Salvia miltiorrhiza stems and leaves total phenolic acids combination with tanshinone protect against DSS-induced ulcerative colitis through inhibiting TLR4/PI3K/AKT/mTOR signaling pathway in mice

Salvia miltiorrhiza Bge. as a traditional Asian medicinal plant, roots and rhizomes (Danshen) are used to treat chronic hepatitis and coronary heart disease. In recent years, the medicinal value of S. miltiorrhiza stems and leaves total phenolic acids extract (JF) similar to roots and rhizomes has received increasing attention. S. miltiorrhiza roots and rhizome tanshinone extract (DT) has a good anti-inflammatory effect. To explore the therapeutic effect and possible molecular mechanisms of JF and DT alone or in combination on dextran sulfate sodium (DSS)-induced colitis mice. Colitis was induced by received 2% DSS in drinking water for 7 consecutive days. Then mice were administered orally for 7 days. Disease activity index (DAI) scores and body weight were recorded daily. After the end of the experiment, colon was removed, colon length was measured and histopathological analysis was performed. Inflammatory factors expression was determined by ELISA, its mRNA expression was detected by real-time quantitative PCR, and the expression of related proteins on TLR4/PI3K/AKT/mTOR signal was analyzed by Western blot. Treatment with JF and DT alone or in combination reduced DAI scores, increase body weight, improved colon shortening, and decreased colon histology scores. In addition, the expression level of inflammatory factors was inhibited. The combination of JF and DT had a better inhibitory effect on inflammatory factors compared to JF alone. We also found that DT alone and JF combined with DT inhibited TLR4/PI3K/AKT/mTOR signaling-related proteins expression levels (including TLR4, p-PI3K p110α/PI3K p110α, p-AKT (ser473)/AKT, mTOR, p-mTOR, NF-κB p65), showing an effective anti-inflammatory effect. We demonstrated for the first time that, JF and DT alone or in combination effectively ameliorated DSS-induced ulcerative colitis in mice, possibly by inhibiting the TLR4/PI3K/AKT/mTOR signaling pathway.