Bioactive seed oils of mangrove associates: Phytochemical profiling, antioxidant activity and <i>in vitro</i> cytotoxicity studies

Mangrove-associated plants are rich reservoirs of unique bioactive compounds, owing to their adaptation to harsh coastal environments, yet many remain underexplored for their therapeutic potential. Seed oils from such species offer a promising source of natural antioxidants and anticancer agents. The present study aimed to conduct phytochemical characterization, antioxidant assessment, and anticancer evaluation of seed oils extracted from selected mangrove-associated plants — Thespesia populnea, Canavalia cathartica, and Derris trifoliata — using n-hexane via Soxhlet extraction. Preliminary phytochemical screening revealed that T. populnea oil possessed the highest total phenolic (65.27 ± 0.25 mg GAE/g) and flavonoid (233.57 ± 1.51 mg QE/g) contents. Gas Chromatography–Mass Spectrometry (GC–MS) and High-Performance Thin-Layer Chromatography (HPTLC) profiling confirmed the presence of diverse bioactive compounds such as tocopherols, flavonoids, sterols, terpenoids, and polyunsaturated fatty acids (PUFAs). Antioxidant activity was assessed through 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS·+) and Superoxide Dismutase (SOD) assays showed that oil of T. populnea exhibited the strongest radical scavenging ability, correlating with its rich flavonoid content. In contrast, D. trifoliata seed oil demonstrated significant cytotoxicity against Dalton’s Lymphoma Ascites (DLA) cells (IC50 of 62.3 µg/mL) and moderate antiproliferative activity against MCF-7 breast cancer cells (EC50 of 80.50 µg/mL), supported by morphological evidence of apoptosis. These bioactivities are likely attributed to the presence of phytochemicals such as the triterpenoid C(14a)-Homo-27-norgammacer-14-ene, sterols like stigmasterol and γ-sitosterol, and flavonoids including rotenone. Overall, the findings suggest that these seed oils, especially those from T. populnea and D. trifoliata, offer promising prospects as sources of natural antioxidants and potential anticancer agents.