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

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.

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. 

The extracts of N. laevis and C. adansonii had a safety level of 200 mg/kg (LD50= 471.43 mg/kg) and 600 mg/kg (LD50=3,500 mg/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±4.76 mg/100 g & 92.71±6.58 mg/100 g) while saponins were the least abundant (15.09±1.13 mg/100 g & 14.08±1.28 mg/100 g) phytochemicals in both extracts.  

The findings support the notion that the traditional use of either plant in the management of malaria in Nigeria appears to be logical.