Induction of oxidative stress in the red macroalga Gracilaria tenuistipitata by pollutant metals

• Published in: Archives of environmental contamination and toxicology 2003-10, Vol.45 (3), p.337-342
• Main Authors: COLIEN, J, PINTO, E, PEDERSEN, M, COLEPICOLO, P
• Format: Article
• Language: English
• Subjects: Algae; Animal, plant and microbial ecology; Antioxidants; Antioxidants - pharmacology; Applied ecology; Ascorbate Peroxidases; Biological and medical sciences; Cadmium; Cadmium - toxicity; Carbonyl compounds; Catalase - pharmacology; Copper - toxicity; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Enzymatic activity; Fundamental and applied biological sciences. Psychology; Gracilaria tenuistipitata; Heavy metals; Lipids; Metabolism; Metal concentrations; Oxidation; Oxidative Stress; Peroxidases - pharmacology; Pollutants; Rhodophyta - physiology; Superoxide Dismutase - pharmacology; Water Pollutants - toxicity
• ISSN: 0090-4341; 1432-0703
• DOI: 10.1007/s00244-003-0196-0

Heavy metals are environmental pollutants that have the potential to induce severe stress-reactions in organisms on land as well as in the sea. We have studied effects of short term sublethal concentrations of copper (Cu2+) and cadmium (Cd2+) on the reactive oxygen metabolism of the marine red macroalga Gracilaria tenuistipitata. Additions of either 0.2 ppm Cu2+ or 1 ppm Cd2+ caused decreased growth (approximately 60%), increased oxidation of lipids and increased oxidative damage to proteins as shown by increased content of protein carbonyl groups. Together this strongly suggests an induction of oxidative stress. Cu2+ caused more oxidative damage than Cd2+. As a response to the increased oxidative stress, addition of Cu2+ induced the activities of catalase, ascorbate peroxidase, and superoxide dismutase. In contrast, Cd2+ only caused increased catalase activity. Ten-fold lower concentrations of the metals did not cause an increase in enzyme activity. Both heavy metals also increased the content of the antioxidants beta-carotene and lutein. The results show that Cd2+ and, to a larger extent, Cu2+ induce oxidative stress in short-term experiments and the seaweed responds by increasing the activity of the reactive oxygen metabolism.