In Vitro Evaluation of Combined Commercialized Ophthalmic Solutions Against Acanthamoeba Strains

Acanthamoeba is a free-living amoebae genus which is present worldwide in natural and artificial environments. These amoebae are clinically important as causative agents of diseases in humans and other animals such as a fatal encephalitis or a sight threatening Acanthamoeba keratitis (AK). Lately; studies have focused on the search of novel therapeutic options for AK but also to prevent infections. Furthermore; the evaluation of commercialized products seems to be an option for this case since not clinical assays would be required. Thus; we aimed to test the amoebicidal activity of different mixtures of two commercial ophthalmic solutions: Systane(®) Ultra; which has already shown anti-Acanthamoeba properties; and Naviblef(®) Daily Care. In addition, we tested their cytotoxic effect against murine macrophages. At the individual level; Naviblef(®) Daily Care showed to be the most active product against Acanthamoeba spp. Nevertheless; the combinations of Systane(®) Ultra and Naviblef(®) Daily Care; showed an improvement in the activity against trophozoites and cysts of Acanthamoeba castellanii Neff. Moreover; the concentration necessary to generate cytotoxic effect against murine macrophages (J774.1) was much higher than the required for the amoebicidal and cysticidal effect achieved in the most effective mixtures.