title: A novel antiamoebic agent against Acanthamoeba sp.--A causative agent for eye keratitis infection.
abstract: The terbium trinitrate.trihydrate.18-crown ether-6, Tb(NO3)3(OH2)3.(18C6) complex has been characterized by elemental analysis, photoluminescence and single X-ray diffraction. The IC50 values were determined based on MTT assay while light and fluorescence microscopy imaging were employed to evaluate the cellular morphological changes. Alkaline comet assay was performed to analyze the DNA damage. The photoluminescence spectrum of the Tb complex excited at 325 nm displayed seven luminescence peaks corresponding to the (5)D4→(7)F(0, 1, 2, 3, 4, 5, 6) transitions. The cytotoxicity and genotoxicity studies indicated that the Tb(NO3)3(OH2)3.(18C6) complex and its salt form as well as the 18C6 molecule have excellent anti-amoebic activity with very low IC50 values are 7, 2.6 and 1.2 μg/mL, respectively, with significant decrease (p<0.05) in Acanthamoeba viability when the concentration was increased from 0 to 30 μg/mL. The mode of cell death in Acanthamoeba cells following treatment with the Tb complex was apoptosis. This is in contrast to the Tb(NO3)3.6H2O salt- and 18C6 molecule-treated Acanthamoeba, which exhibited necrotic type cells. The percentage of DNA damage following treatment with all the compounds at the IC25 values showed high percentage of type 1 with the % nuclei damage are 14.15±2.4; 46.00±4.2; 36.36±2.4; 45.16±0.6%, respectively for untreated, treated with Tb complex, Tb salt and 18C6 molecule. The work features promising potential of Tb(NO3)3(OH2)3.(18C6) complex as anti-amoebic agent, representing a therapeutic option for Acanthamoeba keratitis infection.
authors.affiliation: Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI, 16424, Depok, Indonesia. Electronic address: ekusrini@che.ui.ac.id.
authors.forename: Eny
authors.initials: E
authors.lastname: Kusrini
authors.affiliation: School of Fundamental Science, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia.
authors.forename: Fatimah
authors.initials: F
authors.lastname: Hashim
authors.affiliation: School of Fundamental Science, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia.
authors.forename: Wan Nor Nadhirah Wan Noor
authors.initials: WN
authors.lastname: Azmi
authors.affiliation: School of Fundamental Science, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia.
authors.forename: Nakisah Mat
authors.initials: NM
authors.lastname: Amin
authors.affiliation: Faculty of Medical, Universitas Indonesia, Kampus baru UI, Depok 16424, Indonesia.
authors.forename: Ari
authors.initials: A
authors.lastname: Estuningtyas
mesh_terms: D000048:Acanthamoeba / Q000187:drug effects*; D015823:Acanthamoeba Keratitis / Q000188:drug therapy* / Q000469:parasitology*; D000981:Antiprotozoal Agents / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use*; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D018360:Crystallography, X-Ray; D004249:DNA Damage; D020128:Inhibitory Concentration 50; D049449:Luminescence; D008856:Microscopy, Fluorescence; D008968:Molecular Conformation; D009153:Mutagens / Q000633:toxicity
chemical_list: D000981:Antiprotozoal Agents; D009153:Mutagens
keywords: Anti-amoebic activity; Cytotoxicity; Genotoxicity; Photoluminescence; Terbium