TY - JOUR
T1 - Oleic acid–conjugated silver nanoparticles as efficient antiamoebic agent against Acanthamoeba castellanii
AU - Anwar, Ayaz
AU - Abdalla, Sumayah Abdelnasir Osman
AU - Aslam, Zara
AU - Shah, Muhammad Raza
AU - Siddiqui, Ruqaiyyah
AU - Khan, Naveed Ahmed
PY - 2019/7/1
Y1 - 2019/7/1
N2 - Acanthamoeba castellanii belonging to the T4 genotype is an opportunistic pathogen which is associated with blinding eye keratitis and rare but fatal central nervous system infection. A. castellanii pose serious challenges in antimicrobial chemotherapy due to its ability to convert into resistant, hardy shell-protected cyst form that leads to infection recurrence. The fatty acid composition of A. castellanii trophozoites is known to be most abundant in oleic acid which chemically is an unsaturated cis-9-Octadecanoic acid and naturally found in animal and vegetable fats and oils. This study was designed to evaluate antiacanthamoebic effects of oleic acid against trophozoites, cysts as well as parasite-mediated host cell cytotoxicity. Moreover, oleic acid–conjugated silver nanoparticles (AgNPs) were also synthesized and tested against A. castellanii. Oleic acid–AgNPs were synthesized by chemical reduction method and characterized by ultraviolet-visible spectrophotometry, atomic force microscopy, dynamic light scattering analysis, and Fourier transform infrared spectroscopy. Viability, growth inhibition, encystation, and excystation assays were performed with 10 and 5 μM concentration of oleic acid alone and oleic acid–conjugated AgNPs. Bioassays revealed that oleic acid alone and oleic acid–conjugated AgNPs exhibited significant antiamoebic properties, whereas nanoparticle conjugation further enhanced the efficacy of oleic acid. Phenotype differentiation assays also showed significant inhibition of encystation and excystation at 5 μM. Furthermore, oleic acid and oleic acid–conjugated AgNPs also inhibited amoebae-mediated host cell cytotoxicity as determined by lactate dehydrogenase release. These findings for the first time suggest that oleic acid–conjugated AgNPs exhibit antiacanthamoebic activity that hold potential for therapeutic applications against A. castellanii.
AB - Acanthamoeba castellanii belonging to the T4 genotype is an opportunistic pathogen which is associated with blinding eye keratitis and rare but fatal central nervous system infection. A. castellanii pose serious challenges in antimicrobial chemotherapy due to its ability to convert into resistant, hardy shell-protected cyst form that leads to infection recurrence. The fatty acid composition of A. castellanii trophozoites is known to be most abundant in oleic acid which chemically is an unsaturated cis-9-Octadecanoic acid and naturally found in animal and vegetable fats and oils. This study was designed to evaluate antiacanthamoebic effects of oleic acid against trophozoites, cysts as well as parasite-mediated host cell cytotoxicity. Moreover, oleic acid–conjugated silver nanoparticles (AgNPs) were also synthesized and tested against A. castellanii. Oleic acid–AgNPs were synthesized by chemical reduction method and characterized by ultraviolet-visible spectrophotometry, atomic force microscopy, dynamic light scattering analysis, and Fourier transform infrared spectroscopy. Viability, growth inhibition, encystation, and excystation assays were performed with 10 and 5 μM concentration of oleic acid alone and oleic acid–conjugated AgNPs. Bioassays revealed that oleic acid alone and oleic acid–conjugated AgNPs exhibited significant antiamoebic properties, whereas nanoparticle conjugation further enhanced the efficacy of oleic acid. Phenotype differentiation assays also showed significant inhibition of encystation and excystation at 5 μM. Furthermore, oleic acid and oleic acid–conjugated AgNPs also inhibited amoebae-mediated host cell cytotoxicity as determined by lactate dehydrogenase release. These findings for the first time suggest that oleic acid–conjugated AgNPs exhibit antiacanthamoebic activity that hold potential for therapeutic applications against A. castellanii.
KW - Acanthamoeba
KW - Silver nanoparticles
KW - Oleic acid
KW - Cyst
KW - Cytotoxicity
U2 - 10.1007/s00436-019-06329-3
DO - 10.1007/s00436-019-06329-3
M3 - Article
C2 - 31093751
SN - 0932-0113
VL - 118
SP - 2295
EP - 2304
JO - Parasitology Research
JF - Parasitology Research
ER -