Figure 2. Zingerone inhibits the formation of microvessels inside tumors.

(A) The hemoglobin concentration of the isolated tumor was measured using Drabkin's reagent and was normalized to the tumor weight. (B) Microvessels were detected in tumor sections by immunostaining with an antibody for CD31 (1:200), a specific marker for endothelial cells. a and c, 100× magnification; b and d, 200× magnification.(C) The amount of CD31 was quantified using Image J software, and the data are presented as the means ± S.D. of three independent experiments. **p < 0.01 compared to the control.