Standard glutathione

Methylglyoxal (MG), propidium iodide, [3(4,5-dimethylthi-azol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT), neutral red, carbenoxolone disodium salt (CBX), aminoguanidine hemisulfate salt (AG), standard glutathione, o-phthaldialdehyde, metaphosphoric acid, L-glutamate, N-methyl-D-glucamine, 4-(2-hydroxyethyl) piperazine-L-ethanesulfonic acid (HEPES), and cell culture materials were purchased from Sigma (Saint Louis, MO, USA). Dulbecco's modified Eagle medium (DMEM) and Dulbecco's phosphate-buffered saline (DPBS) were purchased from Gibco BRL (Carlsbad, CA, USA). Fetal bovine serum was obtained from Cultilab (Campinas, SP, Brazil), and L-[2,3-³H] glutamate was purchased from Amersham International (United Kingdom). Polyclonal anti-EAAT1 (GLAST) and anti-EAAT2 (GLT-1) were purchased from Abcam (Cambridge, MA, USA), anti-EAAT3 was purchased from Novus Biologicals (Littleton, CO, USA), and polyclonal anti-glyoxalase 1 was purchased from Santa Cruz Biotechnology Inc. (Dallas, Texas, USA). All other chemicals were purchased from local commercial suppliers.

Cu NPs (spherical morphology, 99.8% purity and average diameter of 25 nm) were purchased from SkySpring Nanomaterials, Inc. Houston, TX, USA. Chitosan (Mv = 200,000 g/mol) was obtained from Marine Chemicals, New Delhi, India. Polyvinyl alcohol (Mw = 30,000–50,000; hydrolysis 98%), l-ascorbic acid, polyvinylpyrrolidone, bovine serum albumin, Bradford reagent, standard glutathione, Folin–Ciocalteu, 5,5-dithio-bis-2-nitro benzoic acid, and l-Phenylalanine were obtained from Sigma Aldrich, St. Louis, MO, USA. The amount of SOD (U/mL) was determined with a commercial Cayman Chemicals kit. ABTS or 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) and potassium persulfate were obtained from Sigma Aldrich, St. Louis, MO, USA. The DPPH (2,2-diphenyl-1-Picrylhydrazyl) used was from Cayman Chemicals. Tomato seeds (hybrid var. “Huno F1” saladette type and indeterminate growth) were purchased from Harris Moran Seed Company (Modesto, CA, USA).