title: Endosulfan induces oxidative stress and changes on detoxication enzymes in the aquatic macrophyte Myriophyllum quitense.
abstract: Endosulfan (1) is a chlorinated insecticide still in use in both developed and emerging countries. Although its toxicity on animals has been studied in the last years, scarce information is available on its effects on plants. In this study, we exposed the aquatic macrophyte Myriophyllum quitense to environmentally relevant concentrations of endosulfan (microg/L) (1) for a short time, simulating exposures that might occur after either accidental spills or toxic run-off from agricultural areas. The main goal was to evaluate changes in both detoxication and antioxidant enzymatic systems of this plant upon exposure to endosulfan (1). Thus, we measured the activities of catalase (CAT), soluble and membrane associated glutathione-S-transferases (s- and m-GSTs) and glutathione reductase (GR), as well as the hydrogen peroxide (H2O2) content. Results showed that endosulfan (1) exerts oxidative stress on M. quitense, which was evidenced by the increase of CAT activity and the H2O2 content in exposed plants. At 5 microg/L endosulfan (1), we found a generalized induction of activities of tested enzymes, indicating that this xenobiotic activates the protection system of this plant, increasing its capacity to scavenge reactive oxygen species. On the other hand, we did not find significant changes at 0.02 microg/L endosulfan (1), which is the maximal concentration allowed for freshwater. We conclude that runoff events, which can produce significant amounts of endosulfan (1) in aquatic environments during short time, can result in oxidative stress on M. quitense, and probably on similar macrophytes.
authors.affiliation: Universidad Nacional de Mar del Plata, Facultad de Cs. Ex. y Nat., Depto. Ciencias Marinas, Lab. Ecotoxicologia Funes 3350, 7600 Mar del Plata, Argentina. lujanm@mdp.edu.ar
authors.forename: Mirta L
authors.initials: ML
authors.lastname: Menone
authors.forename: Silvia F
authors.initials: SF
authors.lastname: Pesce
authors.forename: María P
authors.initials: MP
authors.lastname: Díaz
authors.forename: Víctor J
authors.initials: VJ
authors.lastname: Moreno
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Wunderlin
mesh_terms: D002374:Catalase / Q000032:analysis / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004726:Endosulfan / Q000737:chemistry / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005980:Glutathione Reductase / Q000032:analysis / Q000187:drug effects; D005982:Glutathione Transferase / Q000032:analysis / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism; D019684:Magnoliopsida / Q000187:drug effects* / Q000378:metabolism; D015394:Molecular Structure; D018384:Oxidative Stress / Q000187:drug effects*; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D006861:Hydrogen Peroxide; D002374:Catalase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D004726:Endosulfan