MATERIA MEDICA

Number of subject modules: 15

Subject module 1 of 15

ASTRINGENTS

Introduction

Astringents cause contraction of tissue, binding and wrinkling of skin and mucous membranes, and they dry up or reduce exudations. When applied to wounds they form a thin protective surface. Precipitation of proteins and/or polysaccharides on the surface results in hardening of the epidermis, reducing absorption of toxins, and protecting against irritants. Bleeding is reduced due to constriction of blood vessels.

Active constituents involved

Tannins

Pharmacology

The mechanisms by which tannins exert their biological effects are known to involve precipitation of proteins in aqueous solutions. By forming cross-links with proteins such as collagen, tannins produce the astringent effects which characterise so many herbal medicines. Protein binding enables tannins to inhibit a wide range of enzymes including many involved in infectious and disease processes generally. Like other plant phenols they can become irritants in large doses and should not be used for long periods without careful monitoring.

1. Protect inflamed mucous membranes.
2. Exert a drying effect on mucous membranes, reducing hypersecretions.
3. Reduce inflammation and swelling which accompanies infection.
4. Prevent bleeding from small wounds.
5. Reduce uterine bleeding, as in menorrhagia, metrorrhagia.
6. Have a binding effect in the gut, relieving diarrhoea, dysentery, colitis, etc.
7. Used externally in gargles, skin lotions, douches, snuffs and eyewashes.

Associated actions

Vasoconstrictive, antimicrobial, antioxidant, haemostatic, anticatarrhal, tonic.

Primary astringent herbs

MATERIA MEDICA

Agrimony

Botanical name

Agrimonia eupatoria L.

Synonyms

sticklewort, cocklebur

Family

Rosaceae

Origin and distribution

A roadside weed of Europe. Widely cultivated.

Brief description

Perennial herb growing from basal rosette, with pinnate leaves, small yellow flowers on slender spikes, followed by a small burr-like fruit.

Part used

Dried aerial parts

Active constituents

Tannins - agrimoniin, a dimeric ellagitannin. Condensed tannins

Flavonoids - glucosides of luteolin, apigenin, quercetin

Volatile oil

Polysaccharides

Vitamins B and K, iron, silica

Energetics

Cooling, drying, aromatic, slightly bitter

Actions

Astringent, anti-inflammatory, diuretic, tonic

Systems influenced

Gastrointestinal tract, genito-urinary, respiratory

Therapeutic indications

• diarrhoea in children, gastroenteritis, mucous colitis, appendicitis
• incontinence, enuresis, cystitis
• chronic catarrh
• as a gargle for acute sore throats, laryngitis
• externally as a lotion for wounds

Toxicity and contra-indications

None cited

Preparations and dosage

Infusion or decoction

Tincture 1:5, 1-4 mL three times daily

Fluid extract 1:2, 1-2 mL three times daily

Combinations

With Filipendula, Medicago, Backhousia, Anethum as digestion aid.

Meadowsweet

Botanical name

Filipendula ulmaria

Synonyms

Spiraea ulmaria, queen of the meadow

Family

Rosaceae

Origin and distribution

Northern Europe in woodlands and marshes.

Brief description

Stout perennial with dark green serrated pinnate leaves growing from a thick rootstock. Small white flowers arranged in irregular cymes occur during summer.

Part used

Dried aerial parts

Active constituents

Phenolic glycosides derived from salicylic acid - spiraein, gaultherin

Tannins - rugosin D (molecular wt. 1874) and other hydrolysable tannins

Essential oil - contains salicylic aldehyde, methyl salicylate

Flavonoids - spiraeoside, rutin, hyperoside, avicularin

Citric and ascorbic acids

Energetics

Cooling, drying, aromatic, balsam-like taste

Actions

Astringent, stomachic, diuretic, anti-inflammatory, antipyretic

Systems influenced

Gastrointestinal tract, genito-urinary, musculo-skeletal

Therapeutic indications

• peptic ulcer, dyspepsia, heartburn, diarrhoea, gastritis
• arthritic and rheumatic pains
• urogenital irritation, prostatitis, cystitis, chronic cervicitis and vaginitis

Toxicity and contra-indications

Avoid in salicylate sensitivity. High doses are not recommended due to potential irritation from high levels of phenolics present, however there are no reports of toxicity from use of meadowsweet.

Preparations and dosage

Infusion

Fluid extract 1:2, 1-2 mL three times daily

Combinations

With Glycyrrhiza, Medicago, Mentha piperita for peptic ulcer and heartburn.

Eyebright

Botanical name

Synonyms

Family

Scrophulariaceae

Origin and distribution

A parasite on grasses in meadows and pastures across Europe.

Brief description

A low growing annual parasite with deeply toothed leaves and tiny 2-lipped flowers.

