Soya phytoestrogens, genistein and daidzein, decrease apolipoprotein B secretion from HepG2 cells through multiple mechanisms

Genistein prevents the production of hypospadias induced by Di-(2-ethylhexyl) phthalate through androgen signaling and antioxidant response in rats

Environmental estrogen exposure has increased dramatically over the past 50 years. In particular, prenatal exposure to estrogen causes many congenital diseases, among which reproductive system development disorders are extremely serious. In this study, the molecular mechanism of hypospadias and the therapeutic effect of genistein (GEN) were investigated through in vivo models prepared by Di-(2-ethylhexyl) phthalate (DEHP) exposure between 12 and 19 days of gestation. With increased DEHP concentrations, the incidence of hypospadias increased gradually. DEHP inhibited the key enzymes involved in steroid synthesis, resulting in decreasing testosterone synthesis. At the same time, DEHP increased reactive oxygen species (ROS) and produced inflammatory factors via NADPH oxidase-1 (NOX1) and NADPH oxidase-4 (NOX4) pathways. It also inhibited Steroid 5 α Reductase 2 (Srd5α2) and decreased dihydrotestosterone (DHT) synthesis. Additionally, DEHP inhibited the androgen receptor (AR), resulting in reduced DHT binding to the AR that ultimately retarded the development of the external reproductive system. GEN, a phytoestrogen, competes with DEHP for binding to estrogen receptor β (ERβ). This competition, along with GEN's antiestrogen and antioxidant properties, could potentially reverse impairments. The findings of this study provide valuable insights into the role of phytoestrogens in alleviating environmental estrogen-induced congenital diseases.

Epigenetics and the role of nutraceuticals in health and disease

In the post-genomic era, the data provided by complete genome sequencing could not answer several fundamental questions about the causes of many noninfectious diseases, diagnostic biomarkers, and novel therapeutic approaches. The rapidly expanding understanding of epigenetic mechanisms, as well as widespread acceptance of their hypothesized role in disease induction, facilitated the development of a number of novel diagnostic markers and therapeutic concepts. Epigenetic aberrations are reversible in nature, which enables the treatment of serious incurable diseases. Therefore, the interest in epigenetic modulatory effects has increased over the last decade, so about 60,000 publications discussing the expression of epigenetics could be detected in the PubMed database. Out of these, 58,442 were published alone in the last 10 years, including 17,672 reviews (69 historical articles), 314 clinical trials, 202 case reports, 197 meta-analyses, 156 letters to the editor, 108 randomized controlled trials, 87 observation studies, 40 book chapters, 22 published lectures, and 2 clinical trial protocols. The remaining publications are either miscellaneous or a mixture of the previously mentioned items. According to the species and gender, the publications included 44,589 human studies (17,106 females, 14,509 males, and the gender is not mentioned in the remaining papers) and 30,253 animal studies. In the present work, the role of epigenetic modulations in health and disease and the influencing factors in epigenetics are discussed.

Genistein Up-Regulates the Expression of EGF and E-Cadherin in the Treatment of Senile Vaginitis

Investigating the therapeutic effect of genistein (Gen) on postmenopausal senile vaginitis (SV) and its mechanism of action. Adult SPF female Wistar rats were selected to establish a bilateral ovariectomized animal model (OVX), which simulated senile vaginitis dominated by estrogen deficiency in ovarian dysfunction. After 14 days of continuous treatment, the morphology of vaginal epithelial tissue was observed and various types of epithelial cells were counted, and the body mass and uterine and vaginal index of rats were measured. the levels of vaginal tissue secretion, microorganism, hormone and glycogen in each group were measured and the reproductive health was evaluated clinically. The protein expression and mRNA expression of epidermal growth factor (EGF) and E-cadherin (E-cadherin) in vaginal tissues were detected by immunohistochemistry and RT-PCR, respectively. Result showed that Genistein lowered vaginal pH, increased vaginal index and vaginal health score, thickened epithelial layers and improved vaginal tissue atrophy after administration. Genistein also increased the contents of glycogen and Lactobacillus in vagina, and promoted the expression of EGF, E-cadherin protein and mRNA. To sum up, there is no significant change in serum E2 and FSH levels, indicating that genistein has no effect on hormone levels in rats. genistein promoted the proliferation of vaginal epithelial cells, thickened epithelial layers and the vaginal wall, which improved the resistance of vaginal epithelium, the recovery of self-cleaning ability and healed the vaginal wound and erosive surface to improve atrophy.

Sex Differences in Glomerular Protein Expression and Effects of Soy-Based Diet on Podocyte Signaling

Background:

Kidney disease is a major public health issue arising from loss of glomerular podocyte function, and there are considerable sex differences in its prognosis. Evidence suggests a renoprotective effect of estrogen and soy diet-derived phytoestrogens, although the molecular basis for this is poorly understood.

Objective:

Here, we aim to assess sex differences in expression of key proteins associated with podocyte survival and determine the effects of dietary soy on glomerular and podocyte signaling.

Methods:

Male and female FVB mice were fed control, low (1%), and high (20%) doses of isolated soy protein (ISP) in utero and until 100 days of age. Spot urine was collected to measure proteinuria and isolated glomeruli were used to quantify activated and total levels of nephrin, Akt, and ERK1/2. To investigate protective effects of specific soy phytoestrogens, cultured podocytes were treated with or without daidzein and subject to control or high glucose as a model of podocyte injury.

Results:

Nephrin and Akt were elevated at baseline in glomeruli from females compared to males. Both sexes that were fed 1% and 20% ISP displayed robust increases in total glomerular Akt compared to controls, and these effects were more prominent in females. A similar trend at both doses in both sexes was observed with activated Akt and total nephrin. Notably, males exclusively showed increased phosphorylation of nephrin and extracellular signal-regulated kinase (ERK) at the 1% ISP dose; however, no overt changes in urinary albumin excretion or podocin levels were observed, suggesting that the soy diets did not impair podocyte function. Finally, in cultured male and female podocytes, daidzein treatment suppressed high glucose-induced ERK activation.

Conclusions:

Together, our findings reveal a putative mechanism to explain the protective influence of sex on kidney disease progression, and they provide further evidence to support a beneficial role for dietary soy in preserving glomerular function.

