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.

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.

Microscopy comparative evaluation of the SE systems adhesion to normal and sclerotic dentin.

The purpose of this study was in vitro evaluation and comparison of the adhesion of self-etch (SE) adhesive systems applied on normal and sclerotic dentin. For this study, Class 5 cavities were prepared on sound teeth as well as on teeth with sclerotic dentin. They were then restored by means of the SE 2-step OptiBond XTR (Kerr) and SE 1-step Bond Force (Tokuyama Dental) adhesive systems, as well as the Estelite Sigma Quick (Tokuyama Dental) composite resin. For teeth with sclerotic dentin, the hypermineralized superficial layer was removed by means of round bur on low speed, than the adhesive systems and composite resin were applied. These teeth were prepared for microscopic study according to the protocol specific to each microscope. SEM (scanning electron microscopy) examination reveals that on normal and sclerotic dentin, OptiBond XTR and Bond Force form hybrid layers with about the same thickness, greater in normal dentin, but only OptiBond XTR pervades into the dentinal tubules, both in normal and sclerotic dentin. However, TEM (transmission electron microscopy) examination of Bond Force reveals that it penetrates into the dentinal tubules as well, but only in the case of normal dentin. The thickness of the hybrid layers resulting from the application of the SE adhesive systems to sound dentin is different from the thickness of the hybrid layers obtained when the same adhesive systems have been applied to sclerotic dentin.

Microscopic aspects of the hybrid layer formed by the SE 1-step Futurabond M (Voco) adhesive system applied to normal and sclerotic dentin.

STUDY OBJECTIVES: In vitro evaluation and comparison of the adhesion of a generation-7 adhesive system to normal and sclerotic dentin. MATERIALS AND METHODS: For this study, sound teeth as well as teeth with sclerotic dentin, which had been extracted for periodontal reasons, were prepared. Class 5 cavities were prepared, then restored by means of the SE 1-step Futurabond M (Voco) adhesive system, as well as the Estelite Sigma Quick (Tokuyama Dental) composite resin. For teeth with sclerotic dentin, the hypermineralized superficial layer was removed by means of round bur on low speed, then the adhesive system and composite resin were applied. These teeth were prepared for microscopic study according to the protocol specific to each microscope. For the study involving the confocal microscope, the adhesive was mixed with the Evans Blue dye before being applied to the tooth, then the same protocol was followed. RESULTS: When applied to normal dentin, Futurabond M (Voco), the generation-7 adhesive system, forms a hybrid layer with a depth of 20-25 µm, while it can be noted that it pervades 6-8 µm into the dentinal tubules. When applied to sclerotic dentin, it was noted that the adhesive system does not pervade into the tubules, with an approximately 10-15 µm depth of the hybrid layer. CONCLUSIONS: The adhesion to sclerotic dentin shows particular aspects. When it is desired to employ generation-7 adhesive systems (SE 1-step) on sclerotic dentin, the therapeutic approach needs to include the following supplementary stages: removal of the superficial hypermineralized layer, as well as predemineralization with 37% phosphoric acid; they are the only stages that might improve the adhesion to this substrate.