Author(s)

Minoru Kikuchi, Shusuke Kamimura, Masaaki Nomura, Tatsuo Takahashi, Nobuyoshi Hagino, Shinjiro Kobayashi

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Tetrandrine (1 μM), a bis-benzylisoquinoline alkaloid isolated from Stephania tetrandra S Moore, signifi-cantly decreased tumor necrosis factor alpha (TNFα; 10 ng/ml)-induced increase in the number of micro vessels that budded from cultured rat choroidal explants. Tetrandrine also decreased the TNFα-induced in-crease in the number of cells composing the microvessels. Ammonium pyrrolidine dithiocarbamate (APDC; 0.1-0.3 μM), an inhibitor of nuclear factor-κB (NF-κB), decreased the TNFα-induced increase in the number of microvessels in a concentration-dependent manner. TNFα increased the phosphorylation and degradation of inhibitor of NF-κB (IκBα), as well as increasing the DNA-binding activity of NF-κB in choroidal explants. TNF? induced an increase of vascular endothelial growth factor (VEGF)-A mRNA, but not VEGF-C mRNA or VEGF-D mRNA. TNFα-induced angiogenic action was inhibited by treatment of VEGF-A antibody in cultured choroidal capillaries. Tetrandrine inhibited the TNFα-induced increases of phosphorylation and degradation of IκBα, and reduced the TNFα-induced increase of DNA-binding activity of NF-κB in chor-oidal explants. In conclusion, tetrandrine inhibits TNFα-induced activation of NF-κB in the choroidal capil-laries via inhibition of TNFα-induced phosphorylation of IκBα.

Choroidal Neovascularization, Anti-angiogenesis, Tetrandrine, Tumor Necrosis Factor α, NF-κB Activity, Phosphorylation of IκBα

Kikuchi, M. , Kamimura, S. , Nomura, M. , Takahashi, T. , Hagino, N. and Kobayashi, S. (2010) Inhibitory Actions of Tetrandrine on Tumor Necrosis Factor α-Induced NF-κB Activation in Neovascularization of Cultured Choroidal Explants. Chinese Medicine, 1, 75-83. doi: 10.4236/cm.2010.13015.