introduction: radiation induced bystander effect (ribe) which cause radiation effects in non-irradiated cells, has challenged the principle according to which radiation traversal through the nucleus of a cell is necessary for producing biological responses. what is the mechanism of this phenomenon? to have a better understanding of this rather ambiguous concept substantial number of original an...

the role of oxygen free radicals in the initiation, promotion and progression of carcinogenesis and the protective role of anti-oxidant defenses has been the subject of much speculation in the recent past with conflicting reports in the literature. in recent years, increasing experimental and clinical data have provided compelling evidence for the involvement of oxidative stress in a large numb...

Background: Free radicals and reactive oxygen species(ROS) are the most important factors in formation of oxidative stress reaction. Now, radical damage has been suggested to contribute to a wide variety of diseases such as Alzheimer, atherosclerosis and cancer. Transition metal ions in the presence of the various biomolecules produce these active compounds. The aim of this study is introducing...

n-acetyl cysteine (nac), as a nutritional supplement, is a greatly applied antioxidant in vivo and in vitro. nac is a precursor of l-cysteine that results in glutathione elevation biosynthesis. it acts directly as a scavenger of free radicals, especially oxygen radicals. nac is a powerful antioxidant. it is also recommended as a potential treatment option for different disorders resulted from g...

With a variety of forms of ischemic and toxic tissue injury, cellular accumulation of Ca2+ and generation of oxygen free radicals may have adverse effects upon cellular and, in particular, mitochondrial membranes. Damage to mitochondria, resulting in impaired ATP synthesis and diminished activity of cellular energy-dependent processes, could contribute to cell death. In order to model, in vitro...