Periplocoside E (PSE)
Periplocoside E (PSE), a pregnane glycoside with potent immunosuppressive activity used for treating rheumatoid arthritis, had been identified from a traditional Chinese herb medicine, Periploca sepium Bge. It has been shown that PSE in a dose-dependent manner significantly inhibited the proliferation of splenocytes induced by concanavalin A, and mixed lymphocyte culture reaction at no cytotoxic concentrations. Administration of PSE suppressed a delayed type hypersensitivity reaction, and ovalbumin induced antigenspecific immune responses in mice. In vivo treatment with PSE dose-dependently suppressed ovalbumin-induced proliferation and Th1 cytokine (IL-2 and IFN-γ) production from splenocytes in vitro. In the study of Zhu et al., PSE was shown to dose-dependently inhibit anti-CD3 induced primary T cell proliferation, activation for IL-2R (CD25) expression, and IFN-γ and IL-2 production at the transcriptional level. PSE was highly specific,significantly inhibited the activation of ERK and JNK. These results demonstrated that Periploca sepium Bge can be used for treatment of T cell-mediated disorders, such as autoimmune diseases