Oxidative stress (OS) in the airway epithelium is associated with cell damage, inflammation, and mitochondrial dysfunction that may initiate or worsen respiratory disease. However, it is unclear whether exogenous antioxidants can provide protection to the airway epithelium from OS. Resveratrol and astaxanthin are nutritional compounds that have shown diverse benefits including protection against OS and inflammation in various situations. The aim of this study was to examine the utility of pre-treatment with resveratrol and astaxanthin to prevent the negative effects of oxidant exposure and restore redox homeostasis in a well-differentiated epithelium grown from primary human nasal epithelial cells (NECs) at the air-liquid interface. Fully differentiated NECs were pretreated with the antioxidants for 24 hours and the cultured epithelia was subsequently exposed to hydrogen peroxide (H2O2) for 1 hour to induce an acute OS. Responses measured included mitochondrial reactive oxygen species (mtROS) generation, redox status (GSH/GSSG ratio), cellular ATP, and signaling pathways (SIRT1, FOXO3, p21, PINK1, PARKIN, NRF2). Following H2O2 exposure, mtROS production increased by 4-fold compared with control (p<0.01) and pre-treatment with resveratrol or astaxanthin reduced this by 50% (p<0.05). H2O2 exposure reduced GSH/GSSG ratio and this decline was prevented by antioxidants pre-treatment. H2O2 exposure caused 2.5-fold increase in p21 mRNA expression compared with control (p<0.05), while a slight decrease in p21 mRNA expression was observed when cells were pre-treated with resveratrol or astaxanthin. Our results demonstrate that antioxidants, resveratrol, and astaxanthin were able to protect cells from an acute OS. These agents show promise that encourages further research.
Keywords: Air-liquid interface culture; Airway epithelium; Antioxidant; Astaxanthin; Mitochondria; Oxidative stress; Resveratrol; Signaling pathways.