Hydroethanolic stem bark extract of Vernonia amygdalina Del. (Asteraceae) suppresses yeast-induced pyrexia and Plasmodium berghei malaria in murine models

Abstract

Vernonia amygdalina has been widely utilized in Ghana and other West African states for numerous parasitic infections, diabetes and some inflammatory conditions. In this study we evaluated the antipyretic and antimalarial properties as well as in vitro antioxidant activities of an ethanolic stem bark extract of V. amygdalina (VAE). The antipyretic effect of VAE was assessed using Baker's yeast-induced pyrexia and the antimalarial activities of plant extract against Plasmodium berghei-infected mice in the Peters 4-day suppressive test. The antioxidant activities of the stem bark extract were determined by DPPH radical scavenging and total phenol content assay. Phytochemical screening was carried out using standard methods. V. amygdalina (100-600 mg kg-1) dose related decreased the Baker's yeast-induced fever in young rats. Also, it exhibited a significant (F (5, 24) = 91.35, P < 0.0001) anti-plasmodial activity in the mouse model. It caused a percentage suppression of 81.80 ± 3.76 at 600 mg kg-1 and a relative antioxidant activity in the DPPH radical scavenging assay with an IC 50 of 146.4 ± 2.31 µgml-1 and a total phenol content of 345.7 ± 4.56 mg g-1 of gallic acid equivalence. Preliminary phytochemical screening showed that the extract contained tannins, reducing sugars, flavonoids, terpenoids and alkaloids. V. amygdalina hydroethanolic stem bark extract evoked promising antipyretic, anti-plasmodial and antioxidant effects.