Antiplasmodial Activity of a New Chemotype of Croton sylvaticus Hochst. Ex C. Krauss Essential Oil.

Abstract

Croton sylvaticus, a tropical African plant, is traditionally used to treat several diseases, including fever, inflammation, and malaria. Essential oils (EOs) from the plant's leaves, roots, and trunk bark were obtained by hydrodistillation, and their chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). The major constituents identified were virdiflorene (18.13 ± 0.46%) in root EO, (E)-β-caryophyllene (18.40 ± 0.60%) in trunk bark EO, and farnesyl acetone (15.26 ± 0.25%) in leaf EO. Notably, Cameroonian C. sylvaticus leaf EO exhibited a distinct and newly described chemotype with high levels of farnesyl acetone, β-copaene-4-α-ol, β-cadinene, α-humulene, and trans-longipinocarveol. In vitro testing revealed significant antiplasmodial activity against Plasmodium falciparum asexual (Pf3D7) and sexual (NF-54 strain) stages, with trunk bark EO showing the highest potency (IC₅₀: 9.06 ± 2.15 µg/mL for Pf3D7 and 0.56 µg/mL for gametocytes). These findings support the traditional antimalarial use of C. sylvaticus and represent the first chemical profile and antiplasmodial efficacy report for its root and trunk bark EOs against both parasite stages. To the best of our knowledge, we also report for the first time the antiplasmodial activity of an EO that exerts significant activity against both the asexual and sexual forms of P. falciparum.