title: Citrinin-generated reactive oxygen species cause cell cycle arrest leading to apoptosis via the intrinsic mitochondrial pathway in mouse skin.
abstract: The mycotoxin, citrinin (CTN), is a contaminant of various food and feed materials. Several in vivo and in vitro studies have demonstrated that CTN has broad toxicity spectra; however, dermal toxicity is not known. In the present investigation, dermal exposure to CTN was undertaken to study oxidative stress, DNA damage, cell cycle arrest, and apoptosis in mouse skin. A single topical application of CTN caused significant change in oxidative stress markers, such as lipid peroxidation, protein carbonyl content, glutathione (GSH) content, and antioxidant enzymes in a dose-dependent (25-100 μg/mouse) and time-dependent (12-72 h) manner. Single topical application of CTN (50 μg/mouse) for 12-72 h caused significant enhancement in (1) reactive oxygen species (ROS); (2) cell cycle arrest at the G0/G1 phase (30-71%) and G2/M phase (56-65%) along with the induction of apoptosis (3.6-27%); (3) expression of p53, p21/waf1; (4) Bax/Bcl₂ ratio and cytochome c release; and (5) activities of caspase 9 (22-46%) and 3 (42-54%) as well as increased poly(ADP-ribose) polymerase cleavage. It was also observed that pretreatment with bio-antioxidants viz butylated hydroxyanisole (55 μmol/100 μl), quercetin (10 μmol/100 μl), or α-tocopherol (40 μmol/100 μl) resulted in decreases of ROS generation, arrest in the G0/G1 phase of the cell cycle, and apoptosis. These data confirm the involvement of ROS in apoptosis and suggest that these bio-antioxidants may be useful in the prevention of CTN-induced dermal toxicity.
authors.affiliation: Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Lucknow-226001, India.
authors.forename: Rahul
authors.initials: R
authors.lastname: Kumar
authors.forename: Premendra D
authors.initials: PD
authors.lastname: Dwivedi
authors.forename: Alok
authors.initials: A
authors.lastname: Dhawan
authors.forename: Mukul
authors.initials: M
authors.lastname: Das
authors.forename: Kausar M
authors.initials: KM
authors.lastname: Ansari
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D015415:Biomarkers; D002083:Butylated Hydroxyanisole / Q000494:pharmacology; D053453:Caspase 9 / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002953:Citrinin / Q000633:toxicity*; D004249:DNA Damage / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D016193:G1 Phase / Q000187:drug effects; D059566:M Phase Cell Cycle Checkpoints / Q000187:drug effects; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*; D024502:alpha-Tocopherol / Q000494:pharmacology; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000975:Antioxidants; C494827:Bax protein, mouse; D015415:Biomarkers; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D002083:Butylated Hydroxyanisole; D002953:Citrinin; D011794:Quercetin; D011065:Poly(ADP-ribose) Polymerases; C506434:Casp9 protein, mouse; D053453:Caspase 9; D024502:alpha-Tocopherol