ABSTRACT
Undaria pinnatifida (U. pinnatifida) is a highly invasive species and has caused concern all over the world because it has invaded coastal environments, has the potential to displace native species, significantly alters habitat for associated fauna, and disturbs navigation. Any attempt to eradicate it would be futile, owing to the elusive, microscopic gametophyte, and because the alga thrives in sites rich in anthropic activities. Venice Lagoon is the largest Mediterranean transitional environment and the spot of the highest introduction of non-indigenous species, including U. pinnatifida, which is removed as a waste. We demonstrated that polysaccharide extracts from U. pinnatifida have an anticoagulant effect on human blood in vitro and are not cytotoxic. The results obtained by PT (normal values 70-120%) and APTT (normal values 28-40s) assays were significantly prolonged by the polysaccharide extracts of U. pinnatifida, therefore algal extracts are ideal candidates as antithrombotic agents.