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Patrignoni L, Hurtier A, Orlacchio R, Joushomme A, Poulletier de Gannes F, Lévêque P, Arnaud-Cormos D, Revzani HR, Mahfouf W, Garenne A, Percherancier Y, Lagroye I. Evaluation of mitochondrial stress following ultraviolet radiation and 5G radiofrequency field exposure in human skin cells. Bioelectromagnetics 2024; 45:110-129. [PMID: 38115173 DOI: 10.1002/bem.22495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/14/2023] [Accepted: 11/20/2023] [Indexed: 12/21/2023]
Abstract
Whether human cells are impacted by environmental electromagnetic fields (EMF) is still a matter of debate. With the deployment of the fifth generation (5G) of mobile communication technologies, the carrier frequency is increasing and the human skin becomes the main biological target. Here, we evaluated the impact of 5G-modulated 3.5 GHz radiofrequency (RF) EMF on mitochondrial stress in human fibroblasts and keratinocytes that were exposed for 24 h at specific absorption rate of 0.25, 1, and 4 W/kg. We assessed cell viability, mitochondrial reactive oxygen species (ROS) production, and membrane polarization. Knowing that human skin is the main target of environmental ultraviolet (UV), using the same read-out, we investigated whether subsequent exposure to 5G signal could alter the capacity of UV-B to damage skin cells. We found a statistically significant reduction in mitochondrial ROS concentration in fibroblasts exposed to 5G signal at 1 W/kg. On the contrary, the RF exposure slightly but statistically significantly enhanced the effects of UV-B radiation specifically in keratinocytes at 0.25 and 1 W/kg. No effect was found on mitochondrial membrane potential or apoptosis in any cell types or exposure conditions suggesting that the type and amplitude of the observed effects are very punctual.
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Affiliation(s)
- Lorenza Patrignoni
- Paris Sciences et Lettres Research University-École Pratique des Hautes Études (EPHE), IMS laboratory - SANE team, Paris, France
| | - Annabelle Hurtier
- Univ. Bordeaux, CNRS, IMS laboratory / UMR 5218, SANE Team, Talence, France
| | - Rosa Orlacchio
- Paris Sciences et Lettres Research University-École Pratique des Hautes Études (EPHE), IMS laboratory - SANE team, Paris, France
| | | | | | - Philippe Lévêque
- Univ. Limoges, CNRS, XLIM / UMR 7252, RF-ELITE team, Limoges, France
| | | | | | - Walid Mahfouf
- Univ. Bordeaux, Inserm, BRIC / UMR 1312, TRIO2 team, Bordeaux, France
| | - André Garenne
- Univ. Bordeaux, CNRS, IMS laboratory / UMR 5218, SANE Team, Talence, France
| | - Yann Percherancier
- Univ. Bordeaux, CNRS, IMS laboratory / UMR 5218, SANE Team, Talence, France
| | - Isabelle Lagroye
- Paris Sciences et Lettres Research University-École Pratique des Hautes Études (EPHE), IMS laboratory - SANE team, Paris, France
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2
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Sannino A, Romeo S, Scarfì MR, Pinchera D, Schettino F, Alonzo M, Allocca M, Zeni O. The effect of exposure to radiofrequency LTE signal and coexposure to mitomycin-C in Chinese hamster lung fibroblast V79 cells. Bioelectromagnetics 2024; 45:97-109. [PMID: 37493434 DOI: 10.1002/bem.22478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 06/19/2023] [Indexed: 07/27/2023]
Abstract
This study aims to investigate the cellular effects of radiofrequency exposure, 1950 MHz, long-term evolution (LTE) signal, administered alone and in combination with mitomycin-C (MMC), a well-known cytotoxic agent. Chinese hamster lung fibroblast (V79) cells were exposed/sham exposed in a waveguide-based system under strictly controlled conditions of both electromagnetic and environmental parameters, at specific absorption rate (SAR) of 0.3 and 1.25 W/kg. Chromosomal damage (micronuclei formation), oxidative stress (reactive oxygen species [ROS] formation), and cell cycle progression were analyzed after exposure and coexposure. No differences between exposed samples and sham-controls were detected following radiofrequency exposure alone, for all the experimental conditions tested and biological endpoints investigated. When radiofrequency exposure was followed by MMC treatment, 3 h pre-exposure did not modify MMC-induced micronuclei. Pre-exposure of 20 h at 0.3 W/kg did not modify the number of micronuclei induced by MMC, while 1.25 W/kg resulted in a significant reduction of MMC-induced damage. Absence of effects was also detected when CW was used, at both SAR levels. MMC-induced ROS formation resulted significantly decreased at both SAR levels investigated, while cell proliferation and cell cycle progression were not affected by coexposures. The results here reported provide no evidence of direct effects of 1950 MHz, LTE signal. Moreover, they further support our previous findings on the capability of radiofrequency pre-exposure to induce protection from a subsequent toxic treatment, and the key role of the modulated signals and the experimental conditions adopted in eliciting the effect.
