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

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.

Camellia sinensis solvent extract confers trophocidal and cysticidal effects against Acanthamoeba castellanii

“…The combination of EGCG with C. sinensis matcha tea displayed anti-acanthamoebic activity against trophozoites and cysts (Dickson et al, 2020). EGCG has shown antifolate activity against Stenotrophomonas maltophilia (Navarro-Martínez et al, 2005), via inhibiting dihydrofolate reductase (DHFR), a key enzyme that catalyses the reduction of 7,8-dihydrofolate to 5,6,7,8-tetrahydrofolate, which is involved in nucleotide biosynthesis.…”

“…We recently showed the strong anti-acanthamoebic activity of green tea ( Camellia sinensis ; C. sinensis ) brews against the growth of A. castellanii trophozoites and the encystation ability of trophozoites (Fakae et al, 2020). We have also demonstrated the inhibitory effect of (−)-epigallocatechin-3-gallate (EGCG), a major component of C. sinensis , on A. castellanii growth (Dickson et al, 2020). In addition to EGCG, C. sinensis contains catechin, (−)-epicatechin (EC), (−)-epicatechin-3-gallate (ECG), and (−)-epigallocatechin (EGC) (Mukhtar and Ahmad, 2000), and caffeine (Perva-Uzunalic et al, 2006), among other components.…”

Antiamoebic Properties of Ceftriaxone and Zinc-Oxide–Cyclodextrin-Conjugated Ceftriaxone

“…To investigate the effects of the employed compounds on A. castellanii encystation, encystation assays were carried out as outlined previously [ 24 , 25 , 26 ]. In short, a count of 1 × 10 6 amoebae was incubated with a concentration of 100 μg/mL of each compound ( Table 1 ) in filtered 16% glucose, with amoebae alone in glucose and amoebae with SDS in glucose serving as negative and positive controls, respectively at 37 °C.…”