Research Article
Zeaxanthin Inhibits Hypoxia-Induced VEGF Secretion by RPE Cells through Decreased Protein Levels of Hypoxia-Inducible Factors-1α
Figure 4
Effects of zeaxanthin on secretion of VEGF by RPE cells under hypoxia. RPE cells were seeded into 24-well plates at a density of cells per well. After 24 h, zeaxanthin was added at 50, 100, and 150μM concentrations. One hour later, cells were incubated under 1% O2 (a) or cultured with CoCl2 at 150μM (b). Cells cultured under normoxia and without zeaxanthin were served as negative control. Cells cultured under hypoxia and without zeaxanthin were served as positive control. Conditioned medium was collected 24 hours later; VEGF levels were measured by VEGF ELISA kits and expressed as percentages of the negative control (, ). Zeaxanthin significantly inhibited hypoxia-induced secretion of VEGF. , compared with the negative controls. +, compared with the positive controls.
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