Effects Of Extremely Low Frequency Magnetic Fields Research Articles

Residential extremely low frequency magnetic fields and skin cancer

ObjectivePhotoinduced radical reactions have a fundamental role in skin cancer induced by ultraviolet radiation, and changes in radical reactions have also been proposed as a mechanism for the putative carcinogenic...

Exposure to 50 Hz Extremely-Low-Frequency Magnetic Fields Induces No DNA Damage in Cells by Gamma H2AX Technology.

The current results for extremely-low-frequency magnetic fields (ELF-MF) on DNA damage are still debated. A sensitive indicator and systematic research are needed to assess the effects of ELF-MF. In this study, we used γH2AX as an early and sensitive molecular marker to evaluate the DNA damage effects of ELF-MF in vitro. Human amnion epithelial cells (FLs), human skin fibroblast cells (HSFs), and human umbilical vein endothelial cells (HUVECs) were exposed to 50 Hz ELF-MF at 0.4, 1, and 2 mT for 15 min, 1 h, and 24 h, respectively. After exposure, cells were subjected to γH2AX immunofluorescence and western blot. The results showed no significant difference in the average number of foci per cell, the percentage of γH2AX foci-positive cells, or the expression of γH2AX between the sham and 50 Hz ELF-MF exposure groups (P > 0.05). In conclusion, 50 Hz ELF-MF did not induce DNA damage in FLs, HSFs, or HUVECs, which was independent of the intensity or duration of the exposure.

Extremely Low Frequency Magnetic Fields Increase the Expression of HIF-1 in Prostate Cancer Cells

Background: Increased levels of hypoxia-inducible factor 1α (HIF-1α) are related to poor prognosis and treatment failure in prostate cancer. The effect of extremely low frequency magnetic fields (ELF-MF), generally emitted from electronic devices on HIF-1α in cancer cells and, specifically, in prostate cancer is not well described. This study aimed to investigate the effects of ELF-MF on HIF- 1α protein expression and HIF-1 transcriptional activity in prostate cancer cells. Methods: Prostate cancer cells were irradiated with ELF-MF by means of a frequency generator at 875 MHz with an intensity of 0.07 mW/cm2 at various time periods and with an exposure system housed in a tissue culture incubator. The expression of HIF-1α protein and HIF-1 transcriptional activity at the different conditions were evaluated. Results: HIF-1α expression in different prostate cancer cells was higher after one hour of exposure to ELF-MF. All exposed cells also demonstrated a significant 50% increase in HIF-1 transcriptional activity as measured by an HRE-dependent reporter gene assay after ELF-MF irradiation. Cells exposed to ELF-MF exhibited 3-fold longer HIF-1α half-life compared to non-exposed control cells, while its mRNA levels were not affected. Immunofluorescence staining confirmed nuclear HIF-1α accumulation following exposure to ELF-MF. Cell proliferation was increased following ELF-MF exposure and significantly reduced when HIF-1α was silenced even after exposure to ELF-MF. Conclusions: Exposure of prostate cancer cells to ELF-MF increases HIF-1α protein stability and upregulates HIF-1 transcriptional activity. These findings provide new insights into the effects of ELF-MF on the hypoxic pathway which are important for guiding future implications.

Extremely Low Frequency Magnetic Fields Do Not Affect LTP-Like Plasticity in Healthy Humans

IntroductionSeveral studies explored the biological effects of extremely low-frequency magnetic fields (ELF-MFs) in vitro, reporting the induction of functional changes in neuronal activity. In particular, ELF-MFs can influence synaptic plasticity both in vitro and in animal models but some studies reported an increase in long-term potentiation (LTP) whereas others suggested its reduction. However, no specific study has investigated such effect on humans.AimsTo evaluate whether ELF-MFs affect the propensity of the human cortex to undergo LTP-like plasticity.MethodsWe designed a randomized, single-blind, sham-controlled, cross-over study on 10 healthy subjects. Cortical plasticity was induced by intermittent theta burst stimulation (iTBS) before and after 45-min ELF-MFs (75 Hz; 1.8 mT) or sham exposure and was estimated by measuring the changes of motor evoked potentials (MEP) amplitude before and after each iTBS.ResultsNo adverse events were reported. No significant effects of ELF-MFs on cortical plasticity were found.ConclusionWhole-brain exposure to ELF-MFs (75 Hz; 1.8 mT) is safe and does not seem to significantly affect LTP-like plasticity in human motor cortex.

