In vitro activity of Ricinus communis (castor oil) on cysts of Entamoeba histolytica

Background No descriptions in scientific literature exist about anti Entamoeba histolytica effect of Ricinus communis although is used by traditional medicine in Latin America for treatment or prophylaxis of intestinal amebiasis. Purpose To evaluate the in vitro cysticidal effect of castor oil extracts available as regulated phytotherapeutic products against E. histolytica. Study design In vitro evaluation of the cysticidal effect against E. histolytica of R. communis oil extracts. Methods We analyzed the effects of three commercial castor oil compounds on the viability and morphology of E. histolytica cysts. Results The three samples had significant cysticidal effects and altered cyst morphology after 10 h of exposure. The effective dose 50 % (EC50) ranged between 35 and 50 μg/ml, with a range of estimated EC50 25 and 35 μg/ml in the human intestine in vivo. Conclusion Castor oil pharmaceutical products have good in vitro anti-E. histolytica, which requires clinical trials to confirm its anti-amoebic effect.