Genistein Regulates Lipid Metabolism via Estrogen Receptor β and Its Downstream Signal Akt/mTOR in HepG2 Cells

Genistein (GEN) has been shown to significantly inhibit hepatic triglyceride accretion triggered by estrogen deficiency. The main purpose of this in vitro study was to investigate the function and molecular mechanism of estrogen receptor β (ERβ) in regulating hepatic lipid metabolism induced by GEN. Different doses of GEN or GEN with an ERβ antagonist were treated with HepG2 cells. Results showed that 25 μM GEN significantly diminished triglyceride levels. Meanwhile, GEN downregulated the levels of genes and proteins involved in lipogenesis, such as sterol-regulatory element-binding protein-1c (SREBP-1c), fatty acid synthase (FASN), and stearoyl-coenzyme A desaturase 1 (SCD1), and upregulated the gene and protein levels of the regulation factors responsible for fatty acid β-oxidation, such as carnitine palmitoyltransferase 1α (CPT-1α) and peroxisome proliferator-activated receptor α (PPARα). Furthermore, 25 μM GEN reduced the levels of phosphorylation of protein kinase B (Akt) and mechanistic target of rapamycin (mTOR). Moreover, most of these effects from GEN were reverted by pretreatment with the antagonist of ERβ. In conclusion, GEN improved hepatic lipid metabolism by activating ERβ and further modulation of Akt/mTOR signals. The results provide novel aspects of the regulatory mechanism of ERβ on hepatic lipid metabolism and might help to profoundly understand the functions of food-derived phytoestrogens in preventing and treating hepatic steatosis in postmenopausal women.

Bioactivity of Dietary Polyphenols: The Role in LDL-C Lowering

Cardiovascular diseases are the leading causes of the death around the world. An elevation of the low-density lipoprotein cholesterol (LDL-C) level is one of the most important risk factors for cardiovascular diseases. To achieve optimal plasma LDL-C levels, clinal therapies were investigated which targeted different metabolism pathways. However, some therapies also caused various adverse effects. Thus, there is a need for new treatment options and/or combination therapies to inhibit the LDL-C level. Dietary polyphenols have received much attention in the prevention of cardiovascular diseases due to their potential LDL-C lowering effects. However, the effectiveness and potential mechanisms of polyphenols in lowering LDL-C is not comprehensively summarized. This review focused on dietary polyphenols that could reduce LDL-C and their mechanisms of action. This review also discussed the limitations and suggestions regarding previous studies.

Polyphenols as anticancer agents: Toxicological concern to healthy cells

Polyphenols are a group of diverse chemical compounds present in a wide range of plants. Various biological properties such as antiallergic, antiviral, antibacterial, anticarcinogenic, antiinflammatory, antithrombotic, vasodilatory, and hepatoprotective effect of different polyphenols have been reported in the scientific literature. The major classes of polyphenols are flavonoids, stilbenoids, lignans, and polyphenolic acids. Flavonoids are a large class of food constituents comprising flavones, isoflavanones, flavanones, flavonols, catechins, and anthocyanins sub-classes. Even with seemingly broad biological activities, their use is minimal clinically. Among the other concurrent problems such as limited bioavailability, rapid metabolism, untargeted delivery, the toxicity associated with these polyphenols has been a topic of concern lately. These polyphenols have been reported to result in different forms of toxicity that include organ toxicity, genotoxicity, mutagenicity, cytotoxicity, etc. In the present article, we have tried to unravel the toxicological aspect of these polyphenols to healthy cells. Further high-quality studies are needed to establish the clinical efficacy and toxicology concern leading to further exploration of these polyphenols.

Genistein: Dual Role in Women's Health

Advanced research in recent years has revealed the important role of nutrients in the protection of women's health and in the prevention of women's diseases. Genistein is a phytoestrogen that belongs to a class of compounds known as isoflavones, which structurally resemble endogenous estrogen. Genistein is most often consumed by humans via soybeans or soya products and is, as an auxiliary medicinal, used to treat women's diseases. In this review, we focused on analyzing the geographic distribution of soybean and soya product consumption, global serum concentrations of genistein, and its metabolism and bioactivity. We also explored genistein's dual effects in women's health through gathering, evaluating, and summarizing evidence from current in vivo and in vitro studies, clinical observations, and epidemiological surveys. The dose-dependent effects of genistein, especially when considering its metabolites and factors that vary by individuals, indicate that consumption of genistein may contribute to beneficial effects in women's health and disease prevention and treatment. However, consumption and exposure levels are nuanced because adverse effects have been observed at lower concentrations in in vitro models. Therefore, this points to the duplicity of genistein as a possible therapeutic agent in some instances and as an endocrine disruptor in others.

Intraperitoneal injection of genistein affects the distribution and metabolism of cholesterol in female yellow catfish Tachysurus fulvidraco

Genistein is an abundant phytoestrogen in soybean. This study aimed to determine the effects of genistein on cholesterol distribution and metabolism in female yellow catfish. Three hundred fish (49.2 ± 1.4 g) were randomly divided into five treatments and received intraperitoneal injections as follows: (1) blank, no injection; (2) control, vehicle only; (3) E2, 17β-estradiol at 10 μg·g^-1 body weight; (4) low genistein doses, genistein at 10 μg·g^-1 body weight; (5) high genistein doses, genistein at 100 μg·g^-1 body weight. Both high and low genistein doses significantly reduced (p < 0.05) serum TC and LDL-C 24 h after injection. Moreover, the high genistein doses significantly reduced (p < 0.05) serum HDL-C. Both high and low doses of genistein significantly increased (p < 0.05) hepatic TC. Only high genistein doses significantly increased (p < 0.05) ovary TC. In the liver, both high and low genistein doses significantly increased (p < 0.05) protein and mRNA expression of ldlr. Meanwhile, high genistein doses significantly decreased (p < 0.05) mRNA expression of hmgcr. In ovary tissue, high genistein doses significantly decreased (p < 0.05) mRNA expression of cyp11a1. These results suggested that genistein affected the cholesterol distribution in female yellow catfish. Both high and low doses of genistein reduced cholesterol content in blood and increased its content in the liver by increasing the uptake of blood cholesterol. Meanwhile, high genistein doses may inhibit hepatic cholesterol synthesis. Additionally, high genistein doses could increase cholesterol transfer from serum into the ovary and disturb cholesterol conversion to pregnenolone.

