Plants with medicinal properties have been used in the treatment of several infectious diseases, including Acanthamoeba infections. The medicinal properties of Cambodian plant extracts; Annona muricata and Combretum trifoliatum were investigated against Acanthamoeba triangularis. A total of 39 plant extracts were evaluated and, as a result, 22 extracts showed positive anti-Acanthamoeba activity. Of the 22 extracts, 9 and 4 extracts showed anti-Acanthamoeba activity against trophozoites and cysts of A. triangularis, respectively. The minimum inhibitory concentration of A. muricata and C. trifoliatum extracts against trophozoites and cysts was 500 and 1,000 μg/mL, respectively. The combination of A. muricata at 1/4ÂMIC with chlorhexidine at 1/8ÂMIC 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 1/2ÂMIC 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 pretreatment with A. muricata and C. trifoliatum extracts, respectively. A 90% of cysts adhered to the surface was decreased with pre-treatment of A. muricata at 1/2ÂMIC (P < 0.05). A 75% of trophozoites and cysts from Acanthamoeba adhered to the surface were removed after treatment with both extracts at 4ÂMIC (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 A. muricata and C. trifoliatum as an option treatment against Acanthamoeba infections.

Cambodian medicinal plants have been used to treat different diseases such as cardiovascular diseases, inflammation, cancers, diabetes and AIDS. This study aimed at conducting the Phytochemical analysis and in vitro antioxidant activities of whole plant of Bryophyllumpinnatum (Lam.) Kurz, barks of Dillenia ovata Wall. ex Hook. f. & Thomson, rhizomes of Drynariafortunei (Kunze ex Mett.) J. Sm. and barks of Lophopetalumwallichii Kurz. native to Cambodia. All the plants were extracted with ethanolby maceration extraction method. The Phytochemical analysis for alkaloids, phenolic compounds, tannins, flavonoids, coumarins, steroids, terpenoids, cardiac glycosides, essential oils, saponins and resins by using the standard methods. The in vitro antioxidant property was evaluated by assessing the DPPH˙ radical scavenging ability. The preliminary Phytochemical evaluation of these species exhibited that the ethanolic extracts of B. pinnatum (whole plant), D. ovata (barks), D.fortunei (rhizomes) and L.wallichii (barks) contain alkaloids, phenolic compounds, tannins, flavonoids, terpenoids, cardiac glycosides, saponins and resins. Moreover, the ethanolic extracts of B. pinnatum whole plant, D. ovata barks, and D.fortunei rhizomes possess coumarins and steroids, and of L.wallichii barks have essential oils. The in vitro antioxidant activity of the species B. pinnatum whole plant, D. ovata barks, D.fortunei rhizomes and L.wallichii barks have prominent antioxidant activities. This study suggests the potential source of natural antioxidant in B. pinnatum, D. ovata, D.fortunei and L.wallichii native to Cambodia. Further research is highly recommended on the isolation of the antioxidant compounds from these species.