Morphological and Chemical Changes in the Trophozoites and Cysts of Acanthamoeba Castellanii Induced by Camellia Sinensis Extracts

TY - JOUR

T1 - Morphological and Chemical Changes in the Trophozoites and Cysts of Acanthamoeba Castellanii Induced by Camellia Sinensis Extracts

AU - Fakae, Lenu B.

AU - Zhong, Jizhou

AU - Chan, Ka Lung Andrew

AU - Mekapothula, Subbareddy

AU - Cave, Gareth W.V.

AU - Zhu, Xing Quan

AU - Stevenson, Carl W.

AU - Elsheikha, Hany M.

N1 - Publisher Copyright: © The Author(s) 2025.

PY - 2025/4

Y1 - 2025/4

N2 - Purpose: Acanthamoeba castellanii is an important opportunistic human protozoal pathogen that can cause both skin, ocular and brain infections. Recent studies have established that brews and solvent extract (SE) of green tea (Camellia sinensis) can inhibit the growth and encystation of A. castellanii. Here we characterized those growth and encystation inhibitions. Methods: Herein, we characterize of the morphological and chemical changes that occur in the trophozoites and the encysting stage of A. castellanii after exposure to C. sinensis SE and brew using Transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) microspectroscopy and fluorescence-based assays. Results: TEM showed ultrastructural changes in both A. castellanii stages. FTIR microspectroscopy revealed modifications of amide I and II band peaks in the C. sinensis-treated trophozoites, suggesting an inhibition of protein synthesis. Assessment of the nucleus integrity of trophozoites exposed to SE and brew revealed disruption of the nuclear membrane integrity, nuclear fragmentation, and chromatin degradation, and reduction in the quantity of DNA and RNA, indicating trophozoite death. These results are consistent with C. sinensis acting as a membrane-active anti-acanthamoebic, exhibiting amoebicidal activity against growing and encysting A. castellanii. This work underlines the importance of characterizing the effect of C. sinensis constituents, individually or in combinations, to clarify which ones are the primary components responsible for its action and the observed alterations in the structure and function of A. castellanii. Conclusion: These results demonstrated that exposure to C. sinensis SE or brew alters the synthesis of protein, DNA, RNA and disrupts the cell wall integrity.

AB - Purpose: Acanthamoeba castellanii is an important opportunistic human protozoal pathogen that can cause both skin, ocular and brain infections. Recent studies have established that brews and solvent extract (SE) of green tea (Camellia sinensis) can inhibit the growth and encystation of A. castellanii. Here we characterized those growth and encystation inhibitions. Methods: Herein, we characterize of the morphological and chemical changes that occur in the trophozoites and the encysting stage of A. castellanii after exposure to C. sinensis SE and brew using Transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) microspectroscopy and fluorescence-based assays. Results: TEM showed ultrastructural changes in both A. castellanii stages. FTIR microspectroscopy revealed modifications of amide I and II band peaks in the C. sinensis-treated trophozoites, suggesting an inhibition of protein synthesis. Assessment of the nucleus integrity of trophozoites exposed to SE and brew revealed disruption of the nuclear membrane integrity, nuclear fragmentation, and chromatin degradation, and reduction in the quantity of DNA and RNA, indicating trophozoite death. These results are consistent with C. sinensis acting as a membrane-active anti-acanthamoebic, exhibiting amoebicidal activity against growing and encysting A. castellanii. This work underlines the importance of characterizing the effect of C. sinensis constituents, individually or in combinations, to clarify which ones are the primary components responsible for its action and the observed alterations in the structure and function of A. castellanii. Conclusion: These results demonstrated that exposure to C. sinensis SE or brew alters the synthesis of protein, DNA, RNA and disrupts the cell wall integrity.

KW - Acanthamoeba castellanii

KW - Camellia sinensis

KW - FTIR microspectroscopy

KW - Nuclear integrity

KW - Nucleic acid

UR - https://www.scopus.com/pages/publications/86000041702

U2 - 10.1007/s11686-024-00941-9

DO - 10.1007/s11686-024-00941-9

M3 - Article

C2 - 40032667

AN - SCOPUS:86000041702

SN - 1230-2821

VL - 70

JO - ACTA PARASITOLOGICA

JF - ACTA PARASITOLOGICA

IS - 2

M1 - 63

ER -