The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Satomi Onoue - One of the best experts on this subject based on the ideXlab platform.
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Comparative study on prediction performance of photosafety testing tools on photoallergens.
Toxicology in vitro : an international journal published in association with BIBRA, 2016Co-Authors: Satomi Onoue, Yoshiki Seto, Suzuki, Morihiko Hirota, Hayato Nishida, Hiroto Ohtake, Takao Ashikaga, Hirokazu KouzukiAbstract:Several testing methods have been established to identify potential Phototoxins. The present study was undertaken to clarify the predictive ability of in vitro photosafety assays for photoallergenicity. On the basis of animal and/or clinical photosafety information, 23 photoallergens and 7 non-phototoxic/non-photoallergenic chemicals were selected and subjected to UV/VIS spectral analysis, reactive oxygen species (ROS)/micellar ROS (mROS) assays, and 3T3 neutral red uptake phototoxicity testing (3T3 NRU PT). Of the photoallergens tested, ca. 96% of chemicals had intense UV/VIS absorption with a molar extinction coefficient of over 1000 M(-1) cm(-1), and false-positive predictions were made for 3 non-photoallergenic chemicals. In the ROS assay, all photoallergens were found to be potent ROS generators under exposure to simulated sunlight. In the photosafety prediction based on the ROS assay, the individual specificity was 85.7%, and the positive predictivity and negative predictivity were found to be 95.8% and 100%, respectively. Most of the photoirritant chemicals were correctly identified by the 3T3 NRU PT; however, it provided false predictions for ca. 48% of photoallergens. The orders of sensitivity and specificity for photoallergenicity prediction were estimated to be: [sensitivity] ROS assay>UV/VIS absorption ≫ 3T3 NRU PT, and [specificity] 3T3 NRU PT>ROS assay ≫ UV/VIS absorption. Thus, photochemical assays, in particular the ROS assay, can be used for assessment of photoallergenicity, although there were some false-positive predictions.
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Non-animal photosafety assessment approaches for cosmetics based on the photochemical and photobiochemical properties
Toxicology in vitro : an international journal published in association with BIBRA, 2013Co-Authors: Satomi Onoue, Masashi Kato, Suzuki, Morihiko Hirota, Hayato Nishida, Masato Kitagaki, Hirokazu Kouzuki, Shizuo YamadaAbstract:The main purpose of the present study was to establish a non-animal photosafety assessment approach for cosmetics using in vitro photochemical and photobiochemical screening systems. Fifty-one cosmetics, pharmaceutics and other chemicals were selected as model chemicals on the basis of animal and/or clinical photosafety information. The model chemicals were assessed in terms of photochemical properties by UV/VIS spectral analysis, reactive oxygen species (ROS) assay and 3T3 neutral red uptake phototoxicity testing (3T3 NRU PT). Most Phototoxins exhibited potent UV/VIS absorption with molar extinction coefficients of over 1000M(-1)cm(-1), although false-negative prediction occurred for 2 cosmetic Phototoxins owing to weak UV/VIS absorption. Among all the cosmetic ingredients, ca. 42% of tested chemicals were non-testable in the ROS assay because of low water solubility; thereby, micellar ROS (mROS) assay using a solubilizing surfactant was employed for follow-up screening. Upon combination use of ROS and mROS assays, the individual specificity was 88.2%, and the positive and negative predictivities were estimated to be 94.4% and 100%, respectively. In the 3T3 NRU PT, 3 cosmetics and 4 drugs were incorrectly predicted not to be phototoxic, although some of them were typical photoallergens. Thus, these in vitro screening systems individually provide false predictions; however, a systematic tiered approach using these assays could provide reliable photosafety assessment without any false-negatives. The combined use of in vitro assays might enable simple and fast non-animal photosafety evaluation of cosmetic ingredients.
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Development of micellar reactive oxygen species assay for photosafety evaluation of poorly water-soluble chemicals.
