Evaluating the radioprotective effect of green barley juice on male rats.

PURPOSE: DNA damage accounts for most biological effects of ionizing radiation. Antioxidants are known for their protective effect by preventing DNA damage. This pilot study aimed to evaluate the potential radioprotective effect of Natural SOD®, a green barley juice rich in antioxidants, on DNA damage in the testes and lymphocytes of Wistar rats exposed to ionizing radiation. MATERIALS AND METHODS: Male Wistar rats (n = 15) were selected and equally divided into three groups. Rats in one of the groups were pretreated orally with Natural SOD® for 14 days, while rats in another group were sham-pretreated with saline solution. Rats in both these groups were afterwards subjected to a single dose of 6 Gy X-ray whole-body irradiation. The control group did not receive any treatment and was not irradiated. Shortly after X-ray exposure, all rats were sacrificed and testes and blood were collected. Gamma-H2AX and histopathological assessment in the testes, along with comet assay of lymphocytes were performed. RESULTS: Histopathological examination of the testes showed no significant architectural alterations. Immunofluorescent staining of γ-H2AX revealed more DNA double-strand break sites in testicular cells from sham animals compared to Natural SOD® pretreated rats. Alkaline comet assay results showed increased DNA damage in lymphocytes of irradiated rats compared to the control group with little differences between the pretreated groups. Animals pretreated with Natural SOD showed slightly reduced DNA damage compared to sham-pretreated rats. These findings suggest a potential protective effect of Natural SOD® against radiation-induced DNA damage. CONCLUSIONS: Natural SOD® exhibited a potential prophylactic radioprotective effect in rats, particularly in testes. Further investigations to determine medium and long-term effects of X-ray in animals administered Natural SOD® are needed to better estimate the radioprotective effect.

Pilot Study of the Long-Term Effects of Radiofrequency Electromagnetic Radiation Exposure on the Mouse Brain.

The increasing radiofrequency (RF) electromagnetic radiation pollution resulting from the development and use of technologies utilizing RF has sparked debate about the possible biological effects of said radiation. Of particular concern is the potential impact on the brain, due to the close proximity of communication devices to the head. The main aim of this study was to examine the effects of long-term exposure to RF on the brains of mice in a real-life scenario simulation compared to a laboratory setting. The animals were exposed continuously for 16 weeks to RF using a household Wi-Fi router and a laboratory device with a frequency of 2.45 GHz, and were compared to a sham-exposed group. Before and after exposure, the mice underwent behavioral tests (open-field test and Y-maze); at the end of the exposure period, the brain was harvested for histopathological analysis and assessment of DNA methylation levels. Long-term exposure of mice to 2.45 GHz RF radiation increased their locomotor activity, yet did not cause significant structural or morphological changes in their brains. Global DNA methylation was lower in exposed mice compared to sham mice. Further research is needed to understand the mechanisms behind these effects and to understand the potential effects of RF radiation on brain function.

Hypoxic preconditioning - A nonpharmacological approach in COVID-19 prevention.

Hypoxia is defined by low oxygen concentration in organs, tissues, and cells. Maintaining oxygen homeostasis represents the essential cellular metabolic process for the structural integrity of tissues in different pathological conditions, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Considering the role of hypoxia-inducible factor-1 as the regulator of cellular response to hypoxia and its involvement in angiogenesis, erythropoiesis, glucose metabolism, inflammation, we propose hypoxic preconditioning (HPC) as a novel prevention therapeutic approach on healthy contacts of patients with coronavirus disease-2019 (COVID-19). To date, several studies revealed the beneficial effects of HPC in ischemia, kidney failure, and in pulmonary function recovery of patients who underwent lung surgery. HPC increases the expression of factors that promote cell survival and angiogenesis, induces an anti-inflammatory outcome, triggers coordinated hypoxia responses that promote erythropoiesis, and mobilizes the circulating progenitor cells. Furthermore, the mesenchymal stem cells (MSC) exposed to HPC show improvement of their regenerative capacities and increases the effectiveness of stem cell therapy in different pathologies, including COVID-19. In conclusion, HPC should be considered as an approach with beneficial outcomes and without significant side effects when the organism is severely exposed to the same stressor. HPC appears as a trigger to mechanisms that improve and maintain tissue oxygenation and repair, a main goal in different pathologies, including COVID-19 or other respiratory conditions.

