Effect of dietary flavonols on oestrogen receptor transactivation and cell death induction.

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Leung LK, Po LS, Lau TY, Yuen YM

Effect of dietary flavonols on oestrogen receptor transactivation and cell death induction.

Br J Nutr. 2004 Jun;91(6):831-9.

PubMed ID

15182386 [ View in PubMed

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Abstract

Consumption of fruits and vegetables has been associated with cancer prevention; flavonoids are widely distributed in plant foods and considered to be the active ingredients. Quercetin and kaempferol are two of the most commonly found dietary flavonols, and have been reported to prevent cancer. We have previously reported that the isoflavone genistein and the flavone baicalein exert differential actions on the oestrogen receptor (OR) alpha in HepG2 cells. Because of the structural resemblance to both isoflavone and flavone, we examined the effects of these dietary flavonols on ORalpha- and ORbeta-specific transactivations and their subsequent involvement in inducing MCF-7 cell death. In the present study, both quercetin and kaempferol were able to compete for OR binding in a cell-free system and were agonistic to ORalpha and -beta expressed in HepG2 cells, while some additive effect was observed in the oestrogen response element (ORE)-driven transcription when 17beta-oestradiol was co-administered. Since the bcl-2 promoter contained two ORE, and ORE-driven transcriptional activity and Bcl-2 mRNA expression were increased by treatment with 10 microm-quercetin or kaempferol, it is possible that quercetin and kaempferol might up-regulate Bcl-2 expression through OR transactivation in MCF-7 cells. Cell death ELISA assay performed on MCF-7 cells indicated that an increase of apoptosis occurred at 25 microm-, but not 10 microm-, quercetin or kaempferol. Indirectly the results suggest that OR activation is not sufficient to induce apoptosis and that apoptosis is induced despite an increase in Bcl-2 expression.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Quercetin	Estrogen receptor alpha	Protein	Humans	Unknown	Not Available	Details
Quercetin	Estrogen receptor beta	Protein	Humans	Unknown	Not Available	Details

Pharmaco-transcriptomics

Drug	Drug Groups	Gene	Gene ID	Change	Interaction	Chromosome
Quercetin	Experimental Investigational	ESR2	2100	upregulated	Quercetin results in increased expression of ESR2 mRNA	14q23.2-q23.3