Abstract

Stearyl Glycyrrhetinate is a derivative of Glycyrrhetinic Acid, known in the pharmaceutical and cosmetic industry for its soothing properties. The aim of this study is, after confirming the soothing activity of Glycyrrhetinic Acid with an In Vivo test vs. placebo, to evaluate, again with an In Vitro test, its speed of action, based on a higher bio-availability of the esterified active. The In Vivo test has been carried out using co-culture systems of human keratinocytes and fibroblasts

INTRODUCTION
Glycyrrhetinic Acid and Glycyrrhizic Acid are specific compounds isolated from wild licorice plants. Licorice (Glycyrrhiza glabra L.) has a long history of medicinal use in Europe and Asia and has been widely used in traditional Chinese medicine. It is reported to be effective in the treatment of peptic ulcer disease, constipation, skin damage, coughs and other ailments (1,2).
A large number of components have been isolated from licorice over the years, in particular glycyrrhizic acid, which is normally considered to be the main biologically active component.
Glycyrrhizic Acid is a conjugate of Glycyrrhetinic Acid and two molecules of glucuronic acid, a carbohydrate. Stearyl Glycyrrhetinate is the salt and ester of Glycyrrhetinic Acid (Figure 1).
The anti-inflammatory effect of Glycyrrhizic Acid has been studied chemically and pharmacologically over the years. Glycyrrhetinic Acid is a pentacyclic triterpenoid. The structure of Glycyrrhetinic Acid is similar to that of cortisone. This may be the basis for licorice’s  anti-inflammatory action (3,4).
In Glycyrrhetinic Acid, the functional group (R) is a hydrox ...