Screening of the Antarctic marine sponges (Porifera) as a source of bioactive compounds

Sponges (Porifera) currently represent one of the richest sources of natural products and account for almost half of the pharmacologically active compounds of marine origin. However, to date very little is known about the pharmacological potential of the sponges from polar regions. In this work we report on screening of ethanolic extracts from 24 Antarctic marine sponges for different biological activities. The extracts were tested for cytotoxic effects against normal and transformed cell lines, red blood cells, and algae, for modulation of the activities of selected physiologically important enzymes (acetylcholinesterase, butyrylcholinesterase, and alpha-amylase), and for inhibition of growth of pathogenic and ecologically relevant bacteria and fungi. An extract from Tedania (Tedaniopsis) oxeata was selectively cytotoxic against the cancer cell lines and showed growth inhibition of all of the tested ecologically relevant and potentially pathogenic fungal isolates. The sponge extracts from Isodictya erinacea and Kirkpatrickia variolosa inhibited the activities of the cholinesterase enzymes, while the sponge extracts from Isodictya lankesteri and Inflatella belli reduced the activity of alpha-amylase. Several sponge extracts inhibited the growth of multiresistant pathogenic bacterial isolates of different origins, including extended-spectrum beta-lactamase and carbapenem-resistant strains, while sponge extracts from K. variolosa and Myxilla (Myxilla) mollis were active against a human methicillin-resistant Staphylococcus aureus strain. We conclude that Antarctic marine sponges represent a valuable source of biologically active compounds with pharmacological potential.