Abstract: The purpose of this study was to investigate the in vivo antioxidant properties of salvianolic acid B and its effect on the intestinal microbial community in mice. Kunming mice were administered by gavage with salvianolic acid B solution at low (30 mg/kg mb), medium (60 mg/kg mb), and high (120 mg/kg mb) doses for 42 successive days. At 24 h after the last administration, body mass was recorded, the organ coefficients of heart, liver, kidney and spleen were calculated, and the antioxidant indexes of blood and liver were detected. The results showed that the organ coefficients of liver in the medium-dose, high-dose and VC control groups were significantly lower than that in the normal group (P < 0.05). Similarly, the organ coefficient of kidney in the high-dose group was significantly lower than that in the normal (P < 0.05) and VC control groups (P < 0.01). The antioxidant indexes showed that compared with the normal group, MDA content was significantly decreased in the serum of mice in the middle-dose group (P < 0.05) as well as the high-dose and VC control groups (P < 0.01), and MDA content in the liver was also significantly decreased in the high-dose group (P < 0.05). In contrast, serum glutathione (GSH) levels in the high-dose and VC groups were significantly increased (P < 0.05). Through high-throughput sequencing analysis, the structure of intestinal flora in mice from each group was dominated by Bacteroides, Firmicutes, Proteobacteria, Verrucomicrobia and Actinobacteria. According to LEfSe analysis, the relative abundances of Bacteroides vulgatus and Parabacteroides distasonis were significantly increased in the three dose groups relative to the normal group (P < 0.05), decreasing with increasing dose. Therefore, salvianolic acid B can improve the antioxidant capacity and the intestinal environment of mice, increasing the number of beneficial bacteria. This finding provides new ideas for the treatment of cardiovascular diseases with salvianolic acid B.

Key words: salvianolic acid B, antioxidant, intestinal microbe, Bacteroides vulgatus, Parabacteroides distasonis