Advances in Biology & Earth Sciences

Objective: Acanthamoeba species can cause Acanthamoeba keratitis (AK) and Granulomatous Acanthamoeba encephalitis (GAE). Acanthamoeba keratitis is a corneal infection that causes severe inflammation, intense pain and visual impairment and can lead to loss of the eye if left untreated. Granulomatous Acanthamoeba encephalitis (GAE) is a highly opportunistic infection seen in immunocompromised individuals, in which amoebae invade neural tissue, causing necrosis and severe encephalitis. Method: Neocuproin (2.9-Dimethyl-1,10-phenanthroline), with a molecular weight of 208.26 g/mol and a melting point of 159-160 ⁰C, is a phenanthroline derivative. Neocuproin is a widely used copper chelator. It increases cellular uptake of copper and exhibits cytotoxicity. In the presence of Neocuproin, Cu (II) exhibits increased cytotoxicity and Cu-Neocuproin complexes have been shown to bind to isolated DNA. Furthermore, the addition of Neocuproin can increase the lipophilicity of the complexes and thus improve cellular uptake. Studies have also determined that 100μm Neokuproin reduces oxidative activity and increases antioxidant capacity. It has been concluded that Neokuproin has an anti-cancer effect on the SH-SY5Y cell line. In this context, the study aimed to demonstrate the antiprotozoal effect of neokuproin on Acanthamoeba castellani trophozoites as an alternative treatment agent, considering its low toxicity and presumed greater efficacy. Materials and Methods: Acanthamoeba castellani (T5 genotype) trophozoites, whose antiparasitic effect was to be evaluated, were multiplied in liquid medium and the study was initiated in the logarithmic phase. The final concentration of parasite density was determined to be 28x10⁷ trophozoites/ml. Neocoproin was diluted in 5% DMSO at doses of 62.5, 125, 250, 500, 1000 and 2000 µM. The viability of the parasite was monitored at specific times and recorded. Findings: The viability of the parasite was examined using 0.1% Trypan blue on a Thoma slide. Parasites that took up the dye and showed no movement were considered dead. In addition, the number of live cells was counted using an automatic cell counting device and recorded. The control plate was also checked at similar intervals during the study and it was observed that the parasite remained viable at a similar density. The mortality rate of the parasite increased with increasing concentration and over time. Conclusion: This study aimed to investigate the in vitro antiprotozoal activity of neocuproine (2,9-dimethyl-1,10-phenanthroline), a copper(I) chelator, against Acanthamoeba castellanii (T5 genotype) trophozoites and to assess its general cytotoxic profile using the human bronchial epithelial (BEAS) cell line as a preliminary non-neuronal safety model.