Advances in Biology & Earth Sciences

This study investigates the cytotoxic and antimicrobial activities of methanolic extracts derived from Cystoseira foeniculacea and Sargassum vulgare, two edible brown algae collected from the Mediterranean Sea. Cytotoxic effects were assessed on HepG2, MCF-7 and MDA-MB-231 cell lines, while antimicrobial activity was evaluated against clinically relevant bacteria and yeast strains. Cystoseira foeniculacea exhibited potent antiproliferative effects, particularly on HepG2 (IC₅₀: 35.25 µg/mL) and MCF-7 (IC₅₀: 105.5 µg/mL) cells. In contrast, Sargassum vulgare displayed limited cytotoxicity but demonstrated selective antimicrobial activity against Enterococcus faecalis and Candida albicans, with MIC values of 128 µg/mL and 512 µg/mL, respectively. Both extracts were ineffective against Gram-negative bacteria. The findings highlight species-specific therapeutic potential and support further investigation of these macroalgae as sources of multi-target natural products. Future work should focus on bioactivity-guided fractionation and in vivo validation.