Figure 9. PA inhibits angiogenesis in in vivo murine Matrigel plug assay and in vivo zebrafish angiogenesis models.

(A) PA inhibited angiogenesis induced by VEGF in the murine Matrigel plug model. Female BALB/c mice were injected subcutaneously with 500 µl of Matrigel containing VEGF (150 ng/ml) with or without PA (5 µM). VEGF plus SU5416 (5 µM) was used as positive control. The mice were sacrificed after seven days and the Matrigel plugs were removed and photographed. The degree of angiogenesis was determined indirectly by measuring the content of hemoglobin of the plugs using Drabkin’s assay. Data are expressed as means ± SEM. Statistical significance is expressed as P<0.05 versus VEGF induced control (n = 12–14) (B) PA exhibited anti-angiogenenic potential on the zebrafish angiogenesis model. Zebrafish embryos at 24 hpf were dechorionated and treated with PA (15 µM) or 0.1% DMSO for 24 h at 28.5°C. Thereafter, the treatment was removed and the embryos were maintained in normal embryo medium for another 24 h and fixed in 4% paraformaldehyde prior to in situ staining for endogenous alkaline phosphatase activity to visualize the blood vessels. Arrows denote inhibited ISVs. Embryos are of lateral view, with anterior to the left.