International Journal of Pharmacy and Pharmacology ISSN: 2326-7267 Vol. 2 (9), pp. 131-142, December, 2013. Available online at www.internationalscholarsjournals.org © International Scholars Journals Full Length Research Paper In vivo antimalarial activity of hydromethanolic leaf extract of Calpurnia aurea (Fabaceae) in Mice infected with chloroquine sensitive Plasmodium berghei Mebrahtu Eyasu 1 , Workineh Shibeshi 2 and Mirutse Giday 3 1 Saint Paul’s Hospital Millennium Medical College, Department of Pharmacology, P. O. BOX 1271 Addis Ababa Ethiopia. 2 Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University. P.O. Box 1176 Addis Ababa Ethiopia., 3 Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Ethiopia. Accepted 18 November, 2013 Malaria is one of the most serious health problems worldwide and treatment has been compromised by drug resistance. Consequently, efforts are directed towards discovery of novel agents including from medicinal plants. The present study was aimed to evaluate the suppressive, curative and prophylactic activity of hydroalcoholic leaf extract of Calpurnia aurea in mice infected with chloroquine sensitive Plasmodium berghei (1x10 7 parasites/mouse). The extract (15, 30 and 60 mg/kg), chloroquine (5 mg/kg) and distilled water (0.2ml/day) were administered orally for four days. Then parasitemia, packed cell volume, body weight, rectal temperature and survival time of mice were monitored. The 60 mg/kg dose in 4-day suppressive, curative and prophylactic tests had maximum parasitemia chemosuppression of 51.15, 47.77 and 36.8% (P<0.001 in all cases) respectively with significant effect on survival time (4-day suppressive test) compared to negative control. In 4-day suppressive test, the extract had prevented packed cell volume reduction at 15 and 30 mg/kg doses (P<0.05) compared to negative control. In prophylactic test, extract doses at 15mg/kg (p<0.001) and 60mg/kg (p<0.05) prevented body weight loss compared to negative control. The present work establishes antiplasmodial activity of the plant which can be a potential source of new chemotherapeutic and/or chemoprophylactic compounds. Key words: antimalarial activity, Calpurnia aurea, Plasmodium berghei, Mice, in vivo. INTRODUCTION The number of malaria-related deaths is increasing and one key factor linked to this, is widespread drug resistance to most of the commonly available antimalarial drugs which is greatest challenge against malaria control (Trape et al., 1998; Mendis et al., 2001). Important attributes for the successful implementation of antimalarial drugs are good tolerability and safety, affordability, availability in endemic countries and short course regimens (Petersen et al., 2011). The drug resistance of the malaria parasite is widespread, no new chemical class of antimalarials has been introduced into clinical practice since 1996 and there has recently been an increase in parasite strains with reduced sensitivity to *Corresponding author E-mail: wedidellameb@gmail.com the newest drugs. Several excellent reviews on anti- plasmodial compounds, including natural products, have been published in recent years (Claudio et al., 2011). The wide spread use of traditional medicine could be attributed to cultural acceptability, physical accessibility and economic affordability and efficacy against certain types of diseases, as compared to modern medicine (Deribe et al., 2006). In Africa, the use of indigenous plants still plays an important role in malaria treatment and these plants might be interesting sources for the detection of novel anti-plasmodial compounds (Tekalign et al., 2010). Since malaria is a serious disease in Ethiopia and many developing countries, the list of traditionally used plants to control it must be backed by phytochemical studies to develop an appropriate phytomedicine (Endashaw, 2007). Studies conducted on antimalarial activity of several traditionally claimed Ethiopian medicinal plants