title: Differential oxidative stress responses to pure Microcystin-LR and Microcystin-containing and non-containing cyanobacterial crude extracts on Caco-2 cells.
abstract: Cyanobacterial blooms are a worldwide problem due to the production of cyanotoxins such as microcystins (MCs), causing serious water pollution and public health hazard to humans and livestock. Oxidative stress plays a significant role in MCs toxicity. In the present work the differential oxidative stress responses to pure MCs, and Microcystin-containing and non-containing cyanobacterial crude extracts on the human colon carcinoma cell line Caco-2 has been studied for the first time. After exposure, cells were collected and the antioxidant enzymes activities superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) were measured. Moreover, lipid peroxidation (LPO) induction, reactive oxygen species (ROS) and reduced glutathione (GSH) content were also analyzed. The oxidative stress biomarkers that experienced higher alterations were ROS, CAT, SOD and GR activities. The MC containing cyanobacterial extract showed the higher toxic effects, followed by pure MC-LR. The non-MC containing cyanobacterial extract showed limited effects mainly in SOD activity, GSH content, and GP and GR activities only at the highest concentration used. These results suggest that MC-LR is the responsible of the oxidative stress responses observed in Caco-2 cells, but other compounds contained in the cyanobacterial extracts can contribute to the toxic effects.
authors.affiliation: Area of Toxicology, Faculty of Pharmacy, University of Seville, Profesor García González 2, 41012 Seville, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Puerto
authors.forename: Silvia
authors.initials: S
authors.lastname: Pichardo
authors.forename: Angeles
authors.initials: A
authors.lastname: Jos
authors.forename: Ana I
authors.initials: AI
authors.lastname: Prieto
authors.forename: Emma
authors.initials: E
authors.lastname: Sevilla
authors.forename: José E
authors.initials: JE
authors.lastname: Frías
authors.forename: Ana M
authors.initials: AM
authors.lastname: Cameán
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D018938:Caco-2 Cells; D002470:Cell Survival / Q000187:drug effects; D000458:Cyanobacteria / Q000737:chemistry*; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008387:Marine Toxins; D052998:Microcystins / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D008387:Marine Toxins; D052998:Microcystins; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; C057862:cyanoginosin LR; D005978:Glutathione