Chemical Characterization and In Vitro Anti-Cancer Activities of a Hot Water Soluble Polysaccharide from Hulless Barley Grass
Yijuan Xu, Chuangchuang Zhang, Qi Meng, Wuyang Huang, Zhongquan Sui, Harold Corke
Abstract
Hulless barley grass may confer many health benefits attributed to its bioactive functional components, such as polysaccharides. Here, a hot water soluble polysaccharide was extracted from hulless barley grass, and its chemical characterization and in vitro anti-cancer activities were investigated. The yield of hulless barley grass polysaccharide (HBGP) was 2.3%, and the purity reached 99.1% with a polydispersity index (PDI) of 1.11 after purification by a diethylaminoethyl cellulose (DE-32) column and an S-400 high resolution (HR) column. The molecular weight and number-average molecular weight of HBGP were 3.3 × 104 and 2.9 × 104 Da, respectively. The monosaccharide composition of HBGP included 35.1% galactose, 25.6% arabinose, 5.5% glucose, and 5.3% xylose. Based on infrared spectrum analysis, HBGP possessed pyranose and galactose residues. In addition, this water-soluble polysaccharide showed significant cell proliferation inhibitory effects against cancer cell lines HT29, Caco-2, 4T1, and CT26.WT in a dose-dependent manner, especially for HT29 (the half-inhibitory concentration IC50 value = 2.72 mg/mL). The results provide a basis for the development and utilization of hulless barley grass in functional foods to aid in preventing cancer.