Toxicology in vitro : an international journal published in association with BIBRA, 2013Co-Authors: Yoshiki Seto, Shizuo Yamada, Masashi Kato, Satomi OnoueAbstract:Abstract A reactive oxygen species (ROS) assay was previously developed for photosafety assessment; however, the phototoxic potential of some chemicals cannot be evaluated because of their limited aqueous solubility. The present study was undertaken to develop a new micellar ROS (mROS) assay system for poorly water-soluble chemicals using a micellar solution of 0.5% (v/v) Tween 20 for solubility enhancement. In repeated mROS assay, intra- and inter-day precisions (coefficient of variation) were found to be below 11%, and the Z ′-factors for singlet oxygen and superoxide suggested a large separation band between positive and negative standards. The ROS and mROS assays were applied to 65 Phototoxins and 18 non-phototoxic compounds for comparative purposes. Of all 83 chemicals, 25 were unevaluable in the ROS assay due to poor solubility, but only 2 were in the mROS assay. Upon mROS assay on these model chemicals, the individual specificity was 76.5%, and the positive and negative predictivities were found to be 93.9% and 86.7%, respectively. The mROS assay provided 2 false negative predictions, although negative predictivity for the ROS assay was found to be 100%. Considering the pros and cons of these assays, strategic combined use of the ROS and mROS assays might be efficacious for reliable photosafety assessment with high applicability and predictivity.
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photosafety assessments on pirfenidone photochemical photobiological and pharmacokinetic characterization
Journal of Photochemistry and Photobiology B-biology, 2013Co-Authors: Yoshiki Seto, Shizuo Yamada, Masashi Kato, Ryo Inoue, Satomi OnoueAbstract:Abstract Pirfenidone (PFD), an idiopathic pulmonary fibrosis drug, has phototoxic risk in clinical use, although its detailed mechanisms for the phototoxicity have never been fully elucidated. In the present study, the photochemical properties and in vitro phototoxicity of PFD were evaluated with a focus on ultraviolet absorption, reactive oxygen species (ROS) generation, photodynamic lipid peroxidation, and DNA photocleavage. To clarify the in vivo phototoxic behavior of PFD, photoirritation and pharmacokinetic characteristics were also assessed in rats after its oral administration. There was marked generation of singlet oxygen and superoxide from PFD upon exposure to simulated sunlight, suggesting its high photoreactivity and phototoxic potential. Photobiochemical studies demonstrated the potent in vitro photoirritation of PFD, but not its photogenotoxic risk. Pharmacokinetic profiling and in vivo phototoxicity testing on PFD at a dose of 160 mg/kg suggested that highly concentrated PFD in the skin might cause phototoxic skin reactions in rats, whereas PFD at 30 mg/kg was far less phototoxic, possibly due to the limited skin deposition. From these findings, a high dose of orally administered PFD might cause phototoxic skin responses, possibly via a ROS-mediated photoirritant pathway.
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inhalable powder formulation of pirfenidone with reduced phototoxic risk for treatment of pulmonary fibrosis
Pharmaceutical Research, 2013Co-Authors: Satomi Onoue, Yoshiki Kojo, Yoshiki Seto, Yosuke Aoki, Masashi Kato, Shizuo YamadaAbstract:Purpose Orally-taken pirfenidone (PFD), an idiopathic pulmonary fibrosis drug, often causes severe phototoxicity. Present study aimed to develop a respirable powder formulation for PFD (PFD-RP) to minimize phototoxic risk.
Shizuo Yamada - One of the best experts on this subject based on the ideXlab platform.
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Non-animal photosafety assessment approaches for cosmetics based on the photochemical and photobiochemical properties
Toxicology in vitro : an international journal published in association with BIBRA, 2013Co-Authors: Satomi Onoue, Masashi Kato, Suzuki, Morihiko Hirota, Hayato Nishida, Masato Kitagaki, Hirokazu Kouzuki, Shizuo YamadaAbstract:The main purpose of the present study was to establish a non-animal photosafety assessment approach for cosmetics using in vitro photochemical and photobiochemical screening systems. Fifty-one cosmetics, pharmaceutics and other chemicals were selected as model chemicals on the basis of animal and/or clinical photosafety information. The model chemicals were assessed in terms of photochemical properties by UV/VIS spectral analysis, reactive oxygen species (ROS) assay and 3T3 neutral red uptake phototoxicity testing (3T3 NRU PT). Most Phototoxins exhibited potent UV/VIS absorption with molar extinction coefficients of over 1000M(-1)cm(-1), although false-negative prediction occurred for 2 cosmetic Phototoxins owing to weak UV/VIS absorption. Among all the cosmetic ingredients, ca. 42% of tested chemicals were non-testable in the ROS assay because of low water solubility; thereby, micellar ROS (mROS) assay using a solubilizing surfactant was employed for follow-up screening. Upon combination use of ROS and mROS assays, the individual specificity was 88.2%, and the positive and negative predictivities were estimated to be 94.4% and 100%, respectively. In the 3T3 NRU PT, 3 cosmetics and 4 drugs were incorrectly predicted not to be phototoxic, although some of them were typical photoallergens. Thus, these in vitro screening systems individually provide false predictions; however, a systematic tiered approach using these assays could provide reliable photosafety assessment without any false-negatives. The combined use of in vitro assays might enable simple and fast non-animal photosafety evaluation of cosmetic ingredients.
