Increased DNA damage and oxidative stress in chickens with natural Marek's disease.

Oxidative stress contributes to the accumulation of genomic abnormalities, prevents cellular apoptosis, and also mediates immunosuppression resulting in tumor formation. Marek's Disease provides excellent opportunities for the study of herpesvirus-induced tumors both in experimental- and natural conditions. The aim of this study was to examine the effects of Marek's Disease (MD) on basal levels of DNA strand breaks and on the oxidative-antioxidative status of chickens with MD. White-Lohmann hens-fifteen infected with Marek's Disease Virus (MDV) and fifteen healthy-of same age and sex were included in this study. MD infection was diagnosed via clinical signs, gross- and micro-pathological findings and also by detection of viral antigens in feather follicle epithelium by the indirect immunoperoxidase method. Compared with healthy controls, DNA damage was greater and levels of malondialdehyde (MDA) and plasma protein carbonyl (PCO), and plasma concentration of nitric oxide metabolites (NOx) higher in the MD group. Furthermore, total antioxidant activities (AOAs) were found lowered and glutathione (GSH) levels reduced in the MD group compared to the control group. Significantly positive correlation was found between DNA damage, MDA, PCO, and NOx in the MD group. DNA strand breaks were found negatively associated with AOA and GSH concentrations in the MD group. Our results demonstrated that oxidative stress markers and DNA damage substantially increased in chickens with MD, which indicated that increased DNA damage levels might be related to the increased oxidative stress and reduced antioxidant activity.

The protective potential of Yucca schidigera (Sarsaponin 30) against nitrite-induced oxidative stress in rats.

The present study was designed to determine the protective effects of Yucca schidigera (Ys) against oxidative damage induced by acute nitrite intoxication as well as the histopathological evaluation of Ys in rats. The rats were divided into three groups each containing 12 rats: control (C); nitrite intoxication (N); Ys + nitrite intoxication (NY). C and N groups were fed standard rat feed (SRF). The NY group was fed SRF + 100 ppm Ys powder for 4 weeks. Acute nitrite intoxication was induced by subcutaneous (s.c.) administration of sodium nitrite (60 mg/kg) 1 day after the feeding period. Fifty minutes after sodium nitrite administration, blood samples and tissues including lung, liver, and kidney were collected for clinical biochemistry and histopathological investigations. Ys treatment was found to decrease methemoglobin, blood and tissue malondialdehyde, and tissue nitric oxide concentrations, and to increase the glutathione in blood and various tissues. However, plasma nitric oxide, total antioxidant activity, beta-carotene, and vitamin A did not differ between N and NY groups. While the N group rats showed distinct pathology in various tissues (compared with controls), the NY group had similar lung and liver pathology to the control. Only moderate or mild hemorrhage and hyperemia were seen in kidneys of NY group rats. Consequently, the natural compounds found in Ys, such as polyphenols, steroidal saponins, and other phytonutrients, could be used to substantially protect the organism from nitrite-induced oxidative damage and its complications.

Determination of some heavy metal levels and oxidative status in Carassius carassius L., 1758 from Eber Lake.

In this study, the levels of some heavy metals (Al, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb and Zn) in muscle, gill, and liver of Carassius carassius and in the water samples from Eber Lake (Afyonkarahisar, Turkey) have been investigated. Additionally, one of the lipid peroxidation markers, malondialdehide (MDA) and glutathion (GSH) levels were investigated. All the metal analysis was performed by using ICP-AES. According to results obtained, it was observed that heavy metals were accummulated in liver in the highest degree and lowest one in the muscle tissues. MDA and GSH levels varied in the seasons but their winter levels were found to be statistically meaningful when compared with other seasons. The obtained data of metals from the study were compared with the acceptable levels of Turkish governmental regulation and they were found not to be harmful for human health. On the other hand, it was suggested that oxidative stress markers should be checked regularly in order to get important data for continuous life of aquatic organisms.