Abstract
Tannins are one of the most widely occurring groups of natural substances in different families of higher plants. These secondary metabolites are present in solution form in the cell sap and also in distinct vacuoles. They have been known since long time as the astringent substances, having the capacity to combine with tissue proteins and precipitate them. They are, therefore, used in medicines for allied purposes or as mild antiseptics, in treatment of diarrhea, and to check small haemorrhage. Commercially, they find extensive application in leather industry, when the skins of animals are treated with tannins to prevent the putrefaction. The present review is explained the detailed of tannins and tannin containing pharmacognostical drugs. Total this review explored the tannins structure, identified the drugs presenting the tannins and their uses (Pharmacological activity). Every crude drug having particular tannin constituents also identified here.
