Antiplasmodial, Antioxidant, Hemolytic Activities and Acute Toxicity of Costus afer Ker Gawl (Costaceae) Used in Malaria Healing in Benin.

Abstract

Background and Objective: Overcome the resistance of malaria parasites to most orthodox drugs requires the exploration of different drug sources for new compounds or powerful natural substances against the Plasmodium parasite. The current study was designed to investigate antiplasmodial, antioxidant properties and toxicological profile of Costus afer Ker Gawl, a medicinal plant widely used traditionally in Bénin Republic to treat malaria. Materials and Methods: Crude ethanolic and aqueous extracts were tested in vitro against both field isolates and chloroquine sensitive 3D7 strains of P. falciparum using Plasmodium lactate dehydrogenase (pLDH) assay. Hemoglobin release was measured spectrophotometrically to assess hemolytic power. Antioxidant activity of extracts was assessed in vitro by DPPH radical-scavenging, reducing power (FRAP), superoxide radical scavenging and Hydrogen peroxide scavenging assays. Acute oral toxicity of extracts was evaluated according to OECD 423 guideline. Results: Ethanolic extract exhibited very good antiplasmodial activity against both strains with IC50 values of 3.19±0.13 μg mL–1 on field isolates and 13.68±1.41 μg mL–1 on 3D7. The aqueous extract showed moderate inhibition (<50%) on both strains as well as the fractions obtained from fractionation of ethanolic extract at single dose of 100 μg mL–1. Both extracts exhibited dose-dependent antioxidant activity. Both extracts presented hemolytic power less than 3% with a LD50 greater than 2000 mg kg–1 of b.wt. There was no significant change on biochemical and hematological parameters. Conclusion: The study demonstrated the strongest antiplasmodial and antioxidant properties of Costus afer as well as an absence of acute oral toxicity. It could be used as an alternative in the management of malaria and oxidative diseases through a standard formulation.