Cystoseira barbata C. Agardh from Romanian Black Sea coast : phlorotannins profile, in vitro antioxidant and antiproliferative potential

The Romanian Black Sea has abundant seaweed resources, but little effort has been done to screen their biological potential. The aim of the present study was to assess the in vitro antioxidant and antiproliferative activities of Cystoseira barbata Sargassaceae a brown alga inhbiting the costal line of Romanian Black Sea. 70% acetone, methanol and water were used for the extraction of the algal material. The antioxidant activity of C. barbata extracts was assessed by DPPH and ABTS radicals scavenging assays, reducing power and 15-lipoxygenase inhibition assays. Cytotoxic activity of the extracts was determined by MTT viability assay using three adenocarcinoma cell lines (mammary MCF-7, alveolar A549 and colorectal HT-29). The effect of the extracts in cell cycle distribution was evaluated using flow cytometry (FACS) [1],[2]. 70% acetone extract exhibited the highest antioxidant activities in all assays, with IC50 values comparable or higher than those of known antioxidants. The antitumor tests showed that 70% acetone extract had the most potent antiproliferative effects. MCF-7 was the most sensitive of all cell lines examined. FACS analysis revealed that the 70% acetone extract induced a significant increase in the subG1 fraction in MCF-7 and A549 cells, indicative of apoptosis induction. From these findings, the 70% acetone extract was investigated by HPLC-DAD-QTOF-ESI-MS/MS [3]; phlorotannins with molecular weights ranging from 375 to 870 Da were tentatively identified on the basis of their characteristic MS/MS fragmentation pattern. In conclusion, Cystoseira barbata represents an important source of bioactive compounds, with potential use in food and pharmaceutical industries.