate, serrate, velvety, large, occasionally 3-lobed. Flowers pale pink, axillary, the calyx of each surrounded by a 6-9 cleft involucre. Fruit a set of cocci united into a ring (11).

Plant material of interest: dried roots

General appearance

Cylindrical or tapering, slightly twisted roots, up to 2 cm thick, with deep longitudinal furrows. Outer surface greyish-brown, bearing numerous rootlet scars. Fracture externally fibrous, internally rugged and granular; section shows a thick, whitish bark with brownish periderm, separated by a well-marked, brownish cambium from the white xylem; stratified structure of the bark and radiate structure of xylem become more distinct when moist. Peeled root has greyish-white finely fibrous outer surface; cork and external cortical parenchyma absent (2).

Organoleptic properties

Odour: faint, aromatic; taste: mucilaginous (1).

Microscopic characteristics

Phloem with numerous long, thin-walled, non-lignified fibres arranged in tangential groups alternating with groups of sieve tissue, with a ground tissue of thin-walled parenchyma; xylem containing reticulate or scalariform thickening and bordered pits accompanied by lignified tracheids, a small amount of lignified parenchyma and occasional small groups of fibres with only the middle lamella lignified; xylem and phloem transversed by numerous non-lignified medullary rays, mostly uniseriate; majority of parenchyma cells of the phloem and medullary rays contain abundant small starch grains which are mostly simple, spherical to ovoid, occasionally 2-3 compound, with a well-marked circular or slit-shaped hilum; some of these parenchyma cells contain cluster crystals of calcium oxalate 20-40µm in diameter, while others exist as idioblasts containing mucilage (1).

Powdered plant material

Brownish-grey (unpeeled root) or whitish (peeled root). Fragments of colourless, mainly unlignified, thick-walled fibres with pointed or split ends; fragments of reticulate or scalariform thickening and bordered pits; cluster crystals of calcium oxalate about 20-35µm, mostly 25-30µm, in diameter; parenchyma cells containing mucilage; fragments of cork with thin-walled, tabular cells in the powdered material from the unpeeled root. Numerous starch grains, 3-25µm in diameter, with occasionally a longitudinal hilum; starch grains mostly simple, a few being 2-4 compound (2).

General identity tests

Macroscopic and microscopic examinations (1, 2).

Purity tests

Microbiology

Tests for specific microorganisms and microbial contamination limits are as described in the WHO guidelines on quality control methods for medicinal plants (12).

Foreign organic matter

Not more than 2% of brown, deteriorated drug and not more than 2% of cork in the peeled root (2).

Total ash

Not more than 6% in the peeled root and not more than 8% in the unpeeled root (2).

Acid-insoluble ash

Not more than 3% in the peeled root (1).

Water-soluble extractive

Not less than 22% (1).

Loss on drying

Not more than 12% (2).

Swelling index

Not less than 10 (2).

Pesticide residues

The recommended maximum limit of aldrin and dieldrin is not more than 0.05 mg/kg (2). For other pesticides, see the European pharmacopoeia (2), and the WHO guidelines on quality control methods for medicinal plants (12) and pesticide residues (13).

Heavy metals

For maximum limits and analysis of heavy metals, consult the WHO guidelines on quality control methods for medicinal plants (12).

Radioactive residues

Where applicable, consult the WHO guidelines on quality control methods for medicinal plants (12) for the analysis of radioactive isotopes.

Other purity tests

Chemical, sulfated ash and alcohol-soluble extractive tests to be established in accordance with national requirements.

Chemical assays

Not less than 10% total mucilage in the peeled root as determined by gravimetric analysis (14).

Major chemical constituents

The mucilage content ranges from 10 to 20% and consists of a mixture of acidic galacturonorhamnans, neutral glucans and neutral arabinogalactans (6, 8, 9, 15-17).

Medicinal uses

Uses supported by clinical data

None.

Uses described in pharmacopoeias and in traditional systems of medicine

As a demulcent for symptomatic treatment of dry irritable coughs and irritations of oral and pharyngeal mucosa and as an emollient for wounds and dry skin (8, 18-23). Also used in cough mixtures to mask the bitter or pungent taste of other drugs (16).

