In Vitro Growth- and Encystation-Inhibitory Efficacies of Matcha Green Tea and Epigallocatechin Gallate Against Acanthameoba Castellanii.

Ameliya Dickson,Elise Cooper,Ka Lung Andrew Chan,Lenu B Fakae,Hany M Elsheikha,Bo Wang

doi:10.3390/pathogens9090763

Ameliya Dickson, Elise Cooper + Show 4 more

Open Access

https://doi.org/10.3390/pathogens9090763

Copy DOI

Abstract

We examined the inhibitory effect of matcha green tea (Camellia sinensis) and epigallocatechin gallate (EGCg; the most abundant catechin in tea) on the vegetative growth and encystation of Acanthamoeba castellanii T4 genotype. The sulforhodamine B (SRB) stain-based colorimetric assay and hemocytometer counting were used to determine the reduction in A. castellanii trophozoite proliferation and encystation, in response to treatment with C. sinensis or EGCg. Fourier transform infrared (FTIR) microscopy was used to analyze chemical changes in the trophozoites and cysts due to C. sinensis treatment. Hot brewed and cold brewed matcha inhibited the growth of trophozoites by >40% at a 100 % concentration. EGCg at concentrations of 50 to 500 µM significantly inhibited the trophozoite growth compared to control. Hot brewed matcha (100% concentration) also showed an 87% reduction in the rate of encystation compared to untreated control. Although 500 µM of EGCg increased the rate of encystation by 36.3%, 1000 µM reduced it by 27.7%. Both percentages were not significant compared to control. C. sinensis induced more cytotoxicity to Madin Darby canine kidney cells compared to EGCg. FTIR chemical fingerprinting analysis showed that treatment with brewed matcha significantly increased the levels of glycogen and carbohydrate in trophozoites and cysts.

Highlights

Due to the relative rarity of clinical Acanthamoeba castellanii infections, there are currently limited treatment options available
We investigated the anti-amoebic properties of epigallocatechin gallate (EGCg) using the sulforhodamine B (SRB) assay
The rate of Madin Darby canine kidney (MDCK) cell survival following treatment with EGCg at 500 μM was significantly lower than that treated with other concentrations and the untreated control cells at 24, 48 and 72 h (Figure 3B). These results suggest that EGCg has a clear cytotoxic effect at 500 μM concentration starting at 24 h post treatment, no significant cytotoxicity was observed at lower EGCg concentrations

Summary

Introduction

Due to the relative rarity of clinical Acanthamoeba castellanii infections, there are currently limited treatment options available. Corneal keratocytes [2] by a biguanide antiseptic agent. These drugs require prolonged treatment, on average lasting up to six months [3]. Treatment is further complicated by the presence of amoebic cysts, which prove to be very resistant to many of the currently available drugs. This lack of optimal treatment has inspired researchers to investigate the use of naturally occurring compounds as an alternative to current medicines, or as a reciprocal treatment to help alleviate or prevent A. castellanii infections. Among a plethora of natural compounds tested, a few examples include, Ipomoea spp., Kaempferia galanga, Cananga odorata, oakmoss (a natural fragrance ingredient), hexane fraction of Pathogens 2020, 9, 763; doi:10.3390/pathogens9090763 www.mdpi.com/journal/pathogens

Methods

Results

Discussion

Conclusion