The present invention relates to an extract of Salix spp obtainable by fractioning on a resin and to the process for its preparation.The extract of the invention is characterized by an high content in salicin derivatives, reduced content in high molecular tannins and a content in proanthocyanidins sufficient to inhibit some tissue metal proteases. The product is formulated in oils rich in ω-3 and ω-6 acids which provide a better absorption of the extract active principles, also increasing synergetically their action.