Metal accumulation and oxidative stress biomarkers in octopus (Octopus vulgaris) from Northwest Atlantic

摘要

Metals are ubiquitous in the environment and accumulate in aquatic organisms and are known for their ability toenhance the production of reactive oxygen species (ROS). In aquatic species, oxidative stress mechanisms havebeen studied by measuring antioxidant enzyme activities and oxidative damages in tissues. The aim of thisstudy was to apply and validate a set of oxidative stress biomarkers and correlate responses with metal contentsin tissues of common octopus (Octopus vulgaris). Antioxidant enzyme activity (catalase — CAT, superoxide dismutase— SOD and glutathione S-transferases — GST), oxidative damages (lipid peroxidation — LPO and proteincarbonyl content — PCO) andmetal content (Cu, Zn, Pb, Cd and As) in the digestive gland and armof octopus, collectedin the NWPortuguese coast in different periods, were assessed after capture and after 14 days in captivity.CAT and SOD activitieswere highly responsive to fluctuations inmetal concentrations and able to reduce oxidativedamage, LPO and PCO in the digestive gland. CAT activity was also positively correlated with SOD and GST activities,which emphasizes that the three enzymes respond in a coordinated way to metal induced oxidative stress.Our results validate the use of oxidative stress biomarkers to assess metal pollution effects in this ecological andcommercial relevant species.Moreover, octopus seems to have the ability to control oxidative damage by triggeringan antioxidant enzyme coordinated response in the digestive gland.