Toxicity of cholesterol oxidation products to Caco-2 and HepG2 cells

modulatory effects of alpha- and gamma-tocopherol

A. J. O'Sullivan, Y. C. O'Callaghan, J. A. Woods, N. M. O'Brien'

    Research output: Contribution to journalArticle

    28 Citations (Scopus)

    Abstract

    Cholesterol can be oxidized to form a variety of cholesterol oxidation products also known as oxysterols. The aims of the present study were to compare the cytotoxic effects of four oxysterols, namely 25-hydroxycholesterol (25-OHC), 7beta-hydroxycholesterol (7beta-OHC), cholesterol-5beta,6beta-epoxide (beta-epox) and cholesterol-5alpha,6alpha-epoxide (alpha-epox), in two human cell culture models. Further, the ability of 10 and 100 mum alpha- and gamma-tocopherol (alpha-TOC and gamma-TOC, respectively) to protect against oxysterol-induced cytotoxicity was also assessed. Human colonic adenocarcinoma Caco-2 and human hepatoma HepG2 cells were supplemented with increasing concentrations of 25-OHC, 7beta-OHC, beta-epox and alpha-epox (0-25 mug ml(-1)) for 24,48 or 96 h. Following 24-h and 48-h exposure, test media were replaced with normal growth media and the cells were maintained for 72 and 48 h, respectively. The 96-h exposure represented a constant challenge to the cells. Cytotoxicity was assessed using the neutral red uptake assay. The concentration of compound that inhibited cell viability by 50% (IC50 value) was calculated. All four oxysterols investigated induced the greatest cytotoxic effects following 96 It of exposure. 25-Hydroxycholesterol exhibited the greatest cytotoxicity in both cell lines. Both beta-epox and alpha-epox were more toxic to HepG2 cells than to Caco-2 cells after the 48-h exposure. Pretreatment of cells with either alpha- or gamma-TOC did not protect against oxysterol-induced cytotoxicity. The Caco-2 cells treated with the high concentration (100 mum) of gamma-TOC were found to be more susceptible to oxysterol-induced toxicity under the conditions employed in this study. Copyright (C) 2003 John Wiley Sons, Ltd.

    Original languageEnglish
    Pages (from-to)191-197
    Number of pages7
    JournalJournal of Applied Toxicology
    Volume23
    Issue number3
    DOIs
    Publication statusPublished - 2003

    Keywords

    • Caco-2 cells
    • HepG2 cells
    • Oxysterol
    • α-tocopherol
    • γ-tocopherol
    • alpha-tocopherol
    • gamma-tocopherol

    Cite this

    O'Sullivan, A. J. ; O'Callaghan, Y. C. ; Woods, J. A. ; O'Brien', N. M. . / Toxicity of cholesterol oxidation products to Caco-2 and HepG2 cells : modulatory effects of alpha- and gamma-tocopherol. In: Journal of Applied Toxicology. 2003 ; Vol. 23, No. 3. pp. 191-197.
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    abstract = "Cholesterol can be oxidized to form a variety of cholesterol oxidation products also known as oxysterols. The aims of the present study were to compare the cytotoxic effects of four oxysterols, namely 25-hydroxycholesterol (25-OHC), 7beta-hydroxycholesterol (7beta-OHC), cholesterol-5beta,6beta-epoxide (beta-epox) and cholesterol-5alpha,6alpha-epoxide (alpha-epox), in two human cell culture models. Further, the ability of 10 and 100 mum alpha- and gamma-tocopherol (alpha-TOC and gamma-TOC, respectively) to protect against oxysterol-induced cytotoxicity was also assessed. Human colonic adenocarcinoma Caco-2 and human hepatoma HepG2 cells were supplemented with increasing concentrations of 25-OHC, 7beta-OHC, beta-epox and alpha-epox (0-25 mug ml(-1)) for 24,48 or 96 h. Following 24-h and 48-h exposure, test media were replaced with normal growth media and the cells were maintained for 72 and 48 h, respectively. The 96-h exposure represented a constant challenge to the cells. Cytotoxicity was assessed using the neutral red uptake assay. The concentration of compound that inhibited cell viability by 50{\%} (IC50 value) was calculated. All four oxysterols investigated induced the greatest cytotoxic effects following 96 It of exposure. 25-Hydroxycholesterol exhibited the greatest cytotoxicity in both cell lines. Both beta-epox and alpha-epox were more toxic to HepG2 cells than to Caco-2 cells after the 48-h exposure. Pretreatment of cells with either alpha- or gamma-TOC did not protect against oxysterol-induced cytotoxicity. The Caco-2 cells treated with the high concentration (100 mum) of gamma-TOC were found to be more susceptible to oxysterol-induced toxicity under the conditions employed in this study. Copyright (C) 2003 John Wiley Sons, Ltd.",
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    Toxicity of cholesterol oxidation products to Caco-2 and HepG2 cells : modulatory effects of alpha- and gamma-tocopherol. / O'Sullivan, A. J. ; O'Callaghan, Y. C. ; Woods, J. A. ; O'Brien', N. M. .

