Topical Antioxidant Cocoa Polyphenol Skin Penetration.

Background: Cocoa powder derived from the Theobroma cacao plant is rich in polyphenols, such as catechin and epicatechin. These polyphenols are strong antioxidants when consumed orally; however, their ability to enter the stratum corneum following the topical application has never been demonstrated.

Objective: The objective of this study was to demonstrate the deposition of catechin and epicatechin in the stratum corneum following the topical application of 6% aqueous cocoa powder 1 and 2 h after application.

Methods: Five healthy female subjects aged 25-60 years were enrolled. A 6% aqueous cocoa powder solution was prepared and applied to two randomized designated spots on the left forearm. 2 cc of the solution was applied under a ¼-inch gauze square covered with plastic wrap and held in place with a Coban dressing. The 15 d-squame 7/8-inch circular tape strips were applied to the predetermined area on the forearm 1 h and 2 h after application of the 6% cocoa powder solution. The tape strips were immediately placed in a -80°C freezer for storage until extraction in preparation for LC-MS evaluation for catechin and epicatechin levels.

Results: More catechin and epicatechin were detected at 2 h than 1 h for both compounds, although the difference was not statistically significant. Higher epicatechin levels than catechin levels were detected from the cocoa powder at both time points. This is consistent with published data from food-grade cocoa powder.

Summary: It is detected that 6% aqueous cocoa powder delivers the antioxidants catechin and epicatechin to the stratum corneum 1 h and 2 h after topical application.