In vivo Antiplasmodial Activity and Haematological Parameters of the Methanolic Extract of Clerodendrum polycephalum Baker Leaves on Plasmodium berghei berghei in Mice

Aim: To evaluate the antimalarial effect of the methanol extract of the leaves of Clerodendrum polycephalum.

Study Design: In-vivo assay using albino mice. Three models were used: suppressive, prophylactic and curative.

Place and Duration of Study: The study was carried out at Drug Research and Production Unit, Faculty of Pharmacy, OAU, Ile-Ife, Nigeria from October 2013 to June 2014.

Methodology: Antimalarial activities were evaluated using methanolic extract of Clerodendrum polycephalum and mice containing 1.0 × 107parasitized red blood cells. Suppressive, prophylactic and curative assays were done using 100 – 600 mg/kg body weight. Positive control mice received chloroquine 10 mg/kg in suppressive and curative assays while those of prophylactic received pyrimethamine 1.2 mg/kg body weight. In acute oral toxicity assay, three mice were sequentially dosed with 5000 mg/kg body weight at intervals of 48 hrs; observations were made on the nervous system. Sub-chronic oral toxicity of extract was assessed using Haematological parameters.

Results: At 100 – 600 mg/kg, prophylaxis and suppressive tests exhibited 57.46 – 91.56% chemosuppression and 57.86 -92.63% chemosuppression respectively. The curative test produced concentration dependent chemosuppression from day 3 – day 7; at 600 mg/kg, chemosuppression increased from 71.35 (day 3) to 86.37% (day 7). Positive controls significantly compared well with the activities of the extract (P=.05). By 10th day in acute oral toxicity assay, slight thinning of the fur in the anterior area and loss of appetite were observed. At the end of the assay period, no mortality was observed. Treated animals in the sub-chronic oral toxicity test showed slight decrease and then increase in body weight. Furthermore, slight differences were observed in the values of the haematological parameters (red blood cell count, packed cell volume, haemoglobin estimation) compared to the control (P= .05).

Conclusion: The study corroborates the ethnomedicinal use of Clerodendrum polycephalum as a potent antimalarial remedy. Its use should be encouraged as an alternative to conventional antimalarial drug.