Human Postural Responses to High Vestibular Specific Extremely Low-Frequency Magnetic Stimulations

Background: International agencies recognize the lack of knowledge to further establish standards and guidelines to protect the workers and the public from extremely low-frequency magnetic fields (ELF-MF). In that regard, postural control has been proposed as a biomarker of potential adverse effects in humans. Considering its crucial role in postural control and its specific neurophysiological characteristics, the vestibular system emerges as an ELF-MF likely target. However, postural modulation to vestibular ELF-MF exposure remains inconclusive. Previous studies led us to investigate stimulation orientation and point of application to clarify the ELF-MF impact on balance in humans. Objectives: This research aimed to investigate the acute postural impact of lateral vestibular-specific ELF-MF stimulations. Methods: Postural control of thirty eight healthy participants was analyzed with lateral vestibular-specific ELF-MF stimulations ranging from 20 Hz to 160 Hz, up to 142 T/s and vestibular electrical stimulations at the same frequencies. Both spatial orientation and quantity of movement variables were used to investigate postural modulations. Results: Despite a conclusive positive control effect, no significant effects of ELF-MF and alternating current stimulation exposures were found regardless of frequency conditions. Conclusions: Although important electric fields were generated, no postural modulation was found. However, at these frequencies, the potential vestibular activation did not translate into functional postural sway but might be observed with reflexive vestibular outcomes.

Myrciaria dubia "camu camu" flour as a magnetoprotector in male mouse infertility.

Possible adverse effects of extremely low frequency magnetic fields (ELF-MF) are linked to a decrease of antioxidant defenses and the production of free radicals. The increase of free radicals affects the mitochondrial functionality inducing apoptosis, which affects the phosphorylation and generation of key ATP in fertilization. Myrciaria dubia, known as "camu camu," is a fruit with high levels of ascorbic acid, which exerts an important antioxidant function in the prevention of premature cell damage. In this study, the effect of Myrciaria dubia flour on oxidative damage produced by ELF-MF (610 μT) was evaluated by detecting the activity of endogenous mitochondrial oxidoreductase enzymes in a complete sperm cycle of mice. We found that the MF caused a significant (P < 0.05) decrease in sperm quality, whereas the groups supplied with Myrciaria dubia flour (50 and 75 mg/kg of body mass) in ELF-MF exposure showed a significant recovery (P < 0.05) in parameters of viability, percentage of plasma membrane integrity and mitochondrial activity, and index of epidymal sperm. This suggests that Myrciaria dubia flour would have an antioxidant activity that counteracts the damaging effects of ELF-MF in spermatogenesis and could be used as a natural ELF-MF protector. Bioelectromagnetics. 40:91-103, 2019. © 2019 Bioelectromagnetics Society.

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.

Magnetocarcinogenesis: is there a mechanism for carcinogenic effects of weak magnetic fields?

Extremely low-frequency (ELF) magnetic fields have been classified as possibly carcinogenic, mainly based on rather consistent epidemiological findings suggesting a link between childhood leukaemia and 50-60 Hz magnetic fields from power lines. However, causality is not the only possible explanation for the epidemiological associations, as animal and in vitro experiments have provided only limited support for carcinogenic effects of ELF magnetic fields. Importantly, there is no generally accepted biophysical mechanism that could explain such effects. In this review, we discuss the possibility that carcinogenic effects are based on the radical pair mechanism (RPM), which seems to be involved in magnetoreception in birds and certain other animals, allowing navigation in the geomagnetic field. We review the current understanding of the RPM in magnetoreception, and discuss cryptochromes as the putative magnetosensitive molecules and their possible links to cancer-relevant biological processes. We then propose a hypothesis for explaining the link between ELF fields and childhood leukaemia, discuss the strengths and weaknesses of the current evidence, and make proposals for further research.

Effects of Single and Repeated Exposure to a 50-Hz 2-mT Electromagnetic Field on Primary Cultured Hippocampal Neurons.

