Acute Toxicity Studies and Anti-plasmodial Potentials of Newbouldia laevis and Crateva adansonii in Plasmodium Berghei-infected Mice

Background: Newbouldia laevis and Crateva adansonii are popular plants used traditionally in the management of patients with malaria infection in Nigeria. In this study, the acute toxicity and anti-plasmodial effects of the leaf extracts of Newbouldia laevis and Crateva adansonii were investigated in mice. Methods: The Anti-plasmodial activities of both extracts were investigated individually and combined in mice infected with the chloroquine sensitive ANKA-65 Plasmodium berghei strain. Five groups of four mice each were used in our experiments. The LD50 was determined, using the line equation of the mortality against dose levels plot. Results: The extracts of N. laevis and C. adansonii had a safety level of 200mg/kg (LD50 = 471.43mg/kg) and 600mg/kg (LD50 = 3,500mg/kg), respectively. Each experimental group was infected with P. berghei strain. The percent inhibition of parasitemia induced by the extracts of N. laevis and C. adansonii were 30.14 ± 2.88% and 61.35 ± 1.41%, respectively, compared to the 78.89% achieved for the standard drug (chloroquine). Mice treated with the combined extracts had a parasite inhibition of 24.23 ± 0.86%. Upon the analysis of the extracts, there were tannins, steroids, flavonoids, saponins and alkaloids in both. The quantitative analyses revealed that tannins were the most abundant (261.85±4.76mg/100g & 92.71±6.58mg/100g) while saponins were the least abundant (15.09±1.13mg/100g & 14.08±1.28mg/100g) phytochemicals in both extracts. Conclusions: The findings support the notion that the traditional use of either plant in the management of malaria in Nigeria appears to be logical.