OBJECTIVE: To investigate whether the phenyl-thiophenyl propenone RK-I-123 suppresses interleukin-8 (IL-8) expression and activation of mitogen-activated protein kinases (MAPKs) and transcription factors (nuclear factor-κB [NF-κB] and activator protein-1 [AP-1]) by reducing reactive oxygen species (ROS) levels in Helicobacter pylori-infected gastric epithelial cells. MATERIAL: Helicobacter pylori in Korean isolates, human gastric epithelial AGS cells. TREATMENT: AGS cells pretreated with or without RK-I-123 were cultured in the presence of H. pylori at a bacterium/cell ratio of 300:1. METHODS: Reactive oxygen species and IL-8 levels were determined by dichlorofluorescein fluorescence and enzyme-linked immunosorbent assay. The IL-8 mRNA expression was analyzed by the real-time reverse transcription-polymerase chain reaction (RT-PCR). The MAPK and IκBα levels were determined by western blotting. The activation of NF-κB and AP-1 was determined by the electrophoretic mobility shift assay. RESULTS: Helicobacter pylori induced an increase in ROS and IL-8 expression and activation of MAPKs and transcription factors (NF-κB and AP-1) together with the degradation of IκBα in AGS cells, all of which were inhibited by RK-I-123. CONCLUSIONS: The RK-I-123 suppressed the H. pylori-induced IL-8 expression and activation of MAPKs, NF-κB, and AP-1 by reducing ROS levels in AGS cells. The RK-I-123 may be a potential candidate for the treatment of H. pylori-induced gastric inflammation.
OBJECTIVE: To investigate whether the phenyl-thiophenyl propenone RK-I-123 suppresses interleukin-8 (IL-8) expression and activation of mitogen-activated protein kinases (MAPKs) and transcription factors (nuclear factor-κB [NF-κB] and activator protein-1 [AP-1]) by reducing reactive oxygen species (ROS) levels in Helicobacter pylori-infected gastric epithelial cells. MATERIAL: Helicobacter pylori in Korean isolates, human gastric epithelial AGS cells. TREATMENT: AGS cells pretreated with or without RK-I-123 were cultured in the presence of H. pylori at a bacterium/cell ratio of 300:1. METHODS:Reactive oxygen species and IL-8 levels were determined by dichlorofluorescein fluorescence and enzyme-linked immunosorbent assay. The IL-8 mRNA expression was analyzed by the real-time reverse transcription-polymerase chain reaction (RT-PCR). The MAPK and IκBα levels were determined by western blotting. The activation of NF-κB and AP-1 was determined by the electrophoretic mobility shift assay. RESULTS:Helicobacter pylori induced an increase in ROS and IL-8 expression and activation of MAPKs and transcription factors (NF-κB and AP-1) together with the degradation of IκBα in AGS cells, all of which were inhibited by RK-I-123. CONCLUSIONS: The RK-I-123 suppressed the H. pylori-induced IL-8 expression and activation of MAPKs, NF-κB, and AP-1 by reducing ROS levels in AGS cells. The RK-I-123 may be a potential candidate for the treatment of H. pylori-induced gastric inflammation.