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• Trigonelline suppressed antigen-mediated degranulation of RBL-2H3 cells. • Trigonelline did not interfere with the antigen-antibody interaction. • Decreased phosphorylation of PLCγ1 and PI3 K resulted in suppressed degranulation. • Trigonelline inhibited microtubule formation in RBL-2H3 cells. • Trigonelline showed an effect on in vivo study after oral administration. Trigonelline, one of the alkaloids contained in coffee, is important not only as one of the constituents of aroma and flavor in coffee but also as a useful source of nutrition. Its anti-microbial, anti-carcinogenic, and anti-hyperglycemic effects have been investigated in previous studies. However, there have not been any studies examining the anti-degranulation effect of trigonelline. In this study, the anti-degranulation effect of trigonelline was evaluated in in vitro and in vivo models using a rat basophilic leukemia cell line, RBL-2H3 cells, and a passive cutaneous anaphylaxis (PCA) reaction in mice, respectively. In the β-hexosaminidase release assay, trigonelline effectively suppressed antigen-induced degranulation of RBL-2H3 cells in a dose-dependent manner without cytotoxicity. Trigonelline also inhibited FcεRI-mediated intracellular signaling pathways, such as phosphorylation of PLCγ1, PI3 K, and Akt, in antigen-stimulated RBL-2H3 cells and suppressed the PCA response in mice. Moreover, trigonelline also inhibited the microtubule formation in RBL-2H3 cells, indicating that trigonelline could inhibit IgE-sensitized mast cell degranulation by attenuating both the intracellular calcium-dependent and independent pathways. These results revealed that trigonelline possesses the anti-degranulation effect against the development of allergic diseases. [ABSTRACT FROM AUTHOR]

An array of foodstuffs was screened for the suppressive effect on production of IgE, a key molecule in the type I allergic reaction, using U266 cells. An ethanol extract from passion fruit seeds (PFS) has emerged as a food material with the IgE production-suppressive effect as the result of screening. Real-time RT-PCR analysis revealed that the IgE production-suppressive effect was caused by downregulated IgE gene expression. In addition, PFS selectively suppressed IgE production and did not affect the production of IgG, IgA, or IgM by mouse splenocytes. Resveratrol and piceatannol were identified as bioactive ingredients contained in passion fruit seeds. The effect of oral administration of PFS, resveratrol, and piceatannol was evaluated using a mouse model of allergic contact dermatitis. Both stilbenoids significantly suppressed IgE production in orally administered mice. Overall results indicated that passion fruit seeds are a promising candidate with the antiallergy effect for development of functional foods. [ABSTRACT FROM AUTHOR]

Chlorophyll c2 in a Sargassum horneri extract suppressed the degranulation of rat basophilic leukaemia RBL-2H3 cells. In this contribution, the mode of action of S. horneri extract was revealed. The extract inhibited the elevation of intracellular Ca 2+ concentration induced by the antigen. Immunoblot analysis showed that S. horneri extract down-regulated the phosphorylation of both Syk and PI3K in the signalling pathways involved in degranulation triggered by antigen–antibody interaction. In addition, oral administration of S. horneri extract inhibited mice nasal rubbing behaviour sensitized with anti-DNP IgE. These findings suggest that S. horneri extract has anti-allergic activity via the suppression of degranulation of mast cells and basophils. [ABSTRACT FROM AUTHOR]

Abstract: The inhibitory effect of an aqueous extract from spinach on degranulation of RBL-2H3 cells is herein reported. The extract significantly suppressed antigen-induced degranulation in a dose-dependent manner without affecting cell viability. Active substances in the extract were heat-stable and trypsin-resistant with molecular weights ranging from 500Da to 14kDa. The extract inhibited elevation of the intracellular Ca2+ concentration caused by stimulation by antigen, while not suppressing degranulation induced by a calcium ionophore A23187. Immunoblot analysis revealed that the inhibitory effect results from downregulation of phosphorylation of both Syk kinase and phosphatidylinositol 3-kinase in the signalling pathways involved in degranulation caused by the antigen–antibody interaction. Taken together, these findings suggest that aqueous spinach extract has an anti-allergic activity that controls degranulation. [Copyright &y& Elsevier]

• Caffeine suppressed antigen-mediated degranulation of RBL-2H3 cells. • Caffeine suppressed degranulation by decreased Ca2+ influx into the cells. • Caffeine inhibits the degranulation caused by Ca2+ influx from the endoplasmic reticulum. • Suppressed Ca2+ influx seems to result from decreased phosphorylation of Syk, Btk, PLCγ1, PI3K, and Akt. • Caffeine showed the effect on in vivo study after oral administration. Based on some studies, moderate caffeine consumption provides several benefits to human health. However, there are few reports on the anti-degranulation activity of caffeine. Allergy is a global healthcare problem that is drastically increasing in both developed and developing countries. Meanwhile, allergic reactions are triggered by the presence of chemical mediators released from the granules in mast cells, which are called the degranulation process. In this study, caffeine was evaluated for anti-degranulation activity using basophilic cell line RBL-2H3 cells as the in vitro model and the passive cutaneous anaphylaxis (PCA) model mice in vivo. As a result, caffeine effectively suppressed antigen-induced degranulation by RBL-2H3 cells in a dose-dependent manner without cytotoxicity. Besides, caffeine also inhibited FcεRI-mediated intracellular signaling pathways, such as phosphorylation of Syk, Btk, PLCγ1, PI3K, and Akt in antigen-stimulated RBL-2H3 cells. Caffeine also suppressed PCA response in mice. [ABSTRACT FROM AUTHOR]

We found that a water-soluble extract of coriander (Coriandrum sativum L.) (leaves, petioles and stems) inhibits antigen-induced degranulation of RBL-2H3 cells, a rat basophil leukemia cell line. The aim of this study was to elucidate the anti-degranulation active components in the extract. The methanol-eluate fraction obtained by fractionation of the water-soluble extract using MCI gel column chromatography had strong activity, and eight components were isolated and identified. Two of them were identified as new compounds, (3 S)-3-methyl-6-hydroxyisocoumarin 8- O -β-D-glucopyranoside (compound 1) and (7 S ,8 R)-7,8-dihydro-8-β-D-glucopyranosyloxy-4-methoxy-7-methyl-5 H -fro[2,3-g][2]benzopyran-5-one (compound 2). As a result of evaluation of anti-degranulation activity of eight components, seven of them, such as tryptophan, phenylalanine, dihydroxycoumarin glucoside, quercetin glycoside, rutin, compound 1 , and compound 2 , had the activity. These results indicated that the water-soluble extract of coriander contains several anti-degranulation substances. [Display omitted] • Water-soluble parts of coriander (vegetable) exhibited anti-allergic activity. • Eight compounds from the water-soluble extract were isolated and quantified. • The structures of two new dihydroisocoumarins were identified. • The isolated compounds contributed to degranulation inhibition. [ABSTRACT FROM AUTHOR]