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Development of micellar reactive oxygen species assay for photosafety evaluation of poorly water-soluble chemicals.
Toxicology in vitro : an international journal published in association with BIBRA, 2013Co-Authors: Yoshiki Seto, Shizuo Yamada, Masashi Kato, Satomi OnoueAbstract:Abstract A reactive oxygen species (ROS) assay was previously developed for photosafety assessment; however, the phototoxic potential of some chemicals cannot be evaluated because of their limited aqueous solubility. The present study was undertaken to develop a new micellar ROS (mROS) assay system for poorly water-soluble chemicals using a micellar solution of 0.5% (v/v) Tween 20 for solubility enhancement. In repeated mROS assay, intra- and inter-day precisions (coefficient of variation) were found to be below 11%, and the Z ′-factors for singlet oxygen and superoxide suggested a large separation band between positive and negative standards. The ROS and mROS assays were applied to 65 Phototoxins and 18 non-phototoxic compounds for comparative purposes. Of all 83 chemicals, 25 were unevaluable in the ROS assay due to poor solubility, but only 2 were in the mROS assay. Upon mROS assay on these model chemicals, the individual specificity was 76.5%, and the positive and negative predictivities were found to be 93.9% and 86.7%, respectively. The mROS assay provided 2 false negative predictions, although negative predictivity for the ROS assay was found to be 100%. Considering the pros and cons of these assays, strategic combined use of the ROS and mROS assays might be efficacious for reliable photosafety assessment with high applicability and predictivity.
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photosafety assessments on pirfenidone photochemical photobiological and pharmacokinetic characterization
Journal of Photochemistry and Photobiology B-biology, 2013Co-Authors: Yoshiki Seto, Shizuo Yamada, Masashi Kato, Ryo Inoue, Satomi OnoueAbstract:Abstract Pirfenidone (PFD), an idiopathic pulmonary fibrosis drug, has phototoxic risk in clinical use, although its detailed mechanisms for the phototoxicity have never been fully elucidated. In the present study, the photochemical properties and in vitro phototoxicity of PFD were evaluated with a focus on ultraviolet absorption, reactive oxygen species (ROS) generation, photodynamic lipid peroxidation, and DNA photocleavage. To clarify the in vivo phototoxic behavior of PFD, photoirritation and pharmacokinetic characteristics were also assessed in rats after its oral administration. There was marked generation of singlet oxygen and superoxide from PFD upon exposure to simulated sunlight, suggesting its high photoreactivity and phototoxic potential. Photobiochemical studies demonstrated the potent in vitro photoirritation of PFD, but not its photogenotoxic risk. Pharmacokinetic profiling and in vivo phototoxicity testing on PFD at a dose of 160 mg/kg suggested that highly concentrated PFD in the skin might cause phototoxic skin reactions in rats, whereas PFD at 30 mg/kg was far less phototoxic, possibly due to the limited skin deposition. From these findings, a high dose of orally administered PFD might cause phototoxic skin responses, possibly via a ROS-mediated photoirritant pathway.
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inhalable powder formulation of pirfenidone with reduced phototoxic risk for treatment of pulmonary fibrosis
Pharmaceutical Research, 2013Co-Authors: Satomi Onoue, Yoshiki Kojo, Yoshiki Seto, Yosuke Aoki, Masashi Kato, Shizuo YamadaAbstract:Purpose Orally-taken pirfenidone (PFD), an idiopathic pulmonary fibrosis drug, often causes severe phototoxicity. Present study aimed to develop a respirable powder formulation for PFD (PFD-RP) to minimize phototoxic risk.
