Potential Anti- and Anti-adhesion Activities of and Extracts and Their Synergistic Effects in Combination with Chlorhexidine Against Trophozoites and Cysts

Plants with medicinal properties have been used in the treatment of several infectious diseases, including infections. The medicinal properties of Cambodian plant extracts; and were investigated against . A total of 39 plant extracts were evaluated and, as a result, 22 extracts showed positive anti- activity. Of the 22 extracts, 9 and 4 extracts showed anti- activity against trophozoites and cysts of , respectively. The minimum inhibitory concentration of and extracts against trophozoites and cysts was 500 and 1,000 μg/mL, respectively. The combination of at 1/4×MIC with chlorhexidine at 1/8×MIC demonstrated a synergistic effect against trophozoites, but partial synergy against cysts. A 40% reduction in trophozoites and 60% of cysts adhered to the plastic surface treated with both extracts at 1/2×MIC were noted comparing to the control (P < 0.05). Furthermore, a reduction of 80% and 90% of trophozoites adhered to the surface was observed after pre-treatment with and extracts, respectively. A 90% of cysts adhered to the surface was decreased with pre-treatment of at 1/2×MIC (P < 0.05). A 75% of trophozoites and cysts from adhered to the surface were removed after treatment with both extracts at 4×MIC (P < 0.05). In the model of contact lens, 1 log cells/mL of trophozoites and cysts was significantly decreased post-treatment with both extracts compared to the control. Trophozoites showed strong loss of acanthopodia and thorn-like projection pseudopodia, while cysts demonstrated retraction and folded appearance treated with both extracts when observed by SEM, which suggests the potential benefits of the medicinal plants and as an option treatment against infections.