Crude Ethanolic Stem Bark Extract of Zanthoxylum zanthoxyloides and Its Fractions: In-Vitro and In-Vivo Antiplasmodial Activity

Abstract

Malaria is a global problem, as treatment failure has hampered the efficacy of most anti-malarial medications. The goal of this study was to see if stem bark extract from Zanthoxylum zanthoxyloides had antiplasmodial properties that could be used to treat both susceptible and resistant parasites. The stem bark of Z. zanthoxyloides (500g) was crushed and extracted with ethanol. The extract was tested for antiplasmodial activity in vitro against the chloroquine-sensitive (CQS) strain NF54 and chloroquine-resistant strains (CQR) K1 of P. falciparum, as well as in vivo against the CQS(NK65) strain of P. berghei at 100, 200, and 400 mg/kg bw. Bioassay-guided fractionation of the extract was performed. The crude extract had an in vitro activity of 1076.4 56.4 and 1315.1 121.6 ng/ml against chloroquine sensitive and resistant parasites, respectively while standard drugs (chloroquine and artesunate) were 10.94 nM (3478.92 ng/ml) and 9.24 nM (3215.52ng/ml) for CQS and 310.68 nM (98796 ng/ml) and 10.94 nM (3650.52 ng/ml) for CQR respectively. At Day 7, mice treated with 100, 200, and 400 mg/kg bw crude extract had parasite densities of 1159, 928, and 869 parasites/ µl, respectively (compared to positive control that had 123 parasites /µl). In vitro antiplasmodial activity was best in the K2, K4, and K6 fractions (IC50 were 6670, 6890, and 6480 ng/ml), but in vivo antiplasmodial activity was best in the K4 fraction (1183 parasites/ µl).The stem bark extract of Z. zanthoxyloides have remarkable antiplasmodial activity against both chloroquine sensitive and drug resistant P. falciparum supporting it ethnomedicinal use in malaria treatment.The extract of Z. zanthoxyloides has promising antiplasmodial activity and could be used to generate therapeutic leads against the multidrug-resistant K1 strain of P. falciparum, in addition to providing an alternative allopathic antiplasmodial medication.