In Vitro Dermo-Cosmetic Evaluation of Bark Extracts from Common Temperate Trees

Wood residues produced from forestry activities represent an interesting source of biologically active, high value-added secondary metabolites. In this study, 30 extracts from 10 barks of deciduous and coniferous tree species were investigated for their potential dermo-cosmetic use. The extracts were obtained from <i>Fagus sylvatica, Quercus robur, Alnus glutinosa, Prunus avium, Acer pseudoplatanus, Fraxinus excelsior, Populus robusta, Larix decidua, Picea abies</i>, and <i>Populus tremula</i> after three successive solid/liquid extractions of the barks with <i>n-</i>heptane, methanol, and methanol/water. All extracts were evaluated for their radical scavenging capacity, for their elastase, collagenase, and tyrosinase inhibitory activities, as well as for their antibacterial activity against gram-positive <i>Staphylococcus aureus</i>. In parallel, the global metabolite profiles of all extracts were established by 1D and 2D NMR and related to their biological activity. The results showed that the methanol extracts of <i>Q. robur, A. glutinosa, L. decidua</i>, and <i>P. abies</i> barks exhibit particularly high activities on most bioassays, suggesting their promising use as active ingredients in the dermo-cosmetic industry.