Ultrafiltration tandem mass spectrometry of estrogens for characterization of structure and affinity for human estrogen receptors

Sun, Yongkai; Gu, Chungang; Liu, Xuemei; Liang, Wenzhong; Yao, Ping; Bolton, Judy L.; Breemen, Richard B. van

doi:10.1016/j.jasms.2004.11.002

Cited by 74 publications

(49 citation statements)

References 43 publications

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“…Red clover has been tested in clinical trials as a menopause therapy (27) with formulations based on the active metabolites and their metabolic precursors (13). In the present study we confirmed the presence of 8-PN as the most potent estrogen in hops using a mass spectrometry-based screening assay developed in our laboratory (28). In vivo, additional 8-PN can be formed as a metabolite of the more abundant compounds IX and xanthohumol (XN) (29).…”

Section: Introductionsupporting

confidence: 75%

Comparison of the in Vitro Estrogenic Activities of Compounds from Hops (Humulus lupulus) and Red Clover (Trifolium pratense)

Overk

Yao

Chadwick

et al. 2005

J. Agric. Food Chem.

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106

115

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Since the prevailing form of hormone replacement therapy is associated with the development of cancer in breast and endometrial tissues, alternatives are needed for the management of menopausal symptoms. Formulations of Trifolium pratense L. (red clover) are being used to alleviate menopauseassociated hot flashes but have shown mixed results in clinical trials. The strobiles of Humulus lupulus L. (hops) have been reported to contain the prenylflavanone, 8-prenylnaringenin (8-PN) as the most estrogenic constituent, and this was confirmed using an estrogen receptor ligand screening assay utilizing ultrafiltration mass spectrometry. Extracts of hops and red clover and their individual constituents including 8-PN, 6-prenylnaringenin (6-PN), isoxanthohumol (IX), and xanthohumol (XN) from hops, and daidzein, formononetin, biochanin A, and genistein from red clover, were compared using a variety of in vitro estrogenic assays. The IC 50 values for the estrogen receptor α and β binding assays were 15 and 27 μg/mL, respectively, for hops and 18.0 and 2.0 μg/mL, respectively, for the red clover extract. Both of the extracts, genistein, and 8-PN activated the estrogen response element (ERE) in Ishikawa cells while the extracts, biochanin A, genistein, and 8-PN significantly induced ERE-luciferase expression in MCF-7 cells. Hop and red clover extracts, as well as 8-PN upregulated progesterone receptor (PR) mRNA in the Ishikawa cell line. In the MCF-7 cell line, PR mRNA was significantly upregulated by the extracts, biochanin A, genistein, 8-PN, and IX. The two extracts had EC 50 values of 1.1 and 1.9 μg/mL, respectively, in the alkaline phosphatase induction assay. Based on these data, hops and red clover could be attractive for development as herbal dietary supplements to alleviate menopause-associated symptoms.

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Section: Introductionsupporting

confidence: 75%

Comparison of the in Vitro Estrogenic Activities of Compounds from Hops (Humulus lupulus) and Red Clover (Trifolium pratense)

Overk

Yao

Chadwick

et al. 2005

J. Agric. Food Chem.

Self Cite

106

115

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“…These fragment ions are consistent with a fragmentation pathway that proceeds through ring cleavages and subsequent retrocyclization. [24,25] In addition to the ions described earlier, each estrogen is identified by fragments resulting from the loss of small neutral molecules (Scheme 5). The fragment at m/z 253 derives from the loss of CH 4 from deprotonated E1, leading to two isomers that differ in the position of a double bond.…”

