Abstract: To explore the molecular mechanisms of the antagonistic effect of selenium on aluminum-induced oxidative stress and inflammation in the spleen of mice,mice were divided into four groups as follows:Blank control group,aluminum group,selenium group,and selenium＋aluminum group.The spleen tissues of mice were taken 4 weeks after oral administration.Pathological changes of spleen were evaluated by HE staining and immunofluorescence staining of pathological tissue sections.Glutathione peroxidase (GPx),reduced glutathione (GSH),malondialdehyde (MDA) and nitric oxide (NO) levels were measured by respective commercial kits.IL-1β,IL-4,IL-6,IFN-γ,HO-1 and NF-κB mRNA expression levels were quantified by Real-time PCR,and p-p65,IL-1β and HO-1 proteins expression level were detected by Western blotting.The results showed that aluminum treatment could increase the local cell spacing of the spleen,decrease the number of lymphocytes,accompanied by an increase in neutrophils and red blood cell infiltration.Moreover,the activity of GPx and the content of NO and GSH were reduced,and the content of MDA was significantly increased.Likewise,the mRNA and proteins expression levels of inflammation-related such as IL-1β and NF-κB were increased,indicating oxidative damage and inflammatory reactions to the spleen.Selenium could alleviate the toxicity of aluminum,increase the activity of GPx and the content of other antioxidants,reduce the production of MDA and the expression of mRNA and protein of inflammation related genes.The results showed that aluminum could damage the spleen by inducing oxidative stress and inflammatory reaction in mice,and selenium could alleviate the spleen injury induced by aluminum.The mechanism might be related to selenium enhancing the antioxidant level of spleen and protecting spleen against tissue injury induced by oxidative stress and inflammatory reaction.

Key words: selenium; aluminum; spleen; oxidative stress; inflammation