Hypomagnetic Field Research Articles

Potential health risks of hypomagnetic field for manned deep-space explorations

Potential health risks of hypomagnetic field for manned deep-space explorations

The Role of Oxidative Stress in Hypomagnetic Field Effects.

The geomagnetic field (GMF) is crucial for the survival and evolution of life on Earth. The weakening of the GMF, known as the hypomagnetic field (HMF), significantly affects various aspects of life on Earth. HMF has become a potential health risk for future deep space exploration. Oxidative stress is directly involved in the biological effects of HMF on animals or cells. Oxidative stress occurs when there is an imbalance favoring oxidants over antioxidants, resulting in cellular damage. Oxidative stress is a double-edged sword, depending on the degree of deviation from homeostasis. In this review, we summarize the important experimental findings from animal and cell studies on HMF exposure affecting intracellular reactive oxygen species (ROS), as well as the accompanying many physiological abnormalities, such as cognitive dysfunction, the imbalance of gut microbiota homeostasis, mood disorders, and osteoporosis. We discuss new insights into the molecular mechanisms underlying these HMF effects in the context of the signaling pathways related to ROS. Among them, mitochondria are considered to be the main organelles that respond to HMF-induced stress by regulating metabolism and ROS production in cells. In order to unravel the molecular mechanisms of HMF action, future studies need to consider the upstream and downstream pathways associated with ROS.

СРАВНИТЕЛЬНЫЙ АНАЛИЗ ИНГИБИРУЮЩИХ ЭФФЕКТОВ ГИПОМАГНИТНОГО ПОЛЯ И КОМБИНИРОВАННЫХ МАГНИТНЫХ ПОЛЕЙ НА ПРОДУКЦИЮ АКТИВНЫХ ФОРМ КИСЛОРОДА (АФК) НЕЙТРОФИЛАМИ

The article reveals that a decrease in the background production of reactive oxygen species (ROS) in the peritoneal neutrophils of mice after a short-term (40 minutes) stay in hypomagnetic conditions (residual field  10 nT) at physiological temperatures, detected by the method of lucigenin-dependent chemiluminescence, is not accompanied by a violation of chemiluminescent response to respiratory burst activators: formylated peptide N-formyl-Met-Leu-Phe (fMLF) and phorbol ester of phorbol-12-meristat-13-acetate (PMA). These results were obtained by activated chemiluminescence using lucigenin or luminol and various combinations of ROS production activators (PMA and/or fMLF). In contrast, the action of combined parallel constant (induction 60 μT) and alternating (amplitude range 60-180 nT, frequency 49.5 Hz) magnetic fields (CMF) leads to a decrease in the chemiluminescent response to these activators. These data indicate different sources of ROS that respond to certain modes of CMF and hypomagnetic field in neutrophils. The conducted research and the previously obtained results enable to exclude the systems that control the respiratory burst in neutrophils from the main targets and acceptors that respond to short-term deprivation of the magnetic field.

BIOIMPACT OF HYPOMAGNETIC FIELDS

Hypomagnetic fields (HMF), or nearly zero magnetic fields, are fields with a value of magnetic flux density lower than the Earth's geomagnetic field. The effects of these so-called weak magnetic fields can manifest in living organisms by influencing biological functions such as the circadian system, calcium balance in cells, DNA methylation, concentration of reactive oxygen species, as well as changes in metabolic and developmental processes. This article describes how HMF affects selected cellular structures through specific exposure parameters, whose selective impact has been verified on the proliferative activity of the yeast strain Saccharomyces cerevisiae. In 25 experiments, the inhibitory effect of a time-varying magnetic field at a level of 0.365 µT was confirmed, which corresponds to the magnitude of magnetic flux density in the vicinity of 100 kV power lines. Global organizations also point out the possible correlation between HMF generated by 50 Hz power lines and various diseases, particularly childhood leukemia.

