Effect Of Neohesperidin Dihydrochalcone On OVA-induced Oral Tolerance

Food allergy has been listed by the World Health Organization as one of the five most important public health issues.Early exposure to allergens can induce immune tolerance in the body,but the effects of physiological conditions and diet may break the formation of immune tolerance and induce food allergy.Studies have shown that food sweeteners may break the body's immune tolerance and induce food allergies.Neohesperidin dihydrochalcone is a kind of flavonoid obtained by hydrogenation of neohesperidin.It is a functional sweetener.It is now widely used in food,medical,and feed fields with its priority.However,whether NHDC breaks oral tolerance and induce food allergy has not been reported.In this work,oral tolerance model induced by ovalbumin?OVA?in mice was established,the effect and mechanism of NHDC on oral tolerance were investigated by ELISA and WB;then,the effect of NHDC on cell degranulation was studied by RBL-2H3 cell degranulation model.In vivo,body weight,body temperature,fecal status,and OVA-specific IgE,IgG1,and MCP-1 levels in serum were investigated to study the effect of NHDC on oral tolerance;CD4+T/CD8+ratio,CD4+CD25+T ratio of immune T cells in the spleen,and the expression of GATA3,STAT5,Foxp3,MHC?,CXCR1,CCR7protein levels in colon tissue were applied to clarify the mechanism of the effect.The results show that the tolerance group and the NHDC groups can significantly inhibit weight loss,body temperature drop and diarrhea symptoms caused by food allergies,and significantly reduce serum specific antibody levels,indicating that the establishment of oral tolerance is conducive to reducing the symptoms caused by food allergies,and NHDC can effectively inhibit the increase of specific antibody.The proportion of immune T cells in the tolerance group and the NHDC groups tended to normal levels,and significantly reduced the expression of GATA3,MHC?and CXCR1 protein levels in colon tissue,increased the expression levels of STAT5,Foxp3 and CCR7 protein compared with tolerance group,the NHDC group had a greater influence on protein expression,NHDC has a certain promoting effect on the establishment of oral tolerance.In vitro,investigate the effect of NHDC on cell morphological changes by atomic force microscopy,examin the release of?-HEX,histamine and interleukin-4 in cells,investigate the inhibitory effect of NHDC on degranulation of RBL-2H3cells.Examin Ca²⁺inflow and ERK,JNK,p-38 protein expression to study the mechanism.The results show that NHDC has a certain inhibitory effect on the release of?-HEX,histamine and interleukin-4,which proves that NHDC can significantly inhibit RBL-2H3 cell degranulation,NHDC can inhibit Ca²⁺influx and ERK,JNK,p-38 protein phosphorylation to inhibiting the MAPK pathway,and achieving the inhibition of degranulation of RBL-2H3 cells.