• Food Science and Biotechnology
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• v.18 no.1
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• pp.245-248
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• 2009

Present study was investigated the hepatic effects of equol on the 7,12-dimethylbenz(a)anthracene (DMBA)-induced enzymatic activity and expression of CYP1A1 and CYP1B1 in mice. Equol was administered orally at 5 and 25 mg/kg BW for 4 weeks. Subsequently, mice pretreated with equol received DMBA intragastrically twice a week for 2 weeks. DMBA induced CYP1 activity as well as the expression of CYP1A1 and CYP1B1. Each of these effects was significantly reduced by equol in dose-dependent manner (p<0.05). Equol also reduced the relative AhR mRNA expression, similar to its effect on CYP1A1. These results suggest that equol modulates the CYP1A1 through a reduction of AhR expression in mice treated with DMBA.

• Molecules and Cells
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• v.39 no.10
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• pp.742-749
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• 2016

The cancer chemo-preventive effects of equol have been demonstrated for a wide variety of experimental tumours. In a previous study, we found that equol inhibited proliferation and induced apoptotic death of human gastric cancer MGC-803 cells. However, the mechanisms underlying equol-mediated apoptosis have not been well understood. In the present study, the dual AO (acridine orange)/EB (ethidium bromide) fluorescent assay, the comet assay, MTS, western blotting and flow cytometric assays were performed to further investigate the pro-apoptotic effect of equol and its associated mechanisms in MGC-803 cells. The results demonstrated that equol induced an apoptotic nuclear morphology revealed by AO/EB staining, the presence of a comet tail, the cleavage of caspase-3 and PARP and the depletion of cIAP1, indicating its pro-apoptotic effect. In addition, equol-induced apoptosis involves the mitochondria-dependent cell-death pathway, evidenced by the depolarization of the mitochondrial membrane potential, the cleavage of caspase-9 and the depletion of Bcl-xL and full-length Bid. Moreover, treating MGC-803 cells with equol induced the sustained activation of extracellular signal-regulated kinase (ERK), and inhibiting ERK by U0126, a MEK/ERK pathway inhibitor, significantly attenuated the equol-induced cell apoptosis. These results suggest that equol induces mitochondria-dependent apoptosis in human gastric cancer MGC-803 cells via the sustained activation of the ERK1/2 pathway. Therefore, equol may be a novel candidate for the chemoprevention and therapy of gastric cancer.

• Mycobiology
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• v.38 no.4
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• pp.328-330
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• 2010

In this study, we demonstrate that equol has fungicidal activities against Candida albicans. The minimum inhibitory and minimum fungicidal concentrations of equol against C. albicans were 516 and $1,032{\mu}M$, respectively. Two separate viability assays found that equol changed the integrity of the C. albicans cell membrane, possibly by formation of membrane lesions. Scanning electron microscopy demonstrated ultrastructural changes.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.1-4
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• 2013

Background: The age-adjusted incidence rate of prostate cancer (PCa) has been reported to be lower among Asians than Western populations. A traditional Japanese meal, high in soybean products or isoflavones, may be associated with a decreased risk of PCa. Equol, which is converted from daidzein by human intestinal flora, is biologically more active than any other isoflavone aglycone. Materials and Methods: We reviewed not only recent epidemiological studies on association of isoflavones with PCa risk, but also recent research on human intestinal bacteria responsible for converting daidzein into equol. Studies were systematically searched from the database published within the last 5 years of from 2008-2012. Results: Five out of 6 articles showed significant association of isoflavones with a decreased risk of PCa, and two of them consistently showed that equol-producers carry a significantly reduced risk of PCa. Furthermore, 5 human intestinal bacteria that can convert daidzein into equol were identified in the last 5 years. Conclusions: If equol can reduce risk of PCa, a possible strategy for reducing the risk of PCa may be to increase the proportion of equol-producers by changing the intestinal flora to carrying an equol-producing bacterium with dietary alteration or probiotic technology.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.854-859
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• 2005

Although action modes of equol and genistein have been extensively studied, their precise roles in tumor cells remain elusive. To address possible effects of these compounds on protein expression in mammary tumor cells, proteins modulated in MCF-7 mammary tumor cells when incubated in absence and presence of 10 uM equol or genistein were identified through 2-dimensional gel electrophoresis, MALDI-TOF MS/MS, and NCBInr database search using Mascot software. Most proteins differentially expressed in MCF-7 cells after treatment with 10 uM genistein or equol were identified as being the same. Exposure to both compounds caused decreased cellular expression of RNA-binding protein regulatory subunit and oncogene DJ1 tubulin beta-1 chain, and increased expression of heterogeneous ribonucleoproteins F and L, KH-type splicing regulatory protein, and translation elongation factor EF-Tu precursor. Genistein and equol at dose used in this study showed common action mechanism.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.286-291
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• 2015

