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

AimWe examined the anti-acanthamoebic efficacy of solvent extract of C. sinensis) and its chemical constituents against trophozoites and cysts of A. castellanii. Materials and methodsThe effects of C. sinensis solvent extract on A. castellanii was investigated by using anti-trophozoite, anti-encystation, and anti-excystation assays. The solvent extract was also fractionated using Gas Chromatography and the chemical constituents of C. sinensis were tested, individually or combined, against the trophozoites. ResultsTrophozoite replication was inhibited within 24-72 h with exposure to 625-5000 {micro}g/mL of C. sinensis solvent extract. C. sinensis also exhibited a dose-dependent inhibition of encystation, with a marked cysticidal activity at 2500-5000 {micro}g/mL concentrations. Two constituents of C. sinensis, namely epigallocatechin-3-gallate and caffeine, significantly inhibited trophozoite replication and encystation at 100 M and 200 M, respectively. Cytotoxicity analysis showed that 156.25-2500 {micro}g/mL of solvent extract was not toxic to human corneal epithelial cells, while up to 625 {micro}g/mL was not toxic to Madin-Darby Canine Kidney cells. ConclusionsThis study shows the anti-acanthamoebic potential of C. sinensis solvent extract against trophozoites and cysts. Further pre-clinical studies are required to elucidate the in vivo efficacy and safety of C. sinensis solvent extract. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=152 HEIGHT=200 SRC="FIGDIR/small/507025v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@9850forg.highwire.dtl.DTLVardef@feb98dorg.highwire.dtl.DTLVardef@147fc64org.highwire.dtl.DTLVardef@10b497e_HPS_FORMAT_FIGEXP M_FIG C_FIG