Correction to: Interaction of soy isoflavones and their main metabolites with hOATP2B1 transporter (original) (raw)
Related papers
Cancer Epidemiology Biomarkers & Prevention, 2009
Introduction: In Asian and Asian-American women, soy consumption is associated with reduced breast cancer risk, perhaps due to its effects on estrogen production or metabolism. In a sample of Asian-American women, we investigated the associations of usual adult soy intake with the urinary concentrations of 15 estrogens and estrogen metabolites (EM) measured using liquid chromatography-tandem mass spectrometry. Methods: Participants included 430 Chinese-American, Japanese-American, and Filipino-American women, ages 20 to 55 years, and living in San Francisco-Oakland (California), Los Angeles (California), or Oahu (Hawaii). They were postmenopausal (n = 167) or premenopausal in luteal phase (n = 263) when 12-hour urine samples were collected. Robust linear regression was used to assess soy tertiles as predictors of log-transformed EM measures. Individual and grouped EM were considered as concentrations (pmol/mg creatinine) and as percentages of total EM (%EM). Results: Factor analysis confirmed that EM groups defined by metabolic pathways appropriately captured covariation in EM profiles. Total EM concentrations were not significantly associated with soy in premenopausal or postmenopausal women. Among all women, %2hydroxylated EM and %4-hydroxylation pathway EM were 16% higher (P trend = 0.02) and 19% higher (P trend = 0.03) in the highest versus lowest soy tertiles, respectively. In contrast, 16% hydroxylated EM were 11% lower (P trend < 0.01). Results were consistent across ethnic and menopausal groups and after adjustment for westernization measured by birthplace (Asia or United States). Discussion: Findings suggest that regular soy intake is associated with increased ratios of 2:16-pathway EM and with higher relative levels of 4-hydroxylated EM. The observed variations in estrogen metabolism might modify breast cancer risk.
Soy isoflavones: a safety review
Nutrition …, 2003
Soy isoflavones have been a component of the diet of certain populations for centuries. The consump-tion of soy generally has been considered benefi-cial, with a potentially protective effect against a number of chronic diseases; because of their es-trogenic activity, ...
Dietary Soy Isoflavone: A Mechanistic Insight
Natural product communications, 2017
Soy, a major component of the diet for centuries contains the largest concentration of isoflavones, a class of phytoestrogens. A variety of health benefits are associated with the consumption of soy primarily because of the isoflavones genistein, daidzein, and glycitein with a potential protective effect against a number of chronic diseases. Owing to the pharmaceutical and nutraceutical properties allied with isoflavonoids and their use in functional foods, there is a growing interest in these compounds. This review throws light on the chemistry, and significant pharmacological and biopharmaceutical aspects of soy isoflavones. This article critically describes the mechanisms of action, infers conclusions and shows opportunity for future research.
The Journal of Nutrition, 2002
Equol [7-hydroxy-3-(4Ј-hydroxyphenyl)-chroman] is a nonsteroidal estrogen of the isoflavone class. It is exclusively a product of intestinal bacterial metabolism of dietary isoflavones and it possesses estrogenic activity, having affinity for both estrogen receptors, ER␣ and ER. Equol is superior to all other isoflavones in its antioxidant activity. It is the end product of the biotransformation of the phytoestrogen daidzein, one of the two main isoflavones found in abundance in soybeans and most soy foods. Once formed, it is relatively stable; however, equol is not produced in all healthy adults in response to dietary challenge with soy or daidzein. Several recent dietary intervention studies examining the health effects of soy isoflavones allude to the potential importance of equol by establishing that maximal clinical responses to soy protein diets are observed in people who are good "equol-producers." It is now apparent that there are two distinct subpopulations of people and that "bacteriotyping" individuals for their ability to make equol may hold the clue to the effectiveness of soy protein diets in the treatment or prevention of hormone-dependent conditions. In reviewing the history of equol, its biological properties, factors influencing its formation and clinical data, we propose a new paradigm. The clinical effectiveness of soy protein in cardiovascular, bone and menopausal health may be a function of the ability to biotransform soy isoflavones to the more potent estrogenic isoflavone, equol. The failure to distinguish those subjects who are "equol-producers" from "nonequol producers" in previous clinical studies could plausibly explain the variance in reported data on the health benefits of soy. J. Nutr. 132: 3577-3584, 2002.
