Antiplasmodial Properties of Ethanol Stem-Bark Extract of Newbouldia Laevis (P. Beauv) Seem in P. Berghei Infected Mice

Abstract

BACKGROUND Despite substantial improvement in the management of malaria infection over the last centuries, it remains a significant public threat especially to those in the tropical and subtropical African regions due to the emergence of drug-resistant P. falciparum strains, delayed diagnosis, high cost as well as contraindications of some available antimalarial medications. Hence, the need for necessary measures in terms of alternative therapeutic approaches to counter this threat is of utmost importance. The present study was aimed at determining the antimalarial potential of ethanol stem-bark extract of Newbouldia laevis in P. berghei (NK65) infected mice. METHODOLOGY The antimalarial activity of Newbouldia laevis stem-bark at 250, 500 and 1,000 mg/kg was investigated in mice infected with 1 x 107 parasitized erythrocytes using three experimental animal models: Peter's 4-day suppressive, curative and prophylactic models. Phytochemical screening of the stem bark was also conducted. RESULTS The extract at all tested doses of 250, 500 and 1000 mg/kg showed significant (p<0.01) and dose-dependent reductions in the parasitemia levels of the treated rats with percentage chemosuppresion of 90.7, 91.8 and 94% respectively in the Peters 4-day suppressive test. There were also significant (p<0.01) dose-dependent reductions in parasitemia density of the treated rats at all doses of 250, 500 and 1000 mg/kg in the curative and prophylactic studies compared to the distilled water group. Phytochemical screening revealed the presence of carbohydrates, tannins, alkaloids, flavonoids, saponins, terpenoids, cardiac glycosides, steroids and anthraquinones in the crude extract. CONCLUSION The results suggest that ethanol stem-bark extract of Newbouldia laevis possesses antimalarial activity and this justifies the traditional use of the stem-bark of the plant in antimalarial herbal remedy.