Lê HG, Kang JM, Võ TC, Yoo WG, Hong Y, Na BK. (‒)-Epicatechin reveals amoebicidal activity against Acanthamoeba castellanii by activating the programmed cell death pathway.
PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2024;
125:155389. [PMID:
38306720 DOI:
10.1016/j.phymed.2024.155389]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 12/28/2023] [Accepted: 01/24/2024] [Indexed: 02/04/2024]
Abstract
BACKGROUND
Acanthamoeba is an opportunistic pathogen that can cause human infections such as granulomatous amebic encephalitis and acanthamoeba keratitis. However, no specific drug to treat the diseases has been developed. Therefore, the discovery or development of novel drugs for treating Acanthamoeba infections is urgently needed. The anti-protozoan activity of (‒)-epicatechin (EC) has been reported, suggesting it is an attractive anti-protozoal drug candidate. In this study, the amoebicidal activity of EC against A. castellanii was assessed and its mechanism of action was unveiled.
METHODS
The amoebicidal activity of EC against A. castellanii trophozoites and the cytotoxicity of EC in HCE-2 and C6 cells were determined with cell viability assay. The underlying amoebicidal mechanism of EC against A. castellanii was analyzed by the apoptosis/necrosis assay, TUNEL assay, mitochondrial dysfunction assay, caspase-3 assay, and quantitative reverse transcription polymerase chain reaction. The cysticidal activity of EC was also investigated.
RESULTS
EC revealed amoebicidal activity against A. castellanii trophozoites with an IC50 of 37.01 ± 3.96 µM, but was not cytotoxic to HCE-2 or C6 cells. EC induced apoptotic events such as increases in DNA fragmentation and intracellular reactive oxygen species production in A. castellanii. EC also caused mitochondrial dysfunction in the amoebae, as evidenced by the loss of mitochondrial membrane potential and reductions in ATP production. Caspase-3 activity, autophagosome formation, and the expression levels of autophagy-related genes were also increased in EC-treated amoebae. EC led to the partial death of cysts and the inhibition of excystation.
CONCLUSION
EC revealed promising amoebicidal activity against A. castellanii trophozoites via programmed cell death events. EC could be a candidate drug or supplemental compound for treating Acanthamoeba infections.
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