Fig. 4. Cell viabilities of Hy-HUVEC treated with NC8-alr (a) or NC8-pSIP409-alr-ACEIP (b) for 1 or 2 h determined by MTT assay. NC8-pSIP409-alr-ACEIP promotes proliferation of Hy-HUVEC cells. Cells were plated in the 96-well plates at 7000 cells/well. Next, the cells were treated with bacterium/Hy-HUVEC ratios of 20:1, 40:1, 80:1, 160:1, and 320:1 for 1 and 2 h, while the control group was treated with RPMI-1640. Data are presented as mean±standard deviation (SD) with three independent experiments. ^* P<0.05, ^** P<0.01, ^*** P<0.001, compared with the positive H₂O₂ control group. ACEIP: angiotensin-converting enzyme inhibitory peptide; Hy-HUVEC: H₂O₂-induced human umbilical vein endothelial cell.