title: Apoptotic activity of the marine diatom Cocconeis scutellum and eicosapentaenoic acid in BT20 cells.
abstract: BACKGROUND
  The marine diatoms Cocconeis scutellum Ehrenberg (Bacillariophyceae) are known to trigger apoptosis in the androgenic gland of the Mediterranean crustacean Hippolyte inermis Leach (Decapoda), affecting the shrimp's sex reversal.
  
  
  OBJECTIVE
  The aim of this study was to evaluate a possible apoptotic effect of extracts and fractions from these microalgae also on human tissues.
  
  
  METHODS
  The chemical profile of C. scutellum was determined by gas chromatography-mass spectrometry (GC-MS) and, afterwards, organic extracts and fractions from the diatoms were used to treat to breast cancer BT20 cells. Double labeling with annexin V-FITC and isotonic propidium iodide (PI) along with flow cytometry analysis enabled the evaluate of cell apoptosis and viability, whereas hypotonic PI staining was used to analyze the cell cycle in BT20 lines. The involvement of specific caspases was studied by Western blotting.
  
  
  RESULTS
  Results demonstrated that the diethyl ether extract and, in particular, fraction 3, the richest fraction in eicosapentaenoic acid (EPA) from the diethyl ether extract, selectively induced apoptosis (up to 89.2% at 1 μg/well of fraction 3) and decreased viability in BT20 cells. The apoptotic effect was displayed in a concentration and time-dependent manner, by activating caspases-8 and 3, and arresting the progression of the cell cycle from S to G2-M phase. EPA alone showed similar apoptotic effects in BT20 cells.
  
  
  CONCLUSIONS
  The study demonstrates the apoptotic activity of C. scutellum diatoms on breast cancer cells and suggests their potential use as a source of apoptotic compounds.
authors.affiliation: Department of Natural Products, Plant Biology and Soil Science, Faculty of Pharmacy, University of Barcelona, Spain. mnappo79@libero.it
authors.forename: Michela
authors.initials: M
authors.lastname: Nappo
authors.forename: Strahil
authors.initials: S
authors.lastname: Berkov
authors.forename: Carlotta
authors.initials: C
authors.lastname: Massucco
authors.forename: Valentina
authors.initials: V
authors.lastname: Di Maria
authors.forename: Jaume
authors.initials: J
authors.lastname: Bastida
authors.forename: Carles
authors.initials: C
authors.lastname: Codina
authors.forename: Conxita
authors.initials: C
authors.lastname: Avila
authors.forename: Patrizia
authors.initials: P
authors.lastname: Messina
authors.forename: Valerio
authors.initials: V
authors.lastname: Zupo
authors.forename: Simona
authors.initials: S
authors.lastname: Zupo
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000473:pathology*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005591:Chemical Fractionation; D017377:Diatoms / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D015118:Eicosapentaenoic Acid / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004789:Enzyme Activation; D005260:Female; D005434:Flow Cytometry; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D059807:S Phase Cell Cycle Checkpoints / Q000187:drug effects; D012997:Solvents / Q000737:chemistry; D013997:Time Factors
chemical_list: D000970:Antineoplastic Agents; D012997:Solvents; D015118:Eicosapentaenoic Acid; C505407:CASP3 protein, human; C505530:CASP8 protein, human; D053148:Caspase 3; D053181:Caspase 8