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Affiliation(s)
- Anna Sannino
- National Research Council of Italy (CNR), Institute for Electromagnetic Sensing of the Environment (IREA), Naples, Italy
| | - Stefania Romeo
- National Research Council of Italy (CNR), Institute for Electromagnetic Sensing of the Environment (IREA), Naples, Italy
| | - Maria Rosaria Scarfì
- National Research Council of Italy (CNR), Institute for Electromagnetic Sensing of the Environment (IREA), Naples, Italy
| | - Daniele Pinchera
- Department of Electrical and Information Engineering "Maurizio Scarano" (DIEI), University of Cassino and Southern Lazio, Cassino, Italy
| | - Fulvio Schettino
- Department of Electrical and Information Engineering "Maurizio Scarano" (DIEI), University of Cassino and Southern Lazio, Cassino, Italy
| | - Mario Alonzo
- National Research Council of Italy (CNR), Institute for Electromagnetic Sensing of the Environment (IREA), Naples, Italy
| | - Mariateresa Allocca
- National Research Council of Italy (CNR), Institute for Electromagnetic Sensing of the Environment (IREA), Naples, Italy
| | - Olga Zeni
- National Research Council of Italy (CNR), Institute for Electromagnetic Sensing of the Environment (IREA), Naples, Italy
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3
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Cho CH, Lim W, Sim WJ, Lim TG. Oral administration of collagen peptide in SKH-1 mice suppress UVB-induced wrinkle and dehydration through MAPK and MAPKK signaling pathways, in vitro and in vivo evidence. Food Sci Biotechnol 2024; 33:955-967. [PMID: 38371682 PMCID: PMC10866847 DOI: 10.1007/s10068-023-01362-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/10/2023] [Accepted: 05/29/2023] [Indexed: 02/20/2024] Open
Abstract
Skin aging is induced by exposure to extrinsic factors, causing various diseases and adversely affecting aesthetics. Studies have suggested that as the quality of life improves, demand for beauty and nutritional cosmetics increases. Here, the protective effects of collagen peptide against UV-induced skin damage were evaluated in vitro and in vivo. Collagen peptide inhibited water loss and UVB irradiation-induced HA degradation in the skin of SKH-1 mice. Additionally, collagen peptide dose-dependently inhibited UVB-induced wrinkle formation, epidermal thickness, and elastase activity. These results suggest that collagen peptide regulates collagen degradation through the MAPK and MAPKK pathway. In addition, collagen peptide administration did not affect changes in weight of the liver, spleen, and kidney, or enzymatic indicators of liver damage. Taken together, oral administration of collagen peptide improved the effects of UV-induced skin aging without toxicity. Therefore, this study supports the development of collagen peptide for skin aging prevention in nutricosmetic products. Supplementary Information The online version contains supplementary material available at 10.1007/s10068-023-01362-6.
