Hepatologie und Pankreaswissenschaft

Antioxidant enzyme characterization in the liver of Mediterranean barbel (Barbus merdionalis) from Osor river (Catalonia)

Abstract

Guluzu Atli , Helena Guasch and Francesc Rubio Gracia

Antioxidant system parameters have still gained considerable importance due to their pivotal role in detoxification mechanisms. Optimization assays were carried out for antioxidant enzymes (Superoxide dismutase (SOD); Catalase (CAT); Glutathione peroxidase (GPX); Glutathione reductase (GR) and Glutathione S-transferase (GST) in the liver of Mediterranean barbel (Barbus meridionalis). The characterization of the antioxidant enzymes was carried out for several incubation media parameters. For the pH optimization, the range of 6.0-8.0 was assayed and the maximal enzyme activities were found at pH 7.0 for SOD and GPX and pH 7.5 for the CAT, GST and GR. Phosphate buffer concentrations in the range of 50-150mM were examined and generally, all enzymes showed their highest activities at 100mM phosphate buffer except SOD activity which was maximally at 150mM. Specific enzyme activity (Vmax) and Km values were also determined. Optimal values of other incubation media for each antioxidant enzyme were mostly found in similar ranges when compared to several fish species in the literature. Characterization assays of these parameters in native fish based on its physiological and ecological importance may be useful for biomonitoring of aquatic ecosystems health and also present fundamental data for utilization in further studies in the area of ecotoxicology.