In vitro inhibitory effect of sulfated galactans isolated from red alga Gracilaria fisheri on melanogenesis in B16F10 melanoma cells
Hyperpigmentation of the skin results from excessive melanin formation in melanocytes, and overproduction of melanin frequently leads to melanoma. The aim of this study was to investigate the potential of sulfated galactans (SG) from Gracilaria fisheri to inhibit melanin formation or melanogenesis. Cellular and molecular mechanisms of inhibition were also investigated. SG was evaluated in vitro for its inhibitory effect on mushroom tyrosinase activity, cell-free tyrosinase activity, and cellular tyrosinase activity. B16F10 mouse melanoma cells were cultured with SG and their tyrosinase activity and melanin content was compared with kojic acid, a known tyrosinase inhibitor. Moreover, the levels of expression of melanogenesis-related genes and proteins were determined by quantitative RT-PCR and enzyme-linked immunosorbent assay (ELISA), respectively. The result showed that SG had no inhibitory effect on mushroom tyrosinase activity and cell-free tyrosinase activity. However, SG significantly suppressed cellular tyrosinase activity and melanin production in B16F10 melanoma cells without any apparent cytotoxicity. Quantitative RT-PCR and ELISA revealed that SG downregulated the expression of microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2), and tyrosinase mRNA and proteins. Taken together, the data suggest that SG may act as an anti-melanogenic agent by inhibiting the expression of MITF and cellular tyrosinase activity. SG may show potential as an ingredient in skin-whitening cosmetics or as a topical agent for the treatment of hyperpigmentation disorders.
KeywordsRhodophyta Melanogenesis Melanin Tyrosinase MITF Sulfated galactans
The authors would like to thank Dr. John Swinscoe for the critical review of the manuscript.
This work was financially supported by Navamindradhiraj University Research Fund.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Rudtanatip T, Asuvapongpatana S, Withyachumnarnkul B, Wongprasert K (2014) Sulfated galactans isolated from the red seaweed Gracilaria fisheri target the envelope proteins of white spot syndrome virus and protect against viral infection in shrimp haemocytes. J Gen Virol 95:1126–1134CrossRefPubMedGoogle Scholar
- Urabe K, Nakayama J, Hori Y (1998) Mixed epidermal and dermal hypermelanoses. In: Nordlund JJ, Boissy RE, Hearing VJ, King RA, Oetting WS, Ortonne JP (eds) The pigmentary system: physiology and pathophysiology. Oxford University Press, New York, pp 909–913Google Scholar
- Virador V, Matsunaga N, Matsunaga J, Valencia J, Oldham R, Kameyama K, Peck G, Ferrans V, Vieira W, Abdel-Malek Z, Hearing V (2001) Production of melanocyte-specific antibodies to human melanosomal proteins: expression patterns in normal human skin and in cutaneous pigmented lesions. Pigment Cell Res 14:289–297CrossRefPubMedGoogle Scholar