Structural Characterization and Cytotoxic Effects of Bioactive Compounds Isolated from Caulerpa sertularioides Against Human Cancer Cell Lines

Compounds isolated from the macroalga Caulerpa sertularioides have been reported to exhibit cytotoxic activity. The objective of this study was to assess the antioxidant effects of compounds isolated from C. sertularioides as well as their antiproliferative effect against cancerous cell lines and to elucidate their chemical structure. The antiproliferative activity of C. sertularioides extracts was evaluated using the MTT standard assay in cancerous and non-cancerous cell lines. Morphological changes were observed via fluorescence microscopy, and the chemical structure of bioactive compounds was determined by nuclear magnetic resonance. Antioxidant activity was assessed using ABTS and DPPH methods. Among all extracts, the acetone extract exhibited the highest antioxidant activity (IC50 of 27.3 ± 6.1 μg/mL) in the ABTS assay, which classifies it as a very potent antioxidant. Among the tested extracts, the hexane extract showed the strongest antiproliferative activity in breast (MDA-MB-231) and cervical cancer (HeLa) cell lines. The most active fraction (F15), obtained by open-column chromatography of hexane extract, exhibited the highest bioactivity against the MDA-MB-231 cell line (IC50 of 55 ± 3.1 µg/mL); these cells exhibited morphological changes consistent with apoptosis. NMR analysis revealed signals tentatively assigned to 1-monolinolein, glycerol, bis(2-ethylhexyl) phthalate and bis(2-ethylhexyl) terephthalate. These findings support the potential of C. sertularioides as a source of bioactive compounds with antioxidant and antiproliferative properties.