Nobiletin Inhibits Helicobacterium pylori Infection-Induced Gastric Carcinogenic Signaling by Blocking Inflammation, Apoptosis, and Mitogen-Activated Protein Kinase Events in Gastric Epithelial-1 Cells

Helicobacter pylori causes a Gram-negative bacterial infection that can increase the risk of gastric cancer. Consequently, meticulous prevention of an H. pylori infection is significant for averting gastric cancer in humans. Nobiletin, an important dietary polymethoxylated flavonoid in citrus fruits, possesses multidimensional pharmaceutical properties, including its ability to act as an anticancer, anti-inflammatory, antioxidative, cardiovascularly defensive, neuroprotective, and antimetabolic agent. Our study evaluates the role of nobiletin in inflammation-mediated gastric carcinogenic signaling of H. pylori-arbitrated coculture in the human gastric epithelial (GES)-1 cell line. Our results show that the culture system of H. pylori-tainted GES-1 cells demonstrates maximum fabrication of reactive oxygen species (ROS), mediating DNA injury and augmenting nuclear fragmentations. Treatment with nobiletin reduces ROS levels and apoptotic morphological changes by dual staining and decreases levels of lipid peroxides and glutathione content in H. pylori-infected GES-1 cells. Phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT)/phosphatase and tensin homolog signaling have been implicated to affect cell endurance, inflammation, proliferation, and carcinogenic activity in gastric GES-1 cells. We find that nobiletin strongly impedes tumor necrosis factor-α, interleukin-6, cyclooxygenase-2, PI3K, AKT, and mitogen-activated protein kinase molecules, including p38, extracellular receptor kinase 1, and c-Jun amino-terminal expression in H. pylori-infected GES-1 cells. We conclude that nobiletin potentially impedes H. pylori infection and its related activation, likely preventing H. pylori infection-mediated gastric cancer.