Echinacoside and caffeoyl conjugates protect collagen from free radical-induced degradation: a potential use of Echinacea extracts in the prevention of skin photodamage

Planta Med. 1995 Dec;61(6):510-4. doi: 10.1055/s-2006-959359.


The protective effect of caffeoyl derivatives (echinacoside, chlorogenic acid, chicoric acid, cynarine, and caffeic acid, typical constituents of Echinacea species) on the free radical-induced degradation of Type III collagen has been investigated. The macromolecule was exposed to a flux of oxygen radicals (superoxide anion and hydroxyl radical) generated by the xanthine/xanthine oxidase/Fe2+/EDTA system and its degradation assessed qualitatively by SDS-PAGE and quantitatively as the amount of soluble peptides (according to the 4-hydroxyproline method) released from native collagen after oxidative stress. The SDS-PAGE pattern of native collagen is markedly modified by free radical attack, with formation of a great number of peptide fragments with molecular masses below 97 kDa: in the presence of microM concentrations of echinacoside, there is a complete recovery of the native profile. Collagen degradation was, in fact, dose-dependently inhibited by all the compounds, with the following order of potency: echinacoside approximately chicoric acid > cynarine approximately caffeic acid > chlorogenic acid, with IC50 ranging from 15 to 90 microM. These results indicate that this representative class of polyphenols of Echinacea species protects collagen from free radical damage through a scavenging effect on reactive oxygen species and/or C-, N-, S-centered secondary radicals, and provide an indication for the topical use of extracts from Echinacea species for the prevention/treatment of photodamage of the skin by UVA/UVB radiation, in which oxidative stress plays a crucial role.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Caffeic Acids / pharmacology*
  • Collagen / metabolism*
  • Free Radical Scavengers / pharmacology*
  • Glycosides / pharmacology*
  • Hydrolysis
  • Reactive Oxygen Species
  • Skin / drug effects*
  • Skin / radiation effects*
  • Ultraviolet Rays
  • Xanthine
  • Xanthine Oxidase / metabolism
  • Xanthines / metabolism


  • Caffeic Acids
  • Free Radical Scavengers
  • Glycosides
  • Reactive Oxygen Species
  • Xanthines
  • Xanthine
  • Collagen
  • Xanthine Oxidase
  • echinacoside