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Affiliation(s)
- Cheol Hyeon Cho
- Department of Food Science & Biotechnology, Sejong University, Seoul, 05006 Republic of Korea
| | - Wonchul Lim
- Department of Food Science & Biotechnology, and Carbohydrate Bioproduct Research Center, Sejong University, Seoul, 05006 Republic of Korea
| | - Woo-Jin Sim
- Department of Food Science & Biotechnology, Sejong University, Seoul, 05006 Republic of Korea
| | - Tae-Gyu Lim
- Department of Food Science & Biotechnology, Sejong University, Seoul, 05006 Republic of Korea
- Department of Food Science & Biotechnology, and Carbohydrate Bioproduct Research Center, Sejong University, Seoul, 05006 Republic of Korea
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4
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Benavides RAS, Leiro-Vidal JM, Rodriguez-Gonzalez JA, Ares-Pena FJ, López-Martín E. The HL-60 human promyelocytic cell line constitutes an effective in vitro model for evaluating toxicity, oxidative stress and necrosis/apoptosis after exposure to black carbon particles and 2.45 GHz radio frequency. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 867:161475. [PMID: 36632900 DOI: 10.1016/j.scitotenv.2023.161475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 12/21/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
The cellular and molecular mechanisms by which atmospheric pollution from particulate matter and/or electromagnetic fields (EMFs) may prove harmful to human health have not been extensively researched. We analyzed whether the combined action of EMFs and black carbon (BC) particles induced cell damage and a pro-apoptotic response in the HL-60 promyelocytic cell line when exposed to 2.45 GHz radio frequency (RF) radiation in a gigahertz transverse electromagnetic (GTEM) chamber at sub-thermal specific absorption rate (SAR) levels. RF and BC induced moderately significant levels of cell damage in the first 8 or 24 h for all exposure times/doses and much greater damage after 48 h irradiation and the higher dose of BC. We observed a clear antiproliferative effect that increased with RF exposure time and BC dose. Oxidative stress or ROS production increased with time (24 or 48 h of radiation), BC dose and the combination of both. Significant differences between the proportion of damaged and healthy cells were observed in all groups. Both radiation and BC participated separately and jointly in triggering necrosis and apoptosis in a programmed way. Oxidative-antioxidant action activated mitochondrial anti-apoptotic BCL2a gene expression after 24 h irradiation and exposure to BC. After irradiation of the cells for 48 h, expression of FASR cell death receptors was activated, precipitating the onset of pro-apoptotic phenomena and expression and intracellular activity of caspase-3 in the mitochondrial pathways, all of which can lead to cell death. Our results indicate that the interaction between BC and RF modifies the immune response in the human promyelocytic cell line and that these cells had two fates mediated by different pathways: necrosis and mitochondria-caspase dependent apoptosis. The findings may be important in regard to antimicrobial, inflammatory and autoimmune responses in humans.
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Affiliation(s)
- Rosa Ana Sueiro Benavides
- Institute of Research in Biological and Chemical Analysis, IAQBUS, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - José Manuel Leiro-Vidal
- Institute of Research in Biological and Chemical Analysis, IAQBUS, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - J Antonio Rodriguez-Gonzalez
- Department of Applied Physics, Santiago de Compostela School of Physics, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - Francisco J Ares-Pena
- Department of Applied Physics, Santiago de Compostela School of Physics, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - Elena López-Martín
- Department of Morphological Sciences, Santiago de Compostela School of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain.