The prevalence of domestic and industrial electrical appliances has raised concerns about the health risk of extremely low-frequency magnetic fields (ELF-MFs). At present, the effects of ELF-MFs on the central nervous system are still highly controversial, and few studies have investigated its effects on cultured neurons. Here, we evaluated the biological effects of different patterns of ELF-MF exposure on primary cultured hippocampal neurons in terms of viability, apoptosis, genomic instability, and oxidative stress. The results showed that repeated exposure to 50-Hz 2-mT ELF-MF for 8 h per day after different times in culture decreased the viability and increased the production of intracellular reactive oxidative species in hippocampal neurons. The mechanism was potentially related to the up-regulation of Nox2 expression. Moreover, none of the repeated exposure patterns had significant effects on DNA damage, apoptosis, or autophagy, which suggested that ELF-MF exposure has no severe biological consequences in cultured hippocampal neurons.

Exposure of Extremely-Low Frequency (ELF) magnetic field may cause human cancer

Introduction: Chronic exposure of non-ionizing extremely low-frequency magnetic fields (ELF-EMF) is considered as a health hazard due to its adverse effects on human body such as generation of any type of cancer. Stem cells are appropriate models to assess the effects of ELF-EMF on other cell lines and human beings. Materials and methods: Adipose tissue has been known as source of multi potent stromal human mesenchymal stem cells (MSCs) which can be obtained in less invasive method and in large amounts; so adipose-derived stem cells (ADSCs) were used in this study. Effect of ELF-EMF (intensities of 0.5 and 1 mT and 50 Hz) on proliferation rate of hADSCs was assessed in 20 and 40 min per day for 7 days. Trypan blue assay was performed to assess cell proliferation rate. Result: The results shown that 0.5 and 1 mT magnetic fields can promote the proliferation rate of adipose derived hMSCs according to the duration of exposure. Conclusion: These outcomes could approve the effect of ELF-EMF on cancer induction; although the effective mechanisms in this process are still unknown.

Induction of micronuclei and superoxide production in neuroblastoma and glioma cell lines exposed to weak 50 Hz magnetic fields.

Extremely low-frequency (ELF) magnetic fields (MF) have been associated with adverse health effects in epidemiological studies. However, there is no known mechanism for biological effects of weak environmental MFs. Previous studies indicate MF effects on DNA integrity and reactive oxygen species, but such evidence is limited to MFs higher (greater than or equal to 100 µT) than those generally found in the environment. Effects of 10 and 30 µT fields were studied in SH-SY5Y and C6 cells exposed to 50-Hz MFs for 24 h. Based on earlier findings, menadione (MQ) was used as a cofactor. Responses to MF were observed in both cell lines, but the effects differed between the cell lines. Micronuclei were significantly increased in SH-SY5Y cells at 30 µT. This effect was largest at the highest MQ dose used. Increased cytosolic and mitochondrial superoxide levels were observed in C6 cells. The effects on superoxide levels were independent of MQ, enabling further mechanistic studies without co-exposure to MQ. The micronucleus and mitochondrial superoxide data were consistent with a conventional rising exposure-response relationship. For cytosolic superoxide, the effect size was unexpectedly large at 10 µT. The results indicate that the threshold for biological effects of ELF MFs is 10 µT or less.

Genotoxicity Induced by Foetal and Infant Exposure to Magnetic Fields and Modulation of Ionising Radiation Effects.

BackgroundFew studies have investigated the toxicity and genotoxicity of extremely low frequency magnetic fields (ELF-MF) during prenatal and neonatal development. These phases of life are characterized by cell proliferation and differentiation, which might make them sensitive to environmental stressors. Although in vitro evidences suggest that ELF-MF may modify the effects of ionizing radiation, no research has been conducted so far in vivo on the genotoxic effects of ELF-MF combined with X-rays.Aim and methodsAim of this study was to investigate in somatic and germ cells the effects of chronic ELF-MF exposure from mid gestation until weaning, and any possible modulation produced by ELF-MF exposure on ionizing radiation-induced damage. Mice were exposed to 50 Hz, 65 μT magnetic field, 24 hours/day, for a total of 30 days, starting from 12 days post-conception. Another group was irradiated with 1 Gy X-rays immediately before ELF-MF exposure, other groups were only X-irradiated or sham-exposed. Micronucleus test on blood erythrocytes was performed at multiple times from 1 to 140 days after birth. Additionally, 42 days after birth, genotoxic and cytotoxic effects on male germ cells were assessed by comet assay and flow cytometric analysis.ResultsELF-MF exposure had no teratogenic effect and did not affect survival, growth and development. The micronucleus test indicated that ELF-MF induced a slight genotoxic damage only after the maximum exposure time and that this effect faded away in the months following the end of exposure. ELF-MF had no effects on ionizing radiation (IR)-induced genotoxicity in erythrocytes. Differently, ELF–MF appeared to modulate the response of male germ cells to X-rays with an impact on proliferation/differentiation processes. These results point to the importance of tissue specificity and development on the impact of ELF-MF on the early stages of life and indicate the need of further research on the molecular mechanisms underlying ELF-MF biological effects.

