Activity of Mentha longifolia and Ocimum basilicum against Entamoeba histolytica and Giardia duodenalis

Abstract

Amoebiasis and giardiasis are worldwide spread diseases caused by the protozoans Entamoeba histolytica and several Giardia species, respectively. Their treatment includes drugs which may produce side effects and, in addition, onset of chemical resistance of these pathogenic protozoans. Thus, with the purpose of searching for new natural anti-protozoal chemotherapy, two plants of the family Lamiaceae, Mentha longifolia and Ocimum basilicum used in Saudi traditional medicine against intestinal disorders were selected to evaluate their water, ethanol and chloroform leaves extracts activity against E. histolytica and G. duodenalis trophozoites. Chloroform extract from O. basilicum was strongly active against G. duodenalis (IC 50 = 53.31 μg/ml) and very active against E. histolytica (IC 50 = 68.62 μg/ml). Ethanol extracts of both plants showed moderate activity against tested protozoa. M. longifolia chloroform extract had poor activity against E. histolytica and G. duodenalis . Giardia duodenalis was significantly more susceptible than E. histolytica . None of the water extracts of the two plants were active against tested protozoa. Such results indicate M. longifolia ethanol extracts and chloroform extract from O. basilicum as possible candidates for further investigations to isolate and characterize their active principles as possible new natural anti-protozoal agents.