Evaluation of ethanol extract of <i>Artemisia maciverae</i> aerial part for antiplasmodial activity in mice

Abstract

Malaria is a life-threatening disease with increased mortality rate among infants of less than five years of age, non-immune travellers and pregnant women especially in sub-Saharan Africa. In Nigeria, the most common causative malaria parasite, Plasmodium falciparum rapidly develops resistance to most classes of conventional drugs and this has led researchers to source for new antimalarial drugs from different sources, including higher plants. The causative malaria parasite Plasmodium falciparum rapidly develops resistance to most classes of conventional drugs and this has led researchers to source for new antimalarial drugs from different sources, including higher plants. A decoction of Artemisia maciverae Linn. (Asteraceae) aerial part is used for the treatment of malaria in some parts of Northern Nigeria. The aim of the study was to evaluate the oral acute toxicity and in vivo antiplasmodial effect of an ethanol extract of Artemisia maciverae aerial part. Oral acute toxicity of the extract was evaluated in Swiss albino mice using modified Lorke’s method and the in-vivo antiplasmodial effect against early, established and residual infections in chloroquine-sensitive Plasmodium berghei berghei NK65- infected Swiss albino mice. Chloroquine (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. The oral median lethal dose of A. maciverae in mice was determined to be greater than 5000 mg/kg body weight. The extract at the doses (25, 50 and 100 mg/kg^-1 orally) used produced significant (P< 0.0001), dose-dependent effect against the parasite in the suppressive, curative and prophylactic tests. The extract showed the highest in-vivo antiplasmodial activity at 100 mg/kg^-1. The observed effects were also comparable with those produced by the reference drugs used as controls. Artemisia maciverae extract is practically non-toxic following acute, oral administration and possesses antiplasmodial effects. This suggests that it may be considered for further development as a safe and effective anti-malaria phytomedicine.

Keywords:  Artemisia macivera, Plasmodium berghei berghei, antimalarial activity