Regulation of Apolipoprotein B by Natural Products and Nutraceuticals: A Comprehensive Review

Cardiovascular Disease (CVD) is the most important and the number one cause of mortality in both developing and industrialized nations. The co-morbidities associated with CVD are observed from infancy to old age. Apolipoprotein B100 (Apo B) is the primary apolipoprotein and structural protein of all major atherogenic particles derived from the liver including Very-Low- Density Lipoproteins (VLDL), Intermediate-density Lipoprotein (IDL), and Low-density Lipoprotein (LDL) particles. It has been suggested that measurement of the Apo B concentration is a superior and more reliable index for the prediction of CVD risk than is the measurement of LDL-C. Nutraceuticals and medicinal plants have attracted significant attention as it pertains to the treatment of non-communicable diseases, particularly CVD, diabetes mellitus, hypertension, and Nonalcoholic Fatty Liver Disease (NAFLD). The effect of nutraceuticals and herbal products on CVD, as well as some of its risk factors such as dyslipidemia, have been investigated previously. However, to the best of our knowledge, the effect of these natural products, including herbal supplements and functional foods (e.g. fruits and vegetables as either dry materials, or their extracts) on Apo B has not yet been investigated. Therefore, the primary objective of this paper was to review the effect of bioactive natural compounds on plasma Apo B concentrations. It is concluded that, in general, medicinal plants and nutraceuticals can be used as complementary medicine to reduce plasma Apo B levels in a safe, accessible, and inexpensive manner in an attempt to prevent and treat CVD.

Functional food mixtures: Inhibition of lipid peroxidation, HMGCoA reductase, and ACAT2 in hypercholesterolemia-induced rats

Mixtures of selected functional foods (MSFF) were composed of nattokinase (fermented soybean), red yeast rice extract, Ginkgo biloba, oat fiber, garlic, bee pollen, and propolis as anti-hypercholesterolemic were studied. The goal of this study was to determine the bioactive compounds in these mixtures and their cholesterol-lowering potential effects (biochemical profiles, lipid peroxidation, liver tissue histopathology, and enzymatic activity analysis; HMGCoA reductase and ACAT2. The LC-MS/MS analysis showed that bioactive compounds such as Monacolin K, naringin, tocopherol, and glutamate, which have potential as anti-hypercholesterolemic agents, were present in these functional food mixtures. MSFF supplementation at 50 mg/kg 100 mg/kg and 200 mg/kg showed substantial reductions in serum lipid profiles (TC and LDL) (p < .05). The serum liver profiles of AST (115.33 ± 8.69 U/L) and ALT (61.00 ± 1.00 U/L) were significantly reduced (p < .05) with MSFF supplementation at 200 mg/kg. MDA lipid peroxidation has also decreased significantly (p < .05) in serum (3.69 ± 0.42 μmol/L) and liver (15.04 ± 0.97 μmol/mg) tissues and has been shown to protect against hepatic steatosis. The significant (p < .05) inhibition activity of HMGCoA reductase (163.82 ± 3.50 pg/ml) and ACAT2 (348.35 ± 18.85 pg/ml) was also attributed by the supplementation of MSFF at 200 mg/kg.

Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products

Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.

Effect of Genistein on Cholesterol Metabolism-Related Genes in HepG2 Cell

It has been reported that genistein could improve metabolic syndromes. Our study aimed to investigate the effects and potential mechanisms of genistein on improving cholesterol metabolism in HepG2 cell. HepG2 cells were cultured with 0, 0.01, 1.00, 10.00, and 50.00 µM genistein for 24 hr. The current results showed a dose-dependent manner between genistein and intracellular contents of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), and cellular apolipoprotein A1 (Apo-A1) secretion. TC was increased by 25.69%, meanwhile HDL-C and Apo-A1 were decreased by 56.00% and 25.93%, respectively, when the dosage of genistein was 1.00 µM. Genistein dose-dependently upregulated the protein and mRNA levels of sterol regulatory element binding proteins-2 (SREBP-2), as well as the mRNA levels of low-density lipoprotein receptor (LDLR) and 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGCR), by 145.91%, 72.29%, 310.23%, and 123.08%, respectively, when we gave 1.00 µM genistein, indicating that intracellular cholesterol synthesis and absorption of exogenous cholesterol were increased. In addition, the mRNA levels of peroxisome proliferator-activated receptor-γ (PPARγ) and liver X receptor (LXRα), lowered by 58.23% and 34.86% at 0.01 µM genistein, were reduced in a dose-dependent manner. LXRα and ATP-binding cassette transporter A1 (ABCA1) protein levels were significantly (P < 0.05) decreased by 50.35% and 11.60% at 1.00 µM genistein, which indicated that cellular cholesterol efflux was inhibited. Taken together, our results suggested that genistein at dosage of more than 1.00 µM was able to increase the intracellular cholesterol levels by up regulating SREBP-2/LDLR/HMGCR pathway and suppressing PPARγ/LXRα/ABCA1 pathway. PRACTICAL APPLICATION: In this study, genistein appeared to be effective in reducing plasma cholesterol levels due to increase the intracellular cholesterol levels by upregulating cholesterol absorption through SREBP-2/LDLR/HMGCR pathway, and also downregulating cholesterol efflux via PPARγ/LXRα/ABCA1 pathway in vitro. In addition, plasma cholesterol is regarded as the key indicator of atherosclerosis; therefore, we believe that our findings could be used for further exploration on a possible therapeutic application of genistein for atherosclerosis.

