Baicalein induces CD4+Foxp3+ T cells and enhances intestinal barrier function in a mouse model of food allergy

Abstract

The incidence of food allergy, which is triggered by allergen permeation of the gastrointestinal tract followed by a T-helper (Th) 2-mediated immune response, has been increasing annually worldwide. We examined the effects of baicalein (5,6,7-trihydroxyflavone), a flavonoid from Scutellaria baicalensis used in oriental herbal medicine, on regulatory T (Treg) cell induction and intestinal barrier function through the regulation of tight junctions in a mouse model of food allergy. An allergic response was induced by oral challenge with ovalbumin, and the incidence of allergic symptoms and T cell-related activity in the mesenteric lymph nodes were analyzed with and without the presence of baicalein. Our results demonstrated that the administration of baicalein ameliorated the symptoms of food allergy and attenuated serum IgE and effector T cells. However, Treg-related factors were up-regulated by baicalein. Furthermore, baicalein was shown to enhance intestinal barrier function through the regulation of tight junctions. We also found that baicalein treatment induced the differentiation of Treg cells via aryl hydrocarbon receptors (AhRs). Thus, the action of baicalein as an agonist of AhR can induce Treg differentiation and enhance barrier function, suggesting that baicalein might serve as an effective immune regulator derived from foods for the treatment of food allergy.

Silkworm dropping extract regulates food allergy symptoms via inhibition of Th2‐related responses in an ovalbumin‐induced food allergy model

“…Our results showed that SDE increased TEER value as an index of the intestinal barrier function and reduced the permeation of OVA as an allergen in Caco‐2 cell monolayers. We previously showed that Scutellaria baicalensis and its active compound baicalein inhibited allergen permeation through enhancement of the intestinal barrier . This could function to dramatically attenuate food allergy symptoms.…”

“…We previously showed that Scutellaria baicalensis and its active compound baicalein inhibited allergen permeation through enhancement of the intestinal barrier. 17,18,28 This could function to dramatically attenuate food allergy symptoms. Therefore, we suggest that the effect of SDE Each value is presented as the mean ± standard deviation.…”

Immune Basis of Allergic Reactions to Food

“…By contrast, increased intake of vegetable oil rich in n-6 PUFAs has been described to promote allergenic response to whey proteins [136]. Other dietary components that have been associated with prevention of sensitization to food allergens include polyphenols, in particular flavonoids [137][138][139]. Thus, manipulation of dietary components may help to prevent development of food allergies.…”

Pathogenic T cell subsets in allergic and chronic inflammatory bowel disorders

“…showed that disruption of IgE effector functions leads to the emergence of Tregs and subsequent desensitization. Similarly, oral immune therapy and immunomodulatory substances proposed for treatment of food allergy were shown to act via Treg induction . Enhancing the function of Tregs might therefore be a promising goal for further translational research in gastrointestinal allergy.…”