In Vivo Antimalarial Activity of Solvent Fractions of the Leaves of Justicia schimperiana Hochst. Ex Nees Against Plasmodium berghei in Mice
Increasing resistance of Plasmodium falciparum to almost all the available antimalarial drugs urges a search for newer antimalarial drugs. Justicia schimperiana Hochst. Ex Nees is traditionally used for the treatment of malaria and a study conducted previously on the crude leaf extract confirmed that the plant is endowed with antimalarial activity. The present study was therefore aimed to evaluate antimalarial activities of chloroform, methanol and aqueous fractions of the leaves of J. schimperiana against Plasmodium berghei in mice. A rodent malaria parasite, P. berghei, was used to inoculate healthy male Swiss Albino mice. The extraction was conducted following successive soxhlet extraction and maceration. The resulting fractions were evaluated at doses of 200, 400 and 600 mg/kg. Parameters, such as parasitaemia, survival time, body weight, temperature, and packed cell volume were determined using the 4-day suppressive, curative and prophylactic tests. All the three fractions had shown significant suppression of parasitaemia in the 4-day suppressive test, of which the methanol fraction exerted the highest chemosuppression (65.2%, p<0.001) at 600 mg/kg followed by the aqueous fraction (40.93%, p<0.001) at the same dose. The methanol fraction also showed significant suppression of parasitaemia in both curative (67.44%, p< 0.001) and prophylactic (35.02%, p<0.01) tests at 600 mg/kg dose. All doses of the methanol fraction significantly (p<0.05) prevented the reduction in rectal temperature in the 4-day suppressive and curative tests. In conclusion, the results of the studies demonstrated high antimalarial activities of methanol and aqueous fractions against P. berghei in mice. These findings substantiated the previous activity of crude extract and traditional use of the plant. Therefore, the plant could be potentially utilized as a source of templates for the development of new antimalarial agent.
Keywords: Justicia schimperiana, in vivo, anti-malarial activity, Plasmodium berghei, solvent fractions