title: Inhibitory effects of Sargassum polycystum on tyrosinase activity and melanin formation in B16F10 murine melanoma cells.
abstract: BACKGROUND
  Sargassum polycystum, a type of brown seaweed, has been used for the treatment of skin-related disorders in traditional medicine.
  
  
  OBJECTIVE
  The aim of the present study is to investigate the antimelanogenesis effect of Sargassum polycystum extracts by cell-free mushroom tyrosinase assay followed by cell viability assay, cellular tyrosinase assay and melanin content assay using B16F10 murine melanoma cells.
  
  
  METHODS
  Sargassum polycystum was extracted with 95% ethanol and further fractionated with hexane, ethyl acetate and water. The ethanolic crude extract and its fractionated extracts were tested for their potential to act as antimelanogenesis or skin-whitening agents by their abilities to inhibit tyrosinase activity in the cell-free mushroom tyrosinase assay and cellular tyrosinase derived from melanin-forming B16F10 murine melanoma cells. The tyrosinase inhibitory activity was correlated to the inhibition of melanin production in α-MSH-stimulated and unstimulated B16F10 cells.
  
  
  RESULTS
  Sargassum polycystum ethanolic extract and its fractions had little or no inhibitory effect on mushroom tyrosinase activity. However, when tested on cellular tyrosinase, the ethanolic extract and its non-polar fraction, hexane fraction (SPHF), showed significant inhibition of cellular tyrosinase activity. In parallel to its cellular tyrosinase inhibitory activity, SPHF was also able to inhibit basal and α-MSH-stimulated melanin production in B16F10 cells.
  
  
  CONCLUSIONS
  Our findings showed that (i) cellular tyrosinase assay is more reliable than mushroom tyrosinase assay in the initial testing of potential antimelanogenesis agents and, (ii) SPHF inhibited melanogenesis by inhibiting cellular tyrosinase activity. SPHF may be useful for treating hyperpigmentation and as a skin-whitening agent in cosmetics industry.
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Chan
authors.forename: K H
authors.initials: KH
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Cheah
mesh_terms: D000818:Animals; D057886:Bleaching Agents / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D000431:Ethanol / Q000737:chemistry; D006586:Hexanes / Q000737:chemistry; D008543:Melanins / Q000378:metabolism*; D008544:Melanocytes / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D008546:Melanoma, Experimental / Q000201:enzymology* / Q000473:pathology; D051379:Mice; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D044647:Sargassum / Q000737:chemistry; D012880:Skin Pigmentation / Q000187:drug effects*; D012997:Solvents / Q000737:chemistry; D000521:alpha-MSH / Q000378:metabolism
chemical_list: D057886:Bleaching Agents; D004791:Enzyme Inhibitors; D006586:Hexanes; D008543:Melanins; D012997:Solvents; D000431:Ethanol; D000521:alpha-MSH; D014442:Monophenol Monooxygenase