Sladjan Z. Pavlović

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 Q10 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 enzymes in the liver of Chelidonichthys obscurus from the Montenegrin coastline

The activities of antioxidant defence enzymes — total, manganese and 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) — in the liver of longfin gurnard (Chelidonichthys obscurus) from the Montenegrin coastline (Adriatic sea) were investigated. The specimens were collected in winter (February) and late spring (May) at two localities: Platamuni (PL, potentially unpolluted) and the Estuary of the River Bojana (EB, potentially polluted). The obtained results show that the activities of Mn SOD, CAT, GSH-Px and GST in winter were significantly lower at EB than at PL. In spring, the activities of CAT and GST were decreased, while GR activity was increased at EB in comparison to PL. The activities of Mn SOD and GST at PL were decreased and GSH-Px, GR and GST activities at EB were increased in spring compared to winter. Our work represents the first study of liver antioxidant enzymes of longfin gurnard from the Montenegrin coastline and reveals that locality, as a variable, has a greater influence on antioxidant enzymes and biotransformation phase II enzyme GST activities compared to season.