Antimalarial Activity of Solvent Fractions of the Stem Bark of Periploca linearifolia Quart.-Dill. & A.Rich. (Asclepiadaceae) Against Plasmodium berghei in Mice

BACKGROUND: Currently, malaria elimination is intimidated by the emergence of antimalarial drug and insecticide resistance. This scenario urges scientists to develop new antimalarial drugs, where plant-based compounds are the major candidates. OBJECTIVE: The objective of this experiment was to examine the antimalarial activities of the solvent fractions of the stem bark of P. linearifolia in mice. METHODS: The dried hydromethanolic extract was treated with n-hexane, chloroform, and ethyl acetate solvents based on increasing order of polarity. For the suppressive test, after three hours post-inoculation of P. berghei, the first group was administered the vehicle 2 mL/100 g. The second group was given chloroquine 25 mg/kg, whereas the remaining nine groups were administered 100, 200, and 400 mg/kg of each of the chloroform, ethyl acetate and aqueous fractions. Furthermore, the aqueous fraction was evaluated using Rane’s model for the curative test. The result was statistically analyzed using a one-way analysis of variance (ANOVA). The results were considered significant at P < 0.05. RESULTS: In the suppressive test, the solvent fractions suppressed parasitemia level significantly (P < 0.01 for 100 mg/kg, P < 0.001 for 200 and 400 mg/kg of the aqueous and P < 0.01 for 200 mg/kg, P < 0.001 for 400 mg/kg of chloroform fractions) as compared to vehicle-treated mice, whereas in the curative model 400 mg/kg of the aqueous fraction (P < 0.01) showed a significant parasitemia level reduction. CONCLUSION: The results of this study indicated that the solvent fractions have promising antiplasmodial activity against Plasmodium berghei, which is consistent with the earlier in vivo study of the hydromethanolic extract.