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In vitro photochemical and phototoxicological characterization of major constituents in St. John's Wort (Hypericum perforatum) extracts.
Phytochemistry, 2011Co-Authors: Satomi Onoue, Yoshiki Seto, Masanori Ochi, Ryo Inoue, Hideyuki Ito, Tsutomu Hatano, Shizuo YamadaAbstract:Extracts from St. John's Wort (SJW: Hypericum perforatum) have been used for the treatment of mild-to-moderate depression. In spite of the high therapeutic potential, orally administered SJW sometimes causes phototoxic skin responses. As such, the present study aimed to clarify the phototoxic mechanisms and to identify the major Phototoxins of SJW extract. Photobiochemical properties of SJW extract and 19 known constituents were characterized with focus on generation of reactive oxygen species (ROS), lipid peroxidation, and DNA photocleavage, which are indicative of photosensitive, photoirritant, and photogenotoxic potentials, respectively. ROS assay revealed the photoreactivity of SJW extract and some SJW ingredients as evidenced by type I and/or II photochemical reactions under light exposure. Not all the ROS-generating constituents caused photosensitized peroxidation of linoleic acid and photodynamic cleavage of plasmid DNA, and only hypericin, pseudohypericin, and hyperforin exhibited in vitro photoirritant potential. Concomitant UV exposure of quercitrin, an SJW component with potent UV/Vis absorption, with hyperforin resulted in significant attenuation of photodynamic generation of singlet oxygen from hyperforin, but not with hypericin. In conclusion, our results suggested that hypericin, pseudohypericin, and hyperforin might be responsible for the in vitro phototoxic effects of SJW extract.
Yoshiki Seto - One of the best experts on this subject based on the ideXlab platform.
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Comparative study on prediction performance of photosafety testing tools on photoallergens.
Toxicology in vitro : an international journal published in association with BIBRA, 2016Co-Authors: Satomi Onoue, Yoshiki Seto, Suzuki, Morihiko Hirota, Hayato Nishida, Hiroto Ohtake, Takao Ashikaga, Hirokazu KouzukiAbstract:Several testing methods have been established to identify potential Phototoxins. The present study was undertaken to clarify the predictive ability of in vitro photosafety assays for photoallergenicity. On the basis of animal and/or clinical photosafety information, 23 photoallergens and 7 non-phototoxic/non-photoallergenic chemicals were selected and subjected to UV/VIS spectral analysis, reactive oxygen species (ROS)/micellar ROS (mROS) assays, and 3T3 neutral red uptake phototoxicity testing (3T3 NRU PT). Of the photoallergens tested, ca. 96% of chemicals had intense UV/VIS absorption with a molar extinction coefficient of over 1000 M(-1) cm(-1), and false-positive predictions were made for 3 non-photoallergenic chemicals. In the ROS assay, all photoallergens were found to be potent ROS generators under exposure to simulated sunlight. In the photosafety prediction based on the ROS assay, the individual specificity was 85.7%, and the positive predictivity and negative predictivity were found to be 95.8% and 100%, respectively. Most of the photoirritant chemicals were correctly identified by the 3T3 NRU PT; however, it provided false predictions for ca. 48% of photoallergens. The orders of sensitivity and specificity for photoallergenicity prediction were estimated to be: [sensitivity] ROS assay>UV/VIS absorption ≫ 3T3 NRU PT, and [specificity] 3T3 NRU PT>ROS assay ≫ UV/VIS absorption. Thus, photochemical assays, in particular the ROS assay, can be used for assessment of photoallergenicity, although there were some false-positive predictions.
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Development of micellar reactive oxygen species assay for photosafety evaluation of poorly water-soluble chemicals.
