Cytotoxicity screening of supercritical fluid extracted seaweeds and phenylpropanoids.

Detached leaves of Posidonia oceanica and Zostera marina creating nuisance at the shores were extracted by means of supercritical CO₂ enriched with a co-solvent, compared with that of soxhlet extraction. The extracts and their active compounds which are phenylpropanoids (chicoric, p-coumaric, rosmarinic, benzoic, ferulic and caffeic acids) were screened for cytotoxicity in cancer cell lines including human breast adenocarcinoma (MCF-7, MDA-MB-231, SK-BR-3), human colon adenocarcinoma (HT-29), human cervix adenocarcinoma (HeLa), human prostate adenocarcinoma (PC-3), Mus musculus neuroblastoma (Neuro 2A) cell lines and African green monkey kidney (VERO) as healthy cell line. Supercritical CO₂ extracts proved to be more active than soxhlet counterparts. Particularly, Zostera marina extract obtained by supercritical CO₂ at 250 bar, 80 °C, 20% co-solvent and a total flow rate of 15 g/min revealed the best IC₅₀ values of 25, 20, 8 μg/ml in neuroblastoma, colon and cervix cancer cell lines. Among the major compounds tested, p-coumaric acid exhibited the highest cytotoxic against colon and cervix cell lines by with IC₅₀ values of 25, 11 μg/ml. As for the effects on healthy cells, the extract was not cytotoxic indicating a selective cytotoxicity. Obtained supercritical CO₂ extracts can be utilized as a supplement for preventive purposes.