Abstract
Proanthocyanidins (PACs) have been proven to exert antioxidant and anti-inflammatory effects. In this study, ultra-performance liquid chromatography (UPLC) coupled with linear ion trap-Orbitrap (LTQ-Orbitrap) high-resolution mass spectrometry was first employed to systematically screen PACs from the roots of Ephedra sinica Stapf, and its ethyl acetate extract (ERE) was found to contain PAC monomers and A-type dimeric proanthocyanidins, which were tentatively identified through characteristic fragmentation patterns. In vitro, the antioxidant activity of ERE was tested through 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. In addition, ERE could inhibit the production of nitric oxide (NO) in lipopolysaccharide (LPS)-induced RAW 264.7 cells. In vivo, the preventative effects on dextran-sulfate-sodium-induced ulcerative colitis in mice was investigated. Mice were administered with ERE for 21 days, and during the last 7 days of the treatment period dextran sulfate sodium (DSS) was used to induce experimental colitis. The results showed that ERE treatment alleviated DSS-induced colitis, which was characterized by decreases in disease activity index (DAI) scores, spleen index and colon levels of TNF-α and IL-6, mitigation in pathological damage and oxidative stress and increases in colon length and IL-10 levels. In conclusion, supplementation of PACs derived from ERE may offer a new strategy for the treatment of ulcerative colitis. Moreover, our research will greatly facilitate better utilization of Ephedra plants.