Figure 5.

Effect of tea polyphenol (TP) treatment of bovine mammary epithelial cells (BMEC) on mRNA abundance of mitogen-activated protein kinase 3/1 (MAPK3/1), MAPK8/9/10, MAPK11/12/13/14, and MAPK7 with or without hydrogen peroxide (H₂O₂). (A to D) MAPK3/1, MAPK8/9/10, MAPK11/12/13/14, and MAPK7 mRNA abundance under control and oxidative stress (OS) conditions in BMEC. The BMEC were preincubated with a MAPK-specific inhibitor, 2,4-dinitrochloro-benzene (DNCB), for 30 min and then treated with TP (100 µg/mL) for another 12 h followed by H₂O₂ (600 µM) exposure for 6 h. The mRNA abundance of MAPK3/1, MAPK8/9/10, MAPK11/12/13/14, and MAPK7 was analyzed by quantitative real-time PCR. Means with different superscript letters differ (P < 0.05). There were 5 replications for each experiment and each well.