Effect of Different Antioxidants on X-ray Induced DNA Double-strand Breaks Using γ-H2AX in Human Blood Lymphocytes.

Ionizing radiation exposure produces direct or indirect biological effects on genomic DNA. The latter are ionizing radiation mediated by induction of free radicals and oxygen species (ROS). The study was conducted to evaluate the dose-effect/time-effect of antioxidant treatments in reducing the induction of double-strand breaks in human blood lymphocytes. Human peripheral blood samples of 2 mL each from healthy donors were irradiated with 10 mGy after pre-incubation with different antioxidants (ß-carotene, vitamin E, vitamin C, N-acetyl L-cysteine). In order to assess their efficiency as prophylactic therapy for irradiation, various concentrations and combinations of antioxidants, as well as different incubation times, have been evaluated. To assess double-strand breaks induced by ionizing radiation, the phosphorylated histone γ-H2AX has been used. A significant reduction (p < 0.001) in double-strand breaks studied with a γ-H2AX assay was observed with N-acetyl L-cysteine with a 1-h incubation time, followed by vitamin C, vitamin E, and ß-carotene. The use of antioxidants, especially N-acetyl L-cysteine before irradiation, significantly decreased the occurrence of double-strand breaks, demonstrating the potential radiological protection for exposure to ionizing radiation.

Dynamic analysis of the interactions between Si/SiO2 quantum dots and biomolecules for improving applications based on nano-bio interfaces.

Due to their outstanding properties, quantum dots (QDs) received a growing interest in the biomedical field, but it is of major importance to investigate and to understand their interaction with the biomolecules. We examined the stability of silicon QDs and the time evolution of QDs - protein corona formation in various biological media (bovine serum albumin, cell culture medium without or supplemented with 10% fetal bovine serum-FBS). Changes in the secondary structure of BSA were also investigated over time. Hydrodynamic size and zeta potential measurements showed an evolution in time indicating the nanoparticle-protein interaction. The protein corona formation was also dependent on time, albumin adsorption reaching the peak level after 1 hour. The silicon QDs adsorbed an important amount of FBS proteins from the first 5 minutes of incubation that was maintained for the next 8 hours, and diminished afterwards. Under protein-free conditions the QDs induced cell membrane damage in a time-dependent manner, however the presence of serum proteins attenuated their hemolytic activity and maintained the integrity of phosphatidylcholine layer. This study provides useful insights regarding the dynamics of BSA adsorption and interaction of silicon QDs with proteins and lipids, in order to understand the role of QDs biocorona.

Effects of Cd2+ on the epithelial Na+ channel (ENaC) investigated by experimental and modeling studies.

The function of the epithelial Na+ channel from the apical membrane of many Na+ transporting epithelia is modulated by various chemical compounds from the extracellular space, such as heavy metals, protons or chloride ions. We have studied the effect of extracellular Cd2+ on the function of the epithelial Na+ channel (ENaC) in heterologously expressed Xenopus laevis oocytes and Na+-transporting epithelia. We assayed channel function as the amiloride-sensitive sodium current (I(Na)). Cd2+ rapidly and voltage-independently inhibited INa in oocytes expressing αßγ Xenopus ENaC (xENaC). The extracellular Cd2+ inhibited Na+ transport and showed no influence on ENaC trafficking, as revealed by concomitant measurements of the transepithelial current, conductance and capacitance in Na+-transporting epithelia. Instead, amiloride inhibition was noticeably diminished in the presence of Cd2+ on the apical membrane. Using molecular modeling approaches, we describe the amiloride binding sites in rat and xENaC structures, and we present four putative binding sites for Cd2+. These results indicate that ENaC functions as a sensor for external Cd2+.

Pharmacological descriptors related to the binding of Gp120 to CD4 corresponding to 60 representative HIV-1 strains.

The standardization of HIV-1 strains for vaccine tests include the use of viral reference panels. We determined a series of pharmacological descriptors (molecular surfaces, volumes, electrostatic energies, solvation energies, number of atoms, number of hydrogen donors or acceptors and number of rigid bonds) for the gp120 CD4-binding sites structures in the unliganded state from a reference panel of 60 diverse strains of HIV-1. We identified the descriptors that varied significantly between the strains, the outliner strains for each descriptor set and the possible correlations between the descriptors. Our results improve the knowledge about gp120, its molecular and possible neutralization properties.