Anti-amoebic properties of a Malaysian marine sponge Aaptos sp. on Acanthamoeba castellanii

Abstract

Crude methanol extracts of a marine sponge, Aaptos aaptos, collected from three different localities namely Kapas, Perhentian and Redang Islands, Terengganu, Malaysia, were tested in vitro on a pathogenic Acanthamoeba castellanii (IMR isolate) to examine their anti-amoebic potential. The examination of anti-Acanthamoebic activity of the extracts was conducted in 24 well plates for 72 h at 30 °C. All extracts possessed anti-amoebic activity with their IC(50) values ranging from 0.615 to 0.876 mg/mL. The effect of the methanol extracts on the surface morphology of A. castellanii was analysed under scanning electron microscopy. The ability of the extracts to disrupt the amoeba cell membrane was indicated by extensive cell's blebbing, changes in the surface morphology, reduced in cell size and with cystic appearance of extract-treated Acanthamoeba. Number of acanthapodia and food cup was also reduced in this Acanthamoeba. Morphological criteria of apoptosis in Acanthamoeba following treatment with the sponge's extracts was determined by acridine orange-propidium iodide staining and observed by fluorescence microscopy. By this technique, apoptotic and necrotic cells can be visualized and quantified. The genotoxic potential of the methanol extracts was performed by the alkaline comet assay. All methanol extracts used were significantly induced DNA damage compared to untreated Acanthamoeba by having high percentage of scores 1, 2, and 3 of the DNA damage. Results from cytotoxicity and genotoxicity studies carried out in the present study suggest that all methanol extracts of A. aaptos have anti-amoebic properties against A. castellanii.

Statins and Voriconazole Induce Programmed Cell Death in Acanthamoeba castellanii

“…This cell stage is called pseudocyst, with a wall that does not protect against other adverse conditions (66). Both phenomena described here could be the same if we consider that the description of apoptosis in the first case was performed only by morphology (65).…”

“…Recently, evidence of apoptosis has been described by morphological studies of Acanthamoeba species (clinical isolate, T4) when they were treated with methanol extracts of marine sponges (Aaptos species). The authors distinguish between early apoptotic cells, late apoptotic cells, and necrotic cells by observing chromatin condensation (65). Furthermore, because this process is produced by methanolic extracts, it is necessary to note that in Acanthamoeba, a stress response different from encystment has been described.…”

Toxic effects of selected proprietary dry eye drops on Acanthamoeba

“…The early stage was inferred from phosphatidylserine externalization and chromatin condensation. Since this initial report we 20 , 21 and others 22 , 23 have reported a number of PCD inducing agents in Acanthamoeba . In these reports, authors have been able to distinguish between early PCD cells, late PCD cells.…”

Apoptosis of Acanthamoeba castellanii Trophozoites Induced by Oleic Acid

“…; Nakisah et al. ), but neither analyzed the genetic basis of apoptosis. Because the role of FFAs in inhibiting the growth of Acanthamoeba spp.…”

“…Acanthamoeba has a strong tendency to adapt to an environment and to develop resistance to chemotherapeutic drugs, making it difficult to study apoptosis. Two studies have shown that apoptotic trophozoite death occurs in Acanthamoeba (Feng et al 2009;Nakisah et al 2012), but neither analyzed the genetic basis of apoptosis. Because the role of FFAs in inhibiting the growth of Acanthamoeba spp.…”