Anti-angiogenic effect of G-Rh2 on Tg (Fli1-EGFP) zebrafish embryos. 24 hpf embryos were treated for 12 h with (A) 0.1% DMSO (vehicle control); (B) 5 μM SU5416 (positive control); (C) 30 μM G-Rh2; (D) 42.43 μM G-Rh2; (E) 60 μM G-Rh2; or (F) 84.85 μM G-Rh2. Magnified views of A–F are shown in A′–F′. Morphological observation of zebrafish embryos is shown in G–L. The dorsal longitudinal anastomotic vessel (DLAV), dorsal aorta (DA) and intersegmental vessels (ISVs) of zebrafish embryos are indicated by the yellow arrows. Defects in ISV formation are indicated by the white asterisk.