Effects of Solvents on Phytochemical Composition and Biological Activity of Solanum nigrum Leaf Extracts

Solanum nigrum leaf extracts demonstrate potential for use in cancer therapy owing to their high saponin content; however, the effect of solvent choice on phytochemical yield and biological activity remains unclear. This study evaluated the antioxidant and chemopreventive properties of S. nigrum leaf extracts prepared using different organic solvents at varying concentrations alongside phytochemical characterization via UPLC-QTOF/MS. The 50% and 70% acetone extracts exhibited the strongest antioxidant effects in DPPH and ABTS assays and demonstrated cytotoxicity against HepG2, HCT116, A375, and HeLa cell lines. A total of 32 compounds were identified. Multivariate analysis-including principal component analysis, hierarchical cluster analysis, and loading plots-revealed that solvent-water mixtures significantly enhanced extraction efficiency; 70% and 30% acetone were optimal for extracting furostane-type and spirostane-type saponins, respectively. Moreover, saponin levels are strongly correlated with antioxidant/chemopreventive activity. These findings provide a basis for maximizing the therapeutic potential and compound yields of S. nigrum leaves.