Curcumin

Curcumin (Linnea, cat# CUM 1259) was dissolved in DMSO (MP Biomedicals, USA) to obtain a starting concentration of 10 mM. The treatment of ARPE-19 cells was then performed with three different concentrations of Curcumin: 0.01 mM, 0.05 mM, and 0.1 mM for 24 h. DMSO 0.1%, 0.5%, and 1% were used as the vehicle.

Glyceryl oleate (Tegin O^®, GO), Cetyl palmitate (CP), Methylisothiazolinone and Methylchloroisothiazolinone (Acnibio AC^®) and triethanolamine (TEA) were bought from ACEF (Fiorenzuola D’Arda, Italy). Idebenone (IDE) was obtained from Carbosynth (Berkshire, UK). Polyoxyethylene-20-oleyl ether (Brij 98^®, Oleth-20), 2,2’-Azobis(2-methylpropionamidine) dihydrochloride (AAPH), fluorescin (FL) Trolox (TRL), aminoguanidine carbonate (AMG), bovine serum albumin (BSA), D-fructose, sodium nitroprusside and Griess reagent (1% dihydrochloride sulphanylamide and 0.1% naphthylethylenediamine (NED) dihydrochloride in 5% of hydrochloric acid) and sodium azide were purchased from Sigma-Aldrich srl (Milan, Italy). Curcumin was obtained from MP Biomedicals, (Illkirch cedex, France). Imidazolidinyl urea (Kemipur 100) was obtained from Farmalabor (Canosa di Puglia, Italy).
The following chemicals 2-Pyrrolidone-5-carboxylic acid (PCA), N,N′-dicyclohexylcarbodiimide (DCC), dry acetonitrile (CH₃CN), 4-dimethylaminopyridine (DMAP), ethyl acetate (EtOAc), and hydrochloric acid (HCl), used to synthesize IDE ester (IDEPCA), were reagent grade and were bought from Sigma-Aldrich srl (Milan, Italy). DMSO-d₆ used for NMR analysis was purchased from Sigma-Aldrich srl (Milan, Italy).