Antioxidant and Antiplasmodial Potentials of Methanol Bark Extract of <i>Entada africana </i>Via <i>in Vitro</i> Approaches

Abstract

<i>Plasmodium </i>parasites, which cause malaria, continue to pose a serious threat to global health, necessitating the continuous search for novel antimalarial agents. Oxidative stress has also been linked to the pathophysiology of malaria. <i>Entada africana</i> is a plant known for its ethnomedicinal uses in treating various ailments associated with inflammation including malaria. This study aimed at evaluating the antiplasmodial and antioxidant potentials of methanol bark extract from <i>Entada africana </i>(MBEEA). <i>In vitro </i>approaches were adopted for the study.<i> Plasmodium falciparum-</i>infected erythrocyte samples were cultured in Roswell Park Memorial Institute (RPMI) 1640 media under anaerobic conditions for 72 hours. Eighteen test tubes were labeled and grouped into three replicates per group. Group I (untreated), Group II, and III were treated with chloroquine (CQ) and artemether (AR) at a concentration of 5 mg/dL. Group IV, V, and VI were treated with the extract at respective concentrations of 5 mg/dL, 10 mg/dL, and 20 mg/dL for 72 hours. The parasitemia count and the percentage parasitemia inhibition were determined by microscopic examination of Giemsa-stained smears. The antioxidant potential of the extract was assessed using <i>in vitro</i> assays, including superoxide radical scavenging activity (SRSA), hydroxyl radical scavenging activity (HRSA), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP). Microscopic examination of the treated samples revealed varying degrees of parasitemia inhibition. Group II and III treated with CQ and AR demonstrated a considerable reduction in parasitemia count with percentage inhibition of 100% and 83% respectively. The <i>E. africana</i> extract showed a concentration-dependent effect on parasitemia count. At 5 mg/dL, the extract exhibited 50% parasitemia inhibition, which increased to 100% at 10 mg/dL, and 20 mg/dL respectively. The MBEEA demonstrated significant <i>in vitro </i>antioxidant activities by scavenging DPPH, SRSA, and hydroxyl radical compared to the standard antioxidant (ascorbic acid). MBEEA thus exhibit potent antioxidant and antiplasmodial properties. This plant is therefore offers to be a promising medicinal plant in the treatment of malaria, hence it is recommended as potent antiplasmodial plant usable for treating malaria.