BACKGROUND Magnesium (Mg), selinium (Se), zinc (Zn), manganese (Mn), and copper (Cu) are involved in the mechanisms of antioxidant defense. Mn and Cu, which participate in the generation of reactive oxygen species (ROS), also have pro-oxidative properties. OBJECTIVES To evaluate the levels of Mg, Se, Zn, Mn, and Cu, as well as the effectiveness of antioxidant defense mechanisms in children wi...

Constant generation of Reactive oxygen species (ROS) during normal cellular metabolism of an organism is generally balanced by similar rate of consumption by antioxidants. Imbalance between ROS production and antioxidant defense results in increased level of ROS causing oxidative stress which leads to promotion of malignancy. Queuine is a hyper modified base analogue of guanine, found at first ...

The role of mitogen-activated protein kinase (MAPK) in abscisic acid (ABA)-induced antioxidant defense was investigated in leaves of maize (Zea mays) plants. Treatments with ABA or H(2)O(2) induced the activation of a 46-kD MAPK and enhanced the expression of the antioxidant genes CAT1, cAPX, and GR1 and the total activities of the antioxidant enzymes catalase, ascorbate peroxidase, glutathione...

background: leptin and its receptor are present in spermatozoa; however, the role of leptin in sperm function is still controversial. our present study aimed at demonstrating the effect of cryopreservation on sperm dna fragmentation (dnaf) and investigating the possible effects of sperm capacitation techniques and leptin in vitro incubation on frozen-thawed sperm dnaf and oxidative stress. meth...

The effects of acute exposure to cadmium (Cd) on the blood antioxidant defense system, lipid peroxide concentration and hematological parameters, as well as the possible protective role of vitamin E were studied. Male Wistar albino rats (3 months old) were treated with cadmium (0.4 mg Cd/kg b.m., i.p., 24 h before the experiment) or with vitamin E + Cd (20 IU Vit E/kg b.m., i.m., 48 h + 0.4 mg ...

Melatonin (N-acetyl-5-methoxytryptamine), which is synthesized from tryptophan, is formed during alcoholic fermentation, though its role in yeast is unknown. This study employed Saccharomyces cerevisiae as an eukaryote model to evaluate the possible effects of melatonin supplementation on endogenous cellular defense systems by measuring its effects on various cellular targets. Cell viability, i...

the role of the antioxidant defense system was studied in brassica napus, and subjected todifferent supplementary bands of ultraviolet radiation (uv-a, uv-b and uv-c). this study showed thatuv-b and uv-c induced oxidative stress as evidenced by an increase in lipid peroxidation and totalascorbate content. under uv-b and uv-c treatments, flavonoids and anthocyanins were increasedsignificantly co...