Characterisation of antioxidant, anti-inflammatory, and immunomodulatory activities of polysaccharides derived from Duchesnea indica (Andrews) Focke

Duchesnea indica (Andrews) Focke is a traditional Chinese medicine used as antiviral, astringent, anti-inflammatory, and antitumor agent in various clinical settings. In the present work, D. indica polysaccharides (DIPs) were assessed following hot water extraction, ethanol precipitation, and deproteinisation. The molecular weight of DIPs was estimated by GPC as 3.018 x 10(5) Da. HPLC results indicated that DIPs were mainly composed of D-mannose, D-ribose, L-rhamnose, D-glucosamine, D-glucuronic acid, D-galacturonic acid, D-glucose, D-galactose, and D-arabinose, in a molar ratio of 1.54:0.50:3.83:1.56:1.33:3.39:23.69:15.26:8.86, respectively. With regard to antioxidant activities, DIPs had a strong radical scavenging capacity and protective effect against DNA damage. Furthermore, DIPs presented a significant anti-inflammatory ability in vivo, using both xylene-induced ear oedema and lambda-carrageenan-induced paw oedema models. Lastly, DIPs significantly inhibited generation of NO and cytokines (TNF-a and IL-6) in LPS-induced RAW264.7 macrophages. These data strongly indicate that DIPs could be explored as potentially natural antioxidant, anti-inflammatory, and immunomodulatory agents. (C) All Rights Reserved