ABSTRACT
Benz(a)anthracene (BA) is an ubiquitous environmental pollutant of polycyclic aromatic hydrocarbon's (PAHs) family. We showed superoxide (O2(-)) catalyzed BA photo modification and apoptosis in HaCaT keratinocytes under sunlight exposure. O2(-) generation was confirmed by quenching through superoxide dismutase (SOD). BA induced photocytotoxicity were investigated through MTT and NRU assay. We proposed DNA insults such as single and double strand breakage and CPDs formation which results in cell cycle arrest and apoptosis by photosensitized BA. BA induced apoptosis was caspase dependent and occurred through a mitochondrial pathway. Reduction of mitochondrial membrane potential, translocation of Bax to mitochondria and cytochrome c release favors involvement of mitochondria in BA phototoxicity. AO/EB double staining and TEM analysis also support apoptotic cell death. We propose a p21 regulated apoptosis via expression of Bax, and cleaved PARP under sunlight exposure. Thus, we conclude that it is imperative to avoid solar radiation during peak hr (between 11A.M. and 3P.M.) when the amount of solar radiation is high, in the light of DNA damage which may lead to mutation or skin cancer through photosensitized BA under sunlight exposure. Concomitantly, investigation is urgently required for the photosafety of BA photoproducts reaching in the environment through photomodification.
Subject(s)
Apoptosis/drug effects , Benz(a)Anthracenes/toxicity , DNA Damage/drug effects , Mitochondria/metabolism , Superoxides/chemistry , Apoptosis/radiation effects , Benz(a)Anthracenes/analysis , Benz(a)Anthracenes/chemistry , Catalysis , Cell Cycle Checkpoints/drug effects , Cell Cycle Checkpoints/radiation effects , Cell Line , Cyclin-Dependent Kinase Inhibitor p21/genetics , Cyclin-Dependent Kinase Inhibitor p21/metabolism , DNA Damage/radiation effects , Gas Chromatography-Mass Spectrometry , Humans , Light , Oxidation-Reduction , Oxidative Stress/drug effects , Poly(ADP-ribose) Polymerases/genetics , Poly(ADP-ribose) Polymerases/metabolism , Superoxides/metabolism , Ultraviolet Rays , bcl-2-Associated X Protein/genetics , bcl-2-Associated X Protein/metabolismABSTRACT
Levofloxacin (LVFX) is a broad spectrum third generation fluoroquinolone antibiotic, used in the treatment of severe or life-threatening bacterial infections. Photosensitizing mechanism of LVFX was investigated under the ambient environmental intensities of UV-A, UV-B and sunlight exposure. Phototoxic effects of LVFX were assessed on NIH-3T3 and HaCaT cell lines. Results identified first time three photoproducts of LVFX at ambient levels of UV-R by LC-MS/MS. The generation of reactive oxygen species (ROS) was investigated photochemically as well as intracellularly in HaCaT cell line. ROS were significantly quenched by specific quenchers like DABCO, NaN(3), D-mannitol and NAC. Photosensitized LVFX caused lipid peroxidation at different concentrations. Quenching study with superoxide dismutase confirms the LVFX-induced lipid photoperoxidation. Further, photocytotoxicity of LVFX showed significant reduction in cell viability by MTT and neutral red uptake assays. LVFX caused cell arrest in G2/M phases as well as induced apoptosis through ROS-dependent pathway. In addition, photosensitized LVFX also induced upregulation of p21 and Bax/Bcl-2 genes ratio. India is a tropical country and most of the human activities such as agriculture, commerce, sports, etc. take place in bright sunlight; therefore, photosensitive LVFX may lead to skin/ocular disorders and immune suppression. Information is needed regarding the phototoxicity of LVFX for human safety.
Subject(s)
Cell Cycle Checkpoints/drug effects , Fibroblasts/drug effects , Keratinocytes/drug effects , Levofloxacin , Ofloxacin , Animals , Apoptosis/drug effects , Cell Line , Cell Survival/drug effects , Fibroblasts/radiation effects , Free Radical Scavengers/pharmacology , Humans , Keratinocytes/radiation effects , Lipid Peroxidation/drug effects , Mice , Ofloxacin/adverse effects , Ofloxacin/chemistry , Ofloxacin/metabolism , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Reactive Oxygen Species/antagonists & inhibitors , Reactive Oxygen Species/metabolism , Sunlight , Superoxide Dismutase/antagonists & inhibitors , Superoxide Dismutase/metabolism , Ultraviolet Rays , Up-Regulation , bcl-2-Associated X Protein/genetics , bcl-2-Associated X Protein/metabolism , p21-Activated Kinases/genetics , p21-Activated Kinases/metabolismABSTRACT
The cosmetics are nontoxic or less toxic in perse but photoactivation may then sensitize and could produce additional phototoxicity. Phototoxicity assessment of ten different lipsticks and eight facial creams was conducted. Results revealed that six lipsticks and five facial creams generated reactive oxygen species (ROS), produced haemolysis and caused lipid peroxidation in human erythrocytes (in vitro) under sunlight exposure. Seven creams and one lipstick were alkaline while one cream and two lipsticks were acidic. The test lipsticks and creams showed absorption in UV/visible range. The study demonstrated synergistic action of cosmetic products and sunlight. Therefore, sunlight exposure should be avoided after the use of photosensitive cosmetics.
