Neuroactive compounds produced by bacteria from the marine sponge Halichondria panicea: activation of the neuronal NMDA receptor
Abstract Previous studies revealed that the marine sponge Halichondria panicea habors symbiotic- and commensalic bacteria ( Althoff et al., 1998 . Marine Biol. 130, 529–536). In the present study the hypothesis was tested whether some of those bacteria synthesize neuroactive compounds. For the first time the effect of bacterial bioactive compounds on the neuronal ionotropic glutamate receptors [iGluR], subtype N -methyl- d -aspartate (NMDA) receptor, was checked. In cortical neurons from rats as cell system the supernatant of two bacterial cultures isolated from H. panicea proved to agonize the NMDA receptor. The response of the NMDA receptor to the bioactive compounds was determined by mea…
Changes of ICE protease activities caused by toxic supernatants of dinoflagellates (Prorocentrum species) from marine algal blooms
Summary Marine phytotoxins may become a major health problem for humans because of their ability to contaminate seafood and to cause shellfish poisoning. In this report, the cytotoxic effects and the effects on intracellular caspase activities of culture supernatants from different dinoflagellate Prorocentrum clones were determined. Among the clones tested, P. tepsium BAH ME-140 and P. lima BAH ME-130 K1 and K2 clones but not P. minimum and P. micans were found to be toxic on rat pheochromocytoma PC12 cells, mouse lymphoma L5178Y cells and rat primary neurons. A significant increase in the specific activities of caspase 1 (ICE), caspase 3 (CPP32) and caspase 6 (Mch2) to 149–167% was observe…