Isoquercitrin suppresses the expression of histamine and pro-inflammatory cytokines by inhibiting the activation of MAP Kinases and NF-κB in human KU812 cells / 中国天然药物

Mast cells and basophils are multifunctional effector cells that contain abundant secretory granules in their cytoplasm. Both cell types are involved in a variety of inflammatory and immune events, producing an array of inflammatory mediators, such as cytokines. The aim of the study was to examine whether isoquercitrin modulates allergic and inflammatory reactions in the human basophilic KU812 cells and to elucidate its influence on the phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB activation. The KU812 cells were stimulated with phorbol-12-myristate 13-acetate plus the calcium ionophore A23187 (PMACI). The inhibitory effects of isoquercitrin on the productions of histamine and pro-inflammatory cytokines in the stimulated KU812 cells were measured using cytokine-specific enzyme-linked immunosorbent (ELISA) assays. Western blotting analysis was used to assess the effects of isoquercitrin on the MAPKs and NF-κB protein levels. Our results indicated that the isoquercitrin treatment of PMACI-stimulated KU812 cells significantly reduced the production of histamine and the pro-inflammatory cytokines, such as interleukin (IL)-6, IL-8, IL-1β, and tumor necrosis factor (TNF)-α. The treated cells exhibited decreased phosphorylation of extracellular signal-regulated kinase (ERK), revealing the role of ERK MAPK in isoquercitrin-mediated allergy inhibition. Furthermore, isoquercitrin suppressed the PMACI-mediated activation of NF-κB in the human basophil cells. In conclusion, the results from the present study provide insights into the potential therapeutic use of isoquercitrin for the treatment of inflammatory and allergic reactions.

The Application of Countercurrent Chromatography with Aqueous Two Phase System in the Separation of Proteins / 中国生物工程杂志

Aqueous two phase system(ATPS) provides a gentle, non-denaturing separation environment for proteins, enzymes. While high-speed countercurrent chromatography (HSCCC) is a liquid-liquid partition chromatography which uses centrifugal force to hold the stationary phase and facilities the mobile phase partitioning through the stationary phase, it can produce high separation efficiency with large sample loading capacity. However, the ordinary HSCCC apparatus (Type J ) fails to retention a satisfactory stationary phase of ATPS because of its high viscosity and low interfacial tension. Nevertheless, the later designed cross-axis planetary centrifuge system(X-CPC) can produce a greater lateral force field and enhances significantly the retention of the ATPS stationary phase. A review of the application of these CCC techniques with ATPS in the separation of proteins was given. Meanwhile, new techniques such as pH-peak focusing CCC and dye-ligand affinity CCC and some new CCC column design for improvement of separation efficiency and retention of ATPS stationary phase are introduced.