Phenol esterase activity of porcine skin

Authors: Laszlo, Joseph; Smith, Leslie; Evans, Kervin; Compton, David - Dave

Submitted to: European Journal of Pharmaceutics and Biopharmaceutics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2014
Publication Date: 12/8/2014
Publication URL: http://handle.nal.usda.gov/10113/60485
Citation: Laszlo, J.A., Smith, L.J., Evans, K.O., Compton, D.L. 2014. Phenol esterase activity of porcine skin. European Journal of Pharmaceutics and Biopharmaceutics. 89(1):175-181.

Interpretive Summary: We are developing new, value added uses for commodity crops and crop oils through the development of domestically-derived, bio-based chemicals and products. Several of our vegetable oil derivatives have good antioxidant properties that may have a positive influence on maintaining the health of cellular tissues, particularly skin. Can these molecules be formulated in skin care products so as to provide protective and energizing activities for improved facial skin health and appearance? In the present investigation the stability of our molecules when applied to skin was explored. We found that enzymes in the skin are able to breakdown some of our molecules. The rate of the enzymatic activity was shown to be decreased by encasing the molecules in a specialized lipid carrier. These findings provide researchers with an enhanced understanding of how such molecules may be included in advanced skin care products.

Technical Abstract: The alkyl esters of plant-derived phenols may serve as slow-release sources for cutaneous delivery of antioxidants. The ability of skin esterases to hydrolyze phenolic esters was examined. Esters of tyrosol and hydroxytyrosol were prepared from decanoic and lipoic acids. Ferulic acid was esterified with octadecanol, glycerol, and dioleoylglycerol. These phenolic derivatives were treated in taurodeoxycholate microemulsion and unilamellar liposomes with ex vivo porcine skin and an aqueous extract of the skin. Extracted esterases hydrolyzed the microemulsions at rates in the order: tyrosyl lipoate > tyrosyl decanoate > hydroxytyrosyl lipoate > hydroxytyrosyl decanoate. The tyrosyl decanoate was subject to comparatively little hydrolysis (10–30% after 24 h) when incorporated into liposomes, while hydroxytyrosyl decanoate in liposomes was not hydrolyzed at all by the skin extract. Ferulate esters were not hydrolyzed by the extract in aqueous buffer, microemulsion, nor liposomes. Tyrosyl decanoate applied topically to skin explants in microemulsion were readily hydrolyzed within 4 h, while hydrolysis was minimal when applied in liposomes. These findings indicate that porcine skin displays a general esterase activity towards medium-chain esters of tyrosol and hydroxytyrosol, which can be moderated by the physiochemical properties of the lipid vehicle, but no feruloyl esterase activity.