Exploring the mechanism of chondroitin sulfate-selenium nanoparticles in improving Alzheimer's disease: Insights from intestinal flora evaluation

In this study we have investigated the effect of chondroitin sulfate-selenium nanoparticles (CS@Se) on Alzheimer's disease (AD) mice using 16S rDNA technique. We randomly divided 30 SPF grade male C57BL/6 J mice into 6 groups according to random number table method. The AD mouse model was established by subcutaneous injection of D-galactose (D-gal) combined with gavage of AlCl₃ for 30 consecutive days, and then drug intervention was performed in the administration group for 40 consecutive days. The findings demonstrated several positive effects of CS@Se on AD mice. Firstly, CS@Se improved spatial learning and memory problems and reduces anxiety in AD mice. It also significantly reduced pyramidal cell arrangement disorder and rupture, leading to an improvement in synaptic structure damage between hippocampal neurons. Furthermore, CS@Se reduced mitochondrial swelling and vacuolation while increasing neuron survival in AD mice. Moreover, CS@Se significantly impacted the diversity and richness of intestinal flora in AD mice. It increased the relative abundance of Firmicutes and Actinobacteria while reducing the relative abundance of Bacteroidetes and Proteobacteria. In conclusion, CS@Se effectively reduced the breakdown of hippocampal pyramidal cells, improved the superfiber structure of hippocampal neurons, and restored intestinal flora balance, ultimately contributing to improving learning and memory abilities and alleviating anxiety in AD mice.