Abstract:To study the protective effect and mechanism of astaxanthin (AST) on oral epithelial injury, an arecoline (ARC) induced oral mucosal injury rat model was established. The pathological morphology, the accumulation of collagen fibers, and changes in human early growth response factor 1 (EGR1) in rat oral mucosal tissue was observed. The changes in tight junction related proteins ZO-1 and Occludin, mitochondrial morphology, mitochondrial membrane potential (MMP), mitochondrial reactive oxygen species (mtROS), and EGR1 in human oral keratinocyte (HOK) cells induced by ARC, were measured. And the binding of AST and EGR1 was predicted through molecular docking. The results on pathological of oral mucosal tissues showed that compared with the model group, the symptoms of thinning oral mucosal epithelium and short epithelial nail was improved in the AST intervention group. The relative collagen area and Collagen I area under the mucosa were significantly reduced by 9.84% and 23.01%, respectively. In vitro experiments, the results showed that AST improved the abnormal localization of ZO-1 and Occludin proteins in ARC-induced HOK cells; the abnormal mitochondrial morphological, the decreased level of MMP, and the excessive generation of mtROS were also improved. In addition, AST inhibited the expression level of EGR1 in ARC-induced HOK cells, and significantly downregulating 24.53% at the cellular level. The molecular docking results showed that the docking binding energy between AST and EGR1 was -6.8697 kcal/mol, and had two hydrogen bonding interactions. In summary, AST may improve ARC induced oral mucosal injury by regulating EGR1 and mitochondrial function, and is expected to be developed as a functional food for protecting oral mucosa.