Structural Characterization and Ameliorative Effects of Mesona chinensis Benth Polysaccharide Against Deoxynivalenol-Induced Oxidative Stress in Intestinal Epithelial Cells.

Objectives: Deoxynivalenol (DON) is a ubiquitous mycotoxin detected in the environment and foodstuffs. DON exposure can lead to chronic intestinal inflammation. Therefore, intervention strategy needs to be established to prevent the intestinal inflammation caused by DON. Methods: The structure of Mesona chinensis Benth polysaccharide-3 (MCP-3), a major component isolated and purified from crude MCP, was analyzed using spectroscopic and chromatographic methods. In vitro assays were conducted on the potential antioxidant bioactivities of MCP-3 and its ameliorative effects on deoxynivalenol-induced oxidative stress in intestinal epithelial cells. Results: Saline-eluted MCP-3 was identified as an acidic heterogeneous polysaccharide with an average molecular weight of 16.014 kDa. Its major monosaccharide components were glucose (20.19%), galactose (11.82%), rhamnose (17.23%), galacturonic acid (29.72%), arabinose (7.11%), xylose (8.09%), mannose (2.79%), and glucuronic acid (3.04%). The main backbone of MCP-3 was composed of the following sequence: →4)-α-D-GalpA-6-(1→4)-α-GalpA-(1→4)-α-D-GalpA-6-(1→2)-α-L-Rhap-(1→4)-α-D-GalpA-6-(1→2,4)-α-L-Rhap-(1→. MCP-3 showed strong antioxidant ability in in vitro assays. It effectively prevented redox imbalance induced by the mycotoxin deoxynivalenol in intestinal epithelial cell models based on Caco-2 and NCM460 cells. MCP-3 significantly increased (p < 0.05) the activities of superoxide dismutase, glutathione peroxidase, and catalase, and significantly decreased (p < 0.05) the levels of malondialdehyde and reactive oxygen species, thereby improving redox homeostasis. Conclusions: MCP-3 has potential as a natural antioxidant for use in functional food and nutraceutical industries to help regulate intestinal oxidative stress caused by mycotoxin DON.