*2.6. Melanin Quantification*

In a 6-well plate, murine melanoma B16F10 cells were seeded at a density of 2.5 × 10<sup>5</sup> cells/well. They were pre-treated with 100, 200, and 400 μM of Ectoine for 2 h in the absence or presence of α-MSH (1 μM). The protocol used for the quantification of melanin followed a previously described method [21]. We measured melanin content with the ELISA microplate reader with an absorbance wavelength of 470 nm.
