Folic acid supplementation during pregnancy alleviates food allergy in offspring by inhibiting mast cell degranulation.

Studies have been exploring the connection between vitamins intake and development of food allergy, with a particular focus on folic acid (FA). However, the impact of FA supplementation on food allergy remains a subject of debate. In the present study, the anti-allergic properties of FA and its possible mechanism of action were investigated. In a Brown Norway rat food allergy model, we found that FA downregulated the expressions of specific antibodies, while influencing the Th1/Th2 balance. Furthermore, FA was found to reduce the release of particulate matters such as histamine and mast cell proteinase. Transcriptomic analysis provided evidence that FA intervention could reverse gene expression changes induced by food allergies. The gene Hsp90, responsible for producing heat shock proteins (HSP), emerged as a potential key gene involved in the process. In vitro RBL-2H3 cell-based assays suggested that FA might affect HSP90 expression through the glucocorticoid receptor (GR), leading to a reduction in effector cell degranulation. Overall, the results of this study indicate that FA has an alleviating effect on food allergies, with high doses of FA exhibiting more pronounced effects. Moreover, FA's impact on HSP90 expression through GR seems to contribute to a decrease in degranulation during the effector phase.