Inhibitory Effect of Quassia amara Linn. Crude Bark Extract on Entamoeba histolytica in vitro

Jayson C. Panganiban,1 Annarose L. Patupat,1 Jose Antonio T. Paulino,1
Grace G. Penserga,1 Mar Aristeo G. Poncio,1 Romeo V. Porlas Jr.,1
Anna Sharmie C. Quezon,1 Hernane M. Quicho,1 Everly Faith P. Ramos,1
Edgar F. Remonte, Jr.,1 Julianne Francesca F. Reyes,1 Adovich S. Rivera,1
Kay C. Rivera,1 Manuel Gregorio T. Rivera,1 Paolo Nico A. Rogelio,1
Hope M. Sagayaga III,1 Maria Carmina L. Santiago,1 John Patrick See,1
Waldermar T. Siy,1 Faye S. Cagayan,2 Cecile C. Maramba2 and Pilarita T. Rivera3

1Ther 201 Research Group 7,
College of Medicine, University of the Philippines Manila
2Department of Pharmacology and Toxicology,
College of Medicine, University
of the Philippines Manila
3Department of Parasitology and Medical Entomology,
College of Public
Health, University of the Philippines Manila

Background. Entamoeba histolytica is an important etiologic agent of diarrhea. Globally, it is estimated to infect 40 to 50 million people and cause 40,000 to 100,000 deaths per year. <local studies> Metronidazole is effective but can cause adverse reactions in certain individuals. In search of alternatives, traditional medicinal plants are being studied. Several plants in Family Simaroubaceae have shown anti-amoebic activity. Quassia amara, a member of this family has not been tested.

Objective. To determine the effect of Q. amara crude extract on Entamoeba histolytica in vitro.

Methods. Initial testing of 104 µg/ml ethanolic bark extract was performed. Counts were made after 72 hours. Three trials in triplicates were performed.

Nine (9) dilutions of extract were then tested (18.8 to 5,00 µg/ml). Test tubes were checked for viable amoeba after 24-hour and 72-hour incubation. Minimum inhibitory concentrations (MIC) were determined for the two incubation periods. At least two trials in triplicates for each dilution were performed. metronidazole served as positive control.

Results. At 104 µg/ml incubated for 72 hours, no viable amoeba was obtained and counted. The MIC after 24 hours was 5,000 µg/ml, while the MIC at 72 hours was 37.5 µg/ml.

Conclusion. Q. amara crude extract has inhibitory effects on E. histolycain vitro.

Key Words. Quassia amara, antiprotozoal agents, anti-amebic