Toxicology in vitro : an international journal published in association with BIBRA, 2013Co-Authors: Yoshiki Seto, Shizuo Yamada, Masashi Kato, Satomi OnoueAbstract:Abstract A reactive oxygen species (ROS) assay was previously developed for photosafety assessment; however, the phototoxic potential of some chemicals cannot be evaluated because of their limited aqueous solubility. The present study was undertaken to develop a new micellar ROS (mROS) assay system for poorly water-soluble chemicals using a micellar solution of 0.5% (v/v) Tween 20 for solubility enhancement. In repeated mROS assay, intra- and inter-day precisions (coefficient of variation) were found to be below 11%, and the Z ′-factors for singlet oxygen and superoxide suggested a large separation band between positive and negative standards. The ROS and mROS assays were applied to 65 Phototoxins and 18 non-phototoxic compounds for comparative purposes. Of all 83 chemicals, 25 were unevaluable in the ROS assay due to poor solubility, but only 2 were in the mROS assay. Upon mROS assay on these model chemicals, the individual specificity was 76.5%, and the positive and negative predictivities were found to be 93.9% and 86.7%, respectively. The mROS assay provided 2 false negative predictions, although negative predictivity for the ROS assay was found to be 100%. Considering the pros and cons of these assays, strategic combined use of the ROS and mROS assays might be efficacious for reliable photosafety assessment with high applicability and predictivity.
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photosafety assessments on pirfenidone photochemical photobiological and pharmacokinetic characterization
Journal of Photochemistry and Photobiology B-biology, 2013Co-Authors: Yoshiki Seto, Shizuo Yamada, Masashi Kato, Ryo Inoue, Satomi OnoueAbstract:Abstract Pirfenidone (PFD), an idiopathic pulmonary fibrosis drug, has phototoxic risk in clinical use, although its detailed mechanisms for the phototoxicity have never been fully elucidated. In the present study, the photochemical properties and in vitro phototoxicity of PFD were evaluated with a focus on ultraviolet absorption, reactive oxygen species (ROS) generation, photodynamic lipid peroxidation, and DNA photocleavage. To clarify the in vivo phototoxic behavior of PFD, photoirritation and pharmacokinetic characteristics were also assessed in rats after its oral administration. There was marked generation of singlet oxygen and superoxide from PFD upon exposure to simulated sunlight, suggesting its high photoreactivity and phototoxic potential. Photobiochemical studies demonstrated the potent in vitro photoirritation of PFD, but not its photogenotoxic risk. Pharmacokinetic profiling and in vivo phototoxicity testing on PFD at a dose of 160 mg/kg suggested that highly concentrated PFD in the skin might cause phototoxic skin reactions in rats, whereas PFD at 30 mg/kg was far less phototoxic, possibly due to the limited skin deposition. From these findings, a high dose of orally administered PFD might cause phototoxic skin responses, possibly via a ROS-mediated photoirritant pathway.
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inhalable powder formulation of pirfenidone with reduced phototoxic risk for treatment of pulmonary fibrosis
Pharmaceutical Research, 2013Co-Authors: Satomi Onoue, Yoshiki Kojo, Yoshiki Seto, Yosuke Aoki, Masashi Kato, Shizuo YamadaAbstract:Purpose Orally-taken pirfenidone (PFD), an idiopathic pulmonary fibrosis drug, often causes severe phototoxicity. Present study aimed to develop a respirable powder formulation for PFD (PFD-RP) to minimize phototoxic risk.
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In vitro photochemical and phototoxicological characterization of major constituents in St. John's Wort (Hypericum perforatum) extracts.
Phytochemistry, 2011Co-Authors: Satomi Onoue, Yoshiki Seto, Masanori Ochi, Ryo Inoue, Hideyuki Ito, Tsutomu Hatano, Shizuo YamadaAbstract:Extracts from St. John's Wort (SJW: Hypericum perforatum) have been used for the treatment of mild-to-moderate depression. In spite of the high therapeutic potential, orally administered SJW sometimes causes phototoxic skin responses. As such, the present study aimed to clarify the phototoxic mechanisms and to identify the major Phototoxins of SJW extract. Photobiochemical properties of SJW extract and 19 known constituents were characterized with focus on generation of reactive oxygen species (ROS), lipid peroxidation, and DNA photocleavage, which are indicative of photosensitive, photoirritant, and photogenotoxic potentials, respectively. ROS assay revealed the photoreactivity of SJW extract and some SJW ingredients as evidenced by type I and/or II photochemical reactions under light exposure. Not all the ROS-generating constituents caused photosensitized peroxidation of linoleic acid and photodynamic cleavage of plasmid DNA, and only hypericin, pseudohypericin, and hyperforin exhibited in vitro photoirritant potential. Concomitant UV exposure of quercitrin, an SJW component with potent UV/Vis absorption, with hyperforin resulted in significant attenuation of photodynamic generation of singlet oxygen from hyperforin, but not with hypericin. In conclusion, our results suggested that hypericin, pseudohypericin, and hyperforin might be responsible for the in vitro phototoxic effects of SJW extract.
