Polyphenols: An overview
Polyphenols: A closer look
Synopsis of a study from the International Journal of Cosmetic Science. Oct2013, Vol. 35 Issue 5, p491-501. 11p.
Methods: Mixtures of model substances, consisting of catechin, epigallocatechin gallate (EGCG), resveratrol, quercetin, rutin and protocatechuic acid (PCA), were formulated into o/w emulsions with different oil phase content. The in vitro experiments were carried out in Franz-type diffusion cells by means of ex vivo pig skin and a cellulose membrane.
Results: The increased oil content in the emulsion led to a significant decrease in initial release coefficients (Kr), diffusion coefficients within the formulation (Dv) and skin permeation coefficients (Kp), respectively. The study considered the dependence of Kr on molecular weight and lipophilicity of polyphenolics. For both more hydrophilic and more lipophilic substance groups, the values for Kr were inverse proportional to molecular weight. For catechin, quercetin, rutin, resveratrol and PCA, a good correlation between Kp and Kr parameters was obtained. The most permeable substance was PCA (Kp = 1.2·10−3 cm h−1), and the least permeable was quercetin (Kp = 1.5·10−5 cm h−1).
Conclusion: All substances could pass the SC barrier and were found mostly in the epidermis and dermis, confirming the potential of polyphenols as anti-ageing active cosmetic ingredients.
Wow! In other words, polyphenols like catechin, EGCG, resveratrol, quercetin, rutin, and PCA in lotions permeated our skin! Once in, they can behave as anti-oxidants that scavenge free radicals!
So it's safe to say that the polyphenols we find in our oils can penetrate our skin and work from the inside as anti-oxidants.
Join me tomorrow as we review what we've learned this week and what it all means!