Is vitamin e toxic to neuron cells?

Sue Mian Then, Musalmah Mazlan, Gapor Mat Top, Wan Zurinah Wan Ngah

    Research output: Contribution to journalArticle

    28 Citations (Scopus)

    Abstract

    Besides acting as potent free radical scavengers, tocopherols and tocotrienols have been known to have non-antioxidant properties such as the involvement of α-tocopherol (αT) in PKC pathway and the anti-cancer properties of γ-tocotrienol (γT3). This study aims to elucidate whether protective effects shown by αT and γT3 in H 2O2-induced neuron cultures have anti-apoptotic or pro-apoptotic tendency toward the initiation of neuronal apoptosis. H 2O2 is used to induce apoptosis in primary cerebellar neuron cultures which is attenuated by pretreatment of αT or γT3 at concentrations ≤10 μM. Similar to our previous work, γT3 was found to be neurotoxic at concentrations ≥100 μM, whereas αT showed no neurotoxicity. Cellular uptake of γT3 was higher than that of αT. Treating cells simultaneously with either γT3 or αT and with then H2O2 led to higher expression of Bax and Bcl-2 than in neurons exposed to H2O2 alone. Analysis of Bcl-2/Bax ratio as 'survival index' showed that both pretreatment of γT3 and αT followed by H2O2 increase the 'survival index' of Bcl-2/Bax ratio compared to H2O2-treated cells, while treatment of γT3 alone decrease the ratio compared to unchanged Bcl2/Bax ratio of similar treatment with αT alone. Similar treatment of γT3 decreased p53 expression and activates p38 MAPK phosphorylation, whereas αT did not alter its expression compared to H2O 2-treated cells. Treating neurons with only γT3 or αT increased the expression of Bax, Bcl-2, p53, and p38 MAPK compared to control with γT3 exerting stronger expression for proteins involved than αT. In conclusion, low doses of γT3 and αT confer neuroprotection to H2O2-treated neurons via their antioxidant mechanism but γT3 has stronger pro-apoptosis tendency than αT by activating molecules involved in the neuronal apoptotic pathway in the absence of H 2O2.

    Original languageEnglish
    Pages (from-to)485-496
    Number of pages12
    JournalCellular and Molecular Neurobiology
    Volume29
    Issue number4
    DOIs
    Publication statusPublished - Jun 2009

    Fingerprint

    Poisons
    Vitamins
    Neurons
    Tocotrienols
    Tocopherols
    p38 Mitogen-Activated Protein Kinases
    Apoptosis
    Free Radical Scavengers
    Antioxidants
    Phosphorylation
    Neoplasms
    Proteins

    Keywords

    • Antioxidant
    • Apoptosis
    • Cerebellar neurons
    • Oxidative stress
    • Vitamin E

    ASJC Scopus subject areas

    • Cellular and Molecular Neuroscience
    • Cell Biology

    Cite this

    Then, S. M., Mazlan, M., Mat Top, G., & Wan Ngah, W. Z. (2009). Is vitamin e toxic to neuron cells? Cellular and Molecular Neurobiology, 29(4), 485-496. https://doi.org/10.1007/s10571-008-9340-8

    Is vitamin e toxic to neuron cells? / Then, Sue Mian; Mazlan, Musalmah; Mat Top, Gapor; Wan Ngah, Wan Zurinah.

    In: Cellular and Molecular Neurobiology, Vol. 29, No. 4, 06.2009, p. 485-496.

    Research output: Contribution to journalArticle

    Then, SM, Mazlan, M, Mat Top, G & Wan Ngah, WZ 2009, 'Is vitamin e toxic to neuron cells?', Cellular and Molecular Neurobiology, vol. 29, no. 4, pp. 485-496. https://doi.org/10.1007/s10571-008-9340-8
    Then, Sue Mian ; Mazlan, Musalmah ; Mat Top, Gapor ; Wan Ngah, Wan Zurinah. / Is vitamin e toxic to neuron cells?. In: Cellular and Molecular Neurobiology. 2009 ; Vol. 29, No. 4. pp. 485-496.
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