Changes in antioxidant capacity of blood due to mutual action of electromagnetic field (1800MHz) and opioid drug (tramadol) in animal model of persistent inflammatory state

Tramadol induces apoptosis, inflammation, and oxidative stress in rat choroid plexus

BACKGROUND

The choroid plexus (CP) is the principal source of cerebrospinal fluid (CSF). It can produce and release a wide range of materials, including growth and neurotrophic factors which have a crucial role in the maintenance and proper functioning of the brain. Tramadol is a synthetic analog of codeine, mainly prescribed to alleviate mild to moderate pains. Nevertheless, it causes several side effects, such as emotional instability and anxiety.

METHODS

In this study, we focused on alterations in the expression of inflammatory and apoptotic genes in the CP under chronic tramadol exposure. Herein, rats were treated daily with tramadol at 50 mg/kg doses for three weeks. CSF samples were collected, with superoxide dismutase (SOD) and glutathione (GSH) measured in the CSF.

RESULTS

We found that tramadol reduced the SOD and GSH levels in the CSF. Furthermore, the stereological analysis revealed a significant increase in the CP volume, epithelial cells, and capillary number upon tramadol administration. Tramadol elevated the number of blob mitochondria in CP. Also, we observed the upregulation of inflammatory and apoptosis genes following tramadol administration in the CP.

CONCLUSIONS

Our findings indicate that tramadol induces neurotoxicity in the CP via apoptosis, inflammation, and oxidative stress.

An Evaluation of the Genotoxic Effects of Electromagnetic Radiation at 900 MHz, 1800 MHz, and 2100 MHz Frequencies with a SMART Assay in Drosophila melanogaster

With the development of today's technology, the electromagnetic radiation spread by mobile phones and base stations is also rapidly increasing, and this causes serious concerns about the environment and human health. The Drosophila model organism is widely used in genetic toxicology studies because its genome is highly similar to the genes identified in human diseases. In this study, the genotoxic effects of radiofrequency electromagnetic radiation were evaluated by the wing Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster at 900 MHz, 1800 MHz, and 2100 MHz. The SMART method is based on the observation of genetic changes occurring in the trichomes of the Drosophila wings appearing as mutant clones under the microscope. Throughout the study, total clone parameters were evaluated by exposing the Drosophila larvae to electromagnetic fields for two, four, and six hours per day for two days. As a result of the study, it was observed that the number of mutant clones was statistically increased according to the negative control group in all applications except for the six-hour application at 1800 MHz.

Genotoxicity and repair capability of Mus musculus DNA following the oral exposure to Tramadol

Tramadol is an analgesic and psychoactive drug that acts primarily upon the central nervous system where it alters brain function, resulting in temporary changes in perception, mood, consciousness and behavior. The aim of present study was to analyze the genotoxicity and repair capability of DNA after Tramadol exposure in albino mice (Mus musculus). For this purpose, forty mice were divided equally into four groups as; a control group (without drug) and three treatment groups that were treated with three doses of Tramadol as minimum dose group, Intermediate dose group and maximum dose group, corresponding to 25 mg/kg, 50 mg/kg and 75 mg/kg of body weight respectively. The dose was given orally for 15 days. After 15 days peripheral blood was drawn from half mice of each group and subjected to comet assay. While the remaining half mice were given a recovery period of 15 days and same procedure was used for blood collection and comet assay. Significant difference in various comet parameters was observed among control and exposed groups. Maximum damage was observed at highest concentration 75 mg/kg of Tramadol and minimum damage was observed at dose 25 mg/kg of Tramadol, while results of repaired mice group showed that repair capability of Tramadol was minor and recovery of Tramadol required a lot of time. It can be concluded that Tramadol cause genotoxicity that is dose dependent and has low repair capability.

Protective properties of Myrtus communis extract against oxidative effects of extremely low-frequency magnetic fields on rat plasma and hemoglobin

PURPOSE

This study investigates the protective properties of Myrtus communis extract against the oxidative effects of extremely low-frequency magnetic fields (ELFMF). Also, this study is aimed to analyze the conformational changes of hemoglobin, oxidative damages to plasma proteins and antioxidant power of plasma following exposure to ELFMF.

