Antimalarial Studies and Phytochemical Profiling of Laportea aestuans (L.) Chew Extractives

This study validated the antimalarial efficacy of Laportea aestuans extract using chemosuppressive and curative models, identified its most active fraction, and performed chemical profiling of the active fraction. The aerial part of L. aestuans (LA) was extracted with 80% methanol and assayed for its chemosuppressive and curative antimalarial activities through the oral administration of the extract (100, 200, 400 and 800 mg/kg) to groups consisting of five mice each. The extract was thereafter suspended in water and partitioned with dichloromethane to afford the dichloromethane (DLA) and aqueous (ALA) fractions. The fractions (10, 20, 40, and 80 mg/kg) were thereafter tested for their antimalarial activity followed by GC-MS analysis of the most active fraction. The toxicity level was found to be above 2000 mg/kg. The activity recorded for the four-day chemosuppressive antimalarial tests showed a dose-dependent activity up to 400 mg/kg. The activity was significantly lower than that of chloroquine. The antimalarial activity of the extract at the lowest dose of 100 mg/kg was 42%. In the curative test, the extract of LA gave a dose-dependent activity that was significantly higher than the negative control. The DLA and ALA fractions gave a comparable curative activity across all doses. At 10 mg/kg, ALA and DLA gave percentage clearance of 81.25 ± 1.84 and 87.45 ± 1.35, respectively, which were significantly higher than that of the negative control (0.00 ± 0.00) and significantly lower than that of the positive control (94.93 ± 0.26). The chemical profiling revealed the presence of non-polar and medium-polar constituents in the dichloromethane fraction. The good antimalarial activity elicited by LA extractives supports its usage in ethnomedicine as an antimalarial agent.