The glycoprotein (18 kDa) isolated from Lactobacillus plantarum L67 suppressed ß-hexosaminidase, histamine, and the expression of TNF-α and IL-4 in the BPA-stimulated RBL-2H3 cells

This study investigated the inhibitory effect of the 18 kDa glycoprotein isolated from Lactobacillus plantarum L67 on the bisphenol A-mediated inflammatory reaction in RBL-2H3 cells. The RBL-2H3 cells were treated with bisphenol A (50 μmol) and the glycoprotein isolated from L. plantarum L67 (5-100 μg/ml) for 30 min. Subsequently, the release of histamine and β-hexosaminidase into the medium and the intracellular Ca²⁺ levels were measured. The activities of PKC and iNOS were measured by western blotting. In addition, the gene expression levels of IL-4 and TNF-α were measured by qRT-PCR. In conclusion, the results demonstrated that the degranulation of the BPA-stimulated RBL-2H3 cells and their histamine release were inhibited by the glycoprotein of L. plantarum L67; concurrently, the levels of intracellular Ca²⁺, the activity of iNOS, and the expression of TNF-α and IL-4, two allergy-related cytokines, were also suppressed by the glycoprotein. Taken together, these results indicate that the glycoprotein might help to prevent allergic diseases induced by environmental hormones, such as BPA.