The effects of different durations of exposure to hypomagnetic field on the number of active mitochondria and ROS levels in the mouse hippocampus

Reactive oxygen species (ROS) are one of the potential molecules in response to a hypomagnetic field (HMF), and exposure to an HMF for eight weeks led to an increase in ROS levels in the whole hippocampus area in mice. ROS are mainly derived from the byproducts of mitochondrial metabolism. However, previous in vivo studies mostly focus on the influence of one time point of HMF exposure on the mouse hippocampus and lack comparative studies on the effects of different durations of HMF exposure on the mouse hippocampus. Here, we investigated the effects of different durations of HMF on the number of active mitochondria and ROS levels in mouse hippocampus. Compared with the geomagnetic field (GMF) group, we found that the number of active mitochondria in the hippocampus was significantly reduced during the sixth week of HMF exposure, whereas the number of active mitochondria was significantly reduced and the ROS levels was significantly increased during the eighth week of HMF exposure. The number of active mitochondria gradually decreased and ROS levels gradually increased in both GMF and HMF groups with prolonged exposure time. In addition, the expression level of the PGC-1α gene in the hippocampus, the main regulator of mitochondrial biogenesis, decreased significantly in the eighth week of HMF exposure. These results reveal that the changes in active mitochondria number and ROS levels were dependent on the durations of HMF exposure, and prolonged exposure to HMF exacerbates these changes.

ВЛИЯНИЕ ГИПОМАГНИТНОГО ПОЛЯ НА ХАРАКТЕР РОСТА И МОРФОЛОГИЮ КЛЕТОК БАКТЕРИЙ РОДА BACILLUS

Biological effects induced by hypomagnetic field (HMF) were investigated using g. Bacillus as a model. HMF was found to affect the growth of bacterial population and morphological structure of prokaryotic cells. Cultivation of B. subtilis and B. licheniformis in HMF was characterized by a more active growth and formation of a dense surface film in contrast to a uniform medium turbidity in the geomagnetic field (GMF). Scanning electron microscopy was used to visualize segmentation disorders and morphological modifications of the bacterial cells characterized by changes in the form and size due to, probably, destructive transformation of peptidoglycane. In HMF, sub-inhibiting concentrations of the ultraviolet chemical analog (4-NQO) in the medium have a synergic effect on the microbial growth, and also produce distinct morphological transformations.

Background formation of lower levels of reactive oxygen species by neutrophils after hypomagnetic field exposure is not accompanied by the impairment of chemiluminescence response of neutrophils to respiratory-burst stimuli

This study shows that the background formation of lower levels of reactive oxygen species in mouse peritoneal neutrophils after short-term (40 minutes) exposure to hypomagnetic fields with ~10 nT residual field at physiological temperatures, which has been detected by use of lucigenin-dependent chemiluminescence, is not accompanied by the impairment of chemiluminescence response of neutrophils to respiratory-burst stimuli: the formylated tripeptide N-formyl-Met-Leu-Phe (fMLF) and phorbol ester phorbol-12-myristate-13-ace-tate (PMA). These results were obtained with lucigenin or luminol-enhanced activated chemiluminescence and various combinations of reactive oxygen species production stimuli (phorbol-12-myristate-13-acetate and/or N-formyl-Met-Leu-Phe). Based on the results of the present work as well as on those of previous studies, this study reveal that the systems that control the respiratory burst in neutrophils can be excluded from a list of main targets and acceptors that respond to short-term deprivation of the magnetic field.

A Decrease in the Background Production of Reactive Oxygen Species by Neutrophils after the Action of Hypomagnetic Field Is Not Accompanied by a Violation of Their Chemiluminescent Response to Respiratory Burst Activators

A Decrease in the Background Production of Reactive Oxygen Species by Neutrophils after the Action of Hypomagnetic Field Is Not Accompanied by a Violation of Their Chemiluminescent Response to Respiratory Burst Activators

Effects of a Hypomagnetic Field and Increased Water Temperature on the Production and Morphometric Parameters in Daphnia magna Straus

Effects of a Hypomagnetic Field and Increased Water Temperature on the Production and Morphometric Parameters in Daphnia magna Straus

The effect of hypomagnetic field on survival and mitochondrial functionality of active Paramacrobiotus experimentalis females and males of different age.

