GENTIANACEAE

Members of the Gentianaceae are usually hairless herbs with opposite, entire, usually stalkless leaves without stipules.

• Calyx has 4–5 lobes, the corolla tubular with 5–9 lobes, overlapping and twisted in the bud
• There are 5 stamens attached to the tube
• The ovary is superior, usually one-celled
• The many-seeded fruit is usually a capsule with a persistent corolla

Gentiana lutea

Gentian, yellow gentian

Description

A perennial herbaceous plant with a very long, thick tap-root and erect, stout, smooth, hollow stems, 50–125 cm high. Leaves large, broadly oval, seven-veined, 20–30 cm long, bluish-green. Lower leaves stalked, upper leaves opposite, stalkless and clasping. Flowers numerous, short-stalked, golden yellow, about 2.5 cm long, in dense axillary and terminal whorls. Corolla with 5–9 lance-shaped lobes, more or less spreading in a star, not tubular; calyx papery.

Family Gentianaceae

Habitat and cultivation

Native to southern Europe in mountain pastures. Cultivated elsewhere from seed or root division in deep, rich, moist soil to allow roots to develop. Needs suns and shelter from cold winds and takes up to 3 years to flower. Drought tender, frost resistant.

Parts used

The root and rhizome harvested in the autumn of the second or third year and before the plant is mature enough to flower. Roots, dug in autumn, should be dried quickly to preserve their white colour. Slow-dried gentian becomes reddish and contains less medicinal properties. However, after 6–8 months the root always seems to darken in colour.

Active constituents1

1) Bitter secoiridoids (up to 4%) including predominantly gentiopicroside also amarogentin, sweroside and swertiamarin.^2,3 The level of the bitter secoiridoids is affected by the way the roots are dried, gentiopicroside increases when roots are dried at 40°C,⁴ however this is not the official method of preparation

2) Oligosaccharides including gentianose and polysaccharides—inulin and pectin

3) Xanthones (0.1%) mainly gentisin and isogentisin also gentioside, gentisein and mangiferin.^5–9 Xanthones are chemically related to flavonoids and give the root its yellow colour

4) Phenolic acids including gentisic and caffeic acids

5) Triterpenes including β-sitosterol, campesterol, stigmasterol and squalene^3,10

Also traces of a complex volatile oil and inositol. Alkaloids (e.g. gentianine) are usually reported as being present in Gentiana but are now believed to be created by the isolation procedure which uses ammonia.

Nutritional constituents

Vitamins: Vitamin B complex, especially niacin Minerals: Iron, also calcium, magnesium, manganese, phosphorus, potassium, selenium, sulphur and zinc.

Actions

1) Bitter

2) Gastric stimulant

3) Sialagogue

4) Cholagogue

Scientific information

Gentiana has been an official medicine in a number of countries. It was used as a bitter to stimulate gastric secretions and improve appetite.¹¹ It was valued from very early times and demand for the roots has meant that in some countries the wild variety has become endangered.¹² German Commission E approves its use for digestive disorders including loss of appetite, fullness and flatulence.

Armarogentin, although not the most prevalent glycoside, is 5000 times more bitter than gentiopicroside, the predominant constituent.² Amarogentin and swertiamarin are extremely bitter being detectable at concentrations as low as 1 in 50,000. Gentianose, a trisaccharide, also contributes to the bitterness of Gentiana. The herb is the standard bitter.

There is little clinical data to support traditional uses but earlier research established its action in stimulating digestive function through increased gastric and gall bladder secretions.¹³ The postulated mechanism of the bitter constituents’ action is through the stimulation of nerve endings on the tongue, causing a reflex stimulation of saliva and gastric secretions.

In vitro—Gentiana has a limited inhibitory effect on Helicobacter pylori strains.¹⁴ Gentiopicrin has some fungitoxic activity¹⁵ and isogentisin inhibits monoamine oxidase¹⁶ as well as having antitubercular activity.¹⁷

Medicinal uses

Gastro-intestinal tract

• anorexia
• atonic dyspepsia
• gastritis
• heartburn
• diarrhoea
• nausea
• gastro-intestinal atony
• flatulence
• bloating

Pharmacy

Three times daily
Decoction (dried root)	–   0.6–2 g
Tincture 1:5 (45%)	–   1–4 ml

The herb should be sipped slowly mixed with water 30–60 minutes prior to meals.

CONTRAINDICATIONS—Peptic ulcers (gastric and duodenal).

Precautions and/or safety

Gentisin and isogentisin are mutagenic in the standard Ames test, they occur in the root at an estimated 0.04% and 0.03% respectively. Their in vivo potential to be mutagenic is yet to be established.18,19 In order to benefit from bitters the taste must not be disguised, however if given in too large a dose they can suppress digestive secretions.

There are a number of recorded poisonings due to the mistaken substitution of Veratrum album for Gentiana lutea, the two being similar in appearance prior to flowering and often growing side by side.^20–22

Historical uses

Antidote for many poisons; the bites of mad dogs and venomous beasts. Fevers; lameness arising from cold in the joints; for bruises; as a diuretic and emmenagogue; for cramps and convulsions; for voiding tough phlegm; for a number of skin conditions; jaundice; as a vermifuge. Hysteria; female weakness! To refresh weary travellers; urinary tract stones; cramps and convulsions.