The inhibition of pectin oligosaccharides on degranulation of RBL-2H3 cells from apple pectin with high hydrostatic pressure assisted enzyme treatment

The conditions for the preparation of pectic oligosaccharides (POS) by high hydrostatic pressure-assisted enzymatic (E-HHP) method were explored. The optimal conditions consisted of the pressure of 350 MPa for 20 min, and enzymolysis for 60 min with 0.011 U/mL enzyme. The products were isolated by ion exchange chromatography, galacturonic acid, di- and tri-galacturonides (Tri-GalA) with high purity were obtained. Additionally, the effects of POS on activation and degranulation of RBL-2H3 mast cells were investigated. It was found that TriGalA and POS could attenuate the release of beta-hexosaminidase and histamine, reduce the production of IL-4 and inhibit the extracellular Ca2+ influx of RBL-2H3 cells. Notably, 150 mu g/mL POS significantly alleviated the IgEmediated allergic reaction of RBL-2H3 cells. These results indicate that POS could be used as an inhibitor in regulating mast cell-mediated allergic inflammatory responses.