Even for tardigrades, often called the toughest animals on Earth, a hypomagnetic field (HMF) is an extreme environment. However, studies on the effect of HMF on tardigrades and other invertebrates are scarce. Mitochondria play an important role in an organism's response to extreme conditions. The effect of HMF on the mitochondrial inner membrane potential (Δψ), a well-known marker of mitochondria functionality, shows that mitochondria are very sensitive to HMF. To measure the HMF effect on Paramacrobiotus experimentalis, we calculated the tardigrade survival rate and Δψ level after HMF treatments of different durations. We also estimated the relationship between the age and sex of the tardigrade and the HMF effect. We observed age- and sex-related differences in Δψ and found that Δψ changes after HMF treatment were dependent on its duration as well as the animal's age and sex. Furthermore, active P. experimentalis individuals displayed a high survival rate after HMF treatment. The data may contribute to the understanding of tardigrade aging and their resistance to extreme conditions including HMF, which in turn may be useful for future space explorations.

The radical pair mechanism of biological effects on hypomagnetic fields and one method to verify it

The biological effects due to a hypomagnetic field (HMF) is a very important subject not only for aerospace traveling and space station living but also for some magnetic shielding conditions on the ground just like the underground bunkers and etc. However, to my knowledge, the mechanisms which can be related to the biological effects of a HMF remain unclear. In this study, I firstly summary one radical pair mechanism of biological effects on a HMF based on present researches, and then propose how to prove the radical pair mechanism’s truth in biological effects on a HMF through experiments. In the way of how to prove the radical pair mechanism’s truth I give the relation between the singlet yield of the radical pair and the angle describing the orientation of a HMF to the basis of the hyperfine tensor related to the electron spin and the nuclei spin is the possible one radical pair mechanism on one hand, and give the crucial method which is through that angle changed causes the biological effects in vivo or vitro to prove or disprove the mechanism on the other hand, because the biological effects of a HMF can be related with that angle, which is very easy to be controlled in experiments.

Statistical Amplification of the Effects of Weak Magnetic Fields in Cellular Translation.

We assume that the enzymatic processes of recognition of amino acids and their addition to the synthesized molecule in cellular translation include the formation of intermediate pairs of radicals with spin-correlated electrons. The mathematical model presented describes the changes in the probability of incorrectly synthesized molecules in response to a change in the external weak magnetic field. A relatively high chance of errors has been shown to arise from the statistical enhancement of the low probability of local incorporation errors. This statistical mechanism does not require a long thermal relaxation time of electron spins of about 1 μs-a conjecture often used to match theoretical models of magnetoreception with experiments. The statistical mechanism allows for experimental verification by testing the usual Radical Pair Mechanism properties. In addition, this mechanism localizes the site where magnetic effects originate, the ribosome, which makes it possible to verify it by biochemical methods. This mechanism predicts a random nature of the nonspecific effects caused by weak and hypomagnetic fields and agrees with the diversity of biological responses to a weak magnetic field.

Hypomagnetic field effects as a potential avenue for testing the radical pair mechanism in biology

Near-zero magnetic fields, called hypomagnetic fields, are known to impact biological phenomena, including developmental processes, the circadian system, neuronal and brain activities, DNA methylation, calcium balance in cells, and many more. However, the exact mechanism underlying such effects is still elusive, as the corresponding energies are far smaller than thermal energies. It is known that chemical reactions involving radical pairs can be magnetic field dependent at very low intensities comparable to or less than the geomagnetic field. Here, we review in detail hypomagnetic field effects from the perspective of the radical pair mechanism, pointing out that under certain conditions, they can be comparable or even stronger than the effects of increasing the magnetic field. We suggest that hypomagnetic field effects are an interesting avenue for testing the radical pair mechanism in biology.

Hypomagnetic Fields and Their Multilevel Effects on Living Organisms

The Earth’s magnetic field is one of the basic abiotic factors in all environments, and organisms had to adapt to it during evolution. On some occasions, organisms can be confronted with a significant reduction in a magnetic field, termed a “hypomagnetic field—HMF”, for example, in buildings with steel reinforcement or during interplanetary flight. However, the effects of HMFs on living organisms are still largely unclear. Experimental studies have mostly focused on the human and rodent models. Due to the small number of publications, the effects of HMFs are mostly random, although we detected some similarities. Likely, HMFs can modify cell signalling by affecting the contents of ions (e.g., calcium) or the ROS level, which participate in cell signal transduction. Additionally, HMFs have different effects on the growth or functions of organ systems in different organisms, but negative effects on embryonal development have been shown. Embryonal development is strictly regulated to avoid developmental abnormalities, which have often been observed when exposed to a HMF. Only a few studies have addressed the effects of HMFs on the survival of microorganisms. Studying the magnetoreception of microorganisms could be useful to understand the physical aspects of the magnetoreception of the HMF.

