Effects of various extremely low frequency magnetic fields on the free radical processes, natural antioxidant system and respiratory burst system activities in the heart and liver tissues.

Indian journal of biochemistry & biophysics · 2008 · Mixed · Low evidence

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MixedLow evidencePaper 4988

Guinea pigs exposed to 50 Hz magnetic fields (1, 2, or 3 mT; 4 or 8 h/day for 5 days) showed changes in oxidative stress and related biomarkers in heart and liver compared with controls. Effects varied by intensity and duration, with some groups showing incre…

Study snapshot

PublicationIndian journal of biochemistry & biophysics · 2008

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

Magnetic fields (MFs) can affect biological systems by increasing the release of free radicals that are able to alter cell defense systems and breakdown tissue homeostasis. In the present study, the effects of extremely low frequency (ELF) electromagnetic fields (EMF) were investigated on free radical levels, natural antioxidant systems and respiratory burst system activities in heart and liver tissues of guinea pigs exposed to 50 Hz MFs of 1, 2 and 3 mT for 4 h/day and 8 h/day for 5 days by measuring malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH) levels and myeloperoxidase (MPO) activity. A total of sixty-two male guinea pigs, 10-12 weeks old were studied in seven groups as control and exposure groups: Group I (control), II (1 mT, 4 h/day), III (1 mT, 8 h/day), IV (2 mT, 4 h/day), V (2 mT, 8 h/day), VI (3 mT, 4 h/day), and VII (3 mT, 8 h/day). Controls were kept under the same conditions without any exposure to MF. MDA levels increased in liver in groups II and IV, but decreased in group VII for both liver and heart tissues. NOx levels declined in heart in groups II and III and in liver in groups III, V, and VI, but increased in liver in group VII. GSH levels increased in heart in groups II, IV, V, and in liver in groups V and VI and VI, but decreased in groups II and IV in liver. MPO activity decreased in liver in groups III, IV, VI and VII with respect to controls and in heart tissues in groups II, III and IV; however, there was a significant increase MPO activity in heart in group VII. From the results, it can be concluded that the intensity and exposure duration of MFs are among the effective conditions on the formation of free radicals and behaviour of antioxidant enzymes.

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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

PopulationMale guinea pigs (10–12 weeks old)

Sample size62

ExposureELF · 0.05 MHz · 4 h/day or 8 h/day for 5 days

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Outcomes measured

Malondialdehyde (MDA) levels in heart and liver
Nitric oxide (NOx) levels in heart and liver
Glutathione (GSH) levels in heart and liver
Myeloperoxidase (MPO) activity in heart and liver
Free radical processes / oxidative stress markers
Natural antioxidant system measures
Respiratory burst system activity

Limitations

Exposure source/setup not described in the abstract
No statistical details (e.g., effect sizes, p-values) provided in the abstract
Animal study; generalizability to humans not addressed in the abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": 0.05,
    "sar_wkg": null,
    "duration": "4 h/day or 8 h/day for 5 days"
  },
  "population": "Male guinea pigs (10–12 weeks old)",
  "sample_size": 62,
  "outcomes": [
    "Malondialdehyde (MDA) levels in heart and liver",
    "Nitric oxide (NOx) levels in heart and liver",
    "Glutathione (GSH) levels in heart and liver",
    "Myeloperoxidase (MPO) activity in heart and liver",
    "Free radical processes / oxidative stress markers",
    "Natural antioxidant system measures",
    "Respiratory burst system activity"
  ],
  "main_findings": "Guinea pigs exposed to 50 Hz magnetic fields (1, 2, or 3 mT; 4 or 8 h/day for 5 days) showed changes in oxidative stress and related biomarkers in heart and liver compared with controls. Effects varied by intensity and duration, with some groups showing increases and others decreases in MDA, NOx, GSH, and MPO activity.",
  "effect_direction": "mixed",
  "limitations": [
    "Exposure source/setup not described in the abstract",
    "No statistical details (e.g., effect sizes, p-values) provided in the abstract",
    "Animal study; generalizability to humans not addressed in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency",
    "ELF",
    "magnetic field",
    "50 Hz",
    "guinea pig",
    "heart",
    "liver",
    "oxidative stress",
    "free radicals",
    "malondialdehyde",
    "nitric oxide",
    "glutathione",
    "myeloperoxidase",
    "respiratory burst"
  ],
  "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: Not supplied
PubMed: 19069844

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