In vitro amoebicidal effect of ethanol extract and honey against . cysts.

This study evaluated in vitro effect of different concentrations of () ethanol extract and honey against spp. cysts in comparison with chlorhexidine (the drug of choice for treatment of infection) at different incubation periods. Four different concentrations of the tested agents were used, 100, 200, 400, and 600 μg/ml for and 25, 50, 100, and 200 μg/ml for honey. Isolated spp. cysts from keratitis patients were incubated with different concentrations of the tested agents as well as chlorhexidine 0.02% (drug control) for different incubation periods (24, 48, 72 h). After each incubation period, the effect of extract and honey against cysts was assessed by counting the number of viable cysts, determining the inhibitory percentage and detecting the morphological alternations of treated cysts compared to non-treated and drug controls. Both ethanol extract and honey showed a concentration and time-dependent effect on the viability of cysts. In comparison with chlorhexidine (the drug control), ethanol extract possessed a potent cysticidal activity at all tested concentrations throughout different incubation periods, except for concentration 100 μg/ml which recorded the lower inhibitory effect. With increasing the dose of ethanol extract to 200, 400, 600 µg/ml, the recorded inhibitory percentages of cysts viability were 82.3%, 92.9% and 97.9% respectively, after 72 h compared to 76.3% of chlorhexidine. Similarly, honey at concentrations of 50-100 µg/ml gave higher inhibitory effect of 59% and 76.7%, respectively compared to chlorhexidine which showed an inhibitory percentage of 55.7% after 24 h. Meanwhile, the lowest tested concentration of honey (25 µg/ml) gave an inhibitory effect by 47.7-67% which was less than that of chlorhexidine throughout different incubation periods. With increasing the dose of honey to 200 µg/ml, the inhibitory effect was 98.9% after 72 h higher than that of chlorhexidine (76.9%). Using a scanning electron microscope, cysts treated by ethanol extract showed alternations in their shapes with flattening, collapsing, and laceration of their walls. Also, treated cysts by honey were highly distorted and difficult to identify because most of them were shrinkage and collapsed to a tiny size. On the other hand, chlorhexidine showed less structural and morphological changes of cysts. ethanol extract and honey had considerable cysticidal effects on cysts. They may give promising results for treatment of keratitis.