Effects of Hypoxia and Hypomagnetic Field on Morphometric and Life-History Traits in Freshwater Cladoceran Daphnia magna

The intensity of climatic changes and human activities is increasing every year. The general consequence of these processes for freshwater ecosystems can be a dissolved oxygen decrease. There is also a possibility of a reduction in geomagnetic field intensity due to a reversal of the Earth’s magnetic poles. It is assumed that the magnetic poles’ reversal may proceed relatively quickly and coincide with global climatic changes. To evaluate the influence of these processes on aquatic organisms, we studied the effects of different dissolved oxygen levels (2 mg/L, 5 mg/L, and 8 mg/L) under the geomagnetic field (51.7 ± 0.2 μT) and hypomagnetic field (0 ± 0.2 μT) on the model freshwater crustacean Daphnia magna Straus. It was found that reduced oxygen levels and the hypomagnetic field led to a decrease in the sizes of parental females, a reduction in the number of produced offspring, and an increase in the period between broods. The newborns from the first brood in the hypomagnetic field were larger than that from the geomagnetic field. The dissolved oxygen level and magnetic environment affected the age of the first brood release and caudal spine length. The results imply that the probable coincidence of the geomagnetic pole reversal and the decrease in the dissolved oxygen level due to global climatic and geophysical processes will have a more negative impact on freshwater crustaceans than the occurrence of these processes at different times.

Hypomagnetic Field Exposure Affecting Gut Microbiota, Reactive Oxygen Species Levels, and Colonic Cell Proliferation in Mice.

The gut microbiota has been considered one of the key factors in host health, which is influenced by many environmental factors. The geomagnetic field (GMF) represents one of the important environmental conditions for living organisms. Previous studies have shown that the elimination of GMF, the so-called hypomagnetic field (HMF), could affect the physiological functions and resistance to antibiotics of some microorganisms. However, whether long-term HMF exposure could alter the gut microbiota to some extent in mammals remains unclear. Here, we investigated the effects of long-term (8- and 12-week) HMF exposure on the gut microbiota in C57BL/6J mice. Our results clearly showed that 8-week HMF significantly affected the diversity and function of the mouse gut microbiota. Compared with the GMF group, the concentrations of short-chain fatty acids tended to decrease in the HMF group. Immunofluorescence analysis showed that HMF promoted colonic cell proliferation, concomitant with an increased level of reactive oxygen species (ROS). To our knowledge, this is the first in vivo finding that long-term HMF exposure could affect the mouse gut microbiota, ROS levels, and colonic cell proliferation in the colon. Moreover, the changes in gut microbiota can be restored by returning mice to the GMF environment, thus the possible harm to the microbiota caused by HMF exposure can be alleviated. © 2022 Bioelectromagnetics Society.

Effects of hypomagnetic field on adult hippocampal neurogenic niche and neurogenesis in mice

The elimination of geomagnetic field (GMF), also called hypomagnetic field (HMF), is one of the major environmental hazards faced by deep-space astronauts and the workers in magnetically shielded rooms on Earth. We previously reported that long-term HMF exposure impaired adult hippocampal neurogenesis (AHN) and cognition by reducing endogenous reactive oxygen species (ROS) levels in adult neural stem cells (aNSCs). In addition to the aNSCs themselves, adult neurogenesis is also regulated by the local environment, i.e., the neurogenic niche. Neurogenic niche is mainly composed of astrocyte, microglia, and vascular system. However, whether the HMF exposure affects the neurogenic niche in hippocampus remains unknown. In this study, we investigated the effects of the HMF exposure on the neurogenic niche and adult neurogenesis in hippocampus, as well as the cognitive function in mice. The HMF is simulated by using the newly upgraded double-wrapped coils, different with our previous coils, which are capable of providing a very low-strength static magnetic field and identical electromagnetic field background between the HMF group and the GMF group. Here, we for the first time clearly revealed that 8-week HMF exposure significantly induced microglia activation and increased the number of astrocytes in hippocampal dentate gyrus (DG), suggesting the abnormalities in the neurogenic niche. Meanwhile, 8-week HMF exposure also markedly reduced proliferation and differentiation of aNSCs in the DG, and impaired the cognitive behavior of mice, consistent with our previous findings. In addition, we also found that 8-week HMF exposure significantly induced anxiety-like behaviors of mice. In summary, this study indicates that 8-week HMF exposure induces the neurogenic niche abnormalities, contributing to the AHN impairments, thus leads to the cognitive dysfunction and anxiety-like behaviors in mice.

