Figure 4.

Effect of catechin on expression of HIF-1α protein in hypoxic HKC-8 cells. HKC-8 cells in plastic petri dishes were incubated in an atmosphere containing 1% O₂ (hypoxia) or 20% O₂ (normoxia) in the absence or presence of 100 µM catechin for 24 h. HIF-1α protein levels in cellular protein extracts were semi-quantitatively determined using Western blot analysis. (A) A typical blot of both HIF-1α and GAPDH protein of two separate experiments. (B) HIF-1α/GAPDH ratios in each group. * p = 0.0122 (Medium vs. Normoxia, two-tailed t-test), ** p = 0.01 (Medium vs. Catechin, two-tailed t-test).