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Rhamnus frangula
Natural Encyclopaedia


FAMILY: Rhamnaceae.

HABITAT: Native to central southern Europe.

USED PART: the root.

PHARMACEUTICAL PREPARATIONS: nebulised dry extract titrated in hydroxyanthracene heterosides expressed as frangulin (min.3%) (Italian Pharmacopoeia X), daily dosage ranging from 2 to 3 mg/kg, preferably in a single evening administration.

CHEMICAL COMPOSITION: belongs to plants rich in hydroxyanthracene heterosides. The main compounds are the hydroxyanthracene heterosides, the main one being frangulin. This plant also contains flavonoids and acidic polysaccharides (about 7%). We then have 10 to 12% mineral salts, mainly calcium and potassium.

Laxative action: is known for its laxative action.of the type that stimulates bowel movements. Anthraquinone heterosides are poorly absorbed and hydrolysed in the small Gut. Instead, they are converted by glucosidases and reductases of the bacterial flora of the large Gut into aloe-emodin-anthrone and then absorbed. This results in a latency of the laxative effect of 8-24 hours, which is the time it takes for these substances to reach the colon, where pharmacological activity occurs. Anthracene heterosides can therefore be regarded as prodrugs, in which the glucose ingredient serves to transport them and reduce their absorption until they reach the colon where they are hydrolysed by enzymes of the local bacterial flora.

SIDE EFFECTS: may cause diarrhoea with abdominal pain. Abuse of this and other anthraquinone-rich plants can cause habituation resulting in reduced laxative efficacy.

CONTRAINDICATIONS: It is contraindicated in pregnancy, in children under 12 years of age, in lactation, in intestinal diverticulosis, in patients with intestinal occlusion or subocclusion, in patients with haemorrhoids and/or perianal fistulas.

DRUG INTERACTIONS: It may reduce the efficacy of the following drugs: quinidine-type antiarrhythmics, digitalis, potassium-losing diuretics, vincamine and fenoxedil. Extracts of these plants should not be administered continuously for more than eight to ten days.


It can be found in estilax®