Protective Effects of Salvianolic Acid A against Dextran Sodium Sulfate-Induced Acute Colitis in Rats

Abstract

Salvianolic acid A (SAA) is an active phenolic acid derived from <i>Salvia miltiorrhiza</i> Bunge (Danshen). To explore whether SAA has a therapeutic effect against inflammatory bowel disease (IBD), an acute colitis model was induced in rats by administering 3% dextran sodium sulphate (DSS) for one week. SAA in doses of 4 and 8 mg/kg/day was given by tail vein injection during DSS administration. Both dosages of SAA ameliorated the colitis symptoms, with decreases observed in the disease activity index. A high dosage of SAA (8 mg/kg/day) promoted a longer colon length and an improved colonic tissue structure, compared with the DSS-treated rats not receiving SAA. SAA dose-dependently decreased colonic gene expression of pro-inflammatory cytokines (<i>IL-1&beta;</i>, <i>MCP-1</i> and <i>IL-6</i>). Moreover, a high dosage of SAA protected against DSS-induced damage to tight junctions (TJ) in the rats&rsquo; colons, by increasing TJ-related gene expression (<i>ZO-1</i> and <i>occuldin</i>). Finally, using 16S rRNA phylogenetic sequencing, we found that SAA modulated gut microbiota imbalance during colitis by increasing the gut microbial diversity as well as selectively promoting some probiotic populations, including <i>Akkermansia</i> spp. Our study suggests that SAA is a promising candidate for the treatment of IBD.