3-Deoxy-2β16-dihydroxynagilactone E a natural compound from

摘要

B6 preferentially inhibited the cytokine-induced phosphorylation of STAT3. a Chemical structure of 3-deoxy-2β, 16-dihydroxynagilactone E (B6). b, c Effects of B6 on the luciferase activities of the HepG2/STAT3-luciferase or HepG2/STAT1-luciferase reporter gene-containing cells. The luciferase reporter gene-containing cells were treated with B6 at the indicated concentrations for 1 h, followed by stimulation with IL-6 (10 ng/mL) or IFN-γ (10 ng/mL) for 4 h, and then the luciferase activities were measured. These experiments were performed in triplicates. Data shown are mean ± SD (n = 3). ns, not significant, **P < 0.01 and ***P < 0.001 versus the control group without B6 but with cytokine stimulation. Best-fit curve was determined using Prism software and was used to calculate the IC50 value. d–f Effects of B6 on the phosphorylation of STAT1 and STAT3. HeLa cells were pretreated with B6 at indicated concentrations for 1 h before stimulation with IL-6 (10 ng/mL), IFN-γ (10 ng/mL), or IFN-α (1000 U) for 15 min. The cells were then lysed and analyzed by Western blotting using antibodies as indicated. Densitometric quantification of phospho-proteins normalized to total proteins was graphed below the corresponding Western blots. WB band density was quantified three times. Data shown are mean ± SD (n = 3). ns, not significant, **P < 0.01, ***P < 0.001