Ryo Inoue - One of the best experts on this subject based on the ideXlab platform.
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photosafety assessments on pirfenidone photochemical photobiological and pharmacokinetic characterization
Journal of Photochemistry and Photobiology B-biology, 2013Co-Authors: Yoshiki Seto, Shizuo Yamada, Masashi Kato, Ryo Inoue, Satomi OnoueAbstract:Abstract Pirfenidone (PFD), an idiopathic pulmonary fibrosis drug, has phototoxic risk in clinical use, although its detailed mechanisms for the phototoxicity have never been fully elucidated. In the present study, the photochemical properties and in vitro phototoxicity of PFD were evaluated with a focus on ultraviolet absorption, reactive oxygen species (ROS) generation, photodynamic lipid peroxidation, and DNA photocleavage. To clarify the in vivo phototoxic behavior of PFD, photoirritation and pharmacokinetic characteristics were also assessed in rats after its oral administration. There was marked generation of singlet oxygen and superoxide from PFD upon exposure to simulated sunlight, suggesting its high photoreactivity and phototoxic potential. Photobiochemical studies demonstrated the potent in vitro photoirritation of PFD, but not its photogenotoxic risk. Pharmacokinetic profiling and in vivo phototoxicity testing on PFD at a dose of 160 mg/kg suggested that highly concentrated PFD in the skin might cause phototoxic skin reactions in rats, whereas PFD at 30 mg/kg was far less phototoxic, possibly due to the limited skin deposition. From these findings, a high dose of orally administered PFD might cause phototoxic skin responses, possibly via a ROS-mediated photoirritant pathway.
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In vitro photochemical and phototoxicological characterization of major constituents in St. John's Wort (Hypericum perforatum) extracts.
Phytochemistry, 2011Co-Authors: Satomi Onoue, Yoshiki Seto, Masanori Ochi, Ryo Inoue, Hideyuki Ito, Tsutomu Hatano, Shizuo YamadaAbstract:Extracts from St. John's Wort (SJW: Hypericum perforatum) have been used for the treatment of mild-to-moderate depression. In spite of the high therapeutic potential, orally administered SJW sometimes causes phototoxic skin responses. As such, the present study aimed to clarify the phototoxic mechanisms and to identify the major Phototoxins of SJW extract. Photobiochemical properties of SJW extract and 19 known constituents were characterized with focus on generation of reactive oxygen species (ROS), lipid peroxidation, and DNA photocleavage, which are indicative of photosensitive, photoirritant, and photogenotoxic potentials, respectively. ROS assay revealed the photoreactivity of SJW extract and some SJW ingredients as evidenced by type I and/or II photochemical reactions under light exposure. Not all the ROS-generating constituents caused photosensitized peroxidation of linoleic acid and photodynamic cleavage of plasmid DNA, and only hypericin, pseudohypericin, and hyperforin exhibited in vitro photoirritant potential. Concomitant UV exposure of quercitrin, an SJW component with potent UV/Vis absorption, with hyperforin resulted in significant attenuation of photodynamic generation of singlet oxygen from hyperforin, but not with hypericin. In conclusion, our results suggested that hypericin, pseudohypericin, and hyperforin might be responsible for the in vitro phototoxic effects of SJW extract.