Uses described in folk medicine, not supported by experimental or clinical data

Treatment of asthma, cystitis, dysentery and irritations of the gastric mucosa (7).

Pharmacology

Experimental pharmacology

The demulcent effects of Radix Althaeae are due to its high content of polysaccharide hydrocolloids, which form a protective coating on the oral and pharyngeal mucosa, soothing local irritation and inflammation (24).

Anti-inflammatory activity

A polysaccharide fraction (500µg/ml) isolated from a root extract had anticomplement activity in human serum in vitro (25). Aqueous extracts of the roots stimulated phagocytosis, and the release of oxygen radicals and leukotrienes from human neutrophils in vitro (26). The aqueous extract also induced the release of cytokines, interleukin-6 and tumour necrosis factor from human monocytes in vitro, thereby exhibiting anti-inflammatory and immunostimulant activity (26). Intraperitoneal administration of isolated mucilage polysaccharides to mice (10 mg/kg body weight) induced a 2.2-fold increase in the phagocytic activity of macrophages as measured by the colloidal carbon clearance test (27). However, intragastric administration of an 80% ethanol extract of the roots to rats (100 mg/kg body weight) did not inhibit carrageenan-induced footpad oedema (28).

Weak inhibition (17%) of mucociliary transport in isolated, ciliated epithelium of the frog oesophagus was demonstrated after treatment of the isolated tissues with 200 µl of an aqueous root macerate (6.4 g/140 ml) (29).

Antitussive activity

Intragastric administration of a polysaccharide fraction, isolated from an aqueous root extract, to cats (50 mg/kg body weight) suppressed the intensity and the frequency of coughs induced by mechanical irritation of laryngopharyngeal and tracheobronchial mucosa (30). The antitussive activity of this polysaccharide fraction (50 mg/kg body weight) was as effective as Syrupus Althaeae (1.0g/kg body weight), and more effective than prenoxdiazine (30 mg/kg body weight) (30).

Clinical pharmacology

None.

Contraindications

No information available.

Warnings

No information available.

Precautions

Drug interactions

Simultaneous administration of Radix Althaeae may delay the absorption of other drugs (8).

Other precautions

No information available on general precautions or precautions concerning drug and laboratory test interactions; carcinogenesis, mutagenesis, impairment of fertility; teratogenic and non-teratogenic effects in pregnancy; nursing mothers; or paediatric use. Therefore, Radix Althaeae should not be administered during pregnancy or lactation or to children without medical supervision.

Adverse reactions

No information available.

Dosage forms

Peeled or unpeeled, broken, chopped or powdered crude drug (1, 2) and galenical preparations thereof. Store in a well-closed container, protected from light (2).

Posology

(Unless otherwise indicated)

For dry cough, oral or pharyngeal irritation: 0.5-3.0 g of crude drug as an aqueous, cold macerate (14, 19, 20, 31) or 2-8 ml of syrup (20, 22, 32), which may be repeated up to a daily dose of 15 g of crude drug. For gastric irritation: 3-5g of crude drug as an aqueous, cold macerate up to three times daily (19, 20, 31).

References

1. British herbal pharmacopoeia. London, British Herbal Medicine Association, 1996.

2. European pharmacopoeia, 3rd ed. Strasbourg, Council of Europe, 1996.

3. Farmakopea Polska V, Suplement I. Warsaw, Polskie Towarzystwo Farmaceutyczne, 1995.

4. Pharmacopoeia Hungarica, 7th ed. Budapest, Hungarian Pharmacopoeia Commission, Medicina Konyvkiado, 1986.

5. Hooker JD, Jackson BD. Index Kewensis. Vol. 1. Oxford, Clarendon Press, 1895.

6. Bisset NG. Herbal drugs and phytopharmaceuticals. Boca Raton, FL, CRC Press, 1994.

7. Farnsworth NR, ed. NAPRALERT database. Chicago, University of Illinois at Chicago, IL, February 9, 1998 production (an online database available directly through the University of Illinois at Chicago or through the Scientific and Technical Network [STN] of Chemical Abstracts Services).

8. Hänsel R et al., eds. Hagers Handbuch der pharmazeutischen Praxis. Bd. 6: Drogen P-Z, 5th ed. Berlin, Springer-Verlag, 1994.

9. Leung AY, Foster S. Encyclopedia of common natural ingredients used in food, drugs, and cosmetics, 2nd ed. New York, NY, John Wiley & Sons, 1996.

10. Leung AY. Encyclopedia of common natural ingredients. New York, NY, John Wiley & Sons, 1980.

11. Youngken HW. Textbook of pharmacognosy, 6th ed. Philadelphia, PA, Blakiston, 1950.

12. Quality control methods for medicinal plant materials. Geneva, World Health Organization, 1998.

13. Guidelines for predicting dietary intake of pesticide residues, 2nd rev. ed. Geneva, World Health Organization, 1997 (document WHO/FSF/FOS/97.7).

14. Pharmacopée française. Paris, Adrapharm, 1996.

15. Blaschek W, Franz G. A convenient method for the quantitative determination of mucilage polysaccharides in Althaeae radix. Planta Medica, 1986, 52:537.

16. Samuelsson G, ed. Drugs of natural origin, a textbook of pharmacognosy. Stockholm, Swedish Pharmaceutical Press, 1992.

17. Tomoda M et al. The structural features of Althaea-mucilage representative mucous polysaccharide from the roots of Althaea officinalis. Chemical and Pharmaceutical Bulletin, 1980, 28:824-830.

18. Bone K. Marshmallow soothes cough. British Journal of Phytotherapy, 1993/1994, 3:93.

19. Marshmallow root. In: Bradley PR, ed. British herbal compendium. Vol. 1. Bournemouth, British Herbal Medicine Association, 1992:151-153.

20. ESCOP monographs on the medicinal uses of plant drugs. Fascicule 1. Elberg, European Scientific Cooperative on Phytotherapy, 1996.

21. Blumenthal M et al., eds. The complete German Commission E monographs. Austin, TX, American Botanical Council, 1998.

22. Reynolds JEF, ed. Martindale, the extra pharmacopoeia, 29th ed. London, Pharmaceutical Press, 1989.

23. Weiss RF. Lehrbuch der Phytotherapie, 7th ed. Stuttgart, Hippokrates Verlag, 1991.

24. Franz G. Polysaccharides in pharmacy: current applications and future concepts. Planta Medica, 1989, 55:493-497.

25. Yamada H et al. Relationship between chemical structure and anti-complementary activity of plant polysaccharides. Carbohydrate Research, 1985, 144:101-111.

26. Scheffer J et al. Radix althaeae und Flores chamomillae Extrakte auf Entzündungsreaktionen humaner neutrophiler Granulozyten, Monozyten und Rattenmastzellen. In: Abstracts of the Third Phytotherapy Congress. Lübeck-Travemünde, 1991: Abstract P9.

27. Wagner H, Proksch A. Immunostimulatory drugs of fungi and higher plants. In: Wagner H, Hikino H, Farnsworth NR, eds. Economic and medicinal plant research. Vol. 1. Orlando, FL, Academic Press, 1985:111-153.

28. Mascolo N et al. Biological screening of Italian medicinal plants for antiinflammatory activity. Phytotherapy Research, 1987, 1:28-31.

29. Müller-Limmroth W, Fröhlich HH. Wirkungsnachweis einiger phytotherapeutischer Expektorantien auf den mukoziliaren Transport. Fortschritte der Medizin, 1980, 98: 95-101.

30. Nosal’ova G et al. Antitussive efficacy of the complex extract and the polysaccharide of marshmallow (Althaea officinalis L. var. Robusta). Pharmazie, 1992, 47:224-226.

31. Wichtl M. Eibischwurzel. In: Wichtl M, ed. Teedrogen, 2nd ed. Stuttgart, Wissenschaftliche Verlagsgesellschaft, 1989:146-147.

32. British pharmaceutical codex. London, Pharmaceutical Press, 1934.

 

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