Structure Characterization and Anti‐Rheumatoid Arthritis Activity of a Polysaccharide from Notopterygium incisum

Notopterygium incisum is a traditional Chinese medicine that is commonly used to treat rheumatoid arthritis. Polysaccharides from N. incisum can be one of its main active components. However, there have been little investigations on N. incisum polysaccharides.A novel polysaccharide named NIP is extracted from N. incisum with a molecular weight of 2.34 × 106 Da. NIP, composed of arabinose, galactose, glucose, and galacturonic acid, is linked by methyl esterified 1,4-linked α-galacturonic acid, 1,6-linked β-galactose, 1,5-linked α-arabinose, and 1,4,6-linked β- glucose. In vitro, NIP can inhibit the NO production of LPS-stimulated RAW264.7 cells. In vivo, NIP relieves toe redness and swelling of AIA rats, reduces the release of inflammatory factors in the serum, and inhibits the activation of NF-κB and JAK/STAT3 signaling pathways. In addition, NIP can effectively decrease oxidative stress, reverse intestinal flora imbalance, and promote butyric acid-producing bacteria's proliferation to exert anti-RA activity.NIP may be recommended as a functional food that can alleviate the damage of rheumatoid arthritis.