Abstract
We isolated the 4 kinds of flavonoids from strawberry 'Nohime' and examined the effect of these flavonoids on the degranulation in RBL-2H3 cells. The flavonoids were found to suppress the degranulation from Ag-stimulated RBL-2H3 cells to different extents. To disclose the inhibitory mechanism of degranulation by flavonoids, we examined their effects on the intracellular free Ca(2+) concentration ([Ca(2+)]i) and the intracellular signaling pathway such as Lyn, Syk, and PLCgammas. The intracellular free Ca(2+) concentration ([Ca(2+)]i) was elevated by Fc epsilonRI activation, but these flavonoid treatments reduced the elevation of [Ca(2+)]i by suppressing Ca(2+) influx. Kaempferol strongly suppressed the activation of Syk and PLCgammas. It was thus suggested that suppression of Ag-stimulated degranulation by the flavonoids is mainly due to suppression of [Ca(2+)]i elevation and Syk activation. These results suggested that strawberry would be of some ameliorative benefit for the allergic symptoms.
MeSH terms
-
Animals
-
Anti-Allergic Agents / analysis
-
Anti-Allergic Agents / isolation & purification*
-
Anti-Allergic Agents / pharmacology*
-
Basophil Degranulation Test
-
Basophils / cytology
-
Basophils / drug effects
-
Basophils / enzymology
-
Basophils / immunology
-
Calcium / metabolism
-
Cell Degranulation / drug effects*
-
Cell Line, Tumor
-
Flavonoids / analysis
-
Flavonoids / isolation & purification*
-
Flavonoids / pharmacology*
-
Fragaria / chemistry*
-
Fruit / chemistry*
-
Immunoglobulin E / immunology
-
Intracellular Signaling Peptides and Proteins / metabolism
-
Leukemia / enzymology
-
Leukemia / immunology
-
Molecular Structure
-
Protein-Tyrosine Kinases / metabolism
-
Rats
-
Reactive Oxygen Species / metabolism
-
Receptors, IgE / immunology*
-
Signal Transduction / drug effects
-
Syk Kinase
-
beta-N-Acetylhexosaminidases / antagonists & inhibitors
-
beta-N-Acetylhexosaminidases / metabolism
Substances
-
Anti-Allergic Agents
-
Flavonoids
-
Intracellular Signaling Peptides and Proteins
-
Reactive Oxygen Species
-
Receptors, IgE
-
Immunoglobulin E
-
Protein-Tyrosine Kinases
-
Syk Kinase
-
Syk protein, rat
-
beta-N-Acetylhexosaminidases
-
Calcium