Abstract
BACKGROUND: Malaria remains a significant cause of morbidity and mortality globally. Previous in vitro studies have demonstrated potential anti-plasmodial activity of Zanthoxylum chalybeum. We thus carried out an in vivo study to determine the efficacy of Z.chalybeum on parasite clearance, haemoglobin preservation, and fever reduction in Wistar albino mice infected with Plasmodium berghei NK65. METHODS: This was an in vivo experimental study to determine the curative plasmodial clearance of Z.chalybeum in Wistar albino mice infected with Plasmodium berghei NK65. The mice were cage-housed in three groups; the experimental group A consisting of subgroups A1, A2 and A3 was administered with Z.chalybeum aqueous rootbark extracts at concentrations of 400mg/kg, 200mg/kg, and 100mg/kg respectively. The positive control (B) received Artemether-Lumefantrine at 4mg/kg body weight, and group C (the negative control) was given distilled water used to dilute the rootbark extracts at a dose of 10mL/kg. The treatment period was five days beginning from day three post-infection of the experimental mice. Differences in parasite clearance, hemoglobin concentration and fever reduction among the experimental groups were analyzed using one way analysis of variance (ANOVA). P-values less than 0.05 were considered to be statistically significant. RESULTS: Z. chalybeum aqueous rootbark extracts showed parasite clearance up to 76% in Wistar albino mice infected with P. berghei. Compared to the negative control group, the root bark extracts exhibited significantly higher parasite clearance at 100 mg/kg dose (mean difference (MD) = 15.6, 95%CI = 14.95-16.25; p < 0.001), 200 mg/kg (MD = 16.42, 95%CI = 15.77-17.07; p < 0.001) and 400 mg/kg (MD = 17.24, 95%CI = 16.59-17.89, p < 0.001). Further, the mean temperature difference was found to be significantly lower among the experimental group as compared to the negative control group which was, MD=-1.50, 95%CI = 2.59-0.67; p = 0.009 at 100mg/kg dose; MD=-1.63, 95%CI = 2.74-0.81; p = 0.004 at 200mg/kg and MD=-1.78, 95%CI = 2.46-0.54; p = 0.002 at 400mg/kg of administered dose. There were no remarkable differences between the haemoglobin and haematocrit concentrations of the experimental and negative control groups. CONCLUSION: Z. chalybeum showed efficacy in parasite clearance and maintaining the body temperature of Wistar albino mice infected with P. berghei. Additional studies should be done to determine the anti-plasmodial and anti-pyretic mechanisms of Z. chalybeum root bark extracts.