Abstract Description

Medicinal plants remain a valuable source of pharmacologically active compounds, yet many species remain underexplored. Erythrina caffra, a South African medicinal plant known for its rich phytochemical profile, has undergone limited biological evaluation, restricting its potential in drug discovery. This study investigated the chemical constituents of E. caffra leaves and stem bark and evaluated the cytotoxic, antioxidant, and anti-inflammatory activities of its extracts and isolated compounds. The extract of leaves and stem bark were profiled by LC–MS/MS, and compounds were tentatively identified using MassLynx and the natural product databases LOTUS and npatlas. Isolation of constituents was achieved through open-column chromatography, and structures were elucidated using 1D/2D NMR and HRESIMS data. Cytotoxicity was assessed using resazurin and Crystal Violet assays in HaCaT (keratinocytes), NHEM-Ad (melanocytes), HEK293 (embryonic kidney cells), and HepG2 (hepatoblastoma) cell lines. Antioxidant activity was determined using ORAC and ABTS assays, while anti-inflammatory potential was evaluated by NO inhibition. Twenty-one secondary metabolites were isolated and characterized, including flavonoids, phenolic acids, carotenoids, fatty acids, steroids, and one cerebroside. LC–MS/MS profiling further confirmed the presence of 52 compounds subdivided into phenolic acids, flavonoids, carotenoids, and steroids. Cytotoxicity results demonstrated that the crude extract, fractions, and most isolated compounds were non-toxic or exhibited very low toxicity across all tested cell lines. Several isolated compounds showed varying degrees of antioxidant activity, while only the methanol extract and one isolated metabolite significantly inhibited NO production. The chemical investigation of E. caffra revealed a diverse metabolite profile, including structurally interesting compounds, and demonstrated limited cytotoxicity in normal human cell lines. These findings provide new insight into the phytochemical composition of E. caffra, support its traditional medicinal use, particularly in pain and inflammation management, and highlight its potential as a safe source of bioactive natural products.