Polysaccharide from Moringa oleifera leaf enhances IEC-6 cells stimulated by LPS by inhibiting the inflammatory-related signaling pathway and maintaining the intestinal barrier Provisionally Accepted

Hosameldeen Mohamed Husien¹ WeiLong Peng² Shahab Ur Rehman¹ Mohamed Osman Abdalrahem² Mengzhi Wang^1* Jingui Li^2*

• ¹Laboratory of Metabolic Manipulation of Herbivorous Animal Nutrition, College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, Jiangsu, China., Yangzhou University, China
• ²College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China., Yangzhou University, China

Moringa oleifera (M. oleifera) is a natural plant that has excellent nutritional and medicinal potential. M. oleifera leaves (MOL) contain several bioactive compounds.The aim of this study is to investigate the potential effect of MOL polysaccharide (MOLP) on intestinal epithelial cells-6 (IEC-6) stimulated by lipopolysaccharide (LPS) as well as the underlying mechanism. The safety doses of MOLP on IEC-6 cells were determined by the Cell Counting Kit-8 (CCK-8) method, and the result indicated that the safety range was 0~1280 µg/mL. The effect of cell activities on IEC-6 cells was determined by CCK-8 at 12 to 48 h. IEC-6 cells were cultured in 6well plates (4 × 10 5 cells/well) and incubated for 24 h, then stimulated with MOLP-L (25 µg/mL), MOLP-M (50 µg/mL), MOLP-H (100 µg/mL), or LPS (50 μg/mL) for 24 h, respectively. The results showed that MOLP treatment groups were able to significantly increase cell migration and the level of IL-10. However, it reduced cell apoptosis and the mRNA expression levels of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). Furthermore, all three doses of MOLP treatment significantly reversed the levels of Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), phosphorylation nuclear factor-kappa B-alpha (pIκB-α), and phosphorylation of NF-κB p65, as well as repressed the loss of zonula occludens-1 (ZO-1) and occludin proteins in IEC-6 cells.The above results indicated that MOLP suppressed the production of proinflammatory cytokines by inhibiting the activation of inflammatory-related signaling pathways and protected the intestinal barrier by enhancing the expression of tight junction (TJ) proteins in IEC-6 cells stimulated by LPS. In conclusion, this study will contribute to our knowledge of the anti-inflammatory properties of MOLP.