Figure 2.
The regulation of angiogenesis by apigenin in WT and TKO mice after short-term UVB exposure. Mice (n=5) were subjected to sham (C) or UVB (R) radiation (1300 J/m2 daily, 5 consecutive days). Topical apigenin (AR) (5 μmol in 0.2 ml DMSO/acetone vehicle mix) was applied daily 1 hour prior to UVB exposure. (A) IHC for the endothelial cell marker CD31. Mice were sacrificed 24 hours after final UVB exposure, and dorsal skins were harvested, formalin-fixed, and stained for CD31 to visualize microvessels. Arrows indicate representative microvessels. (B) Quantitative analysis of the vessel area. Vessel area in digital images of CD31-stained slides was quantitated. At least 20 fields were quantitated for each condition, and mean values and SEMs were calculated. Statistical significance was determined in pairwise comparisons using two-sided Student's t test. (C) The effects of apigenin and TSP1 on systemic VEGF induction by UVB irradiation. VEGF level in mouse plasma was determined using specific ELISA kit and recombinant mouse ELISA as a standard. Statistical significance was determined in pairwise comparisons using two-sided Student's t test (*P<.05; **P<.01; ***P<.001; n.s., not significant).