Astringent


Astringent

An astringent (also spelled adstringent) substance is a chemical that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin "adstringere", meaning "to bind fast". Two common examples are calamine lotion and witch hazel.

Astringency is also the dry, puckering mouthfeel caused by tannins found in many fruits such as blackthorn, bird cherry and persimmon fruits. The tannins denature the salivary proteins, causing a rough "sandpapery" sensation in the mouth. Astringency tastes unpleasant to many mammals (including humans), which tend to avoid eating astringent fruit; conversely, birds do not taste astringency and readily eat these fruit. It is thought that fruit astringency gives a selective advantage to some plant varieties because birds are better than mammals at long-distance seed dispersal, often flying a great distance before passing the seeds in their droppings.

Astringent substances are also found in some red wines and teas. A small amount of astringency is expected in some wines, especially young red wines made from grapes such as cabernet sauvignon.

Astringent medicines cause shrinkage of mucous membranes or exposed tissues and are often used internally to check discharge of blood serum or mucous secretions. This can happen with a sore throat, hemorrhages, diarrhea, or with peptic ulcers. Externally applied astringents, which cause mild coagulation of skin proteins, dry, harden, and protect the skin. Acne sufferers are often advised to use astringents if they have oily skin. [http://www.brown.edu/Student_Services/Health_Services/Health_Education/general_health/acne.htm] Astringents also help heal stretch marks and other scarsFact|date=February 2007. Mild astringent solutions are used in the relief of such minor skin irritations as those resulting from superficial cuts, allergies, insect bites, or fungal infections such as athlete's footFact|date=February 2007.

Some common astringent agents include alum, oatmeal, yarrow, witch hazel, bayberry, very cold water, and rubbing alcohol. Astringent preparations include silver nitrate, zinc oxide, zinc sulfate, Burow's solution, tincture of benzoin, and vegetable substances such as tannic and gallic acids. Balaustines are the red rose-like flowers of the pomegranate, which are very bitter to the taste. In medicine, its dried form has been used as an astringent. [ [http://digicoll.library.wisc.edu/cgi-bin/HistSciTech/HistSciTech-idx?type=turn&entity=HistSciTech000900240228&isize=L History of Science: Cyclopædia, or, An universal dictionary of arts and sciences…] ] Some metal salts and acids have also been used as astringents.

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  • astringent — astringent, ente [ astrɛ̃ʒɑ̃, ɑ̃t ] adj. et n. m. • 1537; lat. astringens, de astringere « serrer » 1 ♦ Méd. Qui exerce sur les tissus vivants un resserrement. Remède astringent, lotion astringente. N. m. Les astringents (alun, tanin, quinquina,… …   Encyclopédie Universelle

  • astringent — ASTRINGÉNT, Ă, astringenţi, te, adj., s.n. 1. adj. (Despre substanţe) Care contractează ţesuturile organismului. 2. s.n. Substanţă sau medicament folosit pentru combaterea secreţiilor organice exagerate. – Din fr. astringent, lat. astringens,… …   Dicționar Român

  • Astringent — As*trin gent ( jent), a. [L. astringens, p. pr. of astringere: cf. F. astringent. See {Astringe}.] 1. Drawing together the tissues; binding; contracting; opposed to {laxative}; as, astringent medicines; a butter and astringent taste; astringent… …   The Collaborative International Dictionary of English

  • astringent — [ə strin′jənt] adj. [L astringens, prp. of stringere, to contract < ad , to + stringere, draw tight: see STRICT] 1. that contracts body tissue and checks secretions, capillary bleeding, etc.; styptic 2. having a harsh, biting quality [an… …   English World dictionary

  • astringent — astringent, ente (a strin jan, jan t ) adj. Terme de médecine. Qui a la propriété de déterminer une sorte de crispation dans les tissus. Une substance astringente.    S. m. Les astringents. Le perchlorure de fer est un bon astringent. HISTORIQUE… …   Dictionnaire de la Langue Française d'Émile Littré

  • astringent — ASTRINGENT, ENTE. adj. Qui resserre. Remède astringent. Herbe astringente. Poudre astringente. [b]f♛/b] Il est quelquefois substantif. Arrêter le sang avec des astringens …   Dictionnaire de l'Académie Française 1798

  • astringent — Astringent, [astring]ente. adj. v. Qui resserre. Remede astringent. herbe astringente. poudre astringente. Il est quelquefois subst. On luy a arresté le sang avec des astringents …   Dictionnaire de l'Académie française

  • astringent — ► ADJECTIVE 1) causing the contraction of body tissues. 2) (of taste or smell) sharp or bitter. 3) harsh or severe. ► NOUN ▪ an astringent lotion applied for medical or cosmetic purposes. DERIVATIVES astringency noun astringently …   English terms dictionary

  • Astringent — As*trin gent, n. A medicine or other substance that produces contraction in the soft organic textures, and checks discharges of blood, mucus, etc. [1913 Webster] External astringents are called styptics. Dunglison. [1913 Webster] …   The Collaborative International Dictionary of English

  • astringent — I adjective acid, acrid, acrimonious, adstrictorius, austere, bitter, caustic, dour, exigent, harsh, mordant, rough, severe, stern, strict, stringent, tart II index bitter (penetrating) …   Law dictionary

  • astringent — (adj.) 1540s, from L. astringentum (nom. astringens), prp. of astringere to bind fast, tighten, contract, from ad to (see AD (Cf. ad )) + stringere draw tight (see STRAIN (Cf. strain) (v.)). As a noun from 1620s …   Etymology dictionary


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