Is Chickpea a Potential Substitute for Soybean? Phenolic Bioactives and Potential Health Benefits

Legume seeds are rich sources of protein, fiber, and minerals. In addition, their phenolic compounds as secondary metabolites render health benefits beyond basic nutrition. Lowering apolipoprotein B secretion from HepG2 cells and decreasing the level of low-density lipoprotein (LDL)-cholesterol oxidation are mechanisms related to the prevention of cardiovascular diseases (CVD). Likewise, low-level chronic inflammation and related disorders of the immune system are clinical predictors of cardiovascular pathology. Furthermore, DNA-damage signaling and repair are crucial pathways to the etiology of human cancers. Along CVD and cancer, the prevalence of obesity and diabetes is constantly increasing. Screening the ability of polyphenols in inactivating digestive enzymes is a good option in pre-clinical studies. In addition, in vivo studies support the role of polyphenols in the prevention and/or management of diabetes and obesity. Soybean, a well-recognized source of phenolic isoflavones, exerts health benefits by decreasing oxidative stress and inflammation related to the above-mentioned chronic ailments. Similar to soybeans, chickpeas are good sources of nutrients and phenolic compounds, especially isoflavones. This review summarizes the potential of chickpea as a substitute for soybean in terms of health beneficial outcomes. Therefore, this contribution may guide the industry in manufacturing functional foods and/or ingredients by using an undervalued feedstock.

Anti-inflammatory activity of elicited soybean (Glycine max) extract on Balb/C mice (Mus musculus) with high-fat and -fructose diet

Obesity causes adipocyte hypertrophy, which leads to cell death. Consequently, macrophages and lymphocytes infiltrate into the adipose tissue and elevate pro-inflammatory cytokine production through TLR activation. This study aimed to determine the efficacy of soybean extract, which was elicited by Saccharomyces cerevisiae and light, as an anti-inflammatory agent in mice with a high-fat and -fructose diet (HFFD). The elicited soybean extract (ESE) was administered orally to mice for four weeks after being given an HFFD for 20 weeks. Three different doses were used: (1) low-dose (78 mg/kg BW); (2) normal dose (104 mg/kg BW); and (3) high dose (130 mg/kg BW). HFFD mice model treated with simvastatin 2.8 mg/kg BW considered as drug control. After 24 weeks, the lymphocytes were isolated and the relative number of CD4⁺TLR3⁺ T, CD4⁺TLR4⁺ T, CD4⁺TNF-α⁺ T, and CD4⁺IFN-γ⁺ T cells were analysed using flow cytometry. The results showed that the HFFD mouse model had an increased number of CD4⁺TLR3⁺ T, CD4⁺TLR4⁺ T, CD4⁺TNF-α⁺ T, and CD4⁺IFN-γ⁺ T cells. ESE administration decreased the relative number of CD4⁺TLR3⁺ T, CD4⁺TLR4⁺ T, CD4⁺TNF-α⁺ T, and CD4⁺IFN-γ⁺ T cells. The normal dose of ESE is the most effective dose in suppressing inflammation compared to positive controls. ESE 104 mg/kg BW can be considered as an alternative herbal medicine that may suppress inflammation in HFFD mice.

The effects of Pueraria mirifica extract, diadzein and genistein in testosterone-induced prostate hyperplasia in male Sprague Dawley rats

Pueraria mirifica (PM) is a medicinal plant native to Thailand contained high amount of phytoestrogen and possesses anticancer activity. This study reports the effect of P. mirifica extract, phytoestrogen of diadzein and genistein for its benign prostate hyperplasia properties in testosterone-induced prostate hyperplasia in male Sprague Dawley rats. The P. mirifica extract was evaluated for its total phenols, flavonoid and antioxidant activity using DPPH, FRAP and metal chelating assay. The assessment of P. mirifica, diadzein and genistein against benign prostate hyperplasia was determined in testosterone-induced prostate hyperplasia in male Sprague Dawley rats. The total phenol was higher than flavonoid but showed low antioxidant activity of DPPH, FRAP and metal chelating. The aqueous PM extract at 1000 mg/kg significantly increased testosterone levels in testosterone-induced rats by 13% while diadzein and genistein increased it by 11% and 17% respectively. However, levels of FSH, LH, triglyceride and HDL are not affected by the oral administration of PM, diadzein and genistein to the rats. Similarly, total protein, albumin, globulin, total bilirubin, conjugated bilirubin, alkaline phosphatase, alanine aminotransferase, AST, and G-glutamyltransferase showed no significant difference as compared with negative control rats. The body weight of the rats, testis, kidney and liver showed no toxic effect. The zinc content increased significantly and the zinc transporter gen of ZnT4 and ZIP4 highly expressed suggesting that the PM, diadzein and genistein plays essential role in modulating prostate zinc homeostasis. Similarly, the expression of IL-6, AR and ER was significantly reduced indicating functioning in regulation of prostate growth and acts as anti-inflammatory role in preventing BPH. In conclusion, the results indicated that PM reduced BPH and contributed to the regulation in the zinc transport expression of the prostate cells in the benign prostate hyperplasia (BPH).

The Effect of Soy Isoflavones on Steroid Metabolism

Objective: This study is a post-hoc analysis of steroid hormones before and after administration of pharmacological doses of soy isoflavones in a large cohort of men and women from two independent studies. Isoflavones are reported to inhibit mineralo- and glucocorticoid hormone production as well as reproductive steroids in vivo and in vitro. We focused on cytochrome P450 17α-hydroxylase (CYP17A1) which catalyses the production of dehydroepiandrosterone (DHEA), in the androgen biosynthesis pathway to elucidate effects on sex steroids in vitro. Design and Setting: Effects of soy isoflavones on steroid levels in two studies comprising 400 patients were examined: 200 men (study 1; 3 months duration) and 200 postmenopausal women (study 2; 6 months duration), randomized to consume 15 g soy protein with 66 mg isoflavones (SPI) or 15 g soy protein alone without isoflavones (SP) daily. Effects of genistein and daidzein on steroid metabolism were determined in vitro, in HEK293 cells expressing CYP17A1 and in the human adrenocortical carcinoma H295R cell model. Results: SPI decreased serum dehydroepiandrosterone sulfate (DHEAS) levels in both men and women (P < 0.01), with decreased androstenedione (A4) (P < 0.01) in women not observed in men (P < 0.86). Cortisol, cortisone, 11-deoxycortisol, aldosterone, testosterone (T), or estradiol (E2) levels were unchanged. The dual hydroxylase and lyase activity of CYP17A1, which catalyses the biosynthesis of androgen precursors, and 3β-hydroxysteroid dehydrogenase (3βHSD2) were investigated in vitro. In transiently transfected HEK293 cells, only the lyase activity was inhibited by both genistein, 20% (P < 0.001) and daidzein, 58% (P < 0.0001). In forskolin-stimulated H295R cells DHEA production was decreased by daidzein (P < 0.05) and genistein, confirming inhibition of the lyase activity by the isoflavones. Conclusion: In Vivo clinical data suggested inhibition of CYP17A1 17,20 lyase within the adrenal in men and within the ovary and adrenal in females. This was confirmed in vitro with inhibition of the lyase activity by both genistein and daidzein. In addition, 3βHSD2 was inhibited perhaps accounting for decreased A4 levels observed in females. The decreased DHEAS and A4 levels together with the inhibition of the 17,20 lyase activity of CYP17A1, may impact production of androgens in clinical conditions associated with androgen excess. ISRCTN number: ISRCTN55827330 ISRCTN number: ISRCTN 90604927.

