title: Comparison of delphinidin, quercetin and (-)-epigallocatechin-3-gallate as inhibitors of the EGFR and the ErbB2 receptor phosphorylation.
abstract: In the present study, delphinidin was found to suppress the phosphorylation of the epidermal growth factor receptor (EGFR) within human tumour cells (human colon carcinoma cell line (HT29), human vulva carcinoma cell line (A431)), albeit less effective than the flavonol quercetin. The higher potency of quercetin was also observed downstream on the level of the mitogen-activated protein kinase (MAPK) cascade. In addition, delphinidin, quercetin and (-)-epigallocatechin-3-gallate (EGCG) were found to suppress the phosphorylation of the ErbB2 receptor, with delphinidin exhibiting the strongest inhibitory properties. Their potency to suppress the ErbB2 receptor phosphorylation can be summarised as delphinidin > EGCG > quercetin. The effectiveness of delphinidin against the EGFR and the ErbB2 receptor was comparable, indicating a broader spectrum of activity against receptor tyrosine kinases. At low micromolar concentrations delphinidin showed some preference towards the ErbB2 receptor. In summary, quercetin and delphinidin appear to differ in their activity profile towards the ErbB receptor family members. Whereas quercetin was most effective against the EGFR, delphinidin exhibited some preference towards the ErbB2 receptor.
authors.affiliation: Institute of Applied Biosciences, Section of Food Toxicology, Universität Karlsruhe (TH), Adenauerring 20, 76131 Karlsruhe, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Fridrich
authors.forename: Nicole
authors.initials: N
authors.lastname: Teller
authors.forename: Melanie
authors.initials: M
authors.lastname: Esselen
authors.forename: Gudrun
authors.initials: G
authors.lastname: Pahlke
authors.forename: Doris
authors.initials: D
authors.lastname: Marko
mesh_terms: D000872:Anthocyanins / Q000494:pharmacology*; D002277:Carcinoma; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000037:antagonists & inhibitors*; D005260:Female; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000187:drug effects / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000187:drug effects / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors*; D014846:Vulvar Neoplasms
chemical_list: D000872:Anthocyanins; D002392:Catechin; D066246:ErbB Receptors; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D011794:Quercetin; D018719:Erb-b2 Receptor Tyrosine Kinases; C045651:epigallocatechin gallate; C017185:delphinidin