MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) cell viability assays on HaCaT and B16-F0 cells. (a) Relative cytotoxicity of pigments on HaCaT cells. Values are expressed as mean ± SD of metabolically active cells compared to control (no pigments, 100% of metabolically active cells). (b) Relative cytotoxicity of pigments on B16-F0 cells. Values are expressed as mean ± SD of metabolically active cells compared to control (no pigments, 100% of metabolically active cells). (c) Protective effect of pigments on B16-F0 cells from UV radiation. Values are expressed as mean ± SD of metabolically active cells compared to control (no pigments with UV exposure, 71% of metabolically active cells). Asterisks indicate the statistically significant difference compared to the respective control (**** p ≤ 0.0001, *** p ≤ 0.001, ** p ≤ 0.01, * p ≤ 0.05; Dunnett’s test). Ctr: control.