Isolation,fractionation and evaluation of the antiplasmodial properties of Phyllanthus niruri resident in its chloroform fraction

<正>Objective:To investigate the antiplasmodial activity of Phyllanthus niniri(P.niruri) methanol extract(ME) and its fractions in mice.Methods:P.niruri methanol extract and its chloroform. ethanol and aqueous portions were tested against chloroquine-sensitive Plasmodium berghei berghei in early,established and repository models of infection using Knight and Peter’s 4-day suppressive model,Rvlev and Peters curative model and Peters prophylactic model respectively. Results:Chemosuppression of parasitemia(37.65%-50.53%) was elicited by 100-400 mg/kg(b.w.) of ME.Al doses of 100 mg/kg b.w..the chloroform fraction(F1) significantly(P<0.01) suppressed parasitaemia by 85.29%,while ethanol and aqueous fractions(F2 and F3.respectively) elicited 67.06%and 51.18%chemosuppression.the most active fraction.F1 was selected for further antiplasmodial screening.In established infection.ME reduced parasitaemia(15.81%- 62.96%) while F1 significantly(P<0.01) reduced parasitaemia(44.369—90.48%).with effects comparable to that of chloroquine(96.48%).The prophylactic antiplasmodial activity of ME(92.50%suppression) was also significant(P<0.01) and was more effective than pyrimethamine(85.00%).additionally, cell membrane integrity of non-parasitized erythrocytes intubated with 125-500 mg/mL F1 was maintained.Conclusions:These findings indicate the antiplasmodial efficacy of P.niruri methanol extract,and the localization of this effect in its chloroform fraction.