Effect of extremely low frequency magnetic fields on cell proliferation and gene expression

Owing to concerns regarding possible effects of extremely low frequency magnetic fields (ELF-MF) on human health, many studies have been conducted to elucidate whether ELF-MF can induce modifications in biological processes. Despite this, controversies regarding effects of ELF-MF are still rife. In this study, we investigated biological effects of ELF-MF on MCF10A, MCF7, Jurkat, and NIH3T3 cell lines. ELF-MF with a magnetic flux density of 1 mT at 60 Hz was employed to stimulate cells for 4 or 16 h, after which the effects of ELF-MF on cell proliferation, cell death, cell viability, and DNA synthesis rates were assessed. Whereas Jurkat and NIH3T3 cells showed no consistent variation in cell number, cell viability, and DNA synthesis rate, MCF10A and MCF7 cells showed consistent and significant decreases in cell number, cell viability, and DNA synthesis rates. However, there was no effect of ELF-MF on cell death in any of tested cell lines. Next, to investigate the effect of ELF-MF on gene expression, we exposed MCF7 cells to 2 mT at 60 Hz for 16 h and examined transcriptional responses by using gene expression array. We found a gene, PMAIP1, that exhibited statistically significant variation using two-fold cut-off criteria and certified its expression change by using semi-quantitative and quantitative reverse transcription polymerase chain reaction. From these results, we concluded that ELF-MF could induce the delay of cell cycle progression in MCF7 and MCF10A cells in a cell context-specific manner and could up-regulate PMAIP1 in MCF7 cells.

Effects of 60-Hz Magnetic Fields on DNA Damage Responses in HT22 Mouse Hippocampal Cell Lines

Previously, we investigated extremely low-frequency magnetic fields (ELF-MFs) on diverse DNA damage responses, such as phosphorylated H2AX (<TEX>${\gamma}H2AX$</TEX>), comet tail moments, and aneuploidy production in several non-tumorigenic epithelial or fibroblast cell lines. However, the effect of ELF-MF on DNA damage responses in neuronal cells may not be well evaluated. Here, we investigated the effects of ELF-MF on the DNA damage responses in HT22 non-tumorigenic mouse neuronal cells. Exposure to a 60-Hz, 2 mT ELF-MF did not produce any increased <TEX>${\gamma}H2AX$</TEX> expression, comet tail moments, or aneuploidy formation. However, 2 mT ELF-MF transiently increased the cell number. From the results, ELF-MF could affect the DNA damage responses differently, depending on the cell lines.

Editorial: Introducing Dr. Frank S. Prato.

