Evaluation of the neuroprotective effects of Vitamin E on the rat substantia nigra neural cells exposed to electromagnetic field: An ultrastructural study.

Abstract

Electromagnetic fields (EMFs) could induce oxidative stress (OS) in human tissues. Lipid peroxidation (LPO) is the main hallmark of OS that harms neural cell components, primarily lipids in the myelin sheaths and membranes. Vitamin E is a lipophilic antioxidant that protects cells from OS-related damages and inhibits the LPO process. In this study, male rats were assigned into three groups of Control, EMF, and EMF+ Vitamin E. The EMF producer equipment produced an alternate current of 50 Hz, 3 Mili Tesla (mT). At the end of the experiment, half of the substantia nigra in every sample was used for measurement of the malondialdehyde (MDA) level as the end-product of the LPO and activity of superoxide dismutase (SOD) enzyme. The next half of the tissue was prepared for transmission electron microscopy (TEM). In the EMF group, MDA level was enhanced and SOD value decreased significantly compared to the control group, but Vitamin E could restore these changes. In rats undergone EMF, heterochromatic nucleus and destruction in some portions of the nuclear membrane were detected. The segmental separation or destruction of myelin sheath lamellae was observed in nerve fibers. In treated animals, the nucleus was round, less heterochromatic, with a regular membrane. Separation of myelin sheath lamellae in some nerve fibers was slighter than the radiation group. Considering the results, EMF exposure induces LPO and triggers ultrastructural changes in the cell membranes, nucleus, and myelin sheath of substantia nigra cells, but Vitamin E consumption weakens these neuropathological alterations.

AI evidence extraction

Main findings

Compared with controls, the EMF group showed significantly increased MDA and decreased SOD; Vitamin E co-treatment restored these changes. TEM findings in EMF-exposed rats included heterochromatic nuclei, nuclear membrane destruction in some portions, and segmental separation/destruction of myelin sheath lamellae; these alterations were described as milder in the EMF+Vitamin E group.

Outcomes measured

• Malondialdehyde (MDA) level (lipid peroxidation marker)
• Superoxide dismutase (SOD) activity
• Ultrastructural changes in substantia nigra assessed by transmission electron microscopy (TEM): nucleus/nuclear membrane changes, myelin sheath lamellae separation/destruction

Limitations

• Exposure duration not reported in abstract
• Sample size not reported in abstract
• Animal study; generalizability to humans not addressed in abstract
• Only biochemical markers (MDA, SOD) and ultrastructural endpoints reported in abstract

Suggested hubs

• occupational-exposure (0.2)
  Study involves 50 Hz ELF magnetic field exposure, which can be relevant to occupational ELF contexts, though no specific occupational source is stated.

{
    "study_type": "animal",
    "exposure": {
        "band": "ELF",
        "source": null,
        "frequency_mhz": 0.05000000000000000277555756156289135105907917022705078125,
        "sar_wkg": null,
        "duration": null
    },
    "population": "Male rats",
    "sample_size": null,
    "outcomes": [
        "Malondialdehyde (MDA) level (lipid peroxidation marker)",
        "Superoxide dismutase (SOD) activity",
        "Ultrastructural changes in substantia nigra assessed by transmission electron microscopy (TEM): nucleus/nuclear membrane changes, myelin sheath lamellae separation/destruction"
    ],
    "main_findings": "Compared with controls, the EMF group showed significantly increased MDA and decreased SOD; Vitamin E co-treatment restored these changes. TEM findings in EMF-exposed rats included heterochromatic nuclei, nuclear membrane destruction in some portions, and segmental separation/destruction of myelin sheath lamellae; these alterations were described as milder in the EMF+Vitamin E group.",
    "effect_direction": "harm",
    "limitations": [
        "Exposure duration not reported in abstract",
        "Sample size not reported in abstract",
        "Animal study; generalizability to humans not addressed in abstract",
        "Only biochemical markers (MDA, SOD) and ultrastructural endpoints reported in abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "electromagnetic field",
        "ELF-EMF",
        "50 Hz",
        "3 mT",
        "oxidative stress",
        "lipid peroxidation",
        "malondialdehyde",
        "superoxide dismutase",
        "substantia nigra",
        "myelin sheath",
        "transmission electron microscopy",
        "vitamin E",
        "neuroprotection"
    ],
    "suggested_hubs": [
        {
            "slug": "occupational-exposure",
            "weight": 0.200000000000000011102230246251565404236316680908203125,
            "reason": "Study involves 50 Hz ELF magnetic field exposure, which can be relevant to occupational ELF contexts, though no specific occupational source is stated."
        }
    ]
}

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