Inhibitory Effects Of Astaxanthin On Î'eta-amyloid Induced Toxicity In C. Elegans And The Underlined Mechanisms

In this study, the effect of astaxanthin(AST) on Aβ induced-toxicity is studied in AD c. elegans model. The effects of AST on paralysis rate and related indicators of oxidative stress, such as the levels of reactive oxygen species(ROS) and reduced glutathione(GSH), the expression of superoxide dismutase(SOD) and catalase(CTL), as well as the deposition of Aβ were studied.The results showed that AST inhibited the paralysis induced by Ab in AD c.elegans models. AST treatment significantly inhibited the raise of ROS levels and decrease of GSH level induced by Aβ. The analysis of related genes important for antioxidant system by RT-PCR showed that the expression levels of sod-1 gene and ctl-2 were up-regulated by Ab, while the expressions of sod-2, sod-3, sod-4, ctl-2and ctl-3 had no obvious variation. AST treatment significantly downregulated the upregulation of sod-1 expression. The results indicated that AST significantly inhibited the oxidative stress caused by Aβ in AD nematodes. Moreover, the staining of Ab fiber in AD nematodes showed that AST treatment significantly reduced the Aβ deposition in the animals.In summary, AST significantly inhibited the paralysis induced by Aβ in AD nematodes. And AST may inhibit Aβ toxicity by reducing oxidative stress and decreasing Aβ deposition.