In vitro exploration of ACAT contributions to lipid droplet formation during adipogenesis

As adipose tissue is the major cholesterol storage organ and most of the intracellular cholesterol is distributed to lipid droplets (LDs), cholesterol homeostasis may have a role in the regulation of adipocyte size and function. ACATs catalyze the formation of cholesteryl ester (CE) from free cholesterol to modulate the cholesterol balance. Despite the well-documented role of ACATs in hypercholesterolemia, their role in LD development during adipogenesis remains elusive. Here, we identify ACATs as regulators of de novo lipogenesis and LD formation in murine 3T3-L1 adipocytes. Pharmacological inhibition of ACAT activity suppressed intracellular cholesterol and CE levels, and reduced expression of genes involved in cholesterol uptake and efflux. ACAT inhibition resulted in decreased de novo lipogenesis, as demonstrated by reduced maturation of SREBP1 and SREBP1-downstream lipogenic gene expression. Consistent with this observation, knockdown of either ACAT isoform reduced total adipocyte lipid content by approximately 40%. These results demonstrate that ACATs are required for storage ability of lipids and cholesterol in adipocytes.

Flavonoids and Their Metabolites: Prevention in Cardiovascular Diseases and Diabetes

The occurrence of atherosclerosis and diabetes is expanding rapidly worldwide. These two metabolic disorders often co-occur, and are part of what is often referred to as the metabolic syndrome. In order to determine future therapies, we propose that molecular mechanisms should be investigated. Once the aetiology of the metabolic syndrome is clear, a nutritional intervention should be assessed. Here we focus on the protective effects of some dietary flavonoids, and their metabolites. Further studies may also pave the way for development of novel drug candidates.

Not lost in translation: Emerging clinical importance of the G protein-coupled estrogen receptor GPER

It has been 20years that the G protein-coupled estrogen receptor (GPER) was cloned as the orphan receptor GPR30 from multiple cellular sources, including vascular endothelial cells. Here, I will provide an overview of estrogen biology and the historical background leading to the discovery of rapid vascular estrogen signaling. I will also review the recent advances in the understanding of the mechanisms underlying GPER function, its role in physiology and disease, some of the currently available GPER-targeting drugs approved for clinical use such as SERMs (selective estrogen receptor modulators) and SERDs (selective estrogen receptor downregulators). Many of currently used drugs such as tamoxifen, raloxifene, or faslodex™/fulvestrant were discovered targeting GPER many years after they had been introduced to the clinics for entirely different purposes. This has important implications for the clinical use of these drugs and their modes of action, which I have termed 'reverse translational medicine'. In addition, environmental pollutants known as 'endocrine disruptors' have been found to bind to GPER. This article also discusses recent evidence in these areas as well as opportunities in translational clinical medicine and GPER research, including medical genetics, personalized medicine, prevention, and its theranostic use.

Genistein upregulates LDLR levels via JNK-mediated activation of SREBP-2

Background

Genistein has been proved in vitro and in vivo to lower LDLR level. It is also widely consumed and implicated for its anti-atherogenic effects. However, the molecular mechanism by which genistein lowers the LDL level is still unknown.

Objective

To understand the anti-atherogenic molecular mechanism of action, genistein was investigated for its impact on the expression of LDLR, the receptor for LDL cholesterol, and related signaling pathways in a human hepatoma cell line.

Design

HepG2 cell was used for the experiments. Genistein with different concentrations was diluted in media and was incubated for 24 h or more as indicated. Protein levels were measured by western blotting, and mRNA expression was detected by RT-qPCR. Chromatin immunoprecipitation assay (CHIP) assay was used to determine protein binding levels, and luciferase assay was used to measure promoter activity.

Result

Genistein increased the mRNA and protein levels of LDLR in a time-dependent manner. Genistein increased the transcriptional activity of the LDLR promoter containing the reporter gene (pLDLR-luc, −805 to +50). But the sterol regulatory element deletion mutant construct failed to be activated by genistein. Genistein increased the nuclear fraction of SREBP-2 and the DNA-binding activity of SREBP-2 to LDLR promoter, as assessed by CHIP. The genistein-phosphorylated JNK inhibitor (SP600126) abolished the genistein-stimulated levels of LDLR and the nuclear SREBP-2. The addition of cholesterol up to 5 µg/mL for 24 h did not affect the effect of genistein on LDLR protein expression. Even the addition of 40 µM genistein increased the cholesterol uptake by more than 10% in the human hepatoma cell line.

Conclusion

Our data support the idea that genistein may have anti-atherogenic effects by activating JNK signals and SREBP-2 processing, which is followed by the upregulation of LDLR.

Effect of Genistein and L-Carnitine and Their Combination on Gene Expression of Hepatocyte HMG-COA Reductase and LDL Receptor in Experimental Nephrotic Syndrome

BACKGROUND

Nephrotic syndrome is a disorder that leads to hyperlipidemia. L-carnitine and genistein can effect on lipid metabolism and the syndrome. In the present study, we have delved into the separate and the twin-effects of L-carnitine and genistein on the gene expressions of HMG-COA reductase and LDL receptor in experimental nephrotic syndrome.

METHODS

In this controlled experimental study, 50 male Sprague-Dawley rats were randomly divided into five groups: NC (normal-control), PC (patient-control), LC (L-carnitine), G (genistein), LCG (L-carnitine-genistein). Adriamycin was used for inducing nephrotic syndrome and the spot urine samples and urine protein-to-creatinine ratio were measured. Hepatocytic RNA was extracted and real-time PCR was used for HMG-COA Reductase and LDL receptor gene Expression measurement.

