Antiamoebic activity of Piper longum fruits against Entamoeba histolytica in vitro and in vivo.

The fruits of Piper longum used in traditional remedies against intestinal distress have been tested for their efficacy against experimental caecal amoebiasis of rats. The ethanolic extract, hexane fraction, n-butanol soluble fraction exerted in vitro amoebicidal action at 1000 micrograms/mL and the chloroform fraction at 500 micrograms/mL. The ethanolic extract and piperine, a pure compound, from this plant material cured 90% and 40% of rats with caecal amoebiasis, respectively.