Anti-aging and diversity of intestinal flora in mice

Salvia miltiorrhiza Bunge., as a medicinal and edible plant, was rich in bioactive polysaccharides. To explore the digestive characteristics and anti-aging effect of Salvia miltiorrhiza polysaccharide (SMP), the SMP was prepared through water-extraction and alcohol-precision method. The molecular weight (Mw) of SMP was 1.28\u00d7106 Da. The monosaccharide composition and proportion were rhamnose (Rha):galacturonic acid (GalA):galactose (Gal):arabinose (Ara)=6.15:55.98:21.27:16.69. The results of simulated digestion in vitro showed that SMP was not degraded in saliva, gastric juice and intestinal juice. Cell experiments in vitro showed that SMP could improve the phagocytic ability of RAW264.7 macrophages, promote the secretion of nitric oxide (NO), and improve cell viability. Y maze test and new object recognition test showed that SMP could improve the working memory impairment of aging mice. Hematoxylin-eosin (H-E) staining showed that SMP could alleviate the pathological changes in the hippocampus of aging mice. SMP could also increase the activity of superoxide dismutase (SOD) in serum and brain tissue, decrease the content of malondialdehyde (MDA) in serum and brain tissue, decrease the levels of interleukin-6 (IL-6) and tumor necrosis factor-\u03b1 (TNF-\u03b1) in brain tissue, and increase the content of short-chain fatty acids (SCFAs) in the intestine. In addition, SMP could also regulate the intestinal flora structure, including increasing the relative abundance of Firmicutes and Bacteroidetes, and decreasing the relative abundance of Proteobacteria. To lay a foundation for the development of healthy food and medicine related to Salvia miltiorrhiza.