Abstract
This is the first report demonstrating a relationship between apoptosis induction and changes of intracellular redox potential in the growth-inhibitory effects of high concentrations of beta-carotene in a tumor cell line. beta-Carotene inhibited the growth of human WiDr colon adenocarcinoma cells in a dose- and time-dependent manner, induced apoptosis, and blocked Bcl-2 expression. These effects were accompanied by an enhanced production of intracellular reactive oxygen species (ROS). The addition of the antioxidant alpha-tocopherol blocked both the pro-oxidant and the growth-inhibitory effects of the carotenoid. These findings suggest that beta-carotene may act as an inductor of apoptosis by its pro-oxidant properties.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenocarcinoma / drug therapy
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Adenocarcinoma / metabolism
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Adenocarcinoma / pathology
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Antioxidants / metabolism
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Antioxidants / pharmacology
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Apoptosis / drug effects*
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Cell Division / drug effects
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Cell Survival / drug effects
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Colonic Neoplasms / drug therapy
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Colonic Neoplasms / metabolism
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Colonic Neoplasms / pathology
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Dose-Response Relationship, Drug
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Free Radicals / metabolism
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Growth Inhibitors / administration & dosage
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Growth Inhibitors / pharmacology
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Humans
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Oxidants / administration & dosage
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Oxidants / metabolism
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Oxidants / pharmacology
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Proto-Oncogene Proteins / metabolism
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Proto-Oncogene Proteins c-bcl-2 / metabolism
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Reactive Oxygen Species / metabolism*
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Tumor Cells, Cultured
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Vitamin E / metabolism
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Vitamin E / pharmacology
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bcl-2-Associated X Protein
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bcl-X Protein
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beta Carotene / administration & dosage
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beta Carotene / metabolism
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beta Carotene / pharmacology*
Substances
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Antioxidants
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BCL2L1 protein, human
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Free Radicals
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Growth Inhibitors
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Oxidants
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Proto-Oncogene Proteins
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Proto-Oncogene Proteins c-bcl-2
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Reactive Oxygen Species
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bcl-2-Associated X Protein
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bcl-X Protein
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beta Carotene
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Vitamin E