Influence of hypomagnetic field on the heartbeat in zebrafish embryos.

The magnetic environment may influence the functioning of the cardiovascular system. It was reported that low-frequency and static magnetic fields affect hemodynamics, heart rate, and heart rate variability in animals and humans. Moreover, recent data suggest that magnetic fields affect the circadian rhythms of physiological processes. The influence of the magnetic environment on heart functionating during early development has been studied insufficiently. We utilized transparent zebrafish embryos to evaluate the effect of the hypomagnetic field on the characteristics of cardiac function using a noninvasive optical approach based on photoplethysmographic microscopic imaging. The embryos were exposed to the geomagnetic and hypomagnetic fields from the second to the 116th hour post fertilization under a 16h light/8h dark cycle or constant illumination. The exposure of embryos to the hypomagnetic field in both lighting modes led to increased embryo mortality, the appearance of abnormal phenotypes, and a significant increase in the embryo's heartbeat rate. The difference between maximal and minimal heartbeat intervals, maximal to minimal heartbeat intervals ratio, and the coefficient of variation of heartbeat rate were increased in the embryos exposed to the hypomagnetic field under constant illumination from 96 to 116h post fertilization. The dynamics of heartbeat rate changes followed a circadian pattern in all studied groups except zebrafish exposed to the hypomagnetic field under constant illumination. The results demonstrate the importance of natural magnetic background for the early development of zebrafish. The possible mechanisms of observed effects are discussed.

The light-independent locomotion response to a static magnetic field in Xenopus tadpoles

Increasing numbers of behavioral observations have shown that many organisms can sense magnetic fields in the environment. However, the underlying mechanisms of magnetosensation remain elusive, and a major problem is the lack of an animal model convenient for detecting magnetic responses, especially in vertebrates. We have previously reported that the physical performance of mice decreased after 1 month of exposure to a hypomagnetic field, which probably includes a light-independent mechanism. In this study, we investigated the effects of a static magnetic field on the locomotion of Xenopus tadpoles (stage 48) using a real-time recording system. Because it is speculated that the photosensing system is related to magnetosensation, we triggered the tadpoles to swim by a 30 s light pulse after a 5 min adaptation in the dark and measured the swimming activities of the tadpoles under static magnetic field exposure in both the dark and bright conditions. Compared to the sham control treatment, the presence of a magnet inhibited the movement of the tadpoles under both bright and dark conditions, as shown by reductions in swimming distance, speed, and counts of path adjustment. Moreover, the directional preference for path adaptation was altered when swimming in the dark. These results suggest that tadpoles in the dark can exert a rapid locomotion response to changes in the environmental magnetic field, providing evidence for an intrinsic, light-independent rapid magnetoresponse pathway in tadpoles. In addition, this rapid vertebrate locomotion assay paradigm will be a practical tool to facilitate further investigation of the mechanisms of biomagnetic effects.

Radical triads, not pairs, may explain effects of hypomagnetic fields on neurogenesis.

Adult hippocampal neurogenesis and hippocampus-dependent cognition in mice have been found to be adversely affected by hypomagnetic field exposure. The effect concurred with a reduction of reactive oxygen species in the absence of the geomagnetic field. A recent theoretical study suggests a mechanistic interpretation of this phenomenon in the framework of the Radical Pair Mechanism. According to this model, a flavin-superoxide radical pair, born in the singlet spin configuration, undergoes magnetic field-dependent spin dynamics such that the pair's recombination is enhanced as the applied magnetic field is reduced. This model has two ostensible weaknesses: a) the assumption of a singlet initial state is irreconcilable with known reaction pathways generating such radical pairs, and b) the model neglects the swift spin relaxation of free superoxide, which abolishes any magnetic sensitivity in geomagnetic/hypomagnetic fields. We here suggest that a model based on a radical triad and the assumption of a secondary radical scavenging reaction can, in principle, explain the phenomenon without unnatural assumptions, thus providing a coherent explanation of hypomagnetic field effects in biology.