The Immunosuppressive Activity of Pseudolaric Acid B on T lymphocytes in vitro

Abstract

Pseudolaric acid B (PB) is a major bioactive component extracted from Pseudolarix kaempferi. Traditional medicine practitioners in China have been using the roots of this plant to treat inflammatory and microbial dermatoses for centuries. In this study, the experiments were conducted to investigate immunosuppressive activity of PB on T lymphocytes in vitro. The results show that PB has hypotoxicity on hepatocytes and renal cells assessed by Methyl thiazolyl tetrazoliym (MTT) Assay and selectively inhibits the proliferation of T lymphocytes and antigen-specific T lymphocytes stimulated by concanavalin A and dinitrophenyl-modified spleen cells, respectively. Then, PB also shows suppressive effect on T lymphocytes in mixed lymphocyte reaction. Moreover, PB can depress the production of interleukin-2 (IL-2) secreted by concanavalin A-activated T lymphocytes or dinitrophenyl-modified spleen cells-activated antigen-specific T lymphocytes. It is first found that PB exhibits the inhibitory action on antigen-specific T lymphocytes and on the production of IL-2 from antigen-specific T lymphocytes and selectively inhibits the proliferation of T lymphocytes and the production of IL-2 as well. PB is in need of further study because of its potent immunosuppressive function.

A novel Pseudolaric acid B derivative, Hexahydropseudolaric acid B, exterts an immunomodulatory effect in vitro/in vivo evaluation

“…It has been reported that PAB could inhibit mitogen and alloantigen-induced T cell proliferation and activation (Li et al, 2009;Wei et al, 2013). In the present study, we further measured the activity of HPAB on T cell proliferation in vitro.…”

“…Mixed-leukocyte reaction (MLR) assay was used to assess the effect of HPAB on T cell proliferation induced by alloantigen (Wei et al, 2013). Briefly, C57BL/6 splenic lymphocytes (stimulator cells)…”

“…T cells were purified from the auricular and mandibular lymph nodes (LNs) using immunomagnetic negative selection as described by Wei et al (2013). The purity of T cells was consistently more than 95% as assessed by flow cytometric antibody (BD Biosciences).…”

“…The cytotoxicity of HPB on T cells was assessed by MTT assay as described previously (Wei et al, 2013). The optical density (OD) values were recorded at 570 nm wavelength on a microplate reader (Model 680, Bio-Rad).…”

“…Recent studies have indicated that PAB could play an important role through suppressing T cell proliferation and IL-2 production (Li et al, 2009;Wei et al, 2013). However, the cytotoxicity limits its future clinical application.…”