Bidirectional Effect of Repeated Exposure to Extremely Low-Frequency Electromagnetic Field (50 Hz) of 1 and 7 mT on Oxidative/Antioxidative Status in Rat's Brain: The Prediction for the Vulnerability to Diseases.

Oxidative medicine and cellular longevity · 2022 · Mixed · Low evidence

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MixedLow evidencePaper 5737

Study snapshot

PublicationOxidative medicine and cellular longevity · 2022

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

Studies reported evidence for opposite effects of extremely low-frequency electromagnetic field (EMF): harmful, including the oxidative stress induction, and beneficial, such as the activation of antioxidant defense. People's exposure to EMF is often repeated or prolonged, and it is important to consider the cumulative effect of such kind of exposure on the organism. If changes evoked by repeated exposure to EMF are permanent, responsiveness to other stress factors can be modified. The aims of our study were (1) to evaluate changes in the levels of oxidative stress and antioxidant defense markers in the prefrontal cortex of adult rats after repeated exposure to 1 and 7 mT EMF and (2) to assess whether repeated EMF exposure can modify oxidative/antioxidative status in response to other stress factors. Rats were exposed to EMF 1 h/day for 7 days, one, twice, or three times. After each exposure, 8-isoprostanes, protein carbonyl groups, and the total antioxidant capacity were assessed. Part of the animals, after EMF treatment, was exposed to another stress factor-open field. Results showed that repeated exposure changed the oxidative/antioxidative status depending on the intensity of the EMF and the number of exposures. 1 mT EMF created weak changes in the oxidative status in the brain; however, 7 mT EMF moved the balance to a clearly higher level. The changes in the oxidative status after 1 mT EMF were enough to reduce, and after 7 mT EMF to intensify oxidative processes in response to the next stress. We concluded that the organism might adapt to "weak" EMF, while "strong" EMF exceeds the adaptive capacity of the organism and sensitizes it to subsequent stress, and thus may modulate vulnerability to diseases. Our results also provide new insights into the possible therapeutic properties of the magnetic field, as 1 mT EMF appears to have a potentially protective impact on the brain.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal

Effect directionmixed

PopulationAdult rats

Sample sizeNot supplied

ExposureELF · 0.05 MHz · 1 h/day for 7 days; repeated one, twice, or three times

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Repeated 50 Hz EMF exposure altered oxidative/antioxidative status in rat prefrontal cortex depending on field intensity and number of exposure series. Exposure at 1 mT produced weak changes and was reported to reduce oxidative processes in response to a subsequent open-field stressor, whereas 7 mT shifted the balance toward a higher oxidative level and intensified oxidative processes in response to the subsequent stressor.

Outcomes measured

Oxidative stress markers in prefrontal cortex (8-isoprostanes, protein carbonyl groups)
Total antioxidant capacity
Oxidative/antioxidative response to subsequent stressor (open field)

Limitations

Sample size not reported in abstract
Details of exposure setup and dosimetry beyond field strength/frequency not provided in abstract
Outcome reporting is qualitative in places (e.g., 'weak changes', 'clearly higher level') without numerical results in abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": 0.05,
    "sar_wkg": null,
    "duration": "1 h/day for 7 days; repeated one, twice, or three times"
  },
  "population": "Adult rats",
  "sample_size": null,
  "outcomes": [
    "Oxidative stress markers in prefrontal cortex (8-isoprostanes, protein carbonyl groups)",
    "Total antioxidant capacity",
    "Oxidative/antioxidative response to subsequent stressor (open field)"
  ],
  "main_findings": "Repeated 50 Hz EMF exposure altered oxidative/antioxidative status in rat prefrontal cortex depending on field intensity and number of exposure series. Exposure at 1 mT produced weak changes and was reported to reduce oxidative processes in response to a subsequent open-field stressor, whereas 7 mT shifted the balance toward a higher oxidative level and intensified oxidative processes in response to the subsequent stressor.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in abstract",
    "Details of exposure setup and dosimetry beyond field strength/frequency not provided in abstract",
    "Outcome reporting is qualitative in places (e.g., 'weak changes', 'clearly higher level') without numerical results in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low-frequency electromagnetic field",
    "ELF-EMF",
    "50 Hz",
    "magnetic field",
    "1 mT",
    "7 mT",
    "oxidative stress",
    "antioxidant defense",
    "prefrontal cortex",
    "8-isoprostanes",
    "protein carbonyls",
    "total antioxidant capacity",
    "open field stress",
    "rat"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1155/2022/1031211
PubMed: 35746959

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