Effects of rice bran ash mineral extract (RBM) on pigmentation in zebrafish. (A) Synchronized zebrafish embryos (n = 20) were exposed to RBM, and pigmentation was observed under a stereomicroscope via inferior views of the embryos at 5 dpf; (B) Zebrafish melanin content was detected by melanin content assay at 5 dpf (n = 80); (C) Tyrosinase activity in zebrafish (n = 80) was detected by tyrosinase assay at 5 dpf; (D) Pigmentation density in the indicated white-outlined area was measured in treated embryos and normalized to that of control embryos using the software ImageJ. * p < 0.05, ** p < 0.01, compared to control. Scale bar; 500 µm.

Effects of rice bran ash mineral extract (RBM) on zebrafish at 5dpf. Representative images of Fontana-Masson-stained zebrafish (dark color indicates secreted melanin). (A) Control; (B) RBM; (C) The pigmented area density in (A,B) was normalized to that of the control using ImageJ software. ** p < 0.05, compared to control. Original magnification: ×40 and ×100; scale bar, 100 µm.