It is my privilege and pleasure to introduce the 13th recipient of the D'Arsonval Medal, Dr. Frank S. Prato (Fig. 1). The D'Arsonval Medal is the highest honor bestowed by the Bioelectromagnetics Society (BEMS) and is the Society's highest award for extraordinary accomplishments in the field of bioelectromagnetics. I was honored to present the award to Dr. Prato in Thessaloniki, Greece, in June 2013 Dr. Prato is well known for his remarkable scientific and technical contributions in the field of the use of magnetic resonance imaging (MRI) in sophisticated medical intervention procedures based on assessment of permanent heart muscle damage resulting from a heart attack. Dr. Prato has also extended his discovery to the behavior of opioid receptors in the presence of extremely low frequency magnetic fields (ELF-MF) and his goal is to use these techniques he has discovered to develop image-guided therapy for treatment of heart disease and pain. There is hope that this work may decrease reliance on heart transplants for treatment of intractable heart failure with the enormous benefits of less intervention and no compromise of the patient's immune system. Dr. Prato is currently imaging program leader and assistant scientific director at the Lawson Health Research Institute as well as chief medical physicist at St Joseph's Hospital. When he first entered university, he worked in a nuclear physics laboratory as a summer student and although accepted into the medical course, decided to complete his master's degree in nuclear physics. In 1981, Dr. Prato convinced St. Joseph's Hospital to purchase the first MRI imaging machine in Canada and even the earliest work was so profoundly informative that it took a while for both physicists and clinicians to gain confidence in believing the findings. Dr. Prato's MRI work is already having an impact on treatment of cardiac disease and this alone is well deserving of his D'Arsonval award. However, the paper he presents now outlines and summarizes another path of inquiry in work dating back over three decades. Dr. Prato's distinguished career in bioelectromagnetics has not only paralleled and contributed to the use of MRI at the highest and most sophisticated level, but in the course of this work his interest has included new observations about effects of ELF-MF in pain modulation. Treatment of chronic pain remains an incomplete science still largely reliant on empirical techniques and the inevitable use of dangerous and addictive drugs as a blunt and uncertain means of modulating nociceptive responses. The possibility of intervening at a neuro-cellular level introduces enticing clinical opportunities for precise, adjustable and reversible intervention in patients with chronic pain. In February 2012, Dr. Prato was instrumental in arranging for Canada's first whole body MRI and positron emission tomography (PET) for research use at the Lawson Institute and clinical use at St. Joseph's Hospital. This machine is now being used by researchers improving accuracy of diagnosis and efficacy of treatment in heart disease, neurological disease and cancer. Dr. Prato's research was not always facilitated by commercially available equipment. In 1990, Dr. Prato and his graduate students designed and built a 1-m cubed exposure system of three Helmholtz-like orthogonal coils capable of producing virtually any desired field exposure within the static and ELF range. There was later collaboration with similar research in Russia. The group now based within the Lawson Health Research Institute and affiliated with the University of Western Ontario includes Drs. Prato, Thomas, Carson, Stodilka, and Le Grosse holding professorships within the Department of Biophysics actively working with M.S. and Ph.D. candidates. They are actively engaged in researching the biological effects of ELF-MF, both pulsed and sinusoidal in the μT to mT range. Dr. Prato's D'Arsonval award adds to many distinguished achievements in his career. He is a past president of the Bioelectromagnetics Society. Frank received his M.S. in nuclear physics in 1971 and his Ph.D. in medical biophysics in 1996 from the University of Toronto. It was his laboratory that produced the first MRI image of a brain in Canada and he has published over 120 peer reviewed papers, 350 abstract presentations and 100 invited presentations. Some 50 graduate students and post-doctoral fellows owe their training to Dr. Prato; many of them are now active in the Society. The Bioelectromagnetics Society is proud to congratulate Dr. Frank S. Prato on not only the achievement of this, the Society's most prestigious award, but on the achievements of his whole career. David R. Black, MD Faculty of Medical and Health Sciences University of Auckland, Auckland, New Zealand

Circadian gene expression and extremely low-frequency magnetic fields: an in vitro study.

It is well known that circadian clocks are mainly regulated by light targeting signaling pathways in the hypothalamic suprachiasmatic nucleus. However, an entrainment mediated by non-photic sensory stimuli was also suggested for peripheral clocks. Exposure to extremely low frequency (ELF) electromagnetic fields might affect circadian rhythmicity. The goal of this research was to investigate effects of ELF magnetic fields (ELF-MF) on circadian clock genes in a human fibroblast cell line. We found that an ELF-MF (0.1 mT, 50 Hz) exposure was capable of entraining expression of clock genes BMAL1, PER2, PER3, CRY1, and CRY2. Moreover, ELF-MF treatment induced an alteration in circadian clock gene expression previously entrained by serum shock stimulation. These results support the hypothesis that ELF-MF may be able to drive circadian physiologic processes by modulating peripheral clock gene expression.

Multifractal dimension and lacunarity of yolk sac vasculature after exposure to magnetic field

Several studies have reported about the effects of magnetic fields (MFs) on vascular tissue. Extremely low frequency magnetic fields (ELF-MFs) can promote either inhibition or stimulation of vasculogenesis and angiogenesis, depending upon the intensity and time of exposure to the MF. To investigate the possible effects of ELF-MF on vascular processes, it is necessary to employ methods that allow parameterization of the vascular network. Vascular network is a structure with fractal geometry; therefore, fractal methods have been used to evaluate its morphometric complexity. Here, we used the lacunarity parameter (complementary method of fractal analysis) and multifractal analyses to investigate angiogenesis and vasculogenesis in the embryonic yolk sac membrane (YSM) of Japanese quails (Coturnix japonica) with and without exposure to an external MF of 1mT and 60Hz. Lacunarity results showed that the vascular density was lower for the group exposed to the magnetic field for 9h/day. In addition, multifractal analysis showed reduced vascularization in the experimental groups (6h/day and 9h/day of exposure to MF). Furthermore, multifractal analysis showed difference between the groups exposed for 12 and 24h/day. Using multifractal methods (generalized dimensions and singularity spectrum), it was possible to characterize the vascular network of the quail embryo YSM as a multifractal object, therefore proving this method to be a more appropriate application than the traditional monofractal methods.

