A pectic polysaccharide from Ligusticum chuanxiong promotes intestine antioxidant defense in aged mice

•A pectic polysaccharide LCP-II-I was purified from rhizome of Ligusticum chuanxiong.•Treatment with LCP-II-I in SW480 cells promotes the expression of antioxidant enzymes.•LCP-II-I could significantly promote the intestine antioxidant defense in vivo. The extensive prospects of polysaccharides in medicine and pharmaceuticals have elicited much interest. Ligusticum chuanxiong polysaccharides, previously extracted as neutral polysaccharides, exhibit antioxidant, anticancer, andantibacterial capacities in vitro. Here we show one pectic polysaccharide extracted from rhizome of L. chuanxiong(LCP-II-I). Structural analysis indicated its long homogalacturonan region is interrupted by rhamnogalacturonan type I, with arabinan and arabinogalactan type I as side chains. Intake of the LCP-II-I significantly promoted the expression of antioxidant enzymes and their master regulator PGC-1α, resulting in higher antioxidant capacity in jejunum and cecum of aged mice. Consistently, treatment with LCP-II-I promotes antioxidant enzymes expression, and protects SW480 cells against H2O2 induced oxidative stress. Our work isolates and identifies a pectic polysaccharide, LCP-II-I, and reveals its potential application in antioxidant defense, which will be important for oxidative stress related disorders treatment in aging intestine.