No abstract

Feathers, eggs, and excreta of Gentoo penguin (Pygoscelis papua ellsworthii), adults, from Livingston Island (South Shetlands), chosen as bioindicators, were used to test the quality of the Antarctic environment. Sex was not examined. The bioaccumulations of toxic trace elements (Cd, Pb, Al, and As), essential trace elements (Fe, Cu, Zn, Mn, Cr, V, Ni, and Sr), and major essential elements (Na, K, Mg, Ca, P, and S) were established. For the first time data about the element contents in Gentoo eggs is provided. Two hypotheses were tested: (1) there are differences in the metal levels among eggs and feathers; and (2) the element concentrations are highest in the excreta. The hypotheses were confirmed at 0.01-0.05 confidence levels. The concentrations of almost all trace elements were significantly higher in the feathers compared to those in the eggs. The following values of the concentrations ratio Fe/Zn were obtained: in the embryo, Fe/Zn = 1.5, and in the feathers, Fe/Zn = 0.5. The concentration of Pb in the embryo and excreta was below 0.4 μg/g, and Cd and As in eggs were below 0.05 and 0.3 μg/g, respectively. This indicates that there is no toxic risk for penguin offspring. Arsenic could be considered as a potential pollutant for Antarctic soil due to its relative high concentration in excreta, 5.13 μg/g. The present data (year 2007) were compared to the data for years 2002 and 2003. No trend of toxic element contamination was established. The concentrations of Pb, Cd, and As in representatives from the top of the food chain in the Antarctic (the present study) and Arctic (literature data) were compared. The data supports the hypothesis that there is an abnormality in cadmium levels in polar marine areas. Regarding Pb, the South Shetlands displayed 3-fold lower level compared to the Aleutians.

Selenium (Se) supplementation may prevent the formation of free radicals and lipid peroxidation processes in trichinellosis. The oxidative-antioxidant status of male Wistar rats infected or uninfected with Trichinella spiralis (Nematoda) and supplemented or unsupplemented with Sel-plex (Alltech) was tested through blood biomarkers. Sel-plex was applied to restore antioxidant defense system. The oxidative marker was malondialdehyde (MDA) concentration. The antioxidant markers were superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and concentrations of Se and vitamin E. The animals were allocated into four groups. The experiment covered 8 weeks post infection. A mathematical model was proposed for the time course of host body weight. The model solutions were in good agreement with the experimental data. The relative rates of body weight gain were determined as growth kinetic parameters. The supplementation of the rats with dietary Se improved their antioxidant status. Increases by 10% in SOD activity, 6% in GPx activity, 13% in vitamin E concentration, 17% in plasma Se concentration, and 19% in liver Se concentration, respectively, and a decrease by 18% in serum MDA concentration were recorded in the infected and supplemented towards infected and unsupplemented rats. The reduction of muscle larvae after Sel-plex application was 63%. The mortality in infected and uninfected animals did not differ significantly. No statistically significant differences were established between the growth of the control and infected rats. At week 8, the body weight gain in the supplemented rats (both uninfected and infected) was 30% higher, compared to that in unsupplemented ones. Diet with Se could be beneficial in the treatment of diseases correlated with considerable oxidative stress, particularly parasitoses.