MATERIALS AND METHODS

Adult male rats were divided into 3 groups: (1) control, (2) ELFMF exposure, and (3) ELFMF exposure after M. communis extract administration. The magnetic field (0.7 mT, 50 Hz) was produced by a Helmholtz coil for one month, 2 hours a day. The M. communis extract was injected intraperitoneally at a dose of 0.5 mg/kg before exposure to ELFMF. The oxidative effects of ELFMF were studied by evaluating the hemoglobin, methemoglobin (metHb) and hemichrome levels, absorption spectrum of hemoglobin (200-700 nm), oxidative damage to plasma proteins by measuring protein carbonyl (PCO) levels and plasma antioxidant power according to the ferric reducing ability of plasma (FRAP). The mean and standard errors of the mean were determined for each group. One-way ANOVA analysis was used to compare the means of groups. The significance level was considered to be p < .05. Moreover, artificial neural network (ANN) analysis was used to identify the predictive parameters for estimating the oxyhemoglobin (oxyHb) concentration.

RESULTS

Exposure to ELFMF decreased the FRAP which was in concomitant with a significant increase in plasma PCO, metHb and hemichrome concentrations (p < .001). Oxidative modifications of Hb were shown by reduction in optical density at 340 nm (globin-heme interaction) and 420 nm (heme-heme interaction). Administration of M. communis extract increased FRAP values and decreased plasma POC, metHb, and hemichrome concentrations. Also, a significant increase in Hb absorbance at 340, 420, 542, and 577 nm showed the protective properties of M. communis extract against ELFMF-induced oxidative stress in erythrocytes. ANN analysis showed that optical absorption of hemoglobin at 520, 577, 542, and 630 nm and concentration of metHb and hemichrome were the most important parameters in predicting the oxyHb concentration.

CONCLUSIONS

Myrtus communis extract enhances the ability of erythrocytes and plasma to deal with oxidative conditions during exposure to ELFMF. Also, ANN analysis can predict the most important parameters in relation to Hb structure during oxidative stress.

Long term exposure to cell phone frequencies (900 and 1800 MHz) induces apoptosis, mitochondrial oxidative stress and TRPV1 channel activation in the hippocampus and dorsal root ganglion of rats

Mobile phone providers use electromagnetic radiation (EMR) with frequencies ranging from 900 to 1800 MHz. The increasing use of mobile phones has been accompanied by several potentially pathological consequences, such as neurological diseases related to hippocampal (HIPPON) and dorsal root ganglion neuron (DRGN). The TRPV1 channel is activated different stimuli, including CapN, high temperature and oxidative stress. We investigated the contribution TRPV1 to mitochondrial oxidative stress and apoptosis in HIPPON and DRGN following long term exposure to 900 and 1800 MHz in a rat model. Twenty-four adult rats were equally divided into the following groups: (1) control, (2) 900 MHz, and (3) 1800 MHz exposure. Each experimental group was exposed to EMR for 60 min/ 5 days of the week during the one year. The 900 and 1800 MHz EMR exposure induced increases in TRPV1 currents, intracellular free calcium influx (Ca²⁺), reactive oxygen species (ROS) production, mitochondrial membrane depolarization (JC-1), apoptosis, and caspase 3 and 9 activities in the HIPPON and DRGN. These deleterious processes were further increased in the 1800 MHz experimental group compared to the 900 MHz exposure group. In conclusion, mitochondrial oxidative stress, programmed cell death and Ca²⁺ entry pathway through TRPV1 activation in the HIPPON and DRGN of rats were increased in the rat model following exposure to 900 and 1800 MHz cell frequencies. Our results suggest that exposure to 900 and 1800 MHz EMR may induce a dose-associated, TRPV1-mediated stress response.

