Trans cinnamic

All chemicals used in the experiments were of analytical grade. Folin-Ciocalteu reagent, sodium carbonate, gallic acid, 1,1-DiPhenyl-2- 113 Picryl Hydrazyl (DPPH), and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid 114 (Trolox), were purchased from Sigma-Aldrich (Darmstadt, Germany). FRAP, CUPRAC and proanthocyanidin assay kits were provided from Bioquochem, (Asturias, Spain). Tween 20 (Polyoxyethylene-20) was purchased from Biotech, (Markham, ON, Canada).
All HPLC standards, gallic acid, protocatechuic acid, (+)-catechin, chlorogenic acid, caffeic acid, p-coumaric acid, rutin, D-malic acid, myricetin, trans-cinnamic, 3,5-dimethoxy-4-hydroxycinnamic acid, quercetin, luteolin and kaempferol were purchased from Sigma-Aldrich (Darmstadt, Germany). Water was purchased from LiChrosolv^® (Darmstadt, Germany), O-phosphoric acid 85% extra pure was provided by Scharlau, Turkey and acetonitrile was provided by VWR Prolabo^® Chemicals (France).
A commercial cream, mostly containing water, glycerin, stabilizers, and preservatives with no bioactive molecules, was locally purchased from a store. A commercial hydro-glyceric extract obtained from grape seed was kindly provided by a cosmetics society in France.

The following standards were obtained from Sigma Chemical Co (St. Louis, MO, USA) at the highest purity available, as shown in Table 1: quinic acid, gallic acid, protocatchuic acid, catechin (+), caffeic acid, syringic acid, 1,3-di-O-caffeoyquinic acid, epicatechin, p-coumaric acid, rutin, trans-ferulic acid, hyperoside (quercetin-3-Ogalactoside), luteolin-7-O-glucoside, 3,4-di-O-caffeoyquinic acid, naringin, rosmarinic acid, 4,5-di-O-caffeoyquinic acid, quercetin (quercetin-3-O-rhamonoside), apigenin-7-O-glucoside, O-coumaric acid, Salvianolic acid, kaempferol, quercetin, trans cinnamic, silymarin, naringenin, apigenin, luteolin, cirsiliol, cirsilineol, acacetin.

Pluronic F 127 and Methylcellulose Ph. Eur. were obtained from Sigma-Aldrich (Saint-Louis, MO, USA). Noaveon AA-1 was kindly gifted by Lubrizol (Wickliffe, OH, USA). AgNO₃ (99.9%) was obtained from Mikrochem (Pezinok, Slovakia). The HPLC standards rutin trihydrate, quercetin, and gallic, caffeic, p-coumaric, o-coumaric, rosmarinic, and trans-cinnamic acids were purchased from Sigma–Aldrich (St. Louis, MO, USA). HPLC solvents were purchased from Fischer (Fisher Scientific UK Ltd., Loughborough, UK).