Antimalarial Activity of Crude Extract and Fractions of Phyllanthus amarus in Plasmodium berghei-Infected Mice

Abstract

Aim: This study evaluated the antimalarial activity of the crude extract and fractions of Phyllanthus amarus in Plasmodium berghei-infected mice. Place and Duration of Study: Department of Biochemistry, Federal University of Technology, Minna, Niger State, Nigeria, between February  2016 and August  2016. Methodology: Mice infected with Plasmodium berghei were administered orally with the crude extract of Phyllanthus amarus whole plant 72 hours post infection at doses ranging from 100-500 mg/kg/day, for five consecutive days. Chloroquine (5 mg/kg/day).and artesunate (50 mg/kg/day) were used as controls, while distilled water was administered to the negative control groups.  N-hexane, chloroform, ethyl acetate and aqueous fractions, obtained from crude aqueous methanolic extract, were also evaluated for their inhibitory effect against P. berghei at doses ranging from 50-200 mg/kg/day. Level of parasitaemia, survival time, variations in the values of body weight and % PCV were monitored throughout the study period. Results: Crude extract of Phyllanthus amarus whole plant showed significant (P < 0.05) antiplasmodial activity in dose dependent pattern with 76.74% inhibition of parasite growth. Aqueous fraction at a dose of 200 mg/kg demonstrated significant antiplasmodial activity with %inhibition of parasite growth of 56.40. The variations in the values of weight and %PCV before and after treatment were not significant in both the crude and aqueous fraction. Significant inhibition of parasite growth by the crude extract and aqueous fraction resulted in longer mouse survival relative to the control, as confirmed in the mean survival time of the mice (27.67±1.45, 22.67±0.67, 29.33±0.67 and 6.67±0.88 days) for the crude extract (500mg/kg), aqueous fraction (200 mg/kg), chloroquine and negative control groups respectively. Phytochemical screening of the extracts revealed the presence of alkaloids, flavonoids, phenol, tannins, steroids, terpenoids and saponins. Conclusion: The results indicate that the whole plant extract and fractions of Phyllanthus amarus have antimalarial property which can serve as a novel source for the development of new and affordable antimalarial agent.