Ultra-high pressure assisted extraction improves fermentation characteristics and in vitro anti-adipogenic effect of Bangia fusco-purpurea polysaccharide

In vitro gut microbiota fermentation characteristics and anti-adipogenic effect of Bangia fusco-purpurea polysaccharide extracted with ultra-high pressure assisted extraction (UBFP) were investigated. Compared with polysaccharide obtained with traditional hot water extraction (BFP), UBFP significantly increased intestinal flora diversity and induced a beneficial shift in the microbial composition, which could suppress the growth of opportunistic pathogens such as Escherichia-Shigella and Streptococcus , while enriching the abundance of beneficial bacteria such as Enterococcus . Both BFP and UBFP increased short-chain fatty acids (SCFAs) production, particularly acetic acid. The total SCFAs content in the UBFP group showed a 1.83-fold greater increase than that in the BFP group relative to the control. Furthermore, UBFP fermented products could better inhibit 3T3-L1 preadipocytes from differentiating into mature adipocytes as well as lowering triglyceride and total cholesterol contents and inhibiting lipid droplet formation. Notably, the reduction of TG content by UBFP fermented products showed 1.07- to 2.87-fold greater efficacy than BFP fermented products ( p  < 0.05). Western blot analysis revealed that UBFP fermentation products upregulated the pAMPK/AMPK ratio and downregulated PPARγ expression in 3T3-L1 cells, suggesting that the anti-adipogenic effect may be mediated through activation of the AMPK signaling pathway and inhibition of PPARγ expression. Although these bioactivities of UBFP were assessed using in vitro models and requires further validation through in vivo studies, this research nevertheless provided valuable insights into the potential role of UBFP in promoting intestinal health and regulating lipid metabolism.