RESUMEN
Aims@#Piper sarmentosum or locally known as Kaduk, is a tropical herb plant that was investigated for its phenolic content by previous researchers. The present study aimed at the analysis of crude methanolic extract of P. sarmentosum leaves for phenolic compounds identification and its anti-amoebic properties against pathogenic Acanthamoeba castellanii.@*Methodology and results@#Folin-Ciocalteu assay was used to determine P. sarmentosum leaves methanolic extract (PSLME)’s total phenolic content (TPC). The extract was further characterized by using gas chromatography-mass spectrometry (GC-MS), reverse phase-high performance liquid chromatography (RP-HPLC) and liquid chromatography-mass spectrometry (LC-MS) analyses to determine the chemical constituents in methanolic PSLME extract. The cytotoxicity of the extract was evaluated through the determination of inhibition concentration for half of cell population (IC50) of pathogenic A. castellanii followed by cell morphological analysis using inverted light and scanning electron microscopies. Acridine-orange/Propidium iodide (AOPI) staining was also conducted to determine the integrity of cell membrane for quantitative analysis. The results demonstrated that the TPC from PSLME was 142.72 mg [GAE]/g with a total of 33 phenolic compounds identified. The IC50 value obtained for A. castellanii was low (74.64 μg/mL) which indicates promising anti-acanthamoebic activity. Microscopy analyses showed that the plant extract caused cells encystment, in which exhibited by distinctive morphological changes on the cells shape and organelle, as well as shortening of acanthopodia. The dual staining and its quantitative analysis prove compromised membrane integrity in the treated amoeba.@*Conclusion, significance and impact of study@#This finding provides the evidence that PSLME contains active phenolic compounds contributing to the anti-acanthamoebic activity on pathogenic Acanthamoeba species.
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PiperaceaeRESUMEN
Background@#Amoebiasis is a global health problem affecting poor regions in the world. Few drugs such as metronidazole are available to treat this disease; unfortunately, it is associated with several serious side effects. Tsaang gubat and ampalaya have been used by traditional healers from different cultures to treat dysentery.@*Objective@#The aim of this research was to provide evidence to validate the use of tsaang gubat and ampalaya leaf extracts for dysentery by determining their anti-amoebic activity.@*Methods@#The tsaang gubat and ampalaya leaves were sourced from the University of the Philippines at Los Baños and processed into a lyophilized aqueous extract. Anti-amoebic activity was determined in an in vitro assay using Entamoeba histolytica HK-9 strain against 10 dose levels (18-10,000 μg/mL). The amoeba and leaf extracts were incubated for 24, 48, and 72 hours. The trophozoites were stained with Trypan blue and dispensed into chambers of a Neubauer hemocytometer. The live trophozoites (unstained) were counted under a binocular microscope. The MIC and IC50 were determined. Metronidazole and DMSO served as positive and negative controls, respectively.@*Results@#Tsaang gubat and ampalaya leaves failed to show anti-amoebic activity and even had increased growth of amoeba at all dose levels. The IC50 of tsaang gubat and ampalaya leaf extracts were >500 μg/mL at 24, 48, and 72 hours. Metronidazole was able to eradicate the amoeba parasite at 24 and 72 hours, while exposure to DMSO did not result in inhibition nor death of the parasite.@*Conclusion@#Tsaang gubat and ampalaya aqueous leaf extracts did not exhibit any anti-amoeba activity.