Abstract
Helicobacter pylori is a dominant bacterium living in the human gastric tissues. In H. pylori-infected tissues, the infiltrated inflammatory cells produce reactive oxygen species (ROS), leading to gastric inflammation with production of various mediators. According to numerous epidemiological studies, dietary carotenoids may prevent gastric inflammation due to their antioxidant properties. Recent studies showed that antioxidant and anti-inflammatory effects of astaxanthin and β-carotene may contribute to inhibition of H. pylori-induced gastric inflammation. Astaxanthin changes H. pylori-induced activation of T helper cell type 1 response towards T helper cell type 2 response in the infected tissues. Astaxanthin inhibits the growth of H. pylori. Even though astaxanthin reduces H. pylori-induced gastric inflammation, it does not reduce cytokine levels in the infected tissues. β-Carotene suppresses ROS-mediated inflammatory signaling, including mitogen-activated protein kinases and redox-sensitive transcription factors, and reduces expression of inflammatory mediators, including interleukin-8, inducible nitric oxide synthase, and cyclooxygenase-2 in the infected tissues. Therefore, consumption of astaxanthin- and β-carotene-rich foods may be beneficial to prevent H. pylori-induced gastric inflammation. This review will summarize anti-inflammatory mechanisms of astaxanthin and β-carotene in H. pylori-mediated gastric inflammation.