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Assessment of Inflammation in 3D Reconstructed Human Skin Exposed to Combined Exposure to Ultraviolet and Wi-Fi Radiation. Int J Mol Sci 2023; 24:ijms24032853. [PMID: 36769173 PMCID: PMC9917807 DOI: 10.3390/ijms24032853] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/13/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023] Open
Abstract
In the human environment, the increasing exposure to radiofrequency (RF) radiation, especially that emitted by wireless devices, could be absorbed in the body. Recently, mobile and emerging wireless technologies (UMTS, DECT, LTE, and Wi-Fi) have been using higher frequencies than 2G GSM systems (900/1800 MHz), which means that most of the circulating RF currents are absorbed into the skin and the superficial soft tissue. The harmful genotoxic, cytotoxic, and mutagenic effects of solar ultraviolet (UV) radiation on the skin are well-known. This study aimed at investigating whether 2422 MHz (Wi-Fi) RF exposure combined with UV radiation in different sequences has any effect on the inflammation process in the skin. In vitro experiments examined the inflammation process by cytokines (IL-1α, IL-6, IL-8) and MMP-1 enzyme secretion in a 3D full-thickness human skin model. In the first study, UV exposure was immediately followed by RF exposure to measure the potential additive effects, while in the second study, the possible protective phenomenon (i.e., adaptive response) was investigated when adaptive RF exposure was challenged by UV radiation. Our results suggest that 2422 MHz Wi-Fi exposure slightly, not significantly increased cytokine concentrations of the prior UV exposure. We could not detect the adaptive response phenomenon.
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Hesperidin Exhibits Protective Effects against PM2.5-Mediated Mitochondrial Damage, Cell Cycle Arrest, and Cellular Senescence in Human HaCaT Keratinocytes. Molecules 2022; 27:molecules27154800. [PMID: 35956749 PMCID: PMC9369620 DOI: 10.3390/molecules27154800] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/13/2022] Open
Abstract
Particulate matter 2.5 (PM2.5) exposure can trigger adverse health outcomes in the human skin, such as skin aging, wrinkles, pigment spots, and atopic dermatitis. PM2.5 is associated with mitochondrial damage and the generation of reactive oxygen species (ROS). Hesperidin is a bioflavonoid that exhibits antioxidant and anti-inflammatory properties. This study aimed to determine the mechanism underlying the protective effect of hesperidin on human HaCaT keratinocytes against PM2.5-induced mitochondrial damage, cell cycle arrest, and cellular senescence. Human HaCaT keratinocytes were pre-treated with hesperidin and then treated with PM2.5. Hesperidin attenuated PM2.5-induced mitochondrial and DNA damage, G0/G1 cell cycle arrest, and SA-βGal activity, the protein levels of cell cycle regulators, and matrix metalloproteinases (MMPs). Moreover, treatment with a specific c-Jun N-terminal kinase (JNK) inhibitor, SP600125, along with hesperidin markedly restored PM2.5-induced cell cycle arrest and cellular senescence. In addition, hesperidin significantly reduced the activation of MMPs, including MMP-1, MMP-2, and MMP-9, by inhibiting the activation of activator protein 1. In conclusion, hesperidin ameliorates PM2.5-induced mitochondrial damage, cell cycle arrest, and cellular senescence in human HaCaT keratinocytes via the ROS/JNK pathway.
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García-Villegas A, Rojas-García A, Villegas-Aguilar MDC, Fernández-Moreno P, Fernández-Ochoa Á, Cádiz-Gurrea MDLL, Arráez-Román D, Segura-Carretero A. Cosmeceutical Potential of Major Tropical and Subtropical Fruit By-Products for a Sustainable Revalorization. Antioxidants (Basel) 2022; 11:203. [PMID: 35204085 PMCID: PMC8868306 DOI: 10.3390/antiox11020203] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/11/2022] [Accepted: 01/18/2022] [Indexed: 12/10/2022] Open
Abstract
The increasing production of tropical fruits followed by their processing results in tons of waste, such as skins or seeds. However, these by-products have been reported to be rich in bioactive compounds (BACs) with excellent properties of interest in the cosmeceutical industry: antioxidant, anti-aging, anti-inflammatory, antimicrobial and photoprotective properties. This review summarizes the tropical fruits most produced worldwide, their bioactive composition and the most important and studied therapeutic properties that their by-products can contribute to skin health, as well as the different approaches for obtaining these compounds using techniques by conventional (Soxhlet, liquid-liquid extraction or maceration) and non-conventional extractions (supercritical fluid extraction (SFE), ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), pressurized liquid extraction (PLE) and two-phase aqueous system), followed by their identification by HPLC-MS or GC-MS analysis. Moreover, this work encompasses several studies that may prove the effects of seeds and skins from tropical fruits against oxidative stress, hyperpigmentation, acne, aging or UV radiation. Therefore, the investigation of functional components present in tropical fruit by-products under a circular bioeconomy model could be of great interest for the cosmeceutical industry and a very promising option for obtaining new cosmeceutical formulations.