The effects of extremely low frequency magnetic fields on mutation induction in mice

The growing human exposure to extremely low frequency (ELF) magnetic fields has raised a considerable concern regarding their genotoxic effects. The aim of this study was to evaluate the in vivo effects of ELF magnetic fields irradiation on mutation induction in the germline and somatic tissues of male mice. Seven week old BALB/c×CBA/Ca F1 hybrid males were exposed to 10, 100 or 300μT of 50Hz magnetic fields for 2 or 15h. Using single-molecule PCR, the frequency of mutation at the mouse Expanded Simple Tandem Repeat (ESTR) locus Ms6-hm was established in sperm and blood samples of exposed and matched sham-treated males. ESTR mutation frequency was also established in sperm and blood samples taken from male mice exposed to 1Gy of acute X-rays. The frequency of ESTR mutation in DNA samples extracted from blood of mice exposed to magnetic fields did not significantly differ from that in sham-treated controls. However, there was a marginally significant increase in mutation frequency in sperm but this was not dose-dependent. In contrast, acute exposure X-rays led to significant increases in mutation frequency in sperm and blood of exposed males. The results of our study suggest that, within the range of doses analyzed here, the in vivo mutagenic effects of ELF magnetic fields are likely to be minor if not negligible.

Extremely low frequency magnetic fields inhibit adipogenesis of human mesenchymal stem cells.

It was reported that obese (Ob/Ob) mice lose their weight and fat when treated with 0.5 T direct current electromagnetic fields. We also observed that 7.5 Hz, 0.4 T rotation of extremely low frequency magnetic fields (ELF-MF) has an inhibitory effect on obesity. Mesenchymal stem cells (MSCs) are multi-potent cells capable of differentiating to different MSC lineages, including adipose. We hypothesized that inhibitory effects of ELF-MF on obesity may be related to the differentiation of MSCs to adipocytes. In the present study, we investigated the effects of 7.5 Hz, 0.4 T ELF-MF on differentiation of human umbilical cord MSCs. We found that ELF-MF inhibited adipogenic differentiation (exposed 2 h/day for 15 days) of MSCs but had no effect on osteogenic differentiation (exposed 2 h/day for 21 days). Moreover, ELF-MF inhibited adipocyte-specific expression of peroxisome proliferator-activated receptor 2 (PPARγ2). ELF-MF promoted c-Jun N-terminal kinase (JNK)-dependent intracellular signaling in MSCs. Furthermore, activation of the non-canonical Wnt pathway provoked the inhibition of PPARγ2 expression resulting in suppression of adipogenic differentiation. In addition, the effects of ELF-MF on growth and apoptosis of MSCs were not observed. Our data indicated that ELF-MF of 7.5 Hz, 0.4 T inhibited the adipogenic differentiation of MSCs via JNK-dependent Wnt signaling pathway, but had no effect on the growth and function of MSCs, suggesting the inhibitory effect of ELF-MF on obesity may be attributed to the inhibition of differentiation of MSCs into adipocytes. This study may provide a potential approach for the treatment of obesity.

Effects of exposure to 50 Hz electromagnetic fields on Morris water-maze performance of prenatal and neonatal mice

Extremely low-frequency magnetic fields (ELF-MF), such as those originating from residential and occupational power lines, household appliances and medical devices, have been reported repeatedly to produce a variety of biological effects, which may induce a number of changes in behavioral differences of different living species, like insects and rodents. The purpose of the present study is to investigate the possible effect of an extremely low-frequency magnetic field ELF-MF (50Hz, 1mT) on spatial learning and memory functions in mice (prenatal and neonatal exposed mice) following a continuous 7-day exposure, using Morris water-maze. Immature mice have been chosen for this study since; the immature rodent brain still has the capacity to undergo proliferation, differentiation and re-organization and more closely resembles the developing brain of a human child. Thus, the immature rodent brain may provide a sensitive and useful animal model to study the possible biological effects of ELF-MF. Our results provide convincing evidence that long time MF exposure to immature mice; causes appreciable long term deficit in learning abilities.