Acta Pharmacologica Sinica 2006 April; 27 (4): 485-490; doi: 10.1111/j.1745-7254.2006.00284.x

Aim: To determine whether deguelin can regulate the expression of nuclear factor kappa B (NF-kB) binding protein (IkBα) in U937 human leukemia cells and Raji human B lymphoma cells.

Methods: The localization of IkBα protein was investigated by using an immunofluorescence method. The expression of IkBα and NF-kB /p65 proteins in Raji and U937 cells were investigated by using Western blotting. Apoptosis was detected through annexin V/PI double-labeled cytometry.

Results: IkBα localized in the cytoplasm in untreated and deguelin-treated cells. After treatment with tumor necrosis factor a (TNF-α) or deguelin plus TNF-α for 15 min, there was a substantial reduction in the amount of IkBα protein. The expression of IkBα was downregulated by deguelin in Raji and U937 cells. Deguelin induced apoptosis in U937 cells.

Conclusion: Deguelin inhibited the expression of IkBa protein in U937 and Raji cells. The anti-proliferative activity of deguelin is related to the signal pathway of NF-kB.

Keywords: deguelin; IkBα; nuclear factor kappa B; tumor necrosis factor-α; apoptosis; Raji cells; U937 cells