Part used

Dried aerial parts

Active constituents

Iridoid glycosides - aucubin, geniposide

Tannins - condensed and hydrolysable

Phenolic acids - caffeic, ferulic

Sterols, amino acids choline

Vitamins A, B, C, D and E.

Energetics

Cooling, drying, bitter

Actions

Astringent, anti-inflammatory, anticatarrhal

Systems influenced

Upper respiratory tract, eyes

Therapeutic indications

• Sinusitus, nasal catarrh, hay fever
• Weeping and stinging eyes, conjunctivitis, blepharitis
• Externally as an eye wash

Toxicity and contra-indications

None cited

Preparations and dosage

Infusion as tea or eye wash

Tincture 1:5, 2-6 mL three times daily. 1-2 drops in water for eye bath

Fluid extract 1:2, 1-2 mL three times daily

Combinations

With Sambucus, Solidago, Plantago in respiratory catarrhal states.

Cranesbill

Botanical name

Synonyms

American cranesbill, storksbill, alumroot

Family

Geraniaceae

Origin and distribution

Common in woodlands of North America.

Brief description

An erect perennial with palmately divided leaves on a stout rhizome. Pinkish flowers mature into a distinctive beaked dehiscent fruit.

Part used

Rhizome

Active constituents

Tannins, up to 30%, incuding the ellagitannin geraniin (molecular wt. 934)

Calcium oxolate, gum, pectin

Energetics

Drying, cooling, bitter

Actions

Astringent, styptic

Systems influenced

Gastrointestinal tract, genito-urinary

Therapeutic indications

• diarrhoea, dysentry, haemorrhoids, colitis
• gastric and duodenal ulcer
• menorrhagia, metrorrhagia, leucorrhoea
• locally as mouthwash and gargle
• externally for burns

Toxicity and contra-indications

Prolongued use not recommended due to high tannin content.

Preparations and dosage

Infusion or decoction

Tincture 1:5, 2-4 mL three times daily.

Fluid extract 1:2, 1-2 mL three times daily.

Combinations

With Althaea, Agrimonia, Glycyrrhiza for bleeding ulcer.

Raspberry leaf

Botanical name

Synonyms

Red raspberry

Family

Rosaceae

Origin and distribution

The common cultivated plant originally from Europe. The wild species R. strigosus and R. parvifolius are also used.

Brief description

A suckering shrub with spiny cane-like stems, toothed pinnate leaves, white flowers and succulent red fruit.

Part used

Leaves, roots, fruit

Active constituents

Tannins - sanguiin H6, and sanguiin H11 - dimeric and tetrameric ellagitannins, gallotannins

Flavonoids: kaempferol and quercetin

Organic acids (mainly in fruit) - malic, citric, oxalic, tartaric, salicylic

Fragrarine - unknown structure but may be a polypeptide, componds which are difficult to isolate.

Iron, calcium, magnesium, vitamins A, B and C

Energetics

Drying, cooling, sweet

Actions

Astringent, tonic, parturient, febrifuge, stomachic

Systems influenced

Gastrointestinal tract, female reproductive, oral cavity

Therapeutic indications

• diarrhoea, nausea, morning sickness
• pregnancy - as a uterine tonic, dysmenorrhoea, leucorrhoea
• as a gargle for mouth ulcers, bleeding gums, sore throat

Toxicity and contra-indications

None cited

Preparations and dosage

Infusion

Fluid extract 1:2, 1-4 mL three times daily.

Combinations

With Ballota and Zingiber for morning sickness.

Bayberry

Botanical name

Myrica cerifera

Synonyms

Wax-berry

Family

Myricaceae

Origin and distribution

Native of eastern North America

Brief description

Evergreen shrub or small tree with waxy branchlets and simple leaves with a glabrous surface.

Part used

Dried root bark

Active constituents

Triterpenes - taraxerol, taraxerone, myricadiol

Tannins

Flavonoids - myricitrin

Resins, gums

Energetics

Pungent, warming, drying

Actions

Astringent, circulatory stimulant, mild diaphoretic, antibacterial, anticatarrhal

Systems influenced

Circulation, respiratory tract, GIT, female reproductive

Therapeutic indications

• colds, nasal polyps, febrile diseases
• diarrhoea, mucous colitis
• menorrhagia, prolapse uterus, leucorrhoea
• gargle for sore throats
• topically for indolent ulcers

Toxicity and contra-indications

Large doses may produce emesis

Preparations and dosage

Decoction or powder

Fluid extract 1:2, 1-2 mL three times daily

Combinations

With Syzygium aromaticum, Zingiber, Cinnamomum in acute febrile diseases.