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Affiliation(s)
- Abigail García-Villegas
- Department of Analytical Chemistry, University of Granada, 18071 Granada, Spain; (A.G.-V.); (A.R.-G.); (M.d.C.V.-A.); (P.F.-M.); (D.A.-R.); (A.S.-C.)
| | - Alejandro Rojas-García
- Department of Analytical Chemistry, University of Granada, 18071 Granada, Spain; (A.G.-V.); (A.R.-G.); (M.d.C.V.-A.); (P.F.-M.); (D.A.-R.); (A.S.-C.)
| | - María del Carmen Villegas-Aguilar
- Department of Analytical Chemistry, University of Granada, 18071 Granada, Spain; (A.G.-V.); (A.R.-G.); (M.d.C.V.-A.); (P.F.-M.); (D.A.-R.); (A.S.-C.)
| | - Patricia Fernández-Moreno
- Department of Analytical Chemistry, University of Granada, 18071 Granada, Spain; (A.G.-V.); (A.R.-G.); (M.d.C.V.-A.); (P.F.-M.); (D.A.-R.); (A.S.-C.)
| | - Álvaro Fernández-Ochoa
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany;
- Berlin Institute of Health Metabolomics Platform, 13125 Berlin, Germany
| | - María de la Luz Cádiz-Gurrea
- Department of Analytical Chemistry, University of Granada, 18071 Granada, Spain; (A.G.-V.); (A.R.-G.); (M.d.C.V.-A.); (P.F.-M.); (D.A.-R.); (A.S.-C.)
| | - David Arráez-Román
- Department of Analytical Chemistry, University of Granada, 18071 Granada, Spain; (A.G.-V.); (A.R.-G.); (M.d.C.V.-A.); (P.F.-M.); (D.A.-R.); (A.S.-C.)
| | - Antonio Segura-Carretero
- Department of Analytical Chemistry, University of Granada, 18071 Granada, Spain; (A.G.-V.); (A.R.-G.); (M.d.C.V.-A.); (P.F.-M.); (D.A.-R.); (A.S.-C.)
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Sun C, Huang Z, Qin H, Zhang J, Wang S, Xu X, Ying S, Mao G. Exposure to 10 Hz Pulsed Magnetic Fields Do Not Induce Cellular Senescence in Human Fetal Lung Fibroblasts. Front Public Health 2021; 9:761069. [PMID: 34858933 PMCID: PMC8632261 DOI: 10.3389/fpubh.2021.761069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 10/07/2021] [Indexed: 11/13/2022] Open
Abstract
Rapid population aging has led to a global burden of late-life diseases. As the largest risk factor for a multitude of age-related diseases, aging is not only the result of genotype but also closely related to external factors. With the rapid expansion in the usage of electromagnetic fields (EMFs), the effect of EMFs on aging has also attracted attention. Cells are the basic unit of organs and body tissues, and cellular senescence plays an important role in the aging process. The effect of EMFs on cellular senescence has been investigated in a few studies, but the information is limited, and the results are inconsistent; thus, further investigation is required. In this study, we investigated the effect of 10 Hz pulsed magnetic fields (MFs) on cellular senescence in a 2BS cell line, isolated from human fetal lung fibroblasts, and found that intermittent (1 d on/1 d off) exposure to 10 Hz pulsed MFs at 1.0 mT for 2 weeks induced DNA damage, but no other significant phenotype of cellular senescence in 2BS cells.
