title: Radix Saposhnikovia extract suppresses mouse allergic contact dermatitis by regulating dendritic-cell-activated Th1 cells.
abstract: BACKGROUND
  Radix Saposhnikovia (RS), called "Fangfeng" in China, is commonly used in Chinese medicinal formulae to treat allergic and inflammatory diseases. However, the underlying mechanisms of RS in ameliorating allergy remain unknown.
  
  
  OBJECTIVE
  To study the effects of RS extract on allergic contact dermatitis (ACD) in a mouse model and to investigate the underlying mechanisms in vivo and ex vivo.
  
  
  METHODS
  ACD was induced by sensitizing the mice and treating an ear auricle with 1-chloro-2,4-dinitrobenzene (DNCB). RS extract was administered during the sensitization and/or elicitation phase. Ear swelling was noted and lymphocytic infiltration was investigated with hematoxylin and eosin staining. The cytokines in the sera and the supernatants of lymphocyte cultures were determined with enzyme-linked immunosorbent assays. Lymphocyte proliferation was assessed with a 3-(4,5)-dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide (MTT) assay. The maturation of dendritic cells (DCs) and the differentiation of T cells were examined with flow cytometry. The mRNA expression of T-bet, GATA-3, and forkhead box p3 (Foxp3) was evaluated with real-time PCR.
  
  
  RESULTS
  RS extract (1.3 or 2.6 g/kg) markedly reduced the ear swelling and the intense cellular infiltration of inflammatory cells in the ear tissue. The ratio of interferon γ (IFN-γ)/interleukin 4 (IL-4) was reduced in the sera of the DNCB-sensitized mice and the lymphocyte culture supernatants after treatment with the extract. Further study of the initial stage of ACD revealed that RS extract prevented the differentiation of naïve T cells into Th1 cells, reduced the proportion of CD3(+)CD4(+) (Th) cells, and suppressed the secretion of IFN-γ and the expression of T-bet mRNA in lymphocytes. The RS extract also reduced the proportion of DCs in the sensitized mouse lymphocytes and the expression of CD40(+)CD86(+) cells in the DCs.
  
  
  CONCLUSIONS
  RS extract is effective in treating ACD because it regulates the development of DCs and DC-activated Th1 differentiation.
authors.affiliation: Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Jiangsu Key Laboratory of Pediatric Respiratory Disease, Nanjing University of Chinese Medicine, Nanjing 210023, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Yu
authors.affiliation: Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Jiangsu Key Laboratory of Pediatric Respiratory Disease, Nanjing University of Chinese Medicine, Nanjing 210023, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Niu
authors.affiliation: Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Jiangsu Key Laboratory of Pediatric Respiratory Disease, Nanjing University of Chinese Medicine, Nanjing 210023, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Jiangsu Key Laboratory of Pediatric Respiratory Disease, Nanjing University of Chinese Medicine, Nanjing 210023, China.
authors.forename: Hailiang
authors.initials: H
authors.lastname: Liu
authors.affiliation: Suzhou Hospital of Traditional Chinese Medicine, Suzhou 215000, China.
authors.forename: Guorong
authors.initials: G
authors.lastname: Jiang
authors.affiliation: Center of Clinical Laboratory, Gulou Hospital, Nanjing, PR China.
authors.forename: Junhao
authors.initials: J
authors.lastname: Chen
authors.affiliation: Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Jiangsu Key Laboratory of Pediatric Respiratory Disease, Nanjing University of Chinese Medicine, Nanjing 210023, China. Electronic address: hongmin72@126.com.
authors.forename: Min
authors.initials: M
authors.lastname: Hong
mesh_terms: D000818:Animals; D019661:Apiaceae / Q000737:chemistry*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology*; D017449:Dermatitis, Allergic Contact / Q000188:drug therapy*; D004195:Disease Models, Animal; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D007249:Inflammation / Q000188:drug therapy; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010936:Plant Extracts / Q000494:pharmacology*; D018417:Th1 Cells / Q000187:drug effects*
chemical_list: D016207:Cytokines; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts
keywords: Allergic contact dermatitis; Dendritic cells; Radix Saposhnikovia; Th1 cell