Proton pump inhibitors versus Cryptococcus species: effects on in vitro susceptibility and melanin production

This study aimed to evaluate the effects of proton pump inhibitors (PPIs) on growth and melanin production by spp. Minimum inhibitory concentrations (MICs) of omeprazole, esomeprazole, rabeprazole, pantoprazole and lansoprazole against spp. were determined and the effect of PPIs on melanin production was evaluated, in the presence or absence of copper sulfate or glutathione. PPIs showed MICs ranging from 125-1000 μg/ml and decreased melanization by cells. Addition of copper sulfate or gluthatione restored melanogenesis of cells grown in the presence of PPIs. The presence of PPIs and glyphosate decreased copper sulfate toxicity (1 mM). PPIs inhibited melanogenesis of spp., possibly by chelating copper or inhibiting copper ATPase transport.