Antimalarial Activities of Leaf Extract and Fractions of Setaria megaphylla(Willd.) Loes. in Plasmodium berghei Infected Mice.

Setaria megaphylla (Steud) Dur&Schinz (Poaceae), a perennial grass used traditionally in the treatment of various diseases such as malaria was screened for antiplasmodial activity. The leaves extract (200-600 mg/kg) and fractions (hexane, dichloromethane, ethyl acetate and methanol; 400 mg/kg) were investigated for suppressive, prophylactic, and curative antimalarial activities against chloroquine-sensitive Plasmodium berghei infections in Swiss albino mice. Chloroquine (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Thin films made from tail blood of each of the mice were used to assess the level of parasitaemia of the mice. The extract/fractions progressively reduced parasitaemia induced by chloroquine-sensitive P. berghei infection in suppressive (11.12-46.94%), prophylactic (19.20 -47.96%) and curative (20.65-75.06%) models in mice. These reductions were statistically significant (p<0.01-0.001). They also improved significantly (p<0.01-0.001) the mean survival time (MST) from 13.33 to 18.60 d in suppressive, 10.33 to 26.00 in prophylactic and 12.50 to 22.66 days in curative models relative to respective controls. The activities of extract/fractions were not comparable to that of the standard drugs used (chloroquine and pyrimethamine) in all the models. The leaf of S. megaphylla may possess antimalarial effect which may in part be mediated through the chemical constituents of the plant. [ABSTRACT FROM AUTHOR]