Marine benthic diatoms contain compounds able to induce leukemia cell death and modulate blood platelet activity.
In spite of the high abundance and species diversity of diatoms, only a few bioactive compounds from them have been described. The present study reveals a high number of mammalian cell death inducing substances in biofilm-associated diatoms sampled from the intertidal zone. Extracts from the genera Melosira, Amphora, Phaeodactylum and Nitzschia were all found to induce leukemia cell death, with either classical apoptotic or autophagic features. Several extracts also contained inhibitors of thrombin-induced blood platelet activation. Some of this activity was caused by a high content of adenosine in the diatoms, ranging from 0.07 to 0.31 microg/mg dry weight. However, most of the bioactivity was adenosine deaminase-resistant. An adenosine deaminase-resistant active fraction from one of the extracts was partially purified and shown to induce apoptosis with a distinct phenotype. The results show that benthic diatoms typically found in the intertidal zone may represent a richer source of interesting bioactive compounds than hitherto recognized.
Prestegard
Siv Kristin
SK
Department of Biology, University of Bergen, Jahnebakken 5, Bergen, Norway. siv.prestegard@bio.uib.no
Oftedal
Linn
L
Coyne
Rosie Theresa
RT
Nygaard
Gyrid
G
Skjaerven
Kaja Helvik
KH
Knutsen
Gjert
G
Døskeland
Stein Ove
SO
Herfindal
Lars
L
D000241:Adenosine / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D018441:Biofilms; D001685:Biological Factors / Q000494:pharmacology*; D045744:Cell Line, Tumor; D017377:Diatoms / Q000378:metabolism*; D004354:Drug Screening Assays, Antitumor; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects; D006801:Humans; D007938:Leukemia; D008297:Male; D008969:Molecular Sequence Data; D015539:Platelet Activation / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
D000970:Antineoplastic Agents; D001685:Biological Factors; D000241:Adenosine