Curcumin suppresses gastric NF-κB activation and macromolecular leakage inHelicobacter pylori-infected rats

Abstract

To investigate whether curcumin could attenuate nuclear factor (NF)-kappaB p65 expression and macromolecular leakage in the gastric mucosa of Helicobacter pylori (H. pylori)-infected rats. Twenty-five male Sprague-Dawley rats were equally divided into five groups: control rats (Control), control rats supplemented with 600 mg/kg curcumin, H. pylori-infected rats (Hp), H. pylori-infected rats supplemented with 200 mg/kg curcumin (Hp + curI), and H. pylori-infected rats supplemented with 600 mg/kg curcumin (Hp + curII). In H. pylori-infected groups, rats were inoculated with H. pylori suspension twice a day at an interval of 4 h for 3 d. Two weeks later, 200 or 600 mg/kg curcumin was given once daily to curcumin-supplemented groups for 7 d. On the day of the experiment, macromolecular leakage in gastric mucosa was examined by intravital fluorescence microscopy. The stomach tissue was removed to examine NF-kappaB p65 expression in gastric epithelial cells by immunohistochemistry. The expression of NF-kappaB p65 in gastric epithelial cells and the macromolecular leakage from gastric mucosal microcirculation significantly increased in the Hp group compared with the Control group. The percentages of NF-kappaB p65 immunoreactive cells in Control and Hp groups were 10.72% +/- 2.10% vs 16.02% +/- 2.98%, P = 0.004, respectively. The percentages of macromolecular leakage in Control and Hp groups were 10.69% +/- 1.43% vs 15.41% +/- 2.83%, P = 0.001, respectively. Curcumin supplementation in Hp + curI and Hp + curII groups significantly decreased NF-kappaB p65 immunoreactive cells and macromolecular leakage compared with results in the Hp group. The percentages of NF-kappaB p65 immunoreactive cells in Hp + curI and Hp + curII groups were 11.79% +/- 2.13% (P = 0.017) and 11.42% +/- 1.68% (P = 0.010), respectively. The percentages of macromolecular leakage in Hp + curI and Hp + curII groups were 12.32% +/- 2.13% (P = 0.025) and 12.14% +/- 1.86% (P = 0.018), respectively. H. pylori-induced gastric inflammation in rats is associated with increased NF-kappaB activation and macromolecular leakage which can be reduced by curcumin supplementation.