Ascorbic acid

Acetaminophen (N-acetyl-p-aminophenol, APAP), 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT), 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA), 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitroblue tetrazolium (NBT), phenazine methosulfate (PMS), β-nicotinamide adenine dinucleotide, reduced disodium salt, trihydrate (β-NADH), hematoxylin, and eosin were purchased from Sigma-Aldrich (St. Louis, MO, USA); Trizol, PrimeScript™ RT Master Mix, and SYBR Green Master Mix were purchased from Takara Biotechnology (Dalian, China); Oligonucleotides were synthesized by Sangon Biotech (Shanghai, China); Gallic acid and ascorbic acid were purchased from Sangon Biotech (Shanghai, China); assay kits of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), catalase (CAT), superoxide dismutase (SOD), malonaldehyde (MDA), reduced glutathione (GSH), and glutathione peroxidase (GSH-Px) were purchased from Nanjing Jiancheng Institute of Biotechnology (Nanjing, China); Nuclear and Cytoplasmic Protein Extraction Kit was purchased from the Beyotime Institute of Biotechnology (Shanghai, China); Dulbecco's minimum essential medium (DMED), fetal bovine serum (FBS), and penicillin/streptomycin were purchased from Invitrogen (Carlsbad, CA, USA). All other chemicals were of the highest grade available.

The GST-IDO1 gene was cloned by Shanghai Generay Biotech Co. Ltd (Shanghai, China). The BL21(DE3) cells were obtained from TransGen Biotech Co. Ltd (Shanghai, China). Ampicillin, isopropyl β-D-thiogalactoside (IPTG), 5-Aminolevulinic acid (5-ALA), phenylmethanesulfonyl fluoride (PMSF), DNase I (from bovine pancreas), reduced glutathione, L-tryptophan, ascorbic acid, methylene blue, catalase, and sodium dithionite were obtained from Sangon Biotech (Shanghai, China) Co. Ltd. DMSO was purchased from Sigma-Aldrich. The CCK8 kit was purchased from Beyotime Biotechnology Co. Ltd.(Shanghai, China). Glutathione agarose beads were purchased from Changzhou Smart-Lifesciences Biotechnology Co. Ltd. (Changzhou, China) PD-10 desalting column was purchased from GE Healthcare Biosciences. HRV 3C Protease was purchased from Sino Biological Inc. (Shanghai, China). Cancer cell lines were purchased from the Cell Bank of Chinese Academy of Sciences. The experimental compounds were provided by Professor Zhao (Shanghai Institute of Organic Sciences, Chinese Academy of Sciences). All chemicals of analytical and reagent grade were obtained from commercial sources and used without further purification.