title: Cytotoxicity, fractionation and dereplication of extracts of the dinoflagellate Vulcanodinium rugosum, a producer of pinnatoxin G.
abstract: Pinnatoxin G (PnTX-G) is a marine toxin belonging to the class of cyclic imines and produced by the dinoflagellate Vulcanodinium rugosum. In spite of its strong toxicity to mice, leading to the classification of pinnatoxins into the class of "fast-acting toxins", its hazard for human health has never been demonstrated. In this study, crude extracts of V. rugosum exhibited significant cytotoxicity against Neuro2A and KB cells. IC₅₀ values of 0.38 µg mL⁻¹ and 0.19 µg mL⁻¹ were estimated on Neuro2A cells after only 24 h of incubation and on KB cells after 72 h of incubation, respectively. In the case of Caco-2 cells 48 h after exposure, the crude extract of V. rugosum induced cell cycle arrest accompanied by a dramatic increase in double strand DNA breaks, although only 40% cytotoxicity was observed at the highest concentration tested (5 µg mL⁻¹). However, PnTX-G was not a potent cytotoxic compound as no reduction of the cell viability was observed on the different cell lines. Moreover, no effects on the cell cycle or DNA damage were observed following treatment of undifferentiated Caco-2 cells with PnTX-G. The crude extract of V. rugosum was thus partially purified using liquid-liquid partitioning and SPE clean-up. In vitro assays revealed strong activity of some fractions containing no PnTX-G. The crude extract and the most potent fraction were evaluated using full scan and tandem high resolution mass spectrometry. The dereplication revealed the presence of a major compound that could be putatively annotated as nakijiquinone A, N-carboxy-methyl-smenospongine or stachybotrin A, using the MarinLit™ database. Further investigations will be necessary to confirm the identity of the compounds responsible for the cytotoxicity and genotoxicity of the extracts of V. rugosum.
authors.affiliation: Ifremer, Laboratoire Phycotoxines, Centre Atlantique, 44311 Nantes Cedex, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Geiger
authors.forename: Gwenaëlle
authors.initials: G
authors.lastname: Desanglois
authors.forename: Kevin
authors.initials: K
authors.lastname: Hogeveen
authors.forename: Valérie
authors.initials: V
authors.lastname: Fessard
authors.forename: Thomas
authors.initials: T
authors.lastname: Leprêtre
authors.forename: Florence
authors.initials: F
authors.lastname: Mondeguer
authors.forename: Yann
authors.initials: Y
authors.lastname: Guitton
authors.forename: Fabienne
authors.initials: F
authors.lastname: Hervé
authors.forename: Véronique
authors.initials: V
authors.lastname: Séchet
authors.forename: Olivier
authors.initials: O
authors.lastname: Grovel
authors.forename: Yves-François
authors.initials: YF
authors.lastname: Pouchus
authors.forename: Philipp
authors.initials: P
authors.lastname: Hess
mesh_terms: D000470:Alkaloids / Q000737:chemistry* / Q000494:pharmacology*; D018938:Caco-2 Cells; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects; D004141:Dinoflagellida / Q000737:chemistry*; D006801:Humans; D007624:KB Cells; D008387:Marine Toxins / Q000737:chemistry* / Q000494:pharmacology*; D013141:Spiro Compounds / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D000470:Alkaloids; D008387:Marine Toxins; D013141:Spiro Compounds; C552840:pinnatoxin G