Generation of reactive oxygen species in vitro by Malassezia yeasts

Free oxygen species are able to destroy cells due to their cytotoxic effect, which is based on lipid peroxidation, enzyme oxidation and protein oxidation. We analyzed the ability of six different Malassezia (M.) species to generate reactive oxygen species (ROS), using the lucigenin-amplified chemiluminescence. Further investigations showed the effect of different concentrations of terbinafine on ROS generation by M. furfur and M. pachydermatis after 10, 30 and 60 minutes. All of the investigated Malassezia species (M. furfur, M. globosa, M. sympodialis, M. slooffiae, M. obtusa, M. pachydermatis) was able to generate reactive oxygen species. Terbinafine inhibited free radical production by M. furfur and M. pachydermatis. Dependent on their cell concentrations, M. species have the ability to generate ROS. The ability of the different Malassezia species to produce ROS should be considered as one further virulence factor of this yeast. The antifungal agent terbinafine (concentrations from 100 A mu g to 1 A mu g ml -1) reduced ROS production by M. furfur and M. pachydermatis. Terbinafine acts as oxygen species scavenger. This could be an additional mechanism supporting the classic antifungal effect of this agent, the inhibition of ergosterol synthesis.