title: Assessment of Cuscuta chinensis seeds׳ effect on melanogenesis: comparison of water and ethanol fractions in vitro and in vivo.
abstract: BACKGROUND
  Cuscuta chinensis seeds have traditionally been used to treat freckles and melasma in Asia, although recent reports have revealed that Semen cuscutae is a promoter of melanogenesis. The present study aims to investigate the mechanism of this opposite effect of Semen cuscutae on melanogenesis.
  
  
  METHODS
  In accordance with traditional usage, the water fraction and the ethanol fraction from Semen cuscutae (WFSC/EFSC) were extracted to determine the herbal effects by examining the activity of mushroom tyrosinase, cellular melanin contents, tyrosinase activity assay, quantitative-reverse transcription polymerase chain reaction (qRT-PCR), and Western blot analysis for tyrosinase in B16F10 mouse melanoma cells. The melanocyte phenotypes of zebrafish larvae were observed while the in vivo melanin contents and tyrosinase activity were determined.
  
  
  RESULTS
  The activity of mushroom tyrosinase assay shown that WFSC was an uncompetitive inhibitor of mushroom tyrosinase, while EFSC indicated dose-dependent activation of the mushroom tyrosinase activity. The WFSC markedly inhibited 3-isobutyl-1-methylxanthine (IBMX)-stimulated melanin synthesis and tyrosinase activity in vitro. Howeveran accelerant role in melanin synthesis and tyosinase activity. Neither fraction had any effect on the IBMX-induced expression of tyrosinase protein or mRNA. The WFSC strongly inhibited melanin synthesis and cellular tyrosinase activity in vivo. Furthermore, with the function of WFSC at a higher concentration, a punctate melanocyte pattern appeared that was similar to the pattern induced by arbutin or Mequinol (MQ). The EFSC had no effect on the melanocytes of zebrafish larvae. It was discovered that WFSC did not show a stable inhibitory effect until it was extracted 1 month later.
  
  
  CONCLUSIONS
  These results suggest that the opposite effects of Cuscuta chinensis seeds were caused by the extraction methods and that time has an important role on the effect of WFSC. Both WFSC and EFSC significantly influence melanogenesis by regulating enzymatic activity of tyrosinase. In addition, the data indicate that wildtype (WT) zebrafish may be an ideal model for testing inhibitors of melanogenesis from clinically active herbs.
authors.affiliation: TCM-Integrated Hospital, Southern Medical University, Guangzhou 510310, China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Tian-Jing
authors.initials: TJ
authors.lastname: Wang
authors.affiliation: Cancer Research Institute, Southern Medical University, Guangzhou 510515, China.
authors.forename: Jing
authors.initials: J
authors.lastname: An
authors.affiliation: Key Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases of Guangdong Higher Education Institutes, Southern Medical University, Guangzhou 510515, China.
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Chen
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Qiu-Di
authors.initials: QD
authors.lastname: Deng
authors.affiliation: TCM-Integrated Hospital, Southern Medical University, Guangzhou 510310, China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China. Electronic address: yangliusmu@163.com.
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D034182:Cuscuta; D000431:Ethanol / Q000737:chemistry; D007814:Larva; D008543:Melanins / Q000378:metabolism*; D008544:Melanocytes / Q000187:drug effects / Q000378:metabolism; D008546:Melanoma, Experimental; D051379:Mice; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry; D015027:Zebrafish
chemical_list: D008543:Melanins; D010936:Plant Extracts; D012997:Solvents; D014867:Water; D000431:Ethanol; D014442:Monophenol Monooxygenase
keywords: 1-Methyl-3-isobutylxanthine (Pubmed Chem CID:3758); Acetic Acid (Pubmed Chem CID:176); Arbutin (Pubmed Chem CID:440936); Cuscuta Chinensis seeds; Dimethyl Sulfoxide (Pubmed Chem CID:679); HPLC; Levodopa (Pubmed Chem CID:6047); Melanin; Mequinol (Pubmed Chem CID:9015); Methanol (Pubmed Chem CID:887); Octoxynol (Pubmed Chem CID:5590); Phenylmethylsulfonyl Fluoride (Pubmed Chem CID:4784); Phenylthiourea (Pubmed Chem CID:676454); Tyrosinase; Zebrafish