Toxicity of Anchomanes difformis, An Antimalarial Herb in Murine Models

Aim: Anchomanes difformis (A. difformis) is commonly used in folkloric medicine for the treatment of malaria. However, there had been no scientific evidence to substantiate this folkloric claim in murine models; hence the study.

Study Design: We employed murine models for this in vivo experiment and Vacuum Liquid Chromatography as our separation techniques for the plant extracts.

Place and Duration of Study: Laboratories for Biomembrane Research and Biotechnology, Department of Biochemistry, Faculty of Basic Medical Sciences and Institute of Advanced Medical Research and Training, College of Medicine, University of Ibadan, Nigeria between June 2014 and August, 2015.

Methodology: Methanol Extract (ME) and methanol Fraction (MF) obtained from A. difformis were used to treat mice for curative and prophylactic experiments. Therapeutic doses (methanol extract therapy [MET] and methanol fraction therapy [MFT] 100, 200 and 400 mg/kg body weight [bw]) were administered daily for seven days after confirming parasitemia. Prophylactic groups (methanol extract prophylaxis [MEP] and methanol fraction prophylaxis [MFP]) were pretreated for seven days before experimental infection.

Results: Observed slides showed that there was no significant suppression, reduction in parasitemia or increase in clearance compared with the positive control. There was a significant reduction in Packed Cell Volume (PCV) in the curative experiment compared with the unparasitized control (UTA). The PCV did not change significantly across the groups in the prophylactic experiment. White Blood Cell (WBC) values decreased significantly (p<0.0001) among the treated groups for MET and MFT compared with Artesunate (ART). The ART’s WBC value increased significantly (p<0.0001) when compared with parasitized control (MCT). In the prophylactic group, WBC values decreased significantly with both MEP and MFP compared with the Sulfadoxine-Pyrimethamine (SP) group. In both curative and prophylactic groups, survival rate decreased significantly as the dose increased. While ME-treated group survived better than MF-treated group, no animal survived under the MFP 400 mg/ kg bw. Histopathology of the liver revealed toxic effects of all drugs used.

Conclusion: The results revealed that doses used did not have significant antiplasmodial activity compared with the control drug used in this research. Extra caution must be taken while taking antimalarial drugs because of their possible toxicity.