    In: Journal of Applied Toxicology, Vol. 23, No. 3, 2003, p. 191-197.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Toxicity of cholesterol oxidation products to Caco-2 and HepG2 cells

    T2 - modulatory effects of alpha- and gamma-tocopherol

    AU - O'Sullivan, A. J.

    AU - O'Callaghan, Y. C.

    AU - Woods, J. A.

    AU - O'Brien', N. M.

    PY - 2003

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    N2 - Cholesterol can be oxidized to form a variety of cholesterol oxidation products also known as oxysterols. The aims of the present study were to compare the cytotoxic effects of four oxysterols, namely 25-hydroxycholesterol (25-OHC), 7beta-hydroxycholesterol (7beta-OHC), cholesterol-5beta,6beta-epoxide (beta-epox) and cholesterol-5alpha,6alpha-epoxide (alpha-epox), in two human cell culture models. Further, the ability of 10 and 100 mum alpha- and gamma-tocopherol (alpha-TOC and gamma-TOC, respectively) to protect against oxysterol-induced cytotoxicity was also assessed. Human colonic adenocarcinoma Caco-2 and human hepatoma HepG2 cells were supplemented with increasing concentrations of 25-OHC, 7beta-OHC, beta-epox and alpha-epox (0-25 mug ml(-1)) for 24,48 or 96 h. Following 24-h and 48-h exposure, test media were replaced with normal growth media and the cells were maintained for 72 and 48 h, respectively. The 96-h exposure represented a constant challenge to the cells. Cytotoxicity was assessed using the neutral red uptake assay. The concentration of compound that inhibited cell viability by 50% (IC50 value) was calculated. All four oxysterols investigated induced the greatest cytotoxic effects following 96 It of exposure. 25-Hydroxycholesterol exhibited the greatest cytotoxicity in both cell lines. Both beta-epox and alpha-epox were more toxic to HepG2 cells than to Caco-2 cells after the 48-h exposure. Pretreatment of cells with either alpha- or gamma-TOC did not protect against oxysterol-induced cytotoxicity. The Caco-2 cells treated with the high concentration (100 mum) of gamma-TOC were found to be more susceptible to oxysterol-induced toxicity under the conditions employed in this study. Copyright (C) 2003 John Wiley Sons, Ltd.

    AB - Cholesterol can be oxidized to form a variety of cholesterol oxidation products also known as oxysterols. The aims of the present study were to compare the cytotoxic effects of four oxysterols, namely 25-hydroxycholesterol (25-OHC), 7beta-hydroxycholesterol (7beta-OHC), cholesterol-5beta,6beta-epoxide (beta-epox) and cholesterol-5alpha,6alpha-epoxide (alpha-epox), in two human cell culture models. Further, the ability of 10 and 100 mum alpha- and gamma-tocopherol (alpha-TOC and gamma-TOC, respectively) to protect against oxysterol-induced cytotoxicity was also assessed. Human colonic adenocarcinoma Caco-2 and human hepatoma HepG2 cells were supplemented with increasing concentrations of 25-OHC, 7beta-OHC, beta-epox and alpha-epox (0-25 mug ml(-1)) for 24,48 or 96 h. Following 24-h and 48-h exposure, test media were replaced with normal growth media and the cells were maintained for 72 and 48 h, respectively. The 96-h exposure represented a constant challenge to the cells. Cytotoxicity was assessed using the neutral red uptake assay. The concentration of compound that inhibited cell viability by 50% (IC50 value) was calculated. All four oxysterols investigated induced the greatest cytotoxic effects following 96 It of exposure. 25-Hydroxycholesterol exhibited the greatest cytotoxicity in both cell lines. Both beta-epox and alpha-epox were more toxic to HepG2 cells than to Caco-2 cells after the 48-h exposure. Pretreatment of cells with either alpha- or gamma-TOC did not protect against oxysterol-induced cytotoxicity. The Caco-2 cells treated with the high concentration (100 mum) of gamma-TOC were found to be more susceptible to oxysterol-induced toxicity under the conditions employed in this study. Copyright (C) 2003 John Wiley Sons, Ltd.

    KW - Caco-2 cells

    KW - HepG2 cells

    KW - Oxysterol

    KW - α-tocopherol

    KW - γ-tocopherol

    KW - alpha-tocopherol

    KW - gamma-tocopherol

    U2 - 10.1002/jat.906

    DO - 10.1002/jat.906

    M3 - Article

    VL - 23

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    SN - 0260-437X

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