Astringents are remedies that have a 'binding' action on tissue, usually due to a group of complex chemicals called tannins. The name tannin derives from their use in the tanning industry, and they share the property of precipitating, or curdling, protein molecules. As saliva and other body fluids contain proteins that are in solution, tannin containing astringents cause them to become insoluble and precipitate. This produces a coating on the surface of tissue composed of the body's own protein, thus there is not problem with allergic reaction and as the precipitate is readily metabolized, the effect is short-lived. This leads to the important inference that astringents are effective mainly on tissue that the tannin content can physically reach.
Similar precipitation also happens with alkaloids and salts of heavy metals. One of the few incompatibilities in herbal medicine making is that astringent remedies will cause a precipitate with alkaloid rich herbs.
Therapeutically useful effects include:
- A reduction of irritation on the surface of tissues due to a form of numbing.
- A reduction in surface inflammation.
- A barrier against infection is created which is of great help in wounds and burns.
Astringents may be indicated in a wide range of problems but especially in wound healing and conditions of the digestive system. Along the whole length of the digestive system they reduce inflammation and inhibit diarrhoea. Long-term use as medicine can be deleterious to health as there may be an eventual inhibition of proper food absorption across the gut wall.
Representative Herbal Astringents
Astringents that are also Anti-Catarrhal: Bearberry, Bistort, Cranesbill, Elecampane, Eyebright, Golden Rod, Ground Ivy, Mullein, Red Sage, Yarrow
Astringents that are also Anti-Inflammatory: Bistort, Cranesbill, Eyebright, Golden Rod, Meadowsweet, Oak Bark, Plantain, Witch Hazel
Astringents that are also Anti-Microbial: Bearberry, Elecampane, Golden Rod, Oak Bark, Red Sage, Rosemary, Yarrow
Astringents that are also Anti-Spasmodic: Bugleweed, , Red Sage, Rosemary, Wild Cherry
Astringents that are also Bitter: Agrimony, Wild Cherry, Yarrow
Astringents that are also Demulcent: Bearberry, Comfrey Root, Lungwort, Mullein, Plantain
Astringents that are also Diaphoretic: Bayberry, Elecampane, GoldenRod, Yarrow
Astringents that are also Diuretic: Agrimony, Bearberry, Bugleweed, Golden Rod, Ground Ivy, Kola Nut, Mullein, Plantain, Yarrow
Astringents that are also Emmenagogue: Raspberry, Yarrow
Astringents that are also Expectorant: Comfrey Root, Elecampane, Ground Ivy, Lungwort, Mullein, Plantain, Wild Cherry
Astringents that are also Hepatic: Agrimony Astringents that are also Hypotensive : Yarrow
Astringents that are also Nervine: KolaNut, Rosemary, Wild Cherry
Astringents that are also Tonic: Agrimony, Mullein, Raspberry, Yarrow
Astringents that are also Vulnerary: Agrimony, Comfrey Root, Cranesbill, Lungwort, Yarrow