Seasonal variations of the activity of antioxidant defense enzymes in the red mullet (Mullus barbatus l.) from the Adriatic Sea.

This study investigated seasonal variations of antioxidant defense enzyme activities: total, manganese, copper zinc containing superoxide dismutase (Tot SOD, Mn SOD, CuZn SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and biotransformation phase II enzyme glutathione-S-transferase (GST) activity in the liver and white muscle of red mullet (Mullus barbatus). The investigations were performed in winter and spring at two localities: Near Bar (NB) and Estuary of the River Bojana (EB) in the Southern Adriatic Sea. At both sites, Mn SOD, GSH-Px, GR and GST activities decreased in the liver in spring. In the white muscle, activities of Mn SOD, GSH-Px, GR and GST in NB decreased in spring. GR decreased in spring in EB, while CAT activity was higher in spring at both sites. The results of Principal Component Analysis (PCA) based on correlations indicated a clear separation of various sampling periods for both investigated tissues and a marked difference between two seasons. Our study is the first report on antioxidant defense enzyme activities in the red mullet in the Southern Adriatic Sea. It indicates that seasonal variations of antioxidant defense enzyme activities should be used in further biomonitoring studies in fish species.

Combined effects of coenzyme Q(10) and Vitamin E in cadmium induced alterations of antioxidant defense system in the rat heart.

Our study investigated the possible protective effects of coenzyme Q(10) (CoQ(10)) and Vitamin E (Vit E) alone or in combination against cadmium (Cd) induced alterations of antioxidant defense system in the rat heart. Male Wistar rats were injected with a single dose of CdCl(2) (0.4mg Cd/kg BW i.p.), CoQ(10) (20mg CoQ(10)/kg BW i.m.) and Vit E (20IU Vit E/kg BW i.m.), alone or in combination. Acute intoxication of rats with Cd were followed by significantly increased activity of antioxidant defense enzymes (CuZn SOD, GSH-Px, GST and GR), while the activity of Mn SOD was decreased in the heart. The treatment with Cd significantly decreased Vit C and Vit E concentrations. Treatment with CoQ(10) and Vit E reversed Cd-induced alterations of antioxidant defense system. The obtained results support the assumption that CoQ(10) and Vit E functions cooperatively with endogenous antioxidants and diminished toxic effects of Cd in rat heart.

Antioxidant defence enzyme activities in hepatopancreas, gills and muscle of Spiny cheek crayfish (Orconectes limosus) from the River Danube.

The aim of our study was to determine the activity of antioxidant defence (AD) enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and the phase II biotransformation enzyme glutathione-S-transferase (GST) in the hepatopancreas, the gills and muscle of Spiny cheek crayfish (Orconectes limosus) from the River Danube and to compare tissue specificities of investigated enzymes. Our results indicated that both specific and total SOD activities in the hepatopancreas were lower compared to the gills and muscle. Total SOD activity in the gills was lower with respect to that in muscle. CAT and GSH-Px (both specific and total) activities were higher in the hepatopancreas compared to those in the gills and muscle. In the gills the specific and total GR activities were higher than in the hepatopancreas and muscle. The specific and total GST activities were higher in the hepatopancreas compared with the gills and muscle. Our study represents the first comprehensive report of AD enzymes in tissues of O. limosus caught in the River Danube. The noted tissue distributions of the investigated AD enzyme activities most likely reflected different metabolic activities and different responses to environmental conditions in the examined tissues.

The activity of antioxidant defence enzymes in the mussel Mytilus galloprovincialis from the Adriatic Sea.

The activity of the antioxidant defence enzymes superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), glutathione peroxidase (GSH-Px, EC 1.11.1.9), glutathione reductase (GR, EC 1.6.4.2) and the phase II biotransformation enzyme glutathione-S-transferase (GST, EC 2.5.1.18) in whole mussels (Mytilus galloprovincialis) were studied. The mussels were collected in winter and in spring at two localities in the Adriatic Sea: Bar Port and Tivat Bay. Our results show that the activities of SOD, GSH-Px and GST were seasonally dependent with higher activities in winter. GR activity was also higher in winter, but only in mussels from Bar Port. In mussels from Tivat Bay, GR activity was lower in winter compared to spring. In addition, a decrease in CAT activity in mussels from Bar Port compared to those from Tivat Bay was found. It can be concluded that seasonal variations should be incorporated into interpretation of biomonitoring studies in mussels.