Apoptogenic metabolites in fractions of the Benthic diatom Cocconeis scutellum parva.
Benthic diatoms of the genus Cocconeis contain a specific apoptogenic activity. It triggers a fast destruction of the androgenic gland in the early post-larval life of the marine shrimp Hippolyte inermis, leading to the generation of small females. Previous in vitro investigations demonstrated that crude extracts of these diatoms specifically activate a dose-dependent apoptotic process in human cancer cells (BT20 breast carcinoma) but not in human normal lymphocytes. Here, a bioassay-guided fractionation has been performed to detect the apoptogenic compound(s). Various HPLC separation systems were needed to isolate the active fractions, since the apoptogenic metabolite is highly active, present in low amounts and is masked by abundant but non-active cellular compounds. The activity is due to at least two compounds characterized by different polarities, a hydrophilic and a lipophilic fraction. We purified the lipophilic fraction, which led to the characterization of an active sub-fraction containing a highly lipophilic compound, whose molecular structure has not yet been identified, but is under investigation. The results point to the possible medical uses of the active compound. Once the molecular structure has been identified, the study and modulation of apoptotic processes in various types of cells will be possible.
Functional and Evolutionary Ecology Laboratory, Stazione Zoologica Anton Dohrn, Punta San Pietro, Ischia 80077, Italy. vzupo@szn.it.
Valerio
V
Zupo
Limnological Station, University of Zurich, Seestrasse 187, Kilchberg CH-8802, Switzerland. juttner@limnol.uzh.ch.
Friedrich
F
Jüttner
Functional and Evolutionary Ecology Laboratory, Stazione Zoologica Anton Dohrn, Punta San Pietro, Ischia 80077, Italy. chingoileima.maibam@szn.it.
Chingoileima
C
Maibam
Functional and Evolutionary Ecology Laboratory, Stazione Zoologica Anton Dohrn, Punta San Pietro, Ischia 80077, Italy. emanuela.butera@szn.it.
Emanuela
E
Butera
Limnological Station, University of Zurich, Seestrasse 187, Kilchberg CH-8802, Switzerland. blom@limnol.uzh.ch.
Judith F
JF
Blom
D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001681:Biological Assay; D002734:Chlorophyll / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D017377:Diatoms / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007814:Larva; D008387:Marine Toxins / Q000737:chemistry / Q000494:pharmacology*; D033561:Penaeidae / Q000502:physiology; D013056:Spectrophotometry, Ultraviolet
D000970:Antineoplastic Agents; D008387:Marine Toxins; D002734:Chlorophyll