title: Effects of total saponins from Rhizoma Dioscoreae Nipponicae on expression of vascular endothelial growth factor and angiopoietin-2 and Tie-2 receptors in the synovium of rats with rheumatoid arthritis.
abstract: BACKGROUND
  This study aimed to determine the effects of total saponins from Rhizoma Dioscoreae Nipponicae (TS-RDN) on the expression of vascular endothelial growth factor (VEGF) and angiopoietin (Ang)-2 and Tie-2 (endothelial tyrosine kinase receptor) receptors in the synovium of rats with rheumatoid arthritis (RA) (collagen-induced arthritis; CIA), and to examine the mechanisms of TS-RDN in alleviating RA.
  
  
  METHODS
  The CIA rat model was established and the animals were randomly divided into control, CIA model, TS-RDN, diosgenin, and tripterygium groups. Fluorescent polymerase chain reaction was performed to detect VEGF expression in the rat knee joint synovium. Additionally, immunohistochemical assay was used to detect protein expression of Ang-2 and Tie-2 in the rat knee joint synovium.
  
  
  RESULTS
  Expression of VEGF, Ang-2, and Tie-2 in the model group was significantly higher than in the control group (p < 0.01). After TS-RDN, tripterygium and diosgenin treatment, VEGF and Ang-2 expression was lower than in the model group (p < 0.01). However, Tie-2 expression showed no significant difference. The effects of TS-RDN on VEGF expression were more marked than those of tripterygium and diosgenin (p < 0.01).
  
  
  CONCLUSIONS
  TS-RDN might reduce the expression of VEGF, Ang-2, and Tie-2 in the synovium, thus inhibiting synovial angiogenesis and playing a therapeutic role in RA.
authors.affiliation: Department of Pathogen Biology, Chengde Medical College, Hebei, China.
authors.forename: Yachun
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Central Laboratory, the Affiliated Hospital of Chengde Medical College, Hebei, China.
authors.forename: Enhong
authors.initials: E
authors.lastname: Xing
authors.affiliation: Institute of Basic Medical Sciences, Chengde Medical College, Hebei, China.
authors.forename: Xiujun
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Immunology, Chengde Medical College, Hebei, China. Electronic address: hongrusong@126.com.
authors.forename: Hongru
authors.initials: H
authors.lastname: Song
authors.affiliation: Department of Pathogen Biology, Chengde Medical College, Hebei, China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Dong
mesh_terms: D042702:Angiopoietin-2 / Q000032:analysis*; D000818:Animals; D001169:Arthritis, Experimental / Q000378:metabolism*; D027742:Dioscorea / Q000737:chemistry*; D005260:Female; D006801:Humans; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D042787:Receptor, TIE-2 / Q000032:analysis*; D012503:Saponins / Q000494:pharmacology*; D013583:Synovial Membrane / Q000737:chemistry*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
chemical_list: D042702:Angiopoietin-2; D012333:RNA, Messenger; D012503:Saponins; D042461:Vascular Endothelial Growth Factor A; D042787:Receptor, TIE-2
keywords: Rhizoma Dioscoreae Nipponicae; Tie-2; angiogenesis; angiopoietin 2; total saponins; vascular endothelial growth factor