title: Superoxide dismutase 1 inhibits alpha-melanocyte stimulating hormone and ultraviolet B-induced melanogenesis in murine skin.
abstract: BACKGROUND
  Over the last decade, the incidence of ultraviolet B (UVB)-related skin problems has increased. Oxidative stress caused by UVB induces the secretion of melanocyte growth and activating factors from keratinocytes, which results in the formation of cutaneous hyperpigmentation. Therefore, increasing the antioxidant abilities of skin cells is thought to be a beneficial strategy for the development of sunscreen agents. Superoxide dismutase 1 (SOD1) is an antioxidant enzyme that is known to exhibit antioxidant properties.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the effect of SOD1 on alpha-melanocyte stimulating hormone (α-MSH) and UVB-induced melanogenesis in B16F10 melanoma cells and HRM-2 melanin-possessing hairless mice.
  
  
  METHODS
  The inhibitory effect of SOD1 on tyrosinase activity was evaluated in a cell-free system. Additional experiments were performed using B16F10 melanoma cells to demonstrate the effects of SOD1 in vitro, and HRM-2 melanin-possessing hairless mice were used to evaluate the antimelanogenic effects of SOD1 in vivo.
  
  
  RESULTS
  We found that SOD1 inhibited melanin production in a dose-dependent manner without causing cytotoxicity in B16F10 melanoma cells. SOD1 did not inhibit tyrosinase activity under cell-free conditions. The results indicate that SOD1 may reduce pigmentation by an indirect, nonenzymatic mechanism. We also found that SOD1 decreased UVB-induced melanogenesis in HRM-2 melanin-possessing hairless mice, as visualized through hematoxylin and eosin staining and Fontana-Masson staining.
  
  
  CONCLUSIONS
  Our results indicate that SOD1 has an inhibitory effect on α-MSH and UVB-induced melanogenesis, indicating that SOD1 may be a promising sunscreen agent.
authors.affiliation: Department of Dermatology, Chung-Ang University College of Medicine, Seoul, Korea. ; Department of Medicine, Graduate School, Chung-Ang University, Seoul, Korea.
authors.forename: Chang Taek
authors.initials: CT
authors.lastname: Oh
authors.affiliation: Nutrex Technology R&D Center, Seoul, Korea.
authors.forename: Dohyun
authors.initials: D
authors.lastname: Lee
authors.affiliation: Nutrex Technology R&D Center, Seoul, Korea.
authors.forename: Kyotan
authors.initials: K
authors.lastname: Koo
authors.affiliation: Biomedical Research Institute, MEDIPOST Co., Ltd., Seongnam, Korea.
authors.forename: Jay
authors.initials: J
authors.lastname: Lee
authors.affiliation: MB Business Development Team, Pacificpharma, Seoul, Korea.
authors.forename: Ho Sang
authors.initials: HS
authors.lastname: Yoon
authors.affiliation: Cosmeceutical Team, Pacificpharma, Seoul, Korea.
authors.forename: Yoo Mi
authors.initials: YM
authors.lastname: Choi
authors.affiliation: Department of Dermatology, Chung-Ang University College of Medicine, Seoul, Korea. ; Department of Medicine, Graduate School, Chung-Ang University, Seoul, Korea.
authors.forename: Tae-Rin
authors.initials: TR
authors.lastname: Kwon
authors.affiliation: Department of Dermatology, Chung-Ang University College of Medicine, Seoul, Korea. ; Department of Medicine, Graduate School, Chung-Ang University, Seoul, Korea.
authors.forename: Beom Joon
authors.initials: BJ
authors.lastname: Kim
keywords: Alpha-MSH; HRM-2; Skin pigmentation; Superoxide dismutase 1; Ultraviolet radiation