Effects of extremely low frequency magnetic field on oxidative balance in brain of rats.

Journal of physiology and pharmacology : an official journal of the Polish Physiological Society · 2011 · Mixed · Low evidence

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MixedLow evidencePaper 3246

Study snapshot

PublicationJournal of physiology and pharmacology : an official journal of the Polish Physiological Society · 2011

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

Extremely low frequency magnetic field (ELF-MF) may result in oxidative DNA damage and lipid peroxidation with an ultimate effect on a number of systemic disturbances and cell death. The aim of the study is to assess the effect of ELF-MF parameters most frequently used in magnetotherapy on reactive oxygen species generation (ROS) in brain tissue of experimental animals depending on the time of exposure to this field. The research material included adult male Sprague-Dawley rats, aged 3-4 months. The animals were divided into 3 groups: I - control (shame) group; II - exposed to the following parameters of the magnetic field: 7 mT, 40 Hz, 30 min/day, 10 days; III - exposed to the ELF-MF parameters of 7 mT, 40 Hz, 60 min/day, 10 days. The selected parameters of oxidative stress: thiobarbituric acid reactive substances (TBARS), hydrogen peroxide (H(2)O(2)), total free sulphydryl groups (-SH groups) and protein in brain homogenates were measured after the exposure of rats to the magnetic field. ELF-MF parameters of 7 mT, 40 Hz, 30 min/day for 10 days caused a significant increase in lipid peroxidation and insignificant increase in H(2)O(2) and free -SH groups. The same ELF-MF parameters but applied for 60 min/day caused a significant increase in free -SH groups and protein concentration in the brain homogenates indicating the adaptive mechanism. The study has shown that ELF-MF applied for 30 min/day for 10 days can affect free radical generation in the brain. Prolongation of the exposure to ELF-MF (60/min/day) caused adaptation to this field. The effect of ELF-MF irradiation on oxidative stress parameters depends on the time of animal exposure to magnetic field.

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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 male Sprague-Dawley rats (3–4 months old)

Sample sizeNot supplied

ExposureELF · 30 or 60 min/day for 10 days

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Rats exposed to ELF-MF (7 mT, 40 Hz) for 30 min/day for 10 days showed a significant increase in lipid peroxidation (TBARS) and non-significant increases in H2O2 and free -SH groups. Exposure with the same field parameters for 60 min/day for 10 days produced a significant increase in free -SH groups and protein concentration, interpreted by the authors as an adaptive response. The authors conclude that effects on oxidative stress parameters depend on exposure duration.

Outcomes measured

TBARS (lipid peroxidation) in brain homogenates
Hydrogen peroxide (H2O2) in brain homogenates
Total free sulphydryl (-SH) groups in brain homogenates
Protein concentration in brain homogenates
Reactive oxygen species (ROS)/free radical generation (as inferred from oxidative stress markers)

Limitations

Sample size not reported in the abstract.
Only male rats were studied.
Outcomes are limited to biochemical markers in brain homogenates; no behavioral or clinical endpoints reported.
Exposure conditions reflect magnetotherapy parameters; generalizability to other ELF sources is unclear from the abstract.

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "magnetotherapy",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "30 or 60 min/day for 10 days"
  },
  "population": "Adult male Sprague-Dawley rats (3–4 months old)",
  "sample_size": null,
  "outcomes": [
    "TBARS (lipid peroxidation) in brain homogenates",
    "Hydrogen peroxide (H2O2) in brain homogenates",
    "Total free sulphydryl (-SH) groups in brain homogenates",
    "Protein concentration in brain homogenates",
    "Reactive oxygen species (ROS)/free radical generation (as inferred from oxidative stress markers)"
  ],
  "main_findings": "Rats exposed to ELF-MF (7 mT, 40 Hz) for 30 min/day for 10 days showed a significant increase in lipid peroxidation (TBARS) and non-significant increases in H2O2 and free -SH groups. Exposure with the same field parameters for 60 min/day for 10 days produced a significant increase in free -SH groups and protein concentration, interpreted by the authors as an adaptive response. The authors conclude that effects on oxidative stress parameters depend on exposure duration.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in the abstract.",
    "Only male rats were studied.",
    "Outcomes are limited to biochemical markers in brain homogenates; no behavioral or clinical endpoints reported.",
    "Exposure conditions reflect magnetotherapy parameters; generalizability to other ELF sources is unclear from the abstract."
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency magnetic field",
    "ELF-MF",
    "magnetotherapy",
    "rats",
    "brain",
    "oxidative stress",
    "TBARS",
    "lipid peroxidation",
    "hydrogen peroxide",
    "sulphydryl groups",
    "adaptation"
  ],
  "suggested_hubs": [
    {
      "slug": "elf-health-effects",
      "weight": 0.9,
      "reason": "Animal study of extremely low frequency magnetic field exposure and oxidative stress outcomes in brain tissue."
    }
  ]
}

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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: Not supplied
PubMed: 22314568

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