In vivo antiplasmodial and antipyretic activities of ethanol leaf extract of ananas comosus (L.) merr

Abstract

Ananas comosus (L.) Merr. (Bromeliaceae), an important herb used traditionally in the treatment of malaria, fever and other diseases was evaluated for antiplasmodial and antipyretic activities to ascertain the folkloric claim of its antimalarial and antipyretic activities. The leaf extract (150-450 mg/kg) was investigated for suppressive and curative antiplasmodial activities against chloroquine-sensitive Plasmodium berghei infection in Swiss albino mice and for antipyretic activity against D-amphetamine, 2,4-dinitrophenol and yeast-induced pyrexia. Artesunate (5 mg/kg) was used as a positive control for antiplasmodial models and acetyl salicylic acid (ASA),(100 mg/kg) was used as a standard for antipyretic models. Thin films made from tail blood of each mouse were used to assess the level of parasitaemia of the mice. The leaf extract progressively reduced parasitaemia induced by chloroquine-sensitive P. berghei infection in suppressive (3.00-36.09%), and curative (14.87– 98.22%) models in mice. These reductions were statistically significant (p<0.01–0.001).They also improved significantly (p<0.01–0.001)the mean survival time (MST)from 13.75 to 26.10 d in curative model relative to control (13.75 d). The extract exerted considerable inhibition of pyrexia on amphetamine, dinitrophenol and yeast-induced pyrexia (5 h).Inhibitions were significant (p<0.05–0.001)from 3 to 5 h post-administration of extract and in a dose-dependent fashion. The plant may possess antiplasmodial and antipyretic effects which may in part be mediated through the chemical constituents of the plant.