Abstract
In this report, we have examined the molecular basis of the photoprotective effect of a hydrophilic extract of the fern Polypodium leucotomos (PL) in vitro, using a solar simulator as the source of UV radiation (SSR). We found that pretreatment of human keratinocytes with PL inhibited SSR-mediated increase of tumor necrosis factor (TNF)-alpha and also abrogated nitric oxide (NO) production. Consistent with this, PL blocked the induction of inducible nitric oxide synthase (iNOS) elicited by SSR. In addition, PL inhibited the SSR-mediated transcriptional activation of NF-kappaB and AP1. Finally, we demonstrated that pretreatment with PL exerted a cytoprotective effect against SSR-induced damage, resulting in increased cell survival. Together, these data postulate a multifactor mechanism of protection not exclusively reliant on the antioxidant capability of PL, and strengthen the basic knowledge on the photoprotective effect of this botanical agent.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Apoptosis / drug effects*
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Apoptosis / radiation effects
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Ascorbic Acid / pharmacology
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Cell Line
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Cell Survival / drug effects
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Cell Survival / radiation effects
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Dose-Response Relationship, Drug
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Gene Expression / drug effects
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Gene Expression / radiation effects
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Humans
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Keratinocytes / drug effects*
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Keratinocytes / metabolism
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Keratinocytes / radiation effects
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Luciferases / genetics
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Luciferases / metabolism
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NF-kappa B / genetics
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NF-kappa B / metabolism
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Nitric Oxide / metabolism
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Nitric Oxide Synthase Type II / metabolism*
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Plant Extracts / pharmacology*
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Plant Leaves / chemistry
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Polypodium / chemistry*
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Sunlight
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Transcription Factor AP-1 / genetics
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Transcription Factor AP-1 / metabolism
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Transcription, Genetic / drug effects
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Transcription, Genetic / radiation effects
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Tumor Necrosis Factor-alpha / metabolism*
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Ultraviolet Rays
Substances
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NF-kappa B
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Plant Extracts
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Transcription Factor AP-1
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Tumor Necrosis Factor-alpha
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Nitric Oxide
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Luciferases
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Nitric Oxide Synthase Type II
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Ascorbic Acid