RESULTS

The final weight of the patients groups were lower than the NC group (P=0.001), and weight gain of the NC group was higher than the other groups (P<0.001). The proteinuria and urine protein-to-creatinine ratio showed significant differences between PC group and LC, G and LCG groups at week 7 (P<0.001). The expression of HMGCOA Reductase mRNA down regulated in LC, G and LCG groups in comparison with PC group (P<0.001). ΔCT of LDLr mRNA showed significant differences between the PC group and the other patient groups (P<0.001).

CONCLUSION

This study shows a significant decreasing (P<0.001) and non-significant increasing trend in HMG-COA Reductase and LDLr gene expression, respectively, and synergistic effect of L-carnitine and genistein on these genes in experimental nephrotic syndrome.

Effects of Dietary Genistein on Plasma and Liver Lipids, Hepatic Gene Expression, and Plasma Metabolic Profiles of Hamsters with Diet-Induced Hyperlipidemia

Male hamsters were fed one of the following three diets for 6 weeks (n = 15): normal-fat diet (NFD), high-fat diet (HFD), or HFD + 2 g/kg genistein; the effects of dietary genistein on hyperlipidemia were investigated using traditional and (1)H NMR metabonomic approaches. At 6 weeks, compared with the hamsters in the NFD group, those in the HFD group had higher plasma and liver lipids (P < 0.05). Hyperlipidemia was alleviated in the genistein group, with lower plasma cholesterol (9.11 ± 0.40 vs 12.4 ± 0.37 mmol/L), triglyceride (8.07 ± 1.08 vs 14.7 ± 1.18 mmol/L), LDL cholesterol (2.69 ± 0.20 vs 4.48 ± 0.27 mmol/L), malondialdehyde (7.77 ± 1.64 vs 14.0 ± 1.15 μmol/L), and liver cholesterol (20.9 ± 1.01 vs 29.9 ± 2.76 μmol/g) than those in the HFD group (P < 0.05). Expression of hepatic LDL receptor and estrogen receptors α and β mRNA in the genistein group were significantly up-regulated, compared with those of the HFD group (P < 0.05). In the (1)H NMR metabonomic analysis, both the small and macromolecular plasma metabolite profiles differed among the three groups, and the metabolic profile of the genistein group was shifted toward that of the NFD group. These results extend our understanding of the beneficial effects of genistein on hyperlipidemia.

Identification of the Flavonoid Luteolin as a Repressor of the Transcription Factor Hepatocyte Nuclear Factor 4α

Hepatocyte nuclear factor 4α (HNF4α) is a nuclear receptor that regulates the expression of genes involved in the secretion of apolipoprotein B (apoB)-containing lipoproteins and in glucose metabolism. In the present study, we identified a naturally occurring flavonoid, luteolin, as a repressor of HNF4α by screening for effectors of the human microsomal triglyceride transfer protein (MTP) promoter. Luciferase reporter gene assays revealed that the activity of the MTP gene promoter was suppressed by luteolin and that the mutation of HNF4α-binding element abolished luteolin responsiveness. Luteolin treatment caused a significant decrease in the mRNA levels of HNF4α target genes in HepG2 cells and inhibited apoB-containing lipoprotein secretion in HepG2 and differentiated Caco2 cells. The interaction between luteolin and HNF4α was demonstrated using absorption spectrum analysis and luteolin-immobilized beads. Luteolin did not affect the DNA binding of HNF4α to the promoter region of its target genes but suppressed the acetylation level of histone H3 in the promoter region of certain HNF4α target genes. Short term treatment of mice with luteolin significantly suppressed the expression of HNF4α target genes in the liver. In addition, long term treatment of mice with luteolin significantly suppressed their diet-induced obesity and improved their serum glucose and lipid parameters. Importantly, long term luteolin treatment lowered serum VLDL and LDL cholesterol and serum apoB protein levels, which was not accompanied by fat accumulation in the liver. These results suggest that the flavonoid luteolin ameliorates an atherogenic lipid profile in vivo that is likely to be mediated through the inactivation of HNF4α.

Functional foods-based diet as a novel dietary approach for management of type 2 diabetes and its complications: A review

Type 2 diabetes is a complicated metabolic disorder with both short- and long-term undesirable complications. In recent years, there has been growing evidence that functional foods and their bioactive compounds, due to their biological properties, may be used as complementary treatment for type 2 diabetes mellitus. In this review, we have highlighted various functional foods as missing part of medical nutrition therapy in diabetic patients. Several in vitro, animal models and some human studies, have demonstrated that functional foods and nutraceuticals may improve postprandial hyperglycemia and adipose tissue metabolism modulate carbohydrate and lipid metabolism. Functional foods may also improve dyslipidemia and insulin resistance, and attenuate oxidative stress and inflammatory processes and subsequently could prevent the development of long-term diabetes complications including cardiovascular disease, neuropathy, nephropathy and retinopathy. In conclusion available data indicate that a functional foods-based diet may be a novel and comprehensive dietary approach for management of type 2 diabetes.

Genistein induces deleterious effects during its acute exposure in Swiss mice

Genistein is a soy derived isoflavone. It has wide variety of therapeutic effects against certain diseases including cancer. Although toxic effects of genistein have been studied, its effect on the gene expression and the reason behind toxicity have not been identified yet. In the present study, genistein was administered to age and body weight matched Swiss mice at the doses of 125, 250, 500 and 1000 mg/kg. The biomarkers of hepatotoxicity in serum, liver histology, oxidative stress parameters in tissue homogenates, and global gene expression were examined. Elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels and degenerated liver tissue were observed in 500, and 1000 mg/kg genistein treated groups. Oxidative stress was significant at these doses as considerable increase in lipid peroxidation (LPO) and decrease in total glutathione (GSH) were observed. Gene expression analysis showed 40 differentially expressed genes at twofold change and P < 0.05. Differentially expressed genes were corresponding to different biologically relevant pathways including metabolic and oxidative stress pathways. In 500 mg/kg group, Cyp4a14, Sult1e1, Gadd45g, Cidec, Mycs, and so forth genes were upregulated. These results suggested that the higher dose of genistein can produce several undesirable effects by affecting multiple cellular pathways.

