Icaritin inhibits T cell activation and prolongs skin allograft survival in mice

• Published in: International immunopharmacology Vol. 13; no. 1; pp. 1 - 7
• Main Authors: Li, Xiaojuan, Hu, Yiping, He, Longgang, Wang, Song, Zhou, Hua, Liu, Shuwen
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.05.2012; Elsevier
• Subjects: Animals; Asthma; Autoimmune diseases; Biological and medical sciences; CD25; CD25 antigen; CD4 antigen; CD4-Positive T-Lymphocytes - drug effects; CD4-Positive T-Lymphocytes - immunology; Cell activation; Cell proliferation; Cell Proliferation - drug effects; Cell survival; Concanavalin A; Cytokines; Dose-Response Relationship, Drug; Drugs, Chinese Herbal - administration & dosage; Drugs, Chinese Herbal - isolation & purification; Drugs, Chinese Herbal - therapeutic use; Epimedium; Female; Flavonoids - administration & dosage; Flavonoids - isolation & purification; Flavonoids - therapeutic use; gamma -Interferon; Graft Survival - drug effects; Helper cells; Herbal medicines; Humans; Icaritin; Immunosuppression; Immunosuppressive Agents - administration & dosage; Immunosuppressive Agents - isolation & purification; Immunosuppressive Agents - therapeutic use; Infection; Interleukin 2; Interleukin 4; Interleukin-2 - antagonists & inhibitors; Interleukin-2 Receptor alpha Subunit - antagonists & inhibitors; Jurkat Cells; Lymphocyte Activation - drug effects; Lymphocytes T; Medical sciences; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mitogens; NF-AT protein; Ovalbumin; Pharmacology. Drug treatments; Skin; Skin Transplantation; Spleen - cytology; Spleen - drug effects; Spleen - immunology; Splenocytes; T cell activation; Th1 Cells - drug effects; Th1 Cells - immunology; Th1/Th2 cytokines; Transplantation, Homologous; Immunosuppression; CD25; Skin transplantation; T cell activation; Th1/Th2 cytokines; Icaritin; Homograft; Th1 lymphocyte; Activation; Transplantation; Surgery; T-Lymphocyte; Graft; Th2 lymphocyte; Rodentia; Cytokine; Survival; Vertebrata; Mammalia; Treatment; Mouse; Animal; Inhibitor; Skin; Prolonged
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/j.intimp.2012.02.011

Icaritin is a native compound from Epimedium Genus, a traditional Chinese herbal medicine which is effective in treating asthma, autoimmune diseases and viral infections. In the present paper, the immunosuppressive effects of icaritin were found through in vitro and in vivo studies. Icaritin could dose-dependently inhibit murine CD4+ T cells proliferation stimulated with mitogens or specific antigen ovabumin (OVA). Icaritin at 0.25–25μM could down-regulate T cell activation marker CD25 expression and inhibit IL-2 production. It could also reduce the Th1 cytokine IFN-γ production significantly if the T cells were activated by ConA or anti-CD3; while the inhibition of IL-4 secretion was only seen on anti-CD3 activated T cells treated with low concentrations of icaritin. In vivo study showed that treatment of icaritin at 10mg/kg/day on mice could suppress the immune response with prolonged allograft skin survival. Further study demonstrated that it reduced the alloantigen-induced splenocytes proliferation and Th1/Th2 cytokines. It could also increase NF-AT luciferase activity in Jurkat-NF-AT-luc T cells. The above results suggested that icaritin might be used to treat Th1 dominated immune diseases by interfering T cells activation with mechanism different to CsA. ► Icaritin could dose-dependently inhibit activated murine T cells proliferation. ► Icaritin could down-regulate CD25 expression and inhibit Th1 cytokines IL-2 and IFN-γ production. ► Icaritin could prolong murine allograft skin survival with mechanism different to CsA. ► Icaritin might be used to treat Th1 dominated immune diseases by interfering T cells activation.