title: Photosensitized 2-amino-3-hydroxypyridine-induced mitochondrial apoptosis via Smac/DIABLO in human skin cells.
abstract: The popularity of hair dyes use has been increasing regularly throughout the world as per the demand of hair coloring fashion trends and other cosmetic products. 2-Amino-3-hydroxypyridine (A132) is widely used as a hair dye ingredient around the world. We are reporting first time the phototoxicity mechanism of A132 under ambient environmental UV-B radiation. It showed maximum absorption in UV-B region (317 nm) and forms a photoproduct within an hour exposure of UV-B irradiation. Photocytotoxicity of A132 in human keratinocytes (HaCaT) was measured by mitochondrial (MTT), lysosomal (NRU) and LDH assays which illustrated the significant reduction in cell viability. The role of reactive oxygen species (ROS) generation for A132 phototoxicity was established photo- chemically as well as intracellularly. Noteworthy, formation of tail DNA (comet assay), micronuclei and cyclobutane pyrimidine dimers (CPDs) (immunocytochemistry) formation confirmed the photogenotoxic potential of dye. Cell cycle study (sub-G1peak) and staining with EB/AO revealed the cell cycle arrest and apoptosis. Further, mitochondrial mediated apoptosis was corroborated by reduced MMP, release of cytochrome c and upregulation of caspase-3. Release of mitochondrial Smac/DIABLO in cytoplasm demonstrated the caspase dependent apoptotic cell death by photolabile A132 dye. In-addition increased Bax/Bcl2 ratio again proved the apoptosis. Thus, study suggests that A132 induces photogenotoxicity, phototoxicity and apoptotic cell death through the involvement of Smac/DIABLO in mitochondrial apoptosis via caspase dependent manner. Therefore, the long term use of A132 dye and sunlight exposure jointly increased the oxidative stress in skin which causes premature hair loss, damage to progenitor cells of hair follicles.
authors.affiliation: Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR - Indian Institute of Toxicology Research (CSIR-IITR), M.G, Marg, Lucknow 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR - IITR, Lucknow 226001, India.
authors.forename: Shruti
authors.initials: S
authors.lastname: Goyal
authors.affiliation: Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR - Indian Institute of Toxicology Research (CSIR-IITR), M.G, Marg, Lucknow 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR - IITR, Lucknow 226001, India.
authors.forename: Saroj Kumar
authors.initials: SK
authors.lastname: Amar
authors.affiliation: Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR - Indian Institute of Toxicology Research (CSIR-IITR), M.G, Marg, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Ashish
authors.initials: A
authors.lastname: Dwivedi
authors.affiliation: Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR - Indian Institute of Toxicology Research (CSIR-IITR), M.G, Marg, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Syed Faiz
authors.initials: SF
authors.lastname: Mujtaba
authors.affiliation: Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR - Indian Institute of Toxicology Research (CSIR-IITR), M.G, Marg, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Hari Narayan
authors.initials: HN
authors.lastname: Kushwaha
authors.affiliation: Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR - Indian Institute of Toxicology Research (CSIR-IITR), M.G, Marg, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Deepti
authors.initials: D
authors.lastname: Chopra
authors.affiliation: Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR - Indian Institute of Toxicology Research (CSIR-IITR), M.G, Marg, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Manish Kumar
authors.initials: MK
authors.lastname: Pal
authors.affiliation: Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR - Indian Institute of Toxicology Research (CSIR-IITR), M.G, Marg, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Dhirendra
authors.initials: D
authors.lastname: Singh
authors.affiliation: Developmental Toxicology Division, CSIR - Indian Institute of Toxicology Research, P. O. Box 80, M.G. Marg, Lucknow 226001, India.
authors.forename: Rajnish Kumar
authors.initials: RK
authors.lastname: Chaturvedi
authors.affiliation: Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR - Indian Institute of Toxicology Research (CSIR-IITR), M.G, Marg, Lucknow 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR - IITR, Lucknow 226001, India. Electronic address: ratanray.2011@rediffmail.com.
authors.forename: Ratan Singh
authors.initials: RS
authors.lastname: Ray
mesh_terms: D000631:Aminopyridines / Q000528:radiation effects / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D004249:DNA Damage; D006202:Hair Dyes / Q000528:radiation effects / Q000633:toxicity; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D024101:Mitochondrial Proteins / Q000378:metabolism*; D009153:Mutagens / Q000528:radiation effects / Q000633:toxicity; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000378:metabolism; D014466:Ultraviolet Rays; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000631:Aminopyridines; D051017:Apoptosis Regulatory Proteins; C494826:BAX protein, human; C412403:DIABLO protein, human; D006202:Hair Dyes; D047908:Intracellular Signaling Peptides and Proteins; D024101:Mitochondrial Proteins; D009153:Mutagens; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D007770:L-Lactate Dehydrogenase; C531569:2-amino-3-hydroxypyridine
keywords: A132 (2-amino-3-hydroxypyridine); Caspase 3; Phototoxicity; Smac/DIABLO; UV radiation