Isolation, Characterization and Antioxidant Activity of Yam Polysaccharides.

Zhedong Li,Wenhao Xiao,Jianhua Xie,Yi Chen,Weidong Zhang,Mingyue Shen,Qiang Yu

doi:10.3390/foods11060800

Abstract

This study aimed to characterize the structure of Chinese yam (Dioscoreae Rhizoma) polysaccharide (CYP) and to investigate its protective effect against H2O2-induced oxidative damage in IEC-6 cells. The chemical composition and structural characteristics of the samples were analyzed by chemical and instrumental methods, including high-performance gel permeation chromatography, high-performance anion-exchange chromatography (HPAEC), Fourier transformed infrared (FT-IR), ultraviolet (UV), and scanning electron microscopy (SEM). Antioxidant activity was evaluated by establishing a cellular model of oxidative damage. The molecular weight of CYP was 20.89 kDa. Analysis of the monosaccharide composition revealed that CYP was primarily comprised of galactose (Gal), glucose (Glu), and galacturonic acid (GalA), and the ratio between them was 28.57:11.28:37.59. Pretreatment with CYP was able to improve cell viability, superoxide dismutase (SOD) activity, and reduce intracellular reactive oxygen species (ROS) production and malondialdehyde (MDA) content after H2O2 injury. CYP also attenuated oxidative damage in cells through the mitogen-activated protein kinase (MAPK) signaling pathway. This study showed that CYP was an acidic heteropolysaccharide with a good protective effect against oxidative damage, and it thus has good prospects in food and biopharmaceutical industries.

Highlights

Cellular and tissue oxidative stress is a response to stimulation by increased reactive oxygen species (ROS) and free radicals in the body, resulting in dysregulation of the intracellular oxidative antioxidant system [1]
Many small intestinal epithelial cells exist on the surface of the intestine, and as a mediator of the internal and external environment of the intestine, the small intestinal epithelial cells are part of the immune barrier that can defend the body against pathogens and other harmful substances [6–9]
Studies have shown that polysaccharides can scavenge ROS and enhance the antioxidant system to improve intestinal inflammation, it is relevant to find an antioxidant to protect the intestine from oxidative damage [10–13]

Summary

Introduction

Cellular and tissue oxidative stress is a response to stimulation by increased reactive oxygen species (ROS) and free radicals in the body, resulting in dysregulation of the intracellular oxidative antioxidant system [1]. Cells can catalyze the superoxide anion produced in oxidative stress into H2O2, which is broken down into water and oxygen in one step by inducing superoxide dismutase (SOD), catalase, and glutathione peroxidase [2,3]. Oxidative stress could disrupt intestinal homeostasis, which is a critical element in the development of intestinal damage. Stress can induce intestinal cells to produce large amounts of ROS metabolites, which affect the stability of intracellular nucleic acids, proteins, and lipids, increase apoptosis, inflict intestinal mucosal damage, and induce inflammatory bowel disease [4,5]. Studies have shown that polysaccharides can scavenge ROS and enhance the antioxidant system to improve intestinal inflammation, it is relevant to find an antioxidant to protect the intestine from oxidative damage [10–13]

Objectives

Methods

Results