Fig. 4
Treatment with BMDA indirectly decreases melanin synthesis. (A) B16 melanoma cells were treated with IBMX at 100 µg/mL for 24–48 h, and the cell viability was measured using an MTT assay. (B) The cells were treated with BMDA (1, 2, 4, or 10 µg/mL) in the presence of IBMX (100 µg/mL) for 24–48 h, and the cell viability was examined using an MTT assay. (*p < 0.05; against “Untreated” group for 24 h, #p < 0.05, against “Untreated” group for 48 h) (C) The cells treated with BMDA under IBMX for 24 h were harvested and lysed with 1 N NaOH at 80 °C for 1 h. The melanin contents were measured at 405 nm using a multi-plate reader. (**p < 0.01, ***p < 0.001, against “Control” group treated with only IBMX) (D) The cells treated with BMDA under IBMX for 24 h were harvested and lysed. After centrifugation, the supernatants were incubated with L-DOPA substrate solution (10 mM) at 37 °C for 60 min to calculate tyrosinase activity, and the absorbance was measured at 490 nm.