The Journal of Nutrition, 2007
The transport and metabolism of xenobiotics is controlled by the drug transporters and drug-metabolizing enzymes in the liver and small intestine. Expression of these genes is 1 factor affecting the half-life of drugs and xenobiotics. Isoflavonecontaining soyfood products and supplements are promoted to treat several different health conditions, including improvement of blood lipid profiles. Because relatively high isoflavone intake may be possible via use of supplements, we tested the hypothesis that isoflavones regulate the expression of genes critical to drug transport and metabolism. Using a gene array screening method, 2 drug transporters, Multidrug restistant-1 and Multidrug-related protein-2; 3 phase I enzymes, cytochrome 1A1, 3A4, and 8B1; and 2 phase II enzymes, carbohydrate sulfotransferase-5 and glutathionesulfotransferase-2, were upregulated 3-fold or more of the initial expression levels in primary human hepatocytes exposed to soy isoflavones for 48 h. Isoflavone-related induction of 12-a-hydroxylase (CYP8B1) was further studied in other in vitro and murine in vivo models. Transfection studies suggest that isoflavones may act as a weak activating ligand for hepatocyte nuclear factor 4a, which in turn may activate the transcription of CYP8B1. The action of soy isoflavones on CYP8B1 may increase the conversion of cholesterol into bile acids and enhance synthesis of cholic acid. These isoflavoneinduced changes in gene expression may help explain how isoflavones modulate cholesterol metabolism.
Soy isoflavones--phytoestrogens and what else?
The Journal of nutrition, 2004
The weak estrogen-like properties of isoflavonoids were discovered over 50 y ago. In recent years, the overall effects of the isoflavones in soy on human health have been the subject of lively debate largely based on their presumed estrogenic properties. Missing from our knowledge base is the systematic identification of the cellular and biochemical targets of isoflavones and the mechanisms that they influence. Because of the benign effects of isoflavones on cellular integrity, a concentration of the isoflavones can be reached in cell culture models where almost any process can be modulated. Modern systems biology approaches and high dimensional analysis techniques offer new ways to better understand the function of how cells and integrated biological mechanisms respond to compounds such as isoflavones. Data from experiments using DNA microarray analysis for examining the effects of genistein in the developing rat uterus indicate that genistein alters the expression of 6-8 times as ...
Absorption, distribution, metabolism, and excretion of isoflavonoids after soy intake
Archives of biochemistry and biophysics, 2014
Soy is the major source of dietary exposure to isoflavonoids (IFLs). Accumulating evidence supports a role for soy and IFLs in the protection against many chronic diseases including cancer. After soy intake we found a biphasic IFL appearance pattern in plasma as well as in urine that we suggest to be due to IFL absorption in the small intestine (ca. 10%) during the first 2h after intake and IFL absorption in the large intestine (ca. 90%) 4-6 h after intake. While each IFL disappears from the circulation at different times excellent correlations between urinary and circulating IFL values were discovered and algorithms to convert urinary excretion values into circulating levels were established. We suggest the term 'apparent bioavailability' when using urinary data to describe IFL exposure. The IFL bioavailability was found to be influenced by gut bacteria, oral antibiotic treatment (OABX), and an individual's age and health status. While daidzein (DE) and genistein start ...
Overview of the chemistry of soy isoflavones, potential threats and potential therapeutic benefits
2010
Isoflavones are phytochemicals that have properties similar to estrogens. They are bioflavonoids. Isoflavones, flavones and coumestans are the most abundant phytoestrogens in the human diet, and soy is by far the richest source of these compounds. The principle soy isoflavones are genistein, daidzein, and their metabolites. Soy isoflavones are naturally occurring non-steroidal compound which are structurally similar to endogenous gonadal steroid 17β-estradiol. They trigger estrogen dependent physiological responses. As result of these actions, there is currently much interest within the scientific community regarding the chemistry, threats and health benefits of dietary soy isoflavones.