Anti-Oxidant Potential and Antimalarial Effects of Acanthus polystachyus Delile (Acanthaceae) Against Plasmodium berghei: Evidence for in vivo Antimalarial Activity

BACKGROUND: Malaria is among the most devastating and widespread tropical parasitic diseases which is more prevalent in developing countries. Acanthus polystachyus (Acanthaceae) leaves are traditionally used for the treatment of malaria in Ethiopia. This study aimed to investigate the in vivo antimalarial and in vitro antioxidant activity of the leaves extract of Acanthus polystachyus. MATERIALS AND METHODS: The leaves part of A. polystachyus were extracted using 80% methanol. The antioxidant effect of Acanthus polystachyus extract was evaluated by using (DPPH) diphenyl-2-picrylhydrazyl assay model. To evaluate the antimalarial effect of the A. polystachyus extract, Plasmodium berghei ANKA strain (chloroquine sensitive) was used to infect the mice in three different experimental protocol: suppressive, curative, and prophylactic test models. RESULTS: The leaves extract of Acanthus polystachyus significantly (P<0.05–0.0001) suppressed the parasitemia in all experimental protocol. The extract exhibited a chemosupression of 27.64%, 33.67% and 49.25% in 4-day suppressive test; 33.76%, 39.24% and 53.59% in curative test, and 25%, 32.84% and 50% in prophylactic tests at dose of 100, 200, and 400mg/kg, respectively. The extract also extended the mean survival time, prevented the bodyweight loss and body temperature drop, and packed cell volume significantly (P<0.05) as compared to the negative control. Dose-dependent antioxidant activity was shown by the leaf extract of A. polystachyus with an IC(50) value of 9.37µg/mL. CONCLUSION: The current finding showed that the leaves extract of Acanthus polystachyus has revealed promising antimalarial effects. Thus, this finding supports the traditional use of A. polystachyus for the treatment of malaria.