The Effect of Long-Term Moderate Static Magnetic Field Exposure on Adult Female Mice

Abstract

Because of the high cost and safety of ultra-high magnetic resonance imaging (MRI), its application has certain limitations. Whereas 0.5–3 T MRI has been widely applied in hospitals, static magnetic fields (SMFs) have been shown to improve mice mental health and have anti-tumor potentials. Here, we compared the effects of the upward and downward 150 mT SMF groups with the sham group on C57BL/6J adult female mice. Locomotor and exploratory activity were also measured by behavioral tests, including the open field and elevated plus test. Additionally, physiology, pathology indicators and gut microbiota were examined. We found that 150 mT SMFs long-term exposure enhanced locomotive and exploratory activity of mice, especially the downward 150 mT SMF. Compared with the downward 150 mT SMF group, the movement speed and distance in the center area of the sham group were increased by 65.99% (p < 0.0001) and 68.58% (p = 0.0038), respectively. Moreover, compared to the sham group, downward 150 mT SMF increased the number of entrances to the center area by 67.0% (p = 0.0082) and time in the center area by 77.12% (p = 0.0054). Additionally, we observed that upward 150 mT SMF improved the number of follicles (~2.5 times, p = 0.0325) and uterine glands through increasing the total antioxidant capacity and reducing lipid peroxidation level in mice. Gut microbiome analysis showed that 150 mT SMFs long-term exposure improved the microbiota abundance (Clostridium, Bifidobacterium, Ralstonia and Yaniella) in the genus level, which may affect metabolism, anxiety and behavior in adult female mice. Our results demonstrated that 150 mT SMFs long-term exposure not only had good biosafety, but also improved athletic performance, emotion and the function of ovarian, uterine and gut microbiota abundance in adult female mice, which unraveled the potential of moderate long-term SMF exposure in clinical applications.

A safety study on ultra‑high or moderate static magnetic fields combined with platycodin D against lung cancer

“…In addition to the tumor inhibition effects, Tian et al (19) found that 200 h exposure to 9.4 T SMF can reduce the toxicity of low-dose imatinib mesylate, and Yu et al (20) found that 24 days (24 h/day) of exposure to moderate SMF can also reduce cisplatin side effects in kidney. In addition, our previous study showed that 150 mT exposure for 18 weeks continuously reduces the anxiety-like emotion (31). Compared with the sham group, the present behavioral experiments showed that PD reduced the anxiety-like emotion in tumor-bearing mice, but neither 150 mT or 22 T ultra-high SMFs ameliorated this phenomenon, suggesting that SMFs disturbed this effect.…”

“…Most of the time, they are exposed to 150-200 mT SMF, or even less (2). Therefore, the present study selected 150 mT SMF for the experiment and the exposure system is the same as our previous reports (31). Briefly, the magnetic plate used in mice experiment was composed of 10 small magnetic plates, each small magnetic plate contained eight north polar magnets, which strength were 500 mT, and formed the upward 150 mT magnetic plate to the surface of mice.…”

A role of cryptochrome for magnetic field‐dependent improvement of sleep quality, lifespan, and motor function in Drosophila

“…Magnetic field exposure improved lifespan and healthspan in mice (Fan et al, 2022). Static magnetic fields have been shown to improve mice mental health (Yang et al, 2022).…”