title: [Role of serotoninergic/melatoninergic system in melanin metabolism in melanocytes exposed to serum of rabbits fed with Liuwei Dihuang decoction].
abstract: OBJECTIVE
  To investigate the effects of Liuwei Dihuang (LWDH) decoction on serotonine (5-HTs), melatonin and the activity of the rate-limiting enzymes ANNAT and HIOMT in cultured human melanocytes and in melanocytes co-cultured with keratinocytes.
  
  
  METHODS
  CCK-8 assay was used to assess the proliferation of melanocytes and melanocytes co-cultured with keratinocytes after treatment with the serum from rabbits fed with LWDH decoction. High-performance liquid chromatography was used to determine 5-HT and melatonin contents, and real-time fluorescent PCR was employed to evaluate the ANNAT and HIOMT activities in the cell cultures.
  
  
  RESULTS
  The serum from rabbits fed with LWDH Decoction at low doses did not affect the proliferation of melanocytes co-cultured with keratinocytes, but at the concentrations of 20%-40%, the serum significantly inhibited the proliferation of melanocytes, and the effect was optimal with a concentration of 40% (P<0.05). 5-HT and melatonin contents in the cell culture decreased as the serum concentration increased (P<0.05), which was the most obvious with a serum concentration of 40% (P<0.01). Exposure of the cells to low and moderate doses of the serum caused a dose-dependent decrease in AANAT activity (P<0.05), but the serum produced no significant changes in the level of HIOMT mRNA expression in the cells.
  
  
  CONCLUSIONS
  The serotoninergic/melatoninergic system mediate the regulation of melanin metabolism by LWDH Decoction, the mechanism of which may involve 5-HTs, melatonin and ANNAT.
authors: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China. E-mail: 362186548@qq.com.
authors: Yan
authors: Y
authors: Deng
authors: Lin
authors: L
authors: Lv
authors: Guang
authors: G
authors: Yang
authors: Yu-Kun
authors: YK
authors: Sui
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D018920:Coculture Techniques; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006801:Humans; D015603:Keratinocytes; D008543:Melanins / Q000378:metabolism*; D008544:Melanocytes / Q000187:drug effects* / Q000378:metabolism; D008550:Melatonin / Q000378:metabolism; D011817:Rabbits; D012701:Serotonin / Q000378:metabolism; D044967:Serum / Q000737:chemistry*
chemical_list: D004365:Drugs, Chinese Herbal; C042579:Liuwei Dihuang Decoction; D008543:Melanins; D012701:Serotonin; D008550:Melatonin