Antioxidative effects and percutaneous absorption of five polyphenols.

A new strategy was designed to evaluate the antioxidant effectiveness of five topically applied polyphenols following skin penetration profiles. The antioxidants were the following polyphenol derivatives: epicatechin, resveratrol, rutin, quercetin, and trolox, which was used as the reference antioxidant. The hydrophilic/lipophilic character of these compounds was evaluated, and their antioxidant activity was measured by the DPPH method. The percutaneous absorption of these polyphenols was obtained by an in vitro methodology using porcine skin biopsies. This methodology involves the quantification of the antioxidants present in each specific skin layer to evaluate antioxidant effectiveness. The antioxidant activity in each skin layer was also determined by the DPPH method. The results indicated that lipophilic antioxidants (epicatechin, resveratrol, quercetin, and trolox) penetrated deeper into the skin layers, whereas a more hydrophilic compound, rutin, remained on the skin surface. The antioxidant evaluation of each skin compartment suggested that resveratrol and rutin were the most effective topically applied compounds in view of their antioxidant activity and their skin penetration profile.