Equol has beneficial effects on human health. Fermented soy products contain equol, and many microbes participate in the equol production process. This study investigated fermented Korean soybean paste, doenjang. Thirty seven doenjang samples collected from different manufacturers were examined. Equol was detected in 3 samples (D2, D13, and D19) at the maximum content of 507 ng/100 g by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Fifteen microbial species were isolated and identified by 16S rRNA gene sequence analysis and by matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Bacillus spp, Paenibacillus spp, Tetragenococcus spp, Stapylococcus spp, and Clostridium species were the predominant bacteria in equol containing doenjang samples.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2693-2697
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• 2014

Background: Isoflavones, which are included in soybeans, have been suggested to protect against prostate cancer. Equol, one of isoflavones, is an intestinally derived bacterial metabolite of daidzein. A newly identified equol-producing bacterium, Slackia sp. strain NATTS, with a high equol-producing activity was isolated from human feces in Japanese adults. Counts of Slackia sp. strain NATTS in intestinal flora have not been assessed with regard to prostate cancer risk. In this study, we investigated the association of serum isoflavones and counts of Slackia sp. strain NATTS with prostate cancer risk in a case-control study. Materials and Methods: Concentrations of isoflavones and counts of Slackia sp. strain NATTS in feces were measured from 44 patients with prostate cancer and 28 hospital controls. The risk of prostate cancer was evaluated in terms of odds ratios (ORs) and 95% confidence intervals (CIs) by the logistic regression analysis. Results: The detection proportions of Slackia sp. strain NATTS in cases and controls were 34.1% and 25.0%, respectively. Counts of Slackia sp. strain NATTS were significantly correlated with serum concentrations of equol both in cases and controls (Spearman correlation coefficients, $r_s$=0.639 and $r_s$=0.572, p<0.01, respectively). Serum concentrations of genistein, daidzein, glycitein, and equol were not significantly associated with risk of prostate cancer. Conclusions: This study found that counts of Slackia sp. strain NATTS correlated with serum concentrations of equol both in prostate cancer cases and controls, but serum isoflavone concentrations were not associated with risk of prostate cancer in our patients.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.125-131
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• 2016

Pueraria lobata is a perennial legume plant that produces a variety of isoflavones, such as puerarin, daidzin and daidzein. These are metabolized to equol via dihydrodaidzein and tetrahydrodaidzein by the bacterial fermentation of natural isoflavone sources in the human intestines. In this study, we described the growth and accumulation of isoflavone in the hairy root of the Korean wild arrowroot according to the culture period, as well as dihydrodaidzein biosynthesis in hairy root extracts fermented with Pediococcus pentosaceus. Daily proliferation was best in DY1 cultured for 1 week. DY1 showed significant differences in daily production of puerarin and daidzin+daidzein, as compared to DJ7; furthermore, both were best in DY1 cultured for 1 week. The hairy root extract was fermented successfully with P. pentosaceus with confirmed production of dihydrodaidzein, an equol precursor formed by biotransformation. The results indicated that the growth of hairy roots and isoflavone accumulation in the hairy roots is best 1 week after culture. These results are expected to contribute to the mass production of hairy root and isoflavones as equol precursors from the Korean wild arrowroot and provide a basis for equol production by biotransformation in vitro.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2191-2199
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• 2013

Breast cancer is one of the most frequently diagnosed cancers and the leading cause of cancer death among women. Soy isoflavones have been widely studied and among all isoflavones equol has been gaining interest with regard to its relationship with breast cancer risk. Obesity has been revealed as one of the breast cancer risk factors, known to be associated with high levels of circulating insulin and decreased levels of adiponectin. Hence there have been many studies investigating relationships between insulin and adiponectin levels and breast cancer risk. Additionally recent findings have suggested that insulin and adiponectin themselves may have influence on breast cancer development, independent of obesity. In the present review, we discuss the relationships between breast cancer risk and equol, insulin and adiponectin levels, which are three important factors in our ongoing hospital-based case-control study. Herein these factors are reviewed not only from the clinical viewpoint but also from possible chemical and biological points of view which may explain clinical observations.

• Journal of Applied Biological Chemistry
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• v.51 no.6
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• pp.253-261
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• 2008

Isoflavone daidzein is a phytoestrogen widely distributed in Leguminosae and is especially rich in the soybean. The C6-C3 (rings B and C) unit of isoflavones is derived from the phenylpropanoid pathway and the remaining C6 (ring A) unit is from the polyketide pathway. This unique carbon skeleton is the result of isomerization of the flavone catalyzed by the isoflavone synthase, a cytochrome P450 enzyme. The isoflavones daidzein and genistein are present in the plant mostly in the glucosylated forms. However, in the human intestine, the glycosidic linkage is broken, and the free form is uptaked into blood stream. The free form is further metabolized into various reduction products to end up at the equol, which is known to have the most potent estrogenic effect among the metabolites. Several human intestinal bacteria that can convert daidzein into equol have been described, and the study into the chemistry and biochemistry of the daizein reduction would be rewarding to the improvement of the human health.