Phytochemical Profile and in vitro Antiplasmodial Activity of Ximenia americana L. (Olacaceae) and Waltheria indica L. (Sterculiaceae)

Abstract

Ximenia americana and Waltheria indica are used in traditional medicine in Burkina Faso for treating malaria in children aged 0–5 years. This study evaluated their phytochemical profiles, antioxidant properties, mineral contents, and in vitro antiplasmodial activities. Leaf and bark extracts of X. americana and whole-plant extracts of W. indica were prepared using solvents of increasing polarity. Phenolic and terpenoid constituents were screened by high-performance thin-layer chromatography, while total phenolic, flavonoid, and terpenoid contents were quantified using colourimetric methods. Mineral contents were determined by inductively coupled plasma atomic emission spectrometry. Antioxidant activity was assessed by DPPH radical-scavenging and ferric-ion-reduction assays. Antiplasmodial activity was evaluated against the chloroquine-sensitive 3D7 and multidrug-resistant Dd2 strains of Plasmodium falciparum by measuring parasite lactate dehydrogenase production. Aqueous leaf and bark extracts of X. americana showed high activity against 3D7, with IC₅₀ values of 4.08 ± 0.00 and 4.41 ± 0.00 µg/mL, respectively. The ethyl acetate fraction of W. indica showed good activity against Dd2, with an IC₅₀ of 7.41 ± 4.45 µg/mL. Both species contained phenolic compounds, flavonoids, terpenoids, and essential minerals and exhibited antioxidant activity. These findings support further investigation of the two species as sources of antiplasmodial and antioxidant constituents, while recognising that the present evidence is limited to in vitro assays.