Fucoidan I nhibition of O steosarcoma C ells is S pecies 2 and M olecular W eight D ependent 3

: Fucoidan is a brown algae-derived polysaccharide having several biomedical applications. This study simultaneously compares the anticancer activities of crude fucoidans from Fucus vesiculosus and Sargassum filipendula , and effects of low (LMW, 10-50kDa), medium (MMW, 50-100kDa) and high (HMW, >100kDa) molecular weight fractions of S. filipendula fucoidan against osteosarcoma cells. Glucose, fucose and acid levels were lower and sulphation was higher in F. vesiculosus crude fucoidan compared to S. filipendula crude fucoidan. MMW had highest the levels of sugars, acids and sulphation among molecular weight fractions. There was a dose dependent drop in focal adhesion formation and proliferation of cells for all fucoidan-types, but F. vesiculosus fucoidan and HMW had the strongest effects. G1-phase arrest was induced by F. vesiculosus fucoidan, MMW and HMW, however F. vesiculosus fucoidan treatment also caused accumulation in sub G1-phase. Mitochondrial damage occurred for all fucoidan-types, however F. vesiculosus fucoidan led to mitochondrial fragmentation. Annexin V/PI, TUNEL and cytochrome c staining confirmed stress induced apoptosis-like cell death for F. vesiculosus fucoidan but features of stress-induced necrosis-like cell death for S. filipendula fucoidans. There was also variation in penetrability of different fucoidans inside the cell. These differences in anti-cancer activity of fucoidans are applicable for osteosarcoma treatment. of fucoidan. compared of two molecular weight (MW) fractions of fucoidan in the ranges of 5-30 kDa and > 30 kDa, from U. pinnatifida found there was almost 2 times stronger dose-dependent to 800 µg/ml) antiproliferative activity of 5-30 kDa compared to the > 30 kDa fraction, against cancer cell line compared < 5, 5-10, 10-30, 30-50, 50-100 and > 100 kDa of fucoidan extracts from S. muticum for their anti-cancer activity against cervical cancer (HeLa 229), ovarian cancer (A2780), (HepG2) and kidney (LLC-PK1) cells. The results showed that overall HeLa 229 and A2780 cells were more strongly inhibited than HepG2 and LLC-PK1 cells and even though the maximal sulphate content was found in the > 100 kDa fraction, the cytotoxic activity was maximal for 5–30 kDa fraction. of blebbing in the cell membrane, extensive ER-like swelling, signs of autophagosome formation, chromatin condensation and marginalization. Some other cells had broken cell or nuclear membranes and their cytoplasm was less granular or dense. The granularity of the nucleoplasm also became less in cells that appeared to be dying. The mitochondria in all these cells were swollen, very dense and seemed to be disintegrating and losing their cristae structure, which appeared like a dense matrix within the cytosol. Moreover, their distribution was visibly less in the cytosol as compared to mitochondria in control. There were also signs of cell debris and fragments, possibly of these ruptured cells, within the same sample. When these cells were compared to the cells treated with crude fucoidan from S. filipendula again there seemed to be signs of significant cell death but with some differences. The occurrence of blebs in the cells was less common and there were more cells in the sample with lost cell membrane integrity and ruptured. These cells, as well as some other less damaged cells, seem to be having visible ER-like swelling and less dense cytoplasm. The mitochondria were also very dense and swollen and their cristae structure seemed to be collapsing into a dense matrix within the mitochondria. However, other mitochondria had visible cristae structure that was not fully disintegrated but lacked orientation and were marginalized towards the edges of the mitochondrial membrane leading to development of gaps inside the mitochondria. The nucleoplasm was less granular and there were also regions of condensed filaments, which may be cytoskeletal actin-filaments in the cytosol. There were also signs of autophagosomes in a few cells but it was not common. These results indicated that while both crude fucoidans at 100 µg/ml were leading to cell death, their mechanism of action may be different.