Abstract

Marine algae represent a potent source of anticancer agents. Brown alga, Padina pavoniaL. was collected from Adriatic Sea, Montenegro. Cytotoxic and apoptosis effects were tested against human cervix (HeLa) and breast cancer (MDA-MB-453) cell lines. P. pavoniamethanol extract possesses cytotoxic activity with IC₅₀ values 86.45 μg/ml related to HeLa cell and 74.59 μg/ml related to MDA-MB-453 cell. The extracts did not exert any significant cytotoxicity toward normal human fetal lung fibroblast cells (MRC-5). Reduction in the number of cells with distorted shapes and condensation of cytoplasm was noticed. An increase in cells containing sub-G1 amounts of DNA was observed, indicating that the tested extract induced apoptosis. Nuclear DNA laddering was noted 24 h after the HeLa cells were exposed to 2´IC₅₀ concentration of P. pavonia methanol extract. As brown algae represent a rich source of polysaccharides and glycosides, this activity could be connected with these compounds, but also with phenolics detected in examined extract (12.2 mg gallic acid equivalents/g dry weight (GAE/g dry weight).

Key words: Brown alga, HeLa, MDA-MB-453, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test.