2-heptyl-formononetin increases cholesterol and induces hepatic steatosis in mice

Consumption of isoflavones may prevent adiposity, hepatic steatosis, and dyslipidaemia. However, studies in the area are few and primarily with genistein. This study investigated the effects of formononetin and its synthetic analogue, 2-heptyl-formononetin (C7F), on lipid and cholesterol metabolism in C57BL/6J mice. The mice were fed a cholesterol-enriched diet for five weeks to induce hypercholesterolemia and were then fed either the cholesterol-enriched diet or the cholesterol-enriched diet-supplemented formononetin or C7F for three weeks. Body weight and composition, glucose homeostasis, and plasma lipids were compared. In another experiment, mice were fed the above diets for five weeks, and hepatic triglyceride accumulation and gene expression and histology of adipose tissue and liver were examined. Supplementation with C7F increased plasma HDL-cholesterol thereby increasing the plasma level of total cholesterol. Supplementation with formononetin did not affect plasma cholesterol but increased plasma triglycerides levels. Supplementation with formononetin and C7F induced hepatic steatosis. However, formononetin decreased markers of inflammation and liver injury. The development of hepatic steatosis was associated with deregulated expression of hepatic genes involved in lipid and lipoprotein metabolism. In conclusion, supplementation with formononetin and C7F to a cholesterol-enriched diet adversely affected lipid and lipoprotein metabolism in C57BL/6J mice.

Phytoestrogens genistein and daidzein affect immunity in the nematode Caenorhabditis elegans via alterations of vitellogenin expression

SCOPE

Phytoestrogens, such as the soy isoflavones genistein and daidzein, are suggested to beneficially affect lipid metabolism in humans and thereby contribute to healthy ageing. New evidences show that phytoestrogens might slow ageing processes also by affecting immune processes.

METHODS AND RESULTS

We tested in the nematode Caenorhabditis elegans the effects of 17β-estradiol, genistein, and daidzein on resistance versus the nematode pathogen Photorhabdus luminescens with focus on vitellogenins, which are invertebrate estrogen-responsive genes that encode homologues to ApoB100 with impact on immune functions. Here, we show that the estrogen 17β-estradiol increases the resistance of C. elegans versus P. luminescens by enhancing vitellogenin-expression at the mRNA and protein level. Knockdown of single out of five functional vits by RNA-interference blunted the life-extending effects under heat-stress of 17β-estradiol, demonstrating a lack of redundancy for the vitellogenins. RNAi for nhr-14, a suggested nuclear hormone receptor for estrogens, displayed no influence on 17β-estradiol effects. The soy isoflavone genistein reduced vitellogenin-expression and also resistance versus P. luminescens whereas daidzein increased resistance versus the pathogen in a vitellogenin-dependent manner.

CONCLUSION

Our studies show that induction of estrogen-responsive vitellogenin(s) by the phytoestrogen daidzein potently increases resistance of C. elegans versus pathogenic bacteria and heat whereas genistein acts in an antiestrogenic manner.

Effect of genistein on cholesterol metabolism-related genes in a colon cancer cell line

The major soy-derived isoflavones such as genistein has been demonstrated to possess anticarcinogenic activity in animal model systems. The present study was designed to investigate the effects of isoflavone genistein exposure at concentrations ranging from 0.01 to 50 muM on the LDL receptor and HMG-CoA reductase gene expression in the estrogen receptor positive DLD-1 human colon cancer cell line. LDL receptor and HMG-CoA reductase gene expressions were evaluated by reverse transcription followed by real-time PCR. Genistein induced an increase of LDL receptor gene expression and later decrease of HMG-CoA reductase mRNA expression in DLD-1 cells. These findings provide direct evidence on the role of genistein in regulating LDL receptor and HMG-CoA reductase gene expression in colon cancer.

Multiple functions of microsomal triglyceride transfer protein

Microsomal triglyceride transfer protein (MTP) was first identified as a major cellular protein capable of transferring neutral lipids between membrane vesicles. Its role as an essential chaperone for the biosynthesis of apolipoprotein B (apoB)-containing triglyceride-rich lipoproteins was established after the realization that abetalipoproteinemia patients carry mutations in the MTTP gene resulting in the loss of its lipid transfer activity. Now it is known that it also plays a role in the biosynthesis of CD1, glycolipid presenting molecules, as well as in the regulation of cholesterol ester biosynthesis. In this review, we will provide a historical perspective about the identification, purification and characterization of MTP, describe methods used to measure its lipid transfer activity, and discuss tissue expression and function. Finally, we will review the role MTP plays in the assembly of apoB-lipoprotein, the regulation of cholesterol ester synthesis, biosynthesis of CD1 proteins and propagation of hepatitis C virus. We will also provide a brief overview about the clinical potentials of MTP inhibition.

Geriatric obesity: evaluating the evidence for the use of flavonoids to promote weight loss

Obesity is a rapidly growing epidemic that now affects approximately 30% of the adult population in the United States. The prevalence of obesity in the geriatric population makes it one of the fastest growing groups due to aging baby boomers. Because of the limited number of available treatments for obese adults, they often turn to supplements and alternative medicine sources to help them lose weight. One such group of supplements contains plant metabolites flavonoids, which includes catechins from tea, quercetin from fruits and vegetables, and isoflavones from soy products. Some flavonoids such as catechins and soy isoflavones can modestly reduce weight. This review examined the clinical evidence for catechins, quercetin, and soy isoflavones for the treatment of obesity and explored the mechanisms of action as related to obesity. Furthermore, flavonoids were evaluated for the treatment of obesity in geriatric populations as well as for safety concerns.

