Flavonoids is a group of polyphenolic compounds C6 — C3 — C6 series, which are synthesized exclusively in higher plants. Numerous biological effects that show flavonoids in the human body are based on two fundamental properties: antioxidant effects and the ability to form complexes with proteins. The interaction of flavonoids with proteins can act as inhibitors of numerous enzymes and/or as ligands of receptors involved in signal transduction. The review deals with the formation of non-covalent bonds between flavonoids and proteins (Van der Waals and electrostatic), nonspecific and specific binding of tannins with proline- and histidine-rich proteins of saliva, leading to precipitation of the complex “flavonoid–protein”, interact with transport proteins of plasma and inhibition by some flavonoids of proteinases.