Effects of electromagnetic fields exposure on the antioxidant defense system

Technological devices have become essential components of daily life. However, their deleterious effects on the body, particularly on the nervous system, are well known. Electromagnetic fields (EMF) have various chemical effects, including causing deterioration in large molecules in cells and imbalance in ionic equilibrium. Despite being essential for life, oxygen molecules can lead to the generation of hazardous by-products, known as reactive oxygen species (ROS), during biological reactions. These reactive oxygen species can damage cellular components such as proteins, lipids and DNA. Antioxidant defense systems exist in order to keep free radical formation under control and to prevent their harmful effects on the biological system. Free radical formation can take place in various ways, including ultraviolet light, drugs, lipid oxidation, immunological reactions, radiation, stress, smoking, alcohol and biochemical redox reactions. Oxidative stress occurs if the antioxidant defense system is unable to prevent the harmful effects of free radicals. Several studies have reported that exposure to EMF results in oxidative stress in many tissues of the body. Exposure to EMF is known to increase free radical concentrations and traceability and can affect the radical couple recombination. The purpose of this review was to highlight the impact of oxidative stress on antioxidant systems. Abbreviations: EMF, electromagnetic fields; RF, radiofrequency; ROS, reactive oxygen species; GSH, glutathione; GPx, glutathione peroxidase; GR, glutathione reductase; GST, glutathione S-transferase; CAT, catalase; SOD, superoxide dismutase; HSP, heat shock protein; EMF/RFR, electromagnetic frequency and radiofrequency exposures; ELF-EMFs, exposure to extremely low frequency; MEL, melatonin; FA, folic acid; MDA, malondialdehyde.

THE ROLE OF ESTROGENS AND ESTROGEN RECEPTORS IN MELANOMA DEVELOPMENT AND PROGRESSION

Melanoma has a significant mortality and its growing incidence is associated with important social and health care costs. Thus, investigation of the complex mechanisms contributing to emergence and development of melanoma are of real interest both in scientific research and clinical practice. Estrogens play an important role in the emergence and development of certain types of cancer, such as breast cancer, endometrial cancer and ovarian cancer, but their role in development of cutaneous melanoma is still a matter of debate. Various data suggest that increased levels of endogenous estrogens during pregnancy or exposure to exogenous estrogens by use of oral contraceptives (OCs) and hormone replacement therapy (HRT) may have a potential role in melanoma development and progression. Moreover, there were revealed several intracellular pathways which can support the connection between estrogens, estrogen receptors (ER) and melanoma. While ER-β plays an antiproliferative role, ER-α promotes cell growth and cellular atypia. Thus, inhibition of ER-β activity in the skin can increase the risk for development of cutaneous melanoma and spread of metastatic cells. However, despite recent advances in this area, the exact role and clinical implications of estrogens and estrogen receptors in melanoma are still not entirely understood and require further investigations.

Disruption of the ovarian follicle reservoir of prepubertal rats following prenatal exposure to a continuous 900-MHz electromagnetic field

The effects on human health of electromagnetic field (EMF) have begun to be seriously questioned with the entry into daily life of devices establishing EMF, such as cell phones, wireless fidelity, and masts. Recent studies have reported that exposure to EMF, particularly during pregnancy, affects the developing embryo/fetus. The aim of this study was therefore to examine the effects of exposure to continuous 900-Megahertz (MHz) EMF applied in the prenatal period on ovarian follicle development and oocyte differentiation. Six pregnant Sprague Dawley rats were divided equally into a non-exposed control group (CNGr) and a group (EMFGr) exposed to continuous 900-MHz EMF for 1 h daily, at the same time every day, on days 13-21 of pregnancy. New groups were established from pups obtained from both groups after birth. One group consisting of female pups from CNGr rats was adopted as newborn CNGr (New-CNGr, n = 6), and another group consisting of female pups from EMFGr rats was adopted as newborn EMFGr (New-EMFGr, n = 6). No procedure was performed on New-CNGr or New-EMFGr rats. All rat pups were sacrificed on the postnatal 34th day, and their ovarian tissues were removed. Follicle count, histological injury scoring and morphological assessment with apoptotic index criteria were performed with sections obtained following routine histological tissue preparation. Follicle count results revealed a statistically significant decrease in primordial and tertiary follicle numbers in New-EMFGr compared to New-CNGr (p < 0.05), while atretic follicle numbers and apoptotic index levels increased significantly (p < 0.05). Histopathological examination revealed severe follicle degeneration, vasocongestion, a low level of increased stromal fibrotic tissue and cytoplasmic vacuolization in granulosa cell in New-EMFGr. Prenatal exposure to continuous 900-MHz EMF for 1 h each day from days 13-21 led to a decrease in ovarian follicle reservoirs in female rat pups at the beginning of the prepubertal period.

