Antimicrobial Activities and Malaria Parasite Clearance of Crude Extract of Carica papaya Seeds in Mice Infected with Plasmodium berghei.

Medicinal plants are known for a number of health benefits. This study investigated the in-vitro antimicrobial activities and in-vivo malaria parasite clearance rate using respectively the methanol and aqueous extracts of Carica papaya seeds. Soxhlet and Cold-maceration extraction techniques were used to obtain the methanol and aqueous extracts, respectively. The phytochemical constituents were quantitatively/qualitatively analyzed. The antimicrobial activities of the extracts were tested Escherichia coli, Salmonella typhi, Staphylococcus aureus, and Pseudomonas aeruginosa using the agar-well-diffusion method. The minimum inhibitory concentration (MIC) of the extracts were determined using the agar-dilution method. Five groups of animals (mice) were used in this study, each having five animals each. The animals in group two to five were induced with Plasmodium berghei after which, those in group two, four, and five were treated with 25 mg/kg bw of artemether/lumefantrine and 200 and 400mg/kg bw of the plant aqueous extract respectively. Group three were not treated, while group one was neither induced nor treated. The phytochemical analysis showed presence/quantities of steroids, saponins, tannins, flavonoids, terpenoids, glycosides, reducing sugars, proteins, phenolic compounds, and alkaloids. With varying preliminary antimicrobial effects, the MIC of the methanol extract against E. coli and S. typhi were 62.5mg/ml and 125 mg/ml, respectively. The aqueous extract showed MIC of 125mg/ml against S. aureus. The antimalarial activity of aqueous extract increased in a dose-dependent manner. The aqueous extract at 400 mg/kg bw dose had a significant therapeutic (P<0.05) response. The study shows that the plant seeds have agents with both antimicrobial and antimalarial effects. [ABSTRACT FROM AUTHOR]