In-vivo antimalarial activity of Cassia occidentalis, Morinda morindoides and Phyllanthus niruri

The ethanolic, dichloromethane and lyophilized aqueous extracts of Cassia o ccidentalis root bark, Morinda morindoides leaves and whole plants of Phyll anthus niruri were evaluated for their antimalarial activity in vivo, in 4- day, suppressive assays against Plasmodium berghei ANKA in mice. No toxic e ffect or mortality was observed in mice treated, orally, with any of the ex tracts as a single dose, of 500 mg/kg body weight, or as the same dose give n twice weekly for 4 weeks (to give a total dose of 4 g/kg). No significant lesions were observed, by eye or during histopathological examinations, in the hearts, lungs, spleens, kidneys, livers, large intestines or brains of any mouse. At doses of 200 mg/kg, all the ethanolic and dichloromethane extracts produ ced significant chemosuppressions of parasitaemia (of > 60% for C. occident alis root bark and Ph. niruri whole plant, and of 30% for M. morindoides le aves) when administered orally. The most active ethanolic extract, that of Ph. niruri, reduced parasitaemia by 73%. The dichloromethane extracts of M. morindoides and Ph. niruri produced similar reductions (74% and 72% chemos uppression, respectively), whereas that of C. occidentalis was slightly les s active (60% chemosuppression). Each lyophilized aqueous extract was less active than the corresponding ethanolic extract.