L-Arabinose Attenuates Gliadin-Induced Food Allergy via Regulation of Th1/Th2 Balance and Upregulation of Regulatory T Cells in Mice

Gliadins are the main cause of wheat allergies, and the prevalence of gliadin allergy has increased in many countries. L-Arabinose, a kind of plant-specific five-carbon aldose, possesses beneficial effects on food allergy to gliadins. This study investigated the antiallergic activities and underlying mechanisms of L-arabinose in a wheat gliadin-sensitized mouse model. BALB/c mice were sensitized to gliadin by intraperitoneal injections with gliadin followed by being given a gliadin challenge. L-arabinose-treated mice exhibited a marked reduction in the productions of total immunoglobulin E (IgE), gliadin-specific IgE, gliadin-specific IgG 1, and histamine, with an increase in IgG2a level as compared with gliadin-sensitized mice. Beside that, a significant decrease in Th2-related cytokine level, IL-4, and an increase in Th1-related cytokine level, IFN-gamma, in the serum and splenocytes were observed after treatment with L-arabinose. L-Arabinose treatment also improved the imbalance of Th1/Th2 immune response on the basis of the expression levels of related cytokines and key transcription factors in the small intestine and spleen of sensitized mice. In addition, gliadininduced intestinal barrier impairment was blocked by L-arabinose treatment via regulation of TJ proteins and suppression of p38 MAPK and p65 NF-kappa B inflammation signaling pathways. Notably, the results confirmed that L-arabinose treatment increased CD4(+) Foxp3(+) T cell populations and Treg-related factors associated with increased expression of IL-2 and activation of STATS in gliadin-sensitized mice. In conclusion, L-arabinose attenuated the gliadin-induced allergic symptoms via maintenance of Th1/Th2 immune balance and regulation of Treg cells in a gliadin-induced mouse model, suggesting L-arabinose could be used as a promising agent to alleviate gliadin allergy.

Automated summary

L-arabinose demonstrates anti-allergic effects by reducing levels of IgE, histamine, and Th2-related cytokines, while increasing levels of Th1-related cytokines. It also improves intestinal barrier function by suppressing inflammation signaling pathways. Additionally, L-arabinose enhances Treg cell populations and related factors, suggesting it as a promising agent for alleviating gliadin allergy.