Immunosuppressive effects of an ethyl acetate extract from Urtica dentata Hand on skin allograft rejection.
OBJECTIVE
To investigate the immunosuppressive effects of HPLC qualitied ethyl acetate extract (EAE) from Urtica dentate Hand on skin allograft rejection in a murine model.


METHODS
Allo-skin transplantation model was established by placing skin allograft of C57BL/6 mice in the wound bed which was on the back of Balb/c mice. We used FACS to study the effects of EAE on dendritic cells (DCs) maturation and CD4(+)CD25(+)T regulatory cells (Tregs) differentiation. We also studied spleen lymphocyte proliferation and T-bet gene expression in DCs. Concentration of Th1/Th2 cytokines was monitored as markers of Th1/Th2 responses by ELISA.


RESULTS
A significant prolongation of skin allografts survival was observed as a dose-dependent manner in the animals treated with EAE. By FACS, we found that treatment with EAE (200 mg kg(-1)) resulted in an immature statement of DCs and stimulated the differentiation of CD4(+)CD25(+)Tregs. Additionally, the expression of T-bet gene and the proliferation of spleen lymphocytes were efficiently abated in EAE treated mice. Comparing to the model control, EAE-treated recipients showed a significant down-regulation (P<0.01) of Th1 cytokines (IL-2, IFN-gamma) and an obviously increase (P<0.01) of Th2 cytokine (IL-10) in the serum, which presented in a dose-related way.


CONCLUSIONS
The anti-allograft rejection effect of EAE by enhancing CD4(+)CD25(+)Tregs differentiation and sustaining DCs immaturation makes EAE to be a possible choice for treating autoimmune diseases in a way of inducing a stable immunological tolerance state.
Xiang
Ming
M
Hubei Key Laboratory of Natural Medicinal Chemistry and Resources Evaluation, School of Pharmacy, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, China.
Hou
Wen-Rui
WR
Xie
Sheng-Nan
SN
Zhang
Wei-Dong
WD
Wang
Xin
X
D000085:Acetates; D000818:Animals; D016207:Cytokines / Q000097:blood; D003713:Dendritic Cells / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000627:therapeutic use*; D006084:Graft Rejection / Q000517:prevention & control*; D006085:Graft Survival / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D008517:Phytotherapy; D018517:Plant Roots / Q000737:chemistry*; D016038:Skin Transplantation / Q000276:immunology*; D020825:T-Box Domain Proteins / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects; D027003:Urticaceae / Q000737:chemistry*; D000098815:T-bet Transcription Factor
D000085:Acetates; D016207:Cytokines; D004365:Drugs, Chinese Herbal; D007166:Immunosuppressive Agents; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; C007650:ethyl acetate