Exploring the therapeutic potential of brown seaweed Sargassum cristaefolium: in vitro and in silico insights into antioxidant, antibacterial, and anticancer properties.

Marine algae are known for producing a wide variety of bioactive secondary metabolites. The present study investigated both in vitro and in silico approaches to evaluate the antioxidant, antibacterial, and anticancer properties of brown seaweed Sargassum cristaefolium, aim of assessing its biological activities. Preliminary phytochemical analysis revealed the presence of eight phytochemical constituents exhibiting notable biological properties. The seaweed extract was characterized using FT-IR and GC-MS, which identified various functional groups, including alkanes and anhydrides as well as bioactive compounds. Among these, phytol (3.66%) was the major bioactive compound in the ethanolic extract. The extract also demonstrated strong antioxidant activity, with an IC₅₀ value of less than 127.96 µg/mL. Furthermore, ethanolic extract exhibited significant antibacterial activity against Mycobacterium smegmatis (15.3 ± 0.50 mm) and anticancer efficiency against the A549 lung cancer cell line with an IC50 value of 222 µg/mL. Computational analysis identified key compounds from S. cristaefolium, which showed strong binding affinities towards specific proteins such as DNA gyrase, human peroxiredoxin 6, and epidermal growth factor receptor (EGFR), supporting their potential as antioxidant, anticancer, and antibacterial agents for novel drug development. Supplementary Information: The online version contains supplementary material available at 10.1007/s40203-025-00465-8.