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In vitro photochemical and phototoxicological characterization of major constituents in St. John’s Wort (Hypericum perforatum) extracts
Phytochemistry, 2011Co-Authors: Satomi Onoue, Yoshiki Seto, Masanori Ochi, Ryo Inoue, Hideyuki Ito, Tsutomu Hatano, Shizuo YamadaAbstract:Extracts from St. John’s Wort (SJW: Hypericum perforatum) have been used for the treatment of mild-to-moderate depression. In spite of the high therapeutic potential, orally administered SJW sometimes causes phototoxic skin responses. As such, the present study aimed to clarify the phototoxic mechanisms and to identify the major Phototoxins of SJW extract. Photobiochemical properties of SJW extract and 19 known constituents were characterized with focus on generation of reactive oxygen species (ROS), lipid peroxidation, and DNA photocleavage, which are indicative of photosensitive, photoirritant, and photogenotoxic potentials, respectively. ROS assay revealed the photoreactivity of SJW extract and some SJW ingredients as evidenced by type I and/or II photochemical reactions under light exposure. Not all the ROS-generating constituents caused photosensitized peroxidation of linoleic acid and photodynamic cleavage of plasmid DNA, and only hypericin, pseudohypericin, and hyperforin exhibited in vitro photoirritant potential. Concomitant UV exposure of quercitrin, an SJW component with potent UV/Vis absorption, with hyperforin resulted in significant attenuation of photodynamic generation of singlet oxygen from hyperforin, but not with hypericin. In conclusion, our results suggested that hypericin, pseudohypericin, and hyperforin might be responsible for the in vitro phototoxic effects of SJW extract.
Masanori Ochi - One of the best experts on this subject based on the ideXlab platform.
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In vitro photochemical and phototoxicological characterization of major constituents in St. John's Wort (Hypericum perforatum) extracts.
Phytochemistry, 2011Co-Authors: Satomi Onoue, Yoshiki Seto, Masanori Ochi, Ryo Inoue, Hideyuki Ito, Tsutomu Hatano, Shizuo YamadaAbstract:Extracts from St. John's Wort (SJW: Hypericum perforatum) have been used for the treatment of mild-to-moderate depression. In spite of the high therapeutic potential, orally administered SJW sometimes causes phototoxic skin responses. As such, the present study aimed to clarify the phototoxic mechanisms and to identify the major Phototoxins of SJW extract. Photobiochemical properties of SJW extract and 19 known constituents were characterized with focus on generation of reactive oxygen species (ROS), lipid peroxidation, and DNA photocleavage, which are indicative of photosensitive, photoirritant, and photogenotoxic potentials, respectively. ROS assay revealed the photoreactivity of SJW extract and some SJW ingredients as evidenced by type I and/or II photochemical reactions under light exposure. Not all the ROS-generating constituents caused photosensitized peroxidation of linoleic acid and photodynamic cleavage of plasmid DNA, and only hypericin, pseudohypericin, and hyperforin exhibited in vitro photoirritant potential. Concomitant UV exposure of quercitrin, an SJW component with potent UV/Vis absorption, with hyperforin resulted in significant attenuation of photodynamic generation of singlet oxygen from hyperforin, but not with hypericin. In conclusion, our results suggested that hypericin, pseudohypericin, and hyperforin might be responsible for the in vitro phototoxic effects of SJW extract.
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In vitro photochemical and phototoxicological characterization of major constituents in St. John’s Wort (Hypericum perforatum) extracts
Phytochemistry, 2011Co-Authors: Satomi Onoue, Yoshiki Seto, Masanori Ochi, Ryo Inoue, Hideyuki Ito, Tsutomu Hatano, Shizuo YamadaAbstract:Extracts from St. John’s Wort (SJW: Hypericum perforatum) have been used for the treatment of mild-to-moderate depression. In spite of the high therapeutic potential, orally administered SJW sometimes causes phototoxic skin responses. As such, the present study aimed to clarify the phototoxic mechanisms and to identify the major Phototoxins of SJW extract. Photobiochemical properties of SJW extract and 19 known constituents were characterized with focus on generation of reactive oxygen species (ROS), lipid peroxidation, and DNA photocleavage, which are indicative of photosensitive, photoirritant, and photogenotoxic potentials, respectively. ROS assay revealed the photoreactivity of SJW extract and some SJW ingredients as evidenced by type I and/or II photochemical reactions under light exposure. Not all the ROS-generating constituents caused photosensitized peroxidation of linoleic acid and photodynamic cleavage of plasmid DNA, and only hypericin, pseudohypericin, and hyperforin exhibited in vitro photoirritant potential. Concomitant UV exposure of quercitrin, an SJW component with potent UV/Vis absorption, with hyperforin resulted in significant attenuation of photodynamic generation of singlet oxygen from hyperforin, but not with hypericin. In conclusion, our results suggested that hypericin, pseudohypericin, and hyperforin might be responsible for the in vitro phototoxic effects of SJW extract.