Inter-relationship between faecal pH and susceptibility to Entamoeba histolytica infection in rats

Potential antiamoebic property of the roots of Piper longum Linn

In an earlier study we reported the effect of ethanol extracts of Piper longum fruit against caecal amoebiasis in rats. A follow-up study to determine whether the roots possess similar antiamoebic activity was carried out. The ethanolic extract of roots was amoebicidal at 1,000 microg/mL in vitro and cured 88% of caecal amoebiasis cases, suggesting that both the root and fruit of P. longum possess antiamoebic activity to approximately the same extent.

3'-deoxyribonucleosides and their derivatives as anti-amoebic agents

In general nucleoside analogues were found to possess in vitro amoebicidal property against trophozoites of Entamoeba histolytica. The acid-labile nature of these compounds completely destroyed their ability to cure caecal amoebiasis of rats. However the therapeutic efficacy of one of these compounds yielded most promising results, with 10% cures when it was administered as enteric coated formulation.

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.