Antioxidant and Immunomodulatory Activities In Vitro of a Neutral Polysaccharide from Ginger (Zingiber Officinale)

Abstract In this study, crude polysaccharides from ginger are obtained by ultrasonic‐assisted enzymatic extraction. After deproteinization using Sevag method, dialysis, and isolation on a DEAE52‐cellulose column and a Sephadex G‐100 column, a neutral heteropolysaccharide purified ginger polysaccharide (pGP) with the molecular weight of 62 500 Da is obtained. Four sugar residues are confirmed in pGP, including →3)‐α‐L‐Ara f ‐(1→, →2)‐α‐L‐Rha p , →3)‐β‐D‐Gal p ‐(1→, →6)‐α‐D‐Glc p ‐(1→. Antioxidant activities analysis confirms that pGP possess good scavenging effects on DPPH, 2,2‐azino‐bis‐3‐ethylbenzthiazoline‐6‐sulphonic acid, and hydroxyl radicals. In addition, pGP significantly stimulates the phagocytic activity of RAW264.7 cells and has strong protection effect against H 2 O 2 ‐induced damage. These results show that pGP can be used as a potential antioxidant agent in medicine or functional food.