Paeoniflorin selectively inhibits LPS-provoked B-cell function.

B cells are important in the development of autoimmune disorders through mechanisms involving dysregulated polyclonal B-cell activation, production of pathogenic antibodies, and targeting which reduces inflammation and tissue damage effectively but often leads to patients suffering from secondary infection. Paeoniflorin (PF) is the main substance of the Total glucosides of peony and has been widely used to treat autoimmune diseases for years. However, whether PF affects B cell activity remains unknown. In this study, using purified murine spleen B cells, we analyzed the effects of PF on B-cell function in vitro. We found that PF inhibited the expression of CD69/CD86 and the proliferation of B cells stimulated by LPS. In addition, PF reduced the B-cell differentiation and immunoglobulin production that was stimulated by LPS. Interestingly, PF did not alter B-cell activation and proliferation provoked by anti-CD40 or IL-4. These results indicated for the first time that PF inhibits B-cell activation, proliferation and differentiation by selectively blocking the LPS/TLR4 signaling pathway. Furthermore, our data suggest that PF selectively inhibits inflammation and tissue damage mediated by LPS-activated B cells but does not alter CD40/CD40L- or IL-4-provoked B-cell function in autoimmune diseases treatment, which might aid in protecting patients from secondary infection.