Reactive oxygen and nitrogen species are crucial for the antifungal activity of amorolfine and ciclopirox olamine against the dermatophyte Trichophyton interdigitale.

Onychomycosis is a nail infection caused by Trichophyton interdigitale and other fungi, which can be treated with topical amorolfine (AMR) and ciclopirox olamine (CPX). Although these drugs are widely used, little is known about the role of reactive oxygen (ROS) and nitrogen (RNS) in their mechanism of action. To better understand the effects of AMR and CPX in dermatophytes, we evaluated whether they act through the production of ROS and peroxynitrite (PRN). We tested a set of strains, all susceptible to AMR and CPX, and these antifungals significantly reduced T. interdigitale viability within 24 h. This effect occurred concomitantly with reduced ergosterol, increased production of ROS and PRN, and consequently increased lipid peroxidation. Together, these mechanisms lead to cell damage and fungal death. These fungicidal effects were abolished when PRN and superoxide scavengers were used in the assays, demonstrating the role of these species in the mechanism of action. We also studied the antioxidant system when T. interdigitale was exposed to AMR and CPX. Interestingly, superoxide dismutase and catalase inhibition lead to altered ROS and PRN production, lipid peroxidation, and ergosterol levels. In fact, the combination of AMR or CPX with a superoxide dismutase inhibitor was antagonistic. Together, these data demonstrate the importance of ROS and PRN in the antifungal action of AMR and CPX against the evaluated T. interdigitale strains. LAY SUMMARY: Onychomycosis is a nail infection, which can be treated with amorolfine and ciclopirox olamine. Here we demonstrate that these drugs exhibit antifungal activity also through the production of oxidative and nitrosative radicals.

Morphology of Peeled Internal Limiting Membrane in Macular Hole Surgery.

PURPOSE: The aim of this work was to describe the ultrastructure and behavior of peeled internal limiting membrane (ILM) in macular hole (MH) surgery. METHODS: Seven patients with MH were included, and vitrectomy with ILM peeling was performed in all patients. The ILM inverted flap technique was used. Two other flaps of ILM of the same patient were collected and studied using light and transmission electron microscopy (TEM). ILM cell type, distribution, and morphology were analyzed, and the proliferation or fusion potential of the ILM interface was evaluated. RESULTS: ILM vitreous sides in apposition showed signs of proliferative fibrotic activity, producing a basal membrane that merges ILM sides. CONCLUSIONS: Epiretinal cells in ILM show proliferative capacity, with formation of microfibrils between adjacent sides of the ILM, which may explain adherence of ILM flaps to the hole border, contributing to closure of the hole in MH surgery. This trail is registered with NCT03799575.