Simultaneous effect of gamma and Wi-Fi radiation on gamma-H2Ax expression in peripheral blood of rat: A radio-protection note.

INTRODUCTION: Nuclear medicine patients are isolated in a room after the injection of a radiopharmaceutical. They may be active Wi-Fi option of its smartphone mobile or other environmental radiofrequency waves. The hypothesis of this study was the evaluation of increased biological effects of the simultaneous exposure to gamma-ray and the Wi-Fi waves by measuring the level of the increased double strand-breaks DNA in peripheral blood lymphocyte in the rat. MATERIALS AND METHODS: Fifty male Wistar rats were exposed for 2, 24, and 72 h only by Wi-Fi, 99m Tc, and simultaneously by Wi-Fi and 99m Tc. The power density levels of Wi-Fi emitter at 15 cm was 4.2nW/ c m 2 . An activity of 100 µCi of 99m Tc was injected intraperitoneally. Blood samples were taken by cardiac puncture following general anesthesia. Mononuclear cells are extraction by Ficoll-Hypaque density gradient centrifugation. The number of gamma-H2AX foci per nucleus was counted by flow cytometry. The statistical differences between experimental groups at 2, 24, and 72 h were determined with a repeated measure's analysis of variance. The significant difference between groups at the same time was analyzed with the Kruskal-Wallis Test. RESULTS: The manner of gamma-H2AX expression was not the same for three groups in time. The number of gamma-H2AX foci between the three groups was a significant difference after 72 h. CONCLUSION: Simultaneous Wi-Fi and gamma-ray exposures can increase the number of double-strand break DNA in peripheral blood lymphocytes to exposure of gamma-ray to 72 h after technetium injection in the rat.

Resveratrol as an Enhancer of Apoptosis in Cancer: A Mechanistic Review.

The resistance to therapy of cancer cells is a challenge for achieving an appropriate therapeutic outcome. Cancer (stem) cells possess several mechanisms for increasing their survival following exposure to toxic agents such as chemotherapy drugs, radiation, as well as immunotherapy. Evidences show that apoptosis plays a key role in the response of cancer (stem) cells and their multi-drug resistance. Modulation of both intrinsic and extrinsic pathways of apoptosis can increase the efficiency of tumor response and amplify the therapeutic effects of radiotherapy, chemotherapy, targeted therapy, and also immunotherapy. To date, several agents, as adjuvant, have been proposed to overcome the resistance of cancer cells to apoptosis. Natural products are interesting because of the low toxicity on normal tissues. Resveratrol is a natural herbal agent that has shown interesting anti-cancer properties. It has been shown to kill cancer cells selectively while protecting normal cells. Resveratrol can augment reduction/oxidation (redox) reactions, thus increases the production of ceramide and the expression of apoptosis receptors, such as Fas Ligand (FasL). Resveratrol also triggers some pathways which induce the mitochondrial pathway of apoptosis. On the other hand, resveratrol has an inhibitory effect on antiapoptotic mediators, such as Nuclear Factor κ B (NF-κB), Cyclooxygenase-2 (COX-2), Phosphatidylinositol 3- Kinase (PI3K), and mTOR. In this review, we explain the modulatory effects of resveratrol on apoptosis, which can augment the therapeutic efficiency of anti-cancer drugs or radiotherapy.

Targeting of cellular redox metabolism for mitigation of radiation injury.

Accidental exposure to ionizing radiation is a serious concern to human life. Studies on the mitigation of side effects following exposure to accidental radiation events are ongoing. Recent studies have shown that radiation can activate several signaling pathways, leading to changes in the metabolism of free radicals including reactive oxygen species (ROS) and nitric oxide (NO). Cellular and molecular mechanisms show that radiation can cause disruption of normal reduction/oxidation (redox) system. Mitochondria malfunction following exposure to radiation and mutations in mitochondria DNA (mtDNA) have a key role in chronic oxidative stress. Furthermore, exposure to radiation leads to infiltration of inflammatory cells such as macrophages, lymphocytes and mast cells, which are important sources of ROS and NO. These cells generate free radicals via upregulation of some pro-oxidant enzymes such as NADPH oxidases, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Epigenetic changes also have a key role in a similar way. Other mediators such as mammalian target of rapamycin (mTOR) and peroxisome proliferator-activated receptor (PPAR), which are involved in the normal metabolism of cells have also been shown to regulate cell death following exposure to radiation. These mechanisms are tissue specific. Inhibition or activation of each of these targets can be suggested for mitigation of radiation injury in a specific tissue. In the current paper, we review the cellular and molecular changes in the metabolism of cells and ROS/NO following exposure to radiation. Furthermore, the possible strategies for mitigation of radiation injury through modulation of cellular metabolism in irradiated organs will be discussed.