Studies On Screening Ent-Kaurene Diterpenoids From Isodon Serra And The Cell-immunosuppressive Mechanism Of The Active Components

In these studies, after set BALB/c mouse splenic lymphocyte as a target, we screened active components from ent-Kaurene Diterpenoids from Isodon Serra, which had cell-immunosuppressive effects. And we investigated the immunosuppressive mechanism of the active components.The results showed that three ent-Kaurene Diterpenoids could effectively suppress the murine splenic T and B lymphocytes overproduction. Enmein, Nodosin, Oridonin, which had concentration and time dependency inhibitive effects, were the most sensitive components with highest IC50/EC50 values. Results further suggested that they should depress the murine ear swelling extent and the level of Interleukin-2 in blood serum. This inhibitive activity was due to interfering DNA replication in G1-S or S-G2/M stages and to regulating cell cycle, according to Flow cytometry analyses (FCAS) results. The studies showed that they could inhibit CD25+ T lymphocytes and decrease the CD4+/CD8+ T lymphocytes level in order to inhibit the over-increased T lymphocytes. Results of ELISA and RT-PCR indicated that the active components could inhibit IL-2, IFN-γmRNA and decrease the level of IL-2 and IFN-γ.