title: Tranexamic acid suppresses ultraviolet B eye irradiation-induced melanocyte activation by decreasing the levels of prohormone convertase 2 and alpha-melanocyte-stimulating hormone.
abstract: BACKGROUND
  Tranexamic acid (trans-4-aminomethylcyclohexanecarboxylic acid) is a medicinal amino acid used in skin whitening care. This study examined the effects of tranexamic acid on the melanocyte activation of the skin induced by an ultraviolet (UV) B eye irradiation.
  
  
  METHODS
  The eye or ear was locally exposed to UVB at a dose of 1.0 kJ/m(2) using a 20SE sunlamp after covering the remaining body surface with aluminum foil.
  
  
  RESULTS
  UVB eye irradiation induced melanocyte activation of the skin, similar to that observed following UVB ear irradiation, which was suppressed by the administration of tranexamic acid treatment. The plasma α-melanocyte-stimulating hormone (α-MSH) content was increased by UVB irradiation of the eye; however, the increase in α-MSH was suppressed by tranexamic acid treatment. In addition, UVB eye irradiation induced the up-regulation of prohormone convertase (PC) 2 in the pituitary gland. Meanwhile, the increase in PC2 induced by UVB eye irradiation was suppressed by tranexamic acid treatment.
  
  
  CONCLUSIONS
  These results clearly indicate that tranexamic acid decreases the expression of PC2, which cleavages from proopiomelanocortin to α-MSH in the pituitary gland, thereby suppressing melanocyte activation.
authors: Department of Pharmaceutical Science, Suzuka University of Medical Science, Mie, Japan; Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors: Keiichi
authors: K
authors: Hiramoto
authors: Yurika
authors: Y
authors: Yamate
authors: Daijiro
authors: D
authors: Sugiyama
authors: Yumi
authors: Y
authors: Takahashi
authors: Eiichi
authors: E
authors: Mafune
mesh_terms: D000818:Animals; D005123:Eye / Q000166:cytology / Q000528:radiation effects*; D008297:Male; D008544:Melanocytes / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects*; D051379:Mice; D008811:Mice, Inbred DBA; D010902:Pituitary Gland / Q000378:metabolism / Q000601:surgery; D045706:Proprotein Convertase 2 / Q000378:metabolism*; D014148:Tranexamic Acid / Q000494:pharmacology*; D014466:Ultraviolet Rays; D000521:alpha-MSH / Q000097:blood / Q000378:metabolism*
chemical_list: D000521:alpha-MSH; D014148:Tranexamic Acid; D045706:Proprotein Convertase 2
keywords: dopa-positive melanocyte; prohormone convertase 2; tranexamic acid; ultraviolet B; α-melanocyte-stimulating hormone