High glucose Dulbecco's modified Eagle's medium (DMEM), fetal bovine serum (FBS), gentamicin solution, and penicillin-streptomycin solution were purchased from GE Healthcare Life Sciences, Inc. (Logan, UT, USA). Protocatechuic aldehyde (3,4-dihydroxybenzaldehyde), Oil Red-O powder, 2,2-Diphenyl-1-picrylhydrazyl (DPPH) powder and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) powder were purchased from Sigma-Aldrich Corp. (St. Louis, MO, USA). The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay solution was purchased from Promega Corporation (Madison, WI, USA). The 5-(and-6)-carboxy-2′,7′-difluorodihydrofluorescein diacetate (Carboxy-H2DFFDA) was purchased from Invitrogen Molecular Probes, Inc. (Willow Creek Road, Eugene, OR, USA). The hyaluronan ELISA (HA ELISA) kit was purchased from Echelon Biosciences, Inc. (Salt Lake, UT, USA). Anti-heme oxygenase-1 (HO-1), anti-PPAR-γ, anti-c/EBP-α, anti-c/EBP-β, and anti-β-actin antibodies were purchased from Santa Cruz Biotechnology (Dallas, TX, USA).