title: Pigment-lightening effect of N,N'-dilinoleylcystamine on human melanoma cells.
abstract: BACKGROUND
  Cystamine and linoleic acid have been reported to reduce melanin synthesis in vitro and in vivo. N,N'-dilinoleylcystamine (DLC) is a compound of cystamine and linoleic acid connected by an ester bond.
  
  
  OBJECTIVE
  To investigate the effects of DLC on melanin synthesis using cultured human melanoma cells.
  
  
  METHODS
  Levels of total melanin, eumelanin and phaeomelanin, tyrosinase protein and tyrosinase activity in situ were measured in HM3KO melanoma cells. Changes in degree of pigmentation were quantified by image analysis and compared with absorbance values. Tyrosinase from HM3KO cells was used to measure the direct effect of DLC on DOPA and DOPAchrome production.
  
  
  RESULTS
  At concentrations of 1.4-14 micromol L-1, DLC reduced the pigmentation of HM3KO melanoma cells but did not affect cell growth. The visual decrease in pigmentation produced by DLC was more dramatic than the decrease in total melanin content as measured by absorbance at 500 nm. DLC treatment decreased eumelanin synthesis and increased phaeomelanin synthesis in HM3KO melanoma cells. An in situ tyrosinase assay showed that DLC inhibited tyrosinase activity, as well as the level of tyrosinase protein.
  
  
  CONCLUSIONS
  These results suggest that DLC has pigment-lightening effects on HM3KO melanoma cells, produced by reducing the level of eumelanin while increasing the level of phaeomelanin.
authors.affiliation: Skin Research Institute, R&D Center, Amore-Pacific Corporation, 314-1 Bora-ri, Yongin-si, Gyeonggi-do 449-729, Korea. jshwang@amorepacific.com
authors.forename: J S
authors.initials: JS
authors.lastname: Hwang
authors.forename: H
authors.initials: H
authors.lastname: Choi
authors.forename: H S
authors.initials: HS
authors.lastname: Rho
authors.forename: H J
authors.initials: HJ
authors.lastname: Shin
authors.forename: D H
authors.initials: DH
authors.lastname: Kim
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.forename: B G
authors.initials: BG
authors.lastname: Lee
authors.forename: I
authors.initials: I
authors.lastname: Chang
mesh_terms: D015153:Blotting, Western; D003538:Cystamine / Q000031:analogs & derivatives / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008543:Melanins / Q000096:biosynthesis*; D008545:Melanoma / Q000378:metabolism* / Q000473:pathology; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010858:Pigmentation / Q000187:drug effects*; D012880:Skin Pigmentation; D014407:Tumor Cells, Cultured
chemical_list: D004791:Enzyme Inhibitors; D008543:Melanins; C483330:N,N'-dilinoleylcystamine; D014442:Monophenol Monooxygenase; D003538:Cystamine