Section: -H]mentioning

confidence: 99%

Determination of endocrine‐disrupting compounds in drinking waters by fast liquid chromatography–tandem mass spectrometry

et al. 2010

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Growing attention has been recently paid to safety of food and drinking water, making necessary the adoption of policies for water sources protection and the development of sensitive and rapid analytical methods to identify micropollutants. Endocrine-disrupting compounds (EDCs) have emerged as a major issue as they alter the functioning of the endocrine system. Since ingestion of EDCs via food is considered the major exposure route, there is a growing interest in understanding EDC fate during drinking water treatment and in monitoring potential contamination of surface waters and groundwaters. In this work, a fast liquid chromatography-electrospray ionization-tandem mass spectrometry method was developed for the determination of 4-n-nonylphenol (NP), bisphenol A (BPA), estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in drinking waters. In the literature analytical articles seldom provide details regarding fragmentation pathways. In this paper spectra of the five EDCs in negative ESI were interpreted with the support of accurate mass spectra acquired by a quadrupole time-of-flight instrument; fragmentation pathways were also proposed. The chromatographic separation of EDCs was optimized on a Pinnacle DB Biphenylic column with a water-acetonitrile gradient. Quantitative analysis was performed in multiple reaction monitoring (MRM) mode using bisphenol A-d(16) (BPA-d(16)) as internal standard; calibration curves showed good correlation coefficients (0.9989-0.9997). All figures of merit of the method were satisfactory; limits of detection were in the range 0.2-0.4 ng/ml. The method was applied to the determination of the analytes in waters sampled by polar organic chemical integrative samplers in a drinking water treatment plant. Rather low concentration of BPA, NP and E1 were measured in the inlet, while none of the considered EDCs was detected in the outlet.

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“…Ultrafiltration LC-MS screening was used to assess the binding of lycopene to the AR ccr in comparison with testosterone as a positive control based on the method of Sun et al (30) with the following modifications. Human AR ccr ligand-binding domain (0.667 Amol/L) was incubated with testosterone or lycopene (1 Amol/L) in 50 mmol/L Tris buffer (pH 7.5), 0.8 mol/L NaCl, 10% glycerol, and 1 mmol/L DTT for 1 hour at 23jC.…”

Section: Subcellular Distribution Of Lycopenementioning

confidence: 99%

Absorption and subcellular localization of lycopene in human prostate cancer cells

Liu

Pajkovic

Pang

et al. 2006

Molecular Cancer Therapeutics

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Lycopene, the red pigment of the tomato, is under investigation for the chemoprevention of prostate cancer. Because dietary lycopene has been reported to concentrate in the human prostate, its uptake and subcellular localization were investigated in the controlled environment of cell culture using the human prostate cancer cell lines LNCaP, PC-3, and DU145. After 24 hours of incubation with 1.48 Mmol/L lycopene, LNCaP cells accumulated 126.6 pmol lycopene/million cells, which was 2.5 times higher than PC-3 cells and 4.5 times higher than DU145 cells. Among these cell lines, only LNCaP cells express prostate-specific antigen and fully functional androgen receptor. Levels of prostate-specific antigen secreted into the incubation medium by LNCaP cells were reduced 55% as a result of lycopene treatment at 1.48 Mmol/L. The binding of lycopene to the ligand-binding domain of the human androgen receptor was carried out, but lycopene was not found to be a ligand for this receptor. Next, subcellular fractionation of LNCaP cells exposed to lycopene was carried out using centrifugation and followed by liquid chromatography-tandem mass spectrometry quantitative analysis to determine the specific cellular locations of lycopene. The majority of lycopene (55%) was localized to the nuclear membranes, followed by 26% in nuclear matrix, and then 19% in microsomes. No lycopene was detected in the cytosol. These data suggest that the rapid uptake of lycopene by LNCaP cells might be facilitated by a receptor or binding protein and that lycopene is stored selectively in the nucleus of LNCaP cells.

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Ultrafiltration tandem mass spectrometry of estrogens for characterization of structure and affinity for human estrogen receptors

Cited by 74 publications

References 43 publications

Comparison of the in Vitro Estrogenic Activities of Compounds from Hops (Humulus lupulus) and Red Clover (Trifolium pratense)

Comparison of the in Vitro Estrogenic Activities of Compounds from Hops (Humulus lupulus) and Red Clover (Trifolium pratense)

Determination of endocrine‐disrupting compounds in drinking waters by fast liquid chromatography–tandem mass spectrometry

Absorption and subcellular localization of lycopene in human prostate cancer cells

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