Phytochemical profile and antioxidant potential of two medicinal plant extracts used in the traditional treatment of malaria in Abengourou (Eastern Côte d'Ivoire)

Abstract

Malaria, like many infectious or chronic diseases, is often associated with excessive production of free radicals. Supplementation with antioxidant compounds could thus promote faster recovery. This study evaluated the antioxidant activity of hydroethanolic extracts from the leaves of Momordica charantia (Cucurbitaceae) L. and Periploca nigrescens (Apocynaceae) Afzel., two plants traditionally used to treat malaria. Sterols, polyterpenes, polyphenols, flavonoids, tannins, quinones, and alkaloids were identified using specific chemical reactions. The total phenol and flavonoid contents were determined using Folin-Ciocalteu reagent and sodium nitrite. Radical scavenging activity was assessed using the DPPH and ABTS assays, and the reducing power was evaluated using the ferric ion reduction method (FRAP assay). The results show that Momordica charantia had the highest concentrations of total polyphenols (200.2 ± 0.92 mg EAG/g) and flavonoids (101.3 ± 1.41 mg ECA/g). The IC₅₀ values for DPPH were 6.92 µg/mL for Periploca nigrescens and 8.28 µg/mL for Momordica
charantia. For the ABTS test, inhibition rates ranged from 0.79 ± 0.02 µM Eq Trolox/g for Momordica charantia to 0.65 ± 0.01 µM Eq Trolox/g for Periploca nigrescens. The extracts showed low chelation powers compared to EDTA. These findings suggest that the extracts possess antioxidant properties that may reduce oxidative stress and enhance the immune system. This justifies their use in traditional malaria treatment.