title: Effects of a synthetic analog of polycavernoside A on human neuroblastoma cells.
abstract: BACKGROUND
  Polycavernoside A is a glycosidic marine toxin first extracted from the red alga Polycavernosa tsudai in 1991 when 3 people died after the ingestion of this food. Polycavernoside A is an interesting molecule because of its complex macrolide structure and strong bioactivity. However, the target site of this toxin has not been characterized.
  
  
  METHODS
  We studied the effects of a synthethic analog of polycavernoside A on human neuroblastoma cells by measuring changes in membrane potential with bis-oxonol and variations in intracellular calcium levels with fura-2. Fluorescent phalloidin was utilized for assaying activity on actin cytoskeleton.
  
  
  RESULTS
  Data showed that this polycavernoside A analog induced a membrane depolarization and an increase in cytosolic calcium levels.
  
  
  CONCLUSIONS
  These results provide the first insight into the mode of action of polycavernoside A, suggesting that: i) this toxin triggers an initial extracellular calcium entry neither produced across L-type voltage-gated calcium channels nor activation of muscarinic receptors ii) there is a depolarization induced by the toxin and due to the extracellular calcium entry.
authors.affiliation: Departamento de Farmacologia. Facultad de Veterinaria. Universidad de Santiago de Compostela. Campus de Lugo. Lugo, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Cagide
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Louzao
authors.forename: Isabel R
authors.initials: IR
authors.lastname: Ares
authors.forename: Mercedes R
authors.initials: MR
authors.lastname: Vieytes
authors.forename: Mari
authors.initials: M
authors.lastname: Yotsu-Yamashita
authors.forename: Leo A
authors.initials: LA
authors.lastname: Paquette
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yasumoto
authors.forename: Luis M
authors.initials: LM
authors.lastname: Botana
mesh_terms: D000199:Actins / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology / Q000502:physiology; D002121:Calcium Channel Blockers; D045744:Cell Line, Tumor; D003600:Cytosol / Q000378:metabolism; D004187:Disaccharides / Q000494:pharmacology*; D004347:Drug Interactions; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D008564:Membrane Potentials; D015394:Molecular Structure; D009447:Neuroblastoma / Q000188:drug therapy*; D009532:Nickel / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000199:Actins; D002121:Calcium Channel Blockers; D004187:Disaccharides; D018942:Macrolides; C121303:polycavernoside A; D009532:Nickel; D009543:Nifedipine; D002118:Calcium