Chemical Composition, Antioxidant and Antibacterial Activities of Extracts from Sesbania sesban Organs Growing in Egypt

Sesbania sesban is a multipurpose leguminous tree widely utilized in agroforestry and traditional medicine. However, its phytochemical composition and bioactivities remain insufficiently characterized, particularly for tree organs cultivated in Egypt. To the best of our knowledge, this is the first comprehensive study to investigate the chemical composition, antioxidant potential, and antibacterial activities of methanolic extracts derived from various organs of S. sesban—including leaves, fruits, bark, wood branches, and roots. Gas chromatography–mass spectrometry (GC–MS) analysis revealed a diverse array of bioactive compounds, such as fatty acids (palmitic, oleic, linoleic), sterols (β-sitosterol, stigmasterol, campesterol), triterpenoids (lupeol, betulin, oleanolic acid, ursolic acid), phenolics, and vitamin E. Quantitative assays demonstrated significant organ-specific variations: leaves exhibited the highest total phenolic content (45.0 ± 2.0 mg TAE/g), flavonoid content (20.0 ± 1.0 mg CAE/g), and antioxidant activity (TAA = 70.0 ± 2.0%, IC₅₀ = 22.0 ± 1.0 µg/mL). Antibacterial assessments showed that leaf extracts possessed notable inhibitory and bactericidal effects against both Gram-positive and Gram-negative bacteria (MIC 4–32 µg/mL, MBC 8–64 µg/mL), comparable to standard antibiotics. Bark and fruit extracts exhibited moderate activity, while root and wood branch extracts showed limited effects. The novelty of this study lies in its organ-specific and solvent-dependent phytochemical and bioactivity profiling of S. sesban cultivated in Egypt. These findings underscore the potential of S. sesban as a natural source of potent antioxidant and antibacterial agents, offering valuable insights for future nutraceutical, pharmaceutical, and industrial applications.