ISSN 2326-7267
International Journal of Pharmacy and Pharmacology ISSN: 2326-7267 Vol. 2 (7), pp. 117-124, October, 2013. © International Scholars Journals
Full Length Research Paper
Antimalarial effects of Anthraquinone, Sodium nitroprusside, NG-nitro-l-arginine methyl ester, and their combinations on Plasmodium berghei in Mice
E.O. Iwalewa1*, T. Roland1 , B. O. Aduloju1, M. O. Ologe2, A. O. Adepiti3, S.A. Odediran3, O. J. Iwalewa4, E.M. Obuotor5, J. I. Olawuni5
1Department of Pharmacology, Obafemi Awolowo University, Ile-Ife, Nigeria
3Department of Pharmacognosy, Obafemi Awolowo University, Ile-Ife, Nigeria
5Department of Biochemistry, Obafemi Awolowo University, Ile-Ife, Nigeria
4University Health Centre, Obafemi Awolowo University, Ile-Ife, Nigeria
2Department of Pharmacology and Therapeutics, University of Ilorin, Ilorin, Nigeria.
*Corresponding author. E-mail: eoiwalewa@yahoo.com
Accepted 1 June, 2013
Abstract
Drug combinations represent current treatment strategies in the management of malaria. Nitric oxide (NO) has been proposed to inhibit Plasmodium growth due to its parasite-scavenging activity thus the effects of various combinations of an NO inducer - anthraquinone (25-100 mg/kg, ANT), an NO donor - sodium nitroprusside (0.5 mg/kg, SNP) and NO inhibitor -nitro-L-arginine methyl ester (40 mg/kg, L-NAME) and their combination drugs were evaluated using the antimalarial curative model in Plasmodium berghei-infected mice. Chloroquine (10 mg/kg, CQ) and distilled water were employed as the positive and negative controls, respectively. The plasma concentrations of nitric oxide in infected mice treated with ANT, SNP and L-NAME were determined spectrophotometrically. A significant (P < 0.05) decrease in the parasitaemia of ANT-treated groups at 50 and 100 mg/kg as well as L-NAME were observed. The result of this study showed the combinations of SNP and ANT (100 mg/kg), L-NAME and ANT, CQ and its combination with SNP and L-NAME were effective as they exhibited significant (p < 0.05) decreases in parasitaemia throughout the period of treatment justifying their antimalarial activity. However, SNP, the combinations of SNP plus ANT (25 and 50 mg/kg), SNP plus L-NAME were not effective as significant increases (P<0.05) in parasitaemia were observed. ANT and CQ demonstrated antiparasitic effect, which may be attributable to nitric oxide. Combinations of the ANT, L-NAME and CQ elicited increases in nitric oxide release, reduced parasitaemia while SNP released no significant amount of nitric oxide.
Key words: Nitric oxide, chloroquine, Plasmodium berghei, curative, drug combinations.