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Affiliation(s)
- Chuan Sun
- Zhejiang Provincial Key Lab of Geriatrics and Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, China
| | - Zheng Huang
- School of Stomatology, Hangzhou Normal University, Hangzhou, China
| | - Houbing Qin
- Department of Respiratory Medicine, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Jing Zhang
- Zhejiang Provincial Key Lab of Geriatrics and Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, China
| | - Sanying Wang
- Zhejiang Provincial Key Lab of Geriatrics and Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, China
| | - Xiaogang Xu
- Zhejiang Provincial Key Lab of Geriatrics and Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, China
| | - Shibo Ying
- Hangzhou Medical College, Hangzhou, China
| | - Genxiang Mao
- Zhejiang Provincial Key Lab of Geriatrics and Geriatrics Institute of Zhejiang Province, Department of Geriatrics, Zhejiang Hospital, Hangzhou, China
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9
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Saleh MM, Lawrence KP, Jones SA, Young AR. The photoprotective properties of α-tocopherol phosphate against long-wave UVA1 (385 nm) radiation in keratinocytes in vitro. Sci Rep 2021; 11:22400. [PMID: 34789788 PMCID: PMC8599454 DOI: 10.1038/s41598-021-01299-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 10/12/2021] [Indexed: 11/14/2022] Open
Abstract
UVA1 radiation (340–400 nm), especially longwave UVA1 (> 370 nm), is often ignored when assessing sun protection due to its low sunburning potential, but it generates reactive oxygen species (ROS) and is poorly attenuated by sunscreens. This study aimed to investigate if α-tocopherol phosphate, (α-TP) a promising new antioxidant, could protect against long-wave UVA1 induced cell death and scavenge UVA1 induced ROS in a skin cell model. HaCaT keratinocyte cell viability (24 h) was assessed with Alamar Blue and Neutral Red assays. The metabolism of α-TP into α-T, assessed using mass spectrometry, and the compound's radical scavenging efficacy, assessed by the dichlorodihydrofluorescein (H2DCFDA) ROS detection assay, was monitored in HaCaTs. The mechanism of α-TP ROS scavenging was determined using non-cell based DPPH and ORAC assays. In HaCaT keratinocytes, irradiated with 226 J/cm2 UVA1 in low-serum (2%, starved) cell culture medium, pretreatment with 80 µM α-TP significantly enhanced cell survival (88%, Alamar Blue) compared to control, whereas α-T pre-treatment had no effect survival (70%, Alamar Blue). Pre-treatment of cells with 100 μM α-TP or 100 μM α-T before 57 J/cm2 UVA1 also significantly reduced ROS generation over 2 h (24.1% and 23.9% respectively) compared to the control and resulted in α-TP bioconversion into α-T. As α-TP displayed weak antioxidant activity in the cell-free assays thus its photoprotection was assigned to its bioconversion to α-T by cellular phosphatases. Through this mechanism α-TP prevented long-wave UVA1 induced cell death and scavenged UVA1 induced ROS in skin cells when added to the starved cell culture medium before UVA1 exposure by bioconversion into α-T.
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Affiliation(s)
- M M Saleh
- Department of Pharmaceutics and Pharmaceutical Technology, School of Pharmacy, The University of Jordan, Amman, 11942, Jordan
| | - K P Lawrence
- St John's Institute of Dermatology, King's College London, London, SE1 9RT, UK
| | - S A Jones
- Institute of Pharmaceutical Science, Faculty of Life Sciences and Medicine, School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK.
| | - A R Young
- St John's Institute of Dermatology, King's College London, London, SE1 9RT, UK
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