2.11. Assessment of Gene Expression Related to Inflammation and Oxidative Stress by Quantitative RT-PCR

Total RNA was extracted from HepG2 cells using TriZol reagent (Invitrogen, Carlsbad, CA, USA) and cDNA was synthesized using the SuperScript II kit (Invitrogen). Using this cDNA as a template, the gene of interest was amplified by quantitative RT-PCR using Power SYBR Green PCR master mix and thermocycler (Applied Biosystems, Foster City, CA, USA). The nucleotide sequence of the primers for human genes used in the PCR assay was as follows: tumor necrosis factor-α (forward, 5′-CCC AGG CAG TCA GAT CAT CTT C-3′; reverse, 5′-AGC TGC CCC TCA GCT TGA-3′), interleukin-6 (forward, 5′-GGT ACA TCC TCG ACG GCA TCT-3′; reverse, 5′-GTG CCT CTT TGC TGC TTT CAC-3′), interleukin-1β (forward, 5′-TGG CAA TGA GGA TGA CTT GTT C-3′; reverse, 5′-CTG TAG TGG TGG TCG GAG ATT-3′), glutathione peroxidase 1 (forward, 5′-GGT TTT CAT CTA TGA GGG TGT TTC C-3′; reverse, 5′-GCC TTG GTC TGG CAG AGA CT-3′), and β-actin (forward, 5′-TGA CGG GGT CAC CCA CAC TGT GCC CAT CTA-3′; reverse, 5′-CTA GAA GCA TTT GCG GTG GAC GAT GGA GGG-3′).