title: A new 2-imino-1,3-thiazoline derivative, KHG22394, inhibits melanin synthesis in mouse B16 melanoma cells.
abstract: During our on-going attempts to develop a new skin-whitening agent, we identified a novel candidate compound KHG22394, a 2-imino-1,3-thiazoline derivative. Our data show that KHG22394 significantly inhibits melanin production in a dose-dependent manner, but that it does not directly inhibit tyrosinase, the rate limiting melanogenic enzyme. It has been reported that the activation of extracellular signal-regulated kinase (ERK) reduces melanin synthesis by downregulating microphthalmia-associated transcription factor (Mitf). Thus, we examined the effects of KHG22394 on the ERK pathway and found that it induced ERK and 90 kDa ribosomal S6 kinase (RSK-1) activation. Moreover, alpha-melanocyte-stimulating hormone (alpha-MSH) is known to increase melanin biosynthesis by increasing tyrosinase production, and here, we found that alpha-MSH-induced Mitf and tyrosinase increases were inhibited in B16 melanoma cells treated with KHG22394. These findings suggest that the hypopigmentary effect of KHG22394 results from the downregulation of Mitf and subsequently of tyrosinase, although KHG22394 did not inhibit tyrosinase activity directly. Our findings indicate that 2-imino-1,3-thiazoline derivatives are potential skin whitening agents.
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, Korea.
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Kim
authors.forename: Yun-Mi
authors.initials: YM
authors.lastname: Jeong
authors.forename: Ik-Kyu
authors.initials: IK
authors.lastname: Park
authors.forename: Hoh-Gyu
authors.initials: HG
authors.lastname: Hahn
authors.forename: Hyun-Kyung
authors.initials: HK
authors.lastname: Lee
authors.forename: Sun-Bang
authors.initials: SB
authors.lastname: Kwon
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Jeong
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Yang
authors.forename: Uy Dong
authors.initials: UD
authors.lastname: Sohn
authors.forename: Kyoung-Chan
authors.initials: KC
authors.lastname: Park
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003879:Dermatologic Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D008543:Melanins / Q000096:biosynthesis*; D008544:Melanocytes / Q000187:drug effects* / Q000378:metabolism; D008546:Melanoma, Experimental; D051379:Mice; D051739:Microphthalmia-Associated Transcription Factor / Q000378:metabolism; D014442:Monophenol Monooxygenase / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D012880:Skin Pigmentation / Q000187:drug effects*; D013844:Thiazoles / Q000494:pharmacology*
chemical_list: D003879:Dermatologic Agents; C517753:KHG22394; D008543:Melanins; D051739:Microphthalmia-Associated Transcription Factor; C497235:Mitf protein, mouse; D013844:Thiazoles; D014442:Monophenol Monooxygenase; D048049:Extracellular Signal-Regulated MAP Kinases