Modified soybean affects cholesterol metabolism in rats similarly to a commercial cultivar

The consumption of soy protein lowers blood cholesterol in humans and animals. Breeding may alter the physiological effects of soybeans, such as its cholesterol-lowering property. Our hypothesis is that breeding affects the hypocholesterolemic effect of soy by modulating the expression of key hepatic enzymes related to cholesterol and bile acid biosynthesis, as well as altering fecal neutral and acidic steroid excretion. Therefore the aim of this study was to evaluate the effect of a new Brazilian soybean cultivar (UFV-116), lacking lipoxygenases 2 and 3, compared with a commercial cultivar (OCEPAR-19), on 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) and cholesterol 7α-hydroxylase (CYP7A) mRNA expression and fecal steroid output in rats. Thirty-six male rats were fed UFV-116, OCEPAR-19, or casein as the protein source, with or without addition of dietary cholesterol (0.25%). Blood and liver cholesterol, HMGR and CYP7A mRNA abundance, and fecal excretion of steroids were measured. Blood and liver cholesterol levels were lowered by both soybean cultivars, with and without cholesterol, but UFV-116 was more effective when included in the cholesterol-free diet. Both soy diets promoted lower levels of HMGR mRNA, higher levels of CYP7A mRNA, and higher excretion of fecal secondary bile acids. There was higher fecal neutral steroid output when cholesterol was added to all diets. These data show that both soybean cultivars acted similarly in lowering serum and hepatic cholesterol; therefore, breeding did not affect the hypocholesterolemic effect of the new cultivar.

Molecular structures of citrus flavonoids determine their effects on lipid metabolism in HepG2 cells by primarily suppressing apoB secretion

This study investigated the underlying mechanisms of action for blood lipid lowering effects of citrus flavonoids and their methoxylated analogues (n = 19; dose range: 0-100 μM) in HepG2 cells. Cholesterol (CH) and triglyceride (TG) syntheses were assessed by measuring the incorporation of (14)C-acetate and (14)C-glycerol, respectively, whereas apoB secretion was determined by ELISA. Results show that two polymethoxylated citrus flavonoids (PMFs), tangeretin and nobiletin, potently inhibited apoB secretion (IC(50) = 13 and 29 μM, respectively) and modestly inhibited CH synthesis (IC(50) = 49 and 68 μM) and TG synthesis (IC(50) = 14 and 73 μM), without effecting LDL-receptor activity. Other PMFs (e.g., sinensetin) and non-PMFs (e.g., hesperetin and naringenin) had only weak effects on CH and TG syntheses and apoB secretion (IC(50) > 100 μM). The structure-activity analysis indicated that a fully methoxylated A-ring of the flavonoid structure was associated with a potent inhibitory activity on hepatic apoB secretion. In conclusion, this study using HepG2 cells indicates that citrus flavonoids with a fully methoxylated A-ring may lower blood CH and TG concentrations primarily by suppressing hepatic apoB secretion as a main underlying mode of action.

Cacao polyphenols influence the regulation of apolipoprotein in HepG2 and Caco2 cells

Cocoa powder is rich in polyphenols, such as catechins and procyanidins, and has been shown to inhibit low-density lipoprotein (LDL) oxidation and atherogenesis in a variety of models. Human studies have also shown daily intake of cocoa increases plasma high-density lipoprotein (HDL) and decreases LDL levels. However, the mechanisms responsible for these effects of cocoa on cholesterol metabolism have yet to be fully elucidated. The present study investigated the effects of cacao polyphenols on the production of apolipoproteins A1 and B in human hepatoma HepG2 and intestinal Caco2 cell lines. The cultured HepG2 cells or Caco2 cells were incubated for 24 h in the presence of cacao polyphenols such as (-)-epicatechin, (+)-catechin, procyanidin B2, procyanidin C1, and cinnamtannin A2. The concentration of apolipoproteins in the cell culture media was quantified using an enzyme-linked immunoassay, and the mRNA expression was quantified by RT-PCR. Cacao polyphenols increased apolipoprotein A1 protein levels and mRNA expression, even though apolipoprotein B protein and the mRNA expression were slightly decreased in both HepG2 cells and Caco2 cells. In addition, cacao polyphenols increased sterol regulatory element binding proteins (SREBPs) and activated LDL receptors in HepG2 cells. These results suggest that cacao polyphenols may increase the production of mature form SREBPs and LDL receptor activity, thereby increasing ApoA1 and decreasing ApoB levels. These results elucidate a novel mechanism by which HDL cholesterol levels become elevated with daily cocoa intake.

Cocoa, chocolate, and cardiovascular disease

A significant body of evidence demonstrates that diets rich in fruits and vegetables promote health and attenuate, or delay, the onset of various diseases, including cardiovascular disease, diabetes, certain cancers, and several other age-related degenerative disorders. The concept that moderate chocolate consumption could be part of a healthy diet has gained acceptance in past years based on the health benefits ascribed to selected cocoa components. Specifically, cocoa as a plant and chocolate as food contain a series of chemicals that can interact with cell and tissue components, providing protection against the development and amelioration of pathological conditions. The most relevant effects of cocoa and chocolate have been related to cardiovascular disease. The mechanisms behind these effects are still under investigation. However, the maintenance or restoration of vascular NO production and bioavailability and the antioxidant effects are the mechanisms most consistently supported by experimental data. This review will summarize the most recent research on the cardiovascular effects of cocoa flavanols and related compounds.

The soy isoflavone genistein induces estrogen synthesis in an extragonadal pathway

Genistein is a phytoestrogen isolated from soyabean, and is a potential nutraceutical gearing for women suffering from perimenopausal symptoms. Because of its differential binding affinity to estrogen receptor (ER) isoforms, genistein is described as a selective estrogen receptor modulator (SERM). The ligand-receptor interaction is established, but the potential confounding factors have not been fully addressed. Alteration in estrogen metabolism is an important issue when determining the downstream effect of ER. Aromatase or CYP19 catalyzes the rate-limiting reaction of estrogen synthesis, and is highly expressed in the ovary. This organ is the source of estrogen in females. After menopause the ovaries cease to produce the hormone, and localized estrogen synthesis in extragonadal tissues could become physiologically significant. In the present study, effect of genistein on CYP19 regulation was investigated in the hepatic cells HepG2. The phytoestrogen induced aromatase activity in the cells. Increased mRNA expression with concurrent elevation in the usage of promoters I.3/II was also demonstrated. Luciferase reporter gene assays verified the transcriptional control dictated by the specific promoters under genistein treatment. Several protein kinases were examined, and PKC?, P38, ERK-1/2 appeared to be activated. Subsequent inhibition and expression experiments demonstrated the involvement of these kinases. The transcriptional factor CREB was ultimately activated in the gene regulation. The present study illustrated an extragonadal pathway by which genistein might increase estrogen synthesis.

Cholesterol-lowering nutraceuticals and functional foods

Epidemiological studies have demonstