Background: Drug-phytochemical interactions sometimes result in various unpredictable outcomes.
Objective: The aim of this study was to evaluate the in vivo antiplasmodial activity of the aqueous leaf extract of Telfairia occidentalis and its potentiation of the activity of amodiaquine (AQ) and dihydroartemisinin (DHA) on mice infected with Plasmodium berghei.
Method: Phytochemical screening of the extract was carried out using standard procedures. The extract prepared in 250 and 500 mg/kg/body weight together with amodiaquine and dihydroartemisinin were administered as single dose and in combination to albino mice by oral gavage, adopting the standard procedures of prophylactic, suppressive and curative antiplasmodial assay models.
Results: Phytochemical screening of the extract confirms the abundance of alkaloids, saponins and tannins. Analysis reveals a significant (p < 0.05) competitive reduction of parasitaemia by the conventional drugs and the extract in a dose dependent order. The aqueous extract of T. occidentalis at 250 and 500 mg/kg gave a percentage parasitaemia reduction of 83.90 % and 85.00% respectively when compared to the negative control. The concurrent administration of the extract and the drugs produced a synergistic effect in a dose-dependent order. When AQ plus DHA were administered concurrently with 250 mg/kg and 500 mg/kg of extract, the percentage reduction in parasitaemia increased to 99.50 % and 99.59 % respectively.
Conclusion: This shows that the aqueous extract of T. occidentalis possesses significant (P < 0.05) antiplasmodial activity which is comparable to AQ and DHA. It also enhances the efficacy of the standard drugs which indicates an advantage in the treatment of uncomplicated falciparum malaria.