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Photodecomposition and phototoxicity of natural retinoids.

Tolleson WH, Cherng SH, Xia Q, Boudreau M, Yin JJ, Wamer WG, Howard PC, Yu H, Fu PP - Int J Environ Res Public Health (2005)

Bottom Line: Sunlight is a known human carcinogen.Many cosmetics contain retinoid-based compounds, such as retinyl palmitate (RP), either to protect the skin or to stimulate skin responses that will correct skin damaged by sunlight.This paper reports the update information and our experimental results on photostability, photoreactions, and phototoxicity of the natural retinoids including retinol (ROH), retinal, retinoid acid (RA), retinyl acetate, and RP (Figure 1).

View Article: PubMed Central - PubMed

Affiliation: National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA.

ABSTRACT
Sunlight is a known human carcinogen. Many cosmetics contain retinoid-based compounds, such as retinyl palmitate (RP), either to protect the skin or to stimulate skin responses that will correct skin damaged by sunlight. However, little is known about the photodecomposition of some retinoids and the toxicity of these retinoids and their sunlight-induced photodecomposition products on skin. Thus, studies are required to test whether topical application of retinoids enhances the phototoxicity and photocarcinogenicity of sunlight and UV light. Mechanistic studies are needed to provide insight into the disposition of retinoids in vitro and on the skin, and to test thoroughly whether genotoxic damage by UV-induced radicals may participate in any toxicity of topically applied retinoids in the presence of UV light. This paper reports the update information and our experimental results on photostability, photoreactions, and phototoxicity of the natural retinoids including retinol (ROH), retinal, retinoid acid (RA), retinyl acetate, and RP (Figure 1).

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A2E, a fluorescent retinoid derivative isolated from retinal pigment epithelial cells
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f11-ijerph-02-00147: A2E, a fluorescent retinoid derivative isolated from retinal pigment epithelial cells

Mentions: Phototoxic autofluorescent lipofusin granules, comprised of complex indigestible lipid/protein aggregates, accumulate intracellularly as a consequence of aging. The accumulation of lipofusin in retinal pigment epithelial (RPE) cells is associated with increased photooxidative damage and is believed to contribute to macular degeneration and blindness. The major fluorophore detected in organic extracts of lipofuscin from RPE cells is an unusual pyridinium bisretinoid called A2E (Figure 11) generated as a byproduct from phosphatidylethanolamine and excess all-trans-retinal that evades recycling by RPE cells. Because it cannot be metabolized further, A2E accumulates in RPE lysosomes where it impairs clearance of phospholipids derived from phagocytosed rod outer segments and sensitizes RPE cells for apoptosis. Irradiation with blue light of the lipofuscin organic extracts of RPE cells generates ROS and produces lipid peroxidation. Irradiation of A2E also releases ROS, but the quantum yield is insufficient to account for the amount of ROS produced by lipofuscin. Ocular lipofuscin granules also contain all-trans-retinal which is 73-fold more efficient than A2E at photochemically generating singlet oxygen and 3.2-fold more efficient at generating superoxide radicals.


Photodecomposition and phototoxicity of natural retinoids.

Tolleson WH, Cherng SH, Xia Q, Boudreau M, Yin JJ, Wamer WG, Howard PC, Yu H, Fu PP - Int J Environ Res Public Health (2005)

A2E, a fluorescent retinoid derivative isolated from retinal pigment epithelial cells
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814709&req=5

f11-ijerph-02-00147: A2E, a fluorescent retinoid derivative isolated from retinal pigment epithelial cells
Mentions: Phototoxic autofluorescent lipofusin granules, comprised of complex indigestible lipid/protein aggregates, accumulate intracellularly as a consequence of aging. The accumulation of lipofusin in retinal pigment epithelial (RPE) cells is associated with increased photooxidative damage and is believed to contribute to macular degeneration and blindness. The major fluorophore detected in organic extracts of lipofuscin from RPE cells is an unusual pyridinium bisretinoid called A2E (Figure 11) generated as a byproduct from phosphatidylethanolamine and excess all-trans-retinal that evades recycling by RPE cells. Because it cannot be metabolized further, A2E accumulates in RPE lysosomes where it impairs clearance of phospholipids derived from phagocytosed rod outer segments and sensitizes RPE cells for apoptosis. Irradiation with blue light of the lipofuscin organic extracts of RPE cells generates ROS and produces lipid peroxidation. Irradiation of A2E also releases ROS, but the quantum yield is insufficient to account for the amount of ROS produced by lipofuscin. Ocular lipofuscin granules also contain all-trans-retinal which is 73-fold more efficient than A2E at photochemically generating singlet oxygen and 3.2-fold more efficient at generating superoxide radicals.

Bottom Line: Sunlight is a known human carcinogen.Many cosmetics contain retinoid-based compounds, such as retinyl palmitate (RP), either to protect the skin or to stimulate skin responses that will correct skin damaged by sunlight.This paper reports the update information and our experimental results on photostability, photoreactions, and phototoxicity of the natural retinoids including retinol (ROH), retinal, retinoid acid (RA), retinyl acetate, and RP (Figure 1).

View Article: PubMed Central - PubMed

Affiliation: National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA.

ABSTRACT
Sunlight is a known human carcinogen. Many cosmetics contain retinoid-based compounds, such as retinyl palmitate (RP), either to protect the skin or to stimulate skin responses that will correct skin damaged by sunlight. However, little is known about the photodecomposition of some retinoids and the toxicity of these retinoids and their sunlight-induced photodecomposition products on skin. Thus, studies are required to test whether topical application of retinoids enhances the phototoxicity and photocarcinogenicity of sunlight and UV light. Mechanistic studies are needed to provide insight into the disposition of retinoids in vitro and on the skin, and to test thoroughly whether genotoxic damage by UV-induced radicals may participate in any toxicity of topically applied retinoids in the presence of UV light. This paper reports the update information and our experimental results on photostability, photoreactions, and phototoxicity of the natural retinoids including retinol (ROH), retinal, retinoid acid (RA), retinyl acetate, and RP (Figure 1).

Show MeSH
Related in: MedlinePlus