Resveratrol

Epigallocathechin-3-gallate (EGCG), resveratrol and curcumin were purchased from LKT laboratories, Inc (St. Paul, MN) (Fig. 1). Hydrogen peroxide (H₂O₂) was obtained from Sigma-Aldrich (St. Louis, MO). Dulbecco's Modified Eagle's Medium (DMEM), F12 medium, antibiotic-antimycotic (Anti-anti), ethylenediaminetetraacetic acid (EDTA), trypsin-EDTA (Invitrogen), penicillin-streptomycin (Pen Strep), fetal bovine serum (FBS), phosphate-buffered saline (PBS), 2′,7′-dichlorodihydrofluorescein diacetate (H₂DCF-DA), 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate (DAF-FM diacetate), Amplex Red Catalase activity assay kit, N_ω-nitro-l-arginine methyl ester hydrochloride (l-NAME) as a NO inhibitor, and S-nitroso-N-acetylpenicillamine (SNAP) were purchased from Invitrogen (Carlsbad, CA). Collagenase type 2 was purchased from Worthington Biochemical Corporation (Lakewood, NJ). Bradford protein assay reagent was purchased from BioRad (Hercules, CA). Stock solutions of 100 mM EGCG, 100 mM curcumin, 1 M NAC, 1 M l-NAME were prepared in DMSO and stored at −20 °C until use. 10 mM H₂DCF-DA and 5 mM DCF-DA-diacetate were prepared as stock solutions in DMSO, stored at −20 °C, and diluted in PBS to 20 μM and 10 μ M, respectively, prior to use.