Magnesium lithospermate B mediates anti-inflammation targeting activator protein-1 and nuclear factor-kappa B signaling pathways in human peripheral T lymphocytes

The activation of T lymphocytes contributes to the inflammatory processes of atherosclerotic diseases. Danshen is a traditional Chinese medicine and has shown therapeutic effects in patients with cardiovascular and cerebrovascular diseases. We investigated the effects of aqueous extract of Danshen (magnesium lithospermate B (MLB)) on phorbol 12-myristate acetate + ionomycin and anti-CD3 + anti-CD28 monoclonal antibody-activated T cells. We showed that MLB inhibited interleukin (IL)-2, IL-4, tumor necrosis factor-alpha and interferon-gamma production from activated T cells. The expressions of T cell activation markers CD 25 and CD 69 were effectively reduced. EMSA analysis indicated that MLB down-regulated activator protein-1 (AP-1), nuclear factor kappa B (NF-κB) and octamer binding transcription factor (Oct-1) DNA-binding activity. In addition, MLB inhibited c-jun N-terminal kinase (JNK) but not extracellular signal regulated protein kinase activity. MLB also inhibited IκBα degradation, nuclear translocation of p65 and p50 as well as decreased IκBα kinase (IKK) activity. Through suppressing JNK–AP-1, IKK–IκBα–NF-κB and Oct-1 signaling pathways by MLB in activated T cells, our results provide support for efficacy of MLB in inflammatory diseases and raise its therapeutic potential in activated T cell-mediated pathologies.

► Magnesium lithospermate B (MLB) is the aqueous extract of dried root of Salvia miltiorrhiza.
► MLB inhibited interleukin (IL)-2, IL-4, TNF-α and INF-γ production from activated T cells.
► MLB inhibited the expressions of T cell activation markers, CD 25 and CD 69.
► JNK–AP-1, IκBα-NF-κB and Oct-1 signaling pathways were suppressed by MLB in activated T cells.
► Our results provide support for the efficacy of MLB in inflammatory diseases.