Insight into inflammatory mice fecal fermentation properties and anti-inflammation activity of Porphyra haitanensis polysaccharides

In this study, the anti-inflammation effects of Porphyra haitanensis polysaccharides (PHP) and sub-fractions (PHP40 and PHP80) isolated from PHP were investigated using an in vitro fermentation system and a lipopolysaccharide (LPS)-stimulated NCM460 (human colon epithelial) cell model. The Mw value of PHP40 was 2.053 × 10 6  g/mol, and the Mw value of PHP80 was 1.172 × 10 6  g/mol. PHP40 had the best effect on Weissella proliferation, followed by PHP and PHP80. PHP, PHP40, and PHP80 inhibited the proliferation of Staphylococcus and Enterorhabdus . Treatment of LPS-induced NCM460 cells with PHP, PHP40, and PHP80 increased cell migration and adhesion, in dose-dependent. PHP exhibited the most pronounced inhibitory effect on TNF-α, while PHP80 demonstrated the strongest inhibitory activity against IL-6 and IL-1. After treatment with PHP, the expression of aPKC, PKCβII (pro-inflammatory kinase), FAK (migration complex proteins) both at mRNA and protein level was down-regulated. PHP, PHP40, and PHP80 decreased the expression of RELA/p65 (a major NF-κB transcription factor subunit driving inflammatory gene expression) at mRNA and protein level, indicating that P. haitanensis polysaccharide had a protective effect against LPS-induced inflammation in NCM460 cells, mediated via the NF-κB signaling pathway, and that P. haitanensis polysaccharide showed potential anti-inflammatory effects. The findings of the present study lay the foundation for future research endeavors that seek to elucidate the mechanism of anti-inflammatory activity within the context of intestinal microbiota.