Figure 4: Effect of MRB on melanogenesis in zebrafish embryos. Six-h post ferritization of embryonic zebrafish was treated with MRB at 10 and 30 mg/mL until 48-h post ferritization. (A) The phenotype-based melanin pigmentation was observed under a stereomicroscope (40×). Dorsal melanophores were visualized (inserted panel, 400×). (B) Melanin content and (C) tyrosinase activity were determined in the lysate samples. PTU at 0.1 mM was used as the positive control. *P < 0.05, **P < 0.01, and ***P < 0.001 indicate significant differences compared with the control. MRB, Modified Riceberry rice; PTU, phenylthiourea.