Figure 4.

Effect of external 0.5 μM zinc pyrithione on accumulation of intracellular free zinc (A) and proliferation/viability (B,C) of explant human melanoma cultures with lower free zinc stores (M5), average free zinc stores (M10) and higher free zinc stores (M9) during 24 h (free zinc content) to 72 h (proliferation/viability). Cells were exposed to zinc pyrithione and intracellular free zinc levels were monitored during 24 h using fluorimetry of the zinc-specific dye Newport Green diacetate. Proliferation/viability of cells exposed to zinc pyrithione was estimated with colorimetric WST-1 assay (determines the rate of metabolic conversion of tetrazolium salt WST-1 by mitochondrial succinate dehydrogenase in viable cells) and via measuring the proportion of S-phase cells using EdU-specific fluorescence. Data represent the mean ± S.D. of three independent experiments. # p < 0.05 Significantly lower than the beginning of treatment with the same concentration with a one-way ANOVA test and Dunnett’s post-test for multiple comparisons.