Piper nigrum extract attenuates food allergy by decreasing Th2 cell response and regulating the Th17/Treg balance

Abstract

Piper nigrum is extensively utilized because of its antioxidation, antiallergic, antitumor, antiinflammatory, antidiarrhea, and gastrointestinal protection. We attempted to indicate whether the Piper nigrum extract (PNE) could alleviate ovalbumin (OVA)-induced food allergy, and to explore its potential mechanism. An OVA-induced food allergy mouse model was established, and different concentrations of PNE were administrated. Symptoms of food allergy, levels of immunoglobulin E (IgE), mucosal mast cell protease-1 (mMCP-1), and intestine pathological changes were assessed. Additionally, the expressions of T helper (Th) 2, Th17 and regulatory T (Treg)-associated cytokines and the proportion of Th17 and Treg cells in CD4 + T cells were measured. We found PNE attenuated symptoms of food allergy and decreased the levels of IgE and mMCP-1. In PNE group, the infiltration degree of inflammatory cells was ameliorated and the villi of small intestine were more complete. Moreover, the expressions of Th2 and Th17 cell-associated cytokines were down-regulated by PNE pretreatment, while the levels of Treg cell-associated cytokines were up-regulated. PNE decreased the number of Th17 cells, while increased the Tregs cells. PNE treatment dosedependently improved the Th17/Treg balance. PNE plays a protective role in OVAinduced food allergy through inhibiting Th2 cell response and regulating the Th17/ Treg balance.

Probiotic strains alleviated OVA-induced food allergy in mice by regulating the gut microbiota and improving the level of indoleacrylic acid in fecal samples

“…4 The increase in sIgE, Th2-type, and Th17-type inflammatory cytokines induces inflammatory infiltration of the intestinal tract and leads to the clinical symptoms of FA. [5][6][7][8][9] Probiotics have been reported to alleviate FA by modulating the immune response of the host body. A probiotic mixture decreased the secretion of IgE and Th2 cytokines (IL-4, IL-5, IL-10, and IL-13) in OVA-induced FA alleviation.…”

Gut Microbiota Promotes Immune Tolerance by Regulating RORγt+ Treg Cells in Food Allergy

“…In contrast, Th2-mediated inflammatory responses were exacerbated in Tregs-deficient mouse models [65]. Furthermore, animals with food allergy model also showed enhanced Th2 cell response, inhibited Treg cell expansion, and significantly increased Th17/Treg ratio [66]. These findings confirm that early gut microbiota changes can affect the proliferation and induction of Treg cells and thus the forming of gut homeostasis.…”

β-Sitosterol protects against food allergic response in BALB/c mice by regulating the intestinal barrier function and reconstructing the gut microbiota structure

“…44 Wang et al revealed that Piper nigrum extract tends to play a protective role in OVA-induced FA by suppressing Th2 cell response and adjusting Th17/Treg balance. 45 Diosgenin was also demonstrated to attenuate allergic reactions in OVA-allergic mice by repression of MC infiltration and degranulation pathways. 46 According to the present results, dramatically promoted the secretion of IL-10 and reduced histamine levels were observed when the sensitized mice were supplied with β-sitosterol.…”