The link between radiofrequencies emitted from wireless technologies and oxidative stress

Wireless communication such as cellular telephones and other types of handheld phones working with frequencies of 900MHz, 1800MHz, 2100MHz, 2450MHz have been increasing rapidly. Therefore, public opinion concern about the potential human health hazards of short and long-term effect of exposure to radiofrequency (RF) radiation. Oxidative stress is a biochemical condition, which is defined by the imbalance between reactive oxygen species (ROS) and the anti-oxidative defense. In this review, we evaluated available in vitro and in vivo studies carried out on the relation between RF emitted from mobile phones and oxidative stress. The results of the studies we reviewed here indicated that mobile phones and similar equipment or radars can be thought as a factor, which cause oxidative stress. Even some of them claimed that oxidative stress originated from radiofrequencies can be resulted with DNA damage. For this reason one of the points to think on is relation between mobile phones and oxidative stress. However, more performance is necessary especially on human exposure studies.

Oxidative mechanisms of biological activity of low-intensity radiofrequency radiation

This review aims to cover experimental data on oxidative effects of low-intensity radiofrequency radiation (RFR) in living cells. Analysis of the currently available peer-reviewed scientific literature reveals molecular effects induced by low-intensity RFR in living cells; this includes significant activation of key pathways generating reactive oxygen species (ROS), activation of peroxidation, oxidative damage of DNA and changes in the activity of antioxidant enzymes. It indicates that among 100 currently available peer-reviewed studies dealing with oxidative effects of low-intensity RFR, in general, 93 confirmed that RFR induces oxidative effects in biological systems. A wide pathogenic potential of the induced ROS and their involvement in cell signaling pathways explains a range of biological/health effects of low-intensity RFR, which include both cancer and non-cancer pathologies. In conclusion, our analysis demonstrates that low-intensity RFR is an expressive oxidative agent for living cells with a high pathogenic potential and that the oxidative stress induced by RFR exposure should be recognized as one of the primary mechanisms of the biological activity of this kind of radiation.

Supression of chronic central pain by superoxide dismutase in rats with spinal cord injury: Inhibition of the NMDA receptor implicated

Superoxide dismutase (SOD) is used to manage chronic pain, including neuropathic and inflammatory pain. However, data regarding the clinical effectiveness are conflicting and the neurophysiological mechanism of SOD has yet to be elucidated. The aim of the present study was to investigate whether SOD relieved chronic central pain (CCP) following spinal cord injury (SCI) and the possible underlying mechanisms. A CCP model was established using the Allen method and the CCP of the rats was measured using the paw withdrawal threshold. SOD was administered intraperitoneally following the establishment of CCP as a result of SCI. The results demonstrated that SOD relieved CCP in rats following SCI. In addition, the expression of spinal phosphorylated N-methyl-D-aspartate(NMDA) receptor subunit 1 (pNR-1) was inhibited in the CCP rats that had been treated with SOD. These observations indicated that SOD reduced mechanical allodynia and attenuated the enhancement of spinal pNR1 expression in rats with CCP. In addition, the results indicated that superoxide, produced via xanthine oxidase, and the participation of superoxide and nitric oxide (NO) as a precursor of peroxynitrite in NMDA, were involved in the mediation of central sensitization. Therefore, the observations support the hypothesis that SOD may have a potential therapeutic role for the treatment of CCP following SCI via the manipulation of superoxide and NO.