title: Ultraviolet A eye irradiation ameliorates colon carcinoma induced by azoxymethane and dextran sodium sulfate through β-endorphin and methionine-enkephalin.
abstract: BACKGROUND
  We previously reported that ultraviolet (UV) A eye irradiation reduces the ulcerative colitis induced by dextran sodium sulfate (DSS). This study examined the effects of UVA on colon carcinoma induced by azoxymethane (AOM) and DSS.
  
  
  METHODS
  We irradiated the eyes of ICR mice with UVA at a dose of 110 kJ/m2using an FL20SBLB-A lamp for the experimental period.
  
  
  RESULTS
  In mice treated with these drugs, the symptom of colon carcinoma was reduced by UVA eye irradiation. The levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in the blood were increased in AOM + DSS-treated mice; however, those levels were reduced by UVA eye irradiation. The expression of β-endorphin, methionine-enkephalin (OGF), μ-opioid receptor, and opioid growth factor receptor (OGFR) of the colon was increased in the AOM + DSS-treated mice, and these levels were increased further following UVA eye irradiation. When β-endorphin inhibitor was administered, the ameliorative effect of UVA eye irradiation was reduced, and the effect of eye irradiation disappeared entirely following the administration of naltrexone (inhibitor of both opioid receptor and OGFR).
  
  
  CONCLUSIONS
  These results suggested that UVA eye irradiation exerts major effects on AOM + DSS-induced colon carcinoma.
authors.affiliation: Department of Pharmaceutical Science, Suzuka University of Medical Science, Mie, Japan.
authors.forename: Keiichi
authors.identifier: http://orcid.org/0000-0001-5208-8719
authors.initials: K
authors.lastname: Hiramoto
authors.affiliation: Department of Pharmaceutical Sciences, Gifu Pharmaceutical University, Gifu, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yokoyama
authors.affiliation: Department of Pharmaceutical Science, Suzuka University of Medical Science, Mie, Japan.
authors.forename: Yurika
authors.initials: Y
authors.lastname: Yamate
mesh_terms: D000634:Aminoquinolines / Q000494:pharmacology; D000818:Animals; D001397:Azoxymethane; D001549:Benzamides / Q000494:pharmacology; D003106:Colon / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D016264:Dextran Sulfate; D004744:Enkephalin, Methionine / Q000378:metabolism*; D005123:Eye / Q000528:radiation effects*; D005260:Female; D015850:Interleukin-6 / Q000097:blood; D019394:Ki-67 Antigen / Q000378:metabolism; D008813:Mice, Inbred ICR; D009271:Naltrexone / Q000494:pharmacology; D011957:Receptors, Opioid / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014466:Ultraviolet Rays; D001615:beta-Endorphin / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000634:Aminoquinolines; D001549:Benzamides; D015850:Interleukin-6; D019394:Ki-67 Antigen; C433236:N-(4-amino-2-methylquinolin-6-yl)-2-(4-ethylphenoxymethyl)benzamide; D011957:Receptors, Opioid; D017450:Receptors, Opioid, mu; D014409:Tumor Necrosis Factor-alpha; C033593:methionine-enkephalin receptor; D004744:Enkephalin, Methionine; D009271:Naltrexone; D001615:beta-Endorphin; D016264:Dextran Sulfate; D001397:Azoxymethane
keywords: AOM + DSS-induced colon carcinoma; Ultraviolet A; methionine-enkephalin; opioid growth factor receptor; β-endorphin; μ-opioid receptor