Figure 2.

Screening for optimum conditions for in vitro culture with tea polyphenol (TP). (A to I) Cell proliferation rate, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, reactive oxygen species (ROS), malondialdehyde (MDA) production, caspase-3 activity, protein carbonyl (PC), 8-hydroxy-2′-deoxyguanosine (8-OHdG), and 8-isoprostaglandin (8-iso-PG) content in control and TP-supplemented bovine mammary epithelial cells (BMEC; 0 to 100 µg/mL) challenged with hydrogen peroxide (H₂O₂; 600 µM). The BMEC were pretreated with TP (0 to 100 µg/mL) for 12 h followed by H₂O₂ (600 µM) challenge for 6 h. The BMEC proliferation rate was measured by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS). Enzyme activities and concentrations of metabolites were measured using commercial kits according to manufacturer’s protocols. Means with different superscript letters differ (P < 0.05). There were 5 replications for each experiment and each well.