Antimalarial and Cytotoxic Activity of Native Plants Used in Cabo Verde Traditional Medicine

Medicinal plants have historically been a source of drugs in multiple applications, including the treatment of malaria infections. The Cabo Verde archipelago harbors a rich diversity of native plants, most of which are used for medicinal purposes. The present study investigated the in vitro antiplasmodial activities of four native plants from Cabo Verde (i.e., Artemisia gorgonum, Lavandula rotundifolia, Sideroxylon marginatum, and Tamarix senegalensis). Traditional preparations of these medicinal plants, namely aqueous extracts (infusions) and ethanolic extracts, were tested against both chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) Plasmodium falciparum strains using the SYBR Green detection method. The in vitro cytotoxicity was evaluated in Caco-2 and PLP2 cells using a sulforhodamine B colorimetric assay. An ethanolic extract of A. gorgonum and infusions of T. senegalensis exhibited high antiplasmodial activities (EC₅₀ < 5 μg/mL) without cytotoxicity (GI₅₀ > 400 μg/mL). Extracts of L. rotundifolia and S. marginatum exhibited moderate activities, with EC₅₀ values ranging from 10-30 μg/mL. The A. gorgonum ethanolic extract showed activity toward early ring stages, and parasites treated with the T. senegalensis infusions progressed to the early trophozoite stage, although did not develop further to the late trophozoite or schizont stages. Antimalarial activities and the lack of cytotoxicity of the extracts are reported in the present study and support previous claims by traditional practitioners for the use of these plants against malaria while suggesting their ethnopharmacological usefulness as future antimalarials.