Although often regarded as compromising the fruit’s sensory quality, pear peel is an edible component that enhances the nutritional and functional value of pears within a whole food diet. Rich in diverse polyphenols with demonstrated bioactivity, the pear peel represents a valuable dietary source of health-promoting compounds, however, its role in ulcerative colitis (UC) remains underexplored. In this study, the protective effect of pear peel polyphenols (PPP) against UC was investigated using both in vitro and in vivo models. PPP markedly suppressed proinflammatory cytokine and enzyme expressions in lipopolysaccharide (LPS) stimulated RAW264.7 macrophages. In dextran sulfate sodium (DSS) induced colitis mice, PPP significantly mitigated UC symptoms, suppressed serum inflammatory cytokine production, and ameliorated histological damage in colon tissues. Moreover, PPP modulated the gut microbiota by reshaping microbial diversity, enriching beneficial taxa such as Akkermansia, and suppressing proinflammatory taxa including Bacteroides, Enterobacteriaceae, and Parabacteroides. Proteomic analysis further demonstrated that PPP modulated mucosal immunity, particularly by rebalancing immunoglobulin-related processes (IgM, IgD, and IgA) and attenuating antigen presentation responses involving major histocompatibility complex (MHC) class II molecules and cluster of differentiation (Cd40) signaling. Together, these findings suggest that PPP exerts a protective effect against colitis through the coordinated regulation of gut microbiota and mucosal immunity, highlighting its potential as a functional food ingredient for intestinal health.
Yanan Liu,Huan Li,Chong Wang,Shanjun Chen,Renjie Lian,Weiqiang Wang,Linglin Fu,Yanbo Wang
Histamine in food has attracted widespread attention due to the potential toxicity and associated health risk. However, its influences on immunological components, especially the function of key immune cells, are still poorly known. In this work, we explored the effects of exogenous histamine on the function of key immune cells such as intestinal epithelial cells, dendritic cells, and T cells. The results showed that histamine could affect the expression of allergy-related genes in CMT93 cells at a high dose of histamine. Moreover, it’s found that histamine could cause an imbalance in the levels of relevant immune factors secreted by dendritic cells and T cells, especially those related to allergy. At the same time, the proportion of MHC class II-positive dendritic cells and the proportion of T helper 2 (Th2) cells in CD4 + T cells increased after histamine stimulation. We concluded that the presence of a certain level of histamine in food may affect the expression of allergy-related cytokines, disrupt the balance of the immune homeostasis, and potentially lead to adverse immune reactions. This work demonstrated the importance of including the estimation of histamine's immune safety in aquatic products rather than merely considering the potential risk of food poisoning.
危险品化学品经营许可证（带存储）