Evaluation of antimalarial compounds in Prosopis africana stem bark fractions against Plasmodium berghei

Abstract

Prosopis africana, a traditional medicinal plant for malaria treatment, requires further scientific evidence. This study aimed to assess the antimalarial potential of Prosopis africana stem bark fractions in Plasmodium berghei-infected mice and identify the responsible compounds. The aqueous extract underwent partitioning with n-hexane, ethyl acetate, and methanol, followed by antimalarial evaluation. F5 was the most potent fraction based on its antimalarial potential. The study pooled 36 chromatographic separation sub-fractions into five using TLC analysis Rf values. In Plasmodium berghei-infected mice, fraction F5 at 6.25, 12.5, 25, and 50 mg/kg body weight (bw) was tested for antimalarial activity. Compound analysis of F5 utilized ultra-performance liquid chromatography-quadrupolar mass spectrometry. Statistical analysis employed Analysis of Variance and Duncan's multiple range tests (p < 0.05). The methanol, n-hexane, and ethylacetate extracts displayed suppression of P. berghei by 90%, 72.2%, and 73.6%, respectively. Methanol, n-hexane, and ethylacetate extracts suppressed P. berghei by 90%, 72.2%, and 73.6% respectively. F5 showed significantly higher chemo-suppression (67.21%) than F1 (63.94%), F2 (6.99%), F3 (2.81%), and F4 (37.3%). At 12.5 mg/kg bw, F5 suppressed P. berghei by 91.09%, surpassing chloroquine (87.79%), and restored altered hematological indices and CD4+ counts. Compounds identified in F5 included caffeate, linalool, terpinene-4-ol, quinovic acid, quercetin, prosopinine, catechin, and apigeninin. In conclusion, the fraction F5 of P. africana stem bark exhibited higher antimalarial activity than chloroquine and the identified compound might likely contribute to its activity.