Witch hazel

Botanical name

Tannins - galloyhamameloses, procyanidins

Flavonoids - quercetin, kaempferol, astragalin

Saponins

Resins, volatile oil - hexonol

Energetics

Cooling, drying, bitter, pungent

Actions

Astringent, haemostatic, antiphlogistic

Systems influenced

Venous system, skin

Therapeutic indications

• haemorrhoids, varicose veins
• internal and external haemorrhages
• sprains and bruises
• burns
• cold sores, acne, skin blemishes

Toxicity and contra-indications

None cited

Preparations and dosage

Infusion or decoction

Tincture 1:5, 2-4 mL three times daily

Fluid extract 1:2, 1-2 mL three times daily

Distilled extract B.P.C. (free of tannin) - topical use

Combinations

With Collinsonia, Plantago, Juglans for haemorrhoids.

TEA

Botanical name

Brief description

Perennial evergreen shrub with narrow, serrate leaves.

Part used

Leaf buds and young leaves. These are roasted to make black tea. Roots.

Active constituents

Purine alkaloids (xanthines) - caffeine, theophylline, theobromine

Tannins - (green tea) gallocatechins especially epigallocatechin gallate

- (black tea) oxidised gallocatechins: theaflavins, thearubigens, proanthocyanidins

Flavonoids - quercetin, kaempferol

Aluminium, manganese

Energetics

Drying, aromatic

Actions

Astringent, stimulant, diuretic, antioxidant

Systems influenced

Nervous, gastrointestinal, cardiovascular, urinary

Therapeutic indications

• cholesterolaemia, atherosclerosis
• diarrhoea, dysentery
• cancer protective
• topical applications for burns

Toxicity and contra-indication

Over-consumption of tea can lead to irritability and insomnia in some people due to caffeine content. Taken with meals tea can disturb assimilation of minerals.

Preparations and dosage

Infusion of green or black tea

Ribwort

Botanical name

Plantago lanceolata

Synonyms

Narrow leafed plantain, lamb’s tongue, white man’s

footstep

Family

Plantaginaceae

Origin and distribution

Roadside weed of almost universal distribution

Brief description

Perennial weed with basal rosette of dark green, ribbed, lanceolate leaves. The short terminal flower spikes grow on long peduncles distinguishing them from other plantain species.

Part used

Leaves, seeds

Active constituents

Tannins

Phenylpropanoid glycosides - verbascoside, citstanoside F, plantamajoside

Iridoid glycoside - aucubin

Mucilage

Silicic acid, potassium, zinc

Energetics

Cooling, soothing, bitter

Actions

Astringent, anti-inflammatory, expectorant, mucous-membrane tonic

Systems influenced

Upper and lower respiratory, skin, urinary, eyes

Therapeutic indications

• rhinitis, sinusitis, middle-ear congestion
• nervous and dry coughs, chronic bronchitis, asthma
• inflammation of eyes and eyelids, conjunctivitis
• diarrhoea, gastritis, peptic ulcer, colitis, haemorrhoids
• haematuria, bladder weakness
• infected wounds, insect bites and stings

Toxicity and contra-indications

None cited

Preparations and dosage

Decoction, fresh juice

Fluid extract 1:2, 1-2 mL three times daily glycetract

Fresh plant tincture 1:10, 1-2 mL three times daily

Syrups and lozenges

Combinations

With Verbascum, Sambucus and Echinacea for respiratory catarrh.

Oak tree

Botanical name

Quercus robur

Synonyms

English Oak

Family

Fagaceae

Origin and distribution

Native throughout Europe, cultivated elsewhere

Brief description

Large deciduous tree with dome-shaped canopy, monoecious with catkins of male flowers and

spikes of female flowers which develop into characteristic acorns.

Part used

Dried inner bark of small branches and young stems, insect galls.

Active constituents

Tannins, up to 20% - phlobotannins, ellagitannins, gallic acid.

Oak galls - contain up to 70% gallotannic acid

Energetics

Drying, cooling, bitter

Actions

Astringent, haemostatic, antimicrobial

Systems influenced

Gastrointestinal tract, upper respiratory tract, female reproductive

Therapeutic indications

• diarrhoea, haemorrhoids
• varicose veins, passive haemorrhages
• pharyngitis, sore throat, mouth ulcers
• leucorrhoea, uterine prolapse

Toxicity and contra-indications

In high doses may cause abdominal pain, constipation and liver damage.

Preparations and dosage

Decoction

Fluid extract 1:2, 1-2 mL three times daily

Decoction or extract used as gargle or for topical application

Combinations

With Filipendula, Rubus and Althaea leaf for diarrhoea.

Review questions

1. Discuss the mode of action of astringents.
1. Write a list of five conditions for which astringents are indicated, and select an appropriate herb for each of the conditions.
1. Suggest a herbal treatment for pharyngitis accompanied by nasal catarrh and mouth ulcers.

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Selected references

Zhu, M.J. Phillipson, D. 1997. Plant polyphenols. Phytochemistry 44: 441-447.