In-vivo Anti-Plasmodial Activity of Enantia chlorantha: A Potential Plasmodium berghei Survival Inhibitor

Abstract

The emergence of resistance to existing antimalarial drugs has intensified the search for novel, effective, and affordable treatments for malaria. The sensitivity of strains of Plasmodium spp. to the commonly known antimalarial drugs over time undermines the effectiveness of treatment. Enantia chlorantha, traditionally used in African folk medicine, has shown potential antimalarial agents that inhibit parasite survival and growth. This study aimed to investigate the antimalarial efficacy of Enantia chlorantha extracts on Plasmodium berghei using in vivo approach. A total of 55 albino mice randomized into 5 groups were inoculated with an infection of 1.0 x 107 chloroquine sensitive strain of Plasmodium berghei intra-peritoneally. Methanol, n-hexane and ethyl acetate extracts of Enantia chlorantha stem-bark was extracted successfully using a Sohxlet extractor. Experimental mice were treated orally with doses of 5mg/kg, 10mg/kg, and 20mg/kg of each plant extract (EC2, EEA and EHEX treated groups), a dose of 10mg/kg chloroquine (standard control group), and a dose of 0.2ml Olive Oil (negative control group). The level of parasitaemia and death per day were used to assess the chemosuppressive effect and survival rate of the extracts. Data were analyzed using One Way Analysis of variance ANOVA followed by post hoc test, and were expressed as mean ± standard error of mean (M ± SEM), and percentage. All analyses were carried out at a 95% confidence interval, with a significance level set at P < 0.05. The treatment with various concentrations of Enantia chlorantha extracts (EC2, EEA, and EHEX) significantly reduced parasitaemia levels, with higher doses showing greater suppression. EC2 reduced parasitaemia from 1.00% (5 mg/kg) to 0.71% (20 mg/kg) with p=0.0003, while EEA reduced it from 1.15% (5 mg/kg) to 0.57% (20 mg/kg) with p=0.0028. EHEX showed a suppression from 1.09% (10 mg/kg) to 0.46% (20 mg/kg) with p=0.0001. Chemosuppression in EC2, EEA, and EHEX increased with dosage, with EEA at 20 mg/kg surpassing chloroquine in chemosuppression (85.64% vs. 69.86%, p=0.0009). In survival outcomes, EC2, EEA, and EHEX exhibited dose-dependent increases in survival index, with EEA at 20 mg/kg reaching 90%, but none matched chloroquine's 100% survival, Enantia chlorantha extracts particularly EEA significantly reduced parasitaemia level and increased chemosuppressive effect and survival index at high doses, indicating the potent antimalarial activity of Enantia chlorantha.