Journal Article

Rehmannia glutinosa Polysaccharides: Optimization of the Decolorization Process and Antioxidant and Anti-Inflammatory Effects in LPS-Stimulated Porcine Intestinal Epithelial Cells

Wang, Jinrong, Wang, Peng, Qi, Liwen, Gan, Liping, Chen, Jun, Qiu, Binhang, Huang, Xiaolu, Xia, Peng, Ren, Heng, Li, Kejie, Luo, Jingxin, Kang, Maoli, Min, Yan, Qiao, Hanzhen, Cui, Yaoming

2023

Overview

Polysaccharide decolorization has a major effect on polysaccharide function. In the present study, the decolorization of Rehmannia glutinosa polysaccharides (RGP) is optimized using two methods—the AB-8 macroporous resin (RGP-1) method and the H2O2 (RGP-2) method. The optimal decolorization parameters for the AB-8 macroporous resin method were as follows: temperature, 50 °C; macroporous resin addition, 8.4%; decolorization duration, 64 min; and pH, 5. Under these conditions, the overall score was 65.29 ± 3.4%. The optimal decolorization conditions for the H2O2 method were as follows: temperature, 51 °C; H2O2 addition, 9.5%; decolorization duration, 2 h; and pH, 8.6. Under these conditions, the overall score was 79.29 ± 4.8%. Two pure polysaccharides (RGP-1-A and RGP-2-A) were isolated from RGP-1 and RGP-2. Subsequently, their antioxidant and anti-inflammatory effects and mechanisms were evaluated. RGP treatment activated the Nrf2/Keap1 pathway and significantly increased the activity of antioxidant enzymes (p < 0.05). It also inhibited the expression of pro-inflammatory factors and suppressed the TLR4/NF-κB pathway (p < 0.05). RGP-1-A had a significantly better protective effect than RGP-2-A, likely owing to the sulfate and uronic groups it contains. Together, the findings indicate that RGP can act as a natural agent for the prevention of oxidation and inflammation-related diseases.

• Publisher: MDPI AG,MDPI
• Subject: anti-inflammatory / antioxidant / Antioxidants / Decolorization / Epithelial cells / epithelium / Hydrogen peroxide / Inflammation / intestines / Methods / NF-κB protein / Optimization / oxidation / Pathogens / pathways / Polysaccharides / porous media / protective effect / Rehmannia glutinosa / Rehmannia glutinosa polysaccharides / sulfates / Sulfuric acid / swine / temperature / TLR4 protein / Toll-like receptors