Morphological changes of zebrafish embryos after G-Rh2 treatment. Zebrafish embryos at 24 hpf were treated with 0.1% DMSO and various concentrations of G-Rh2 (30, 42.43, 60, 84.85, 120 μmol) for 48 h. The arrow denotes pericardial edema after treatment with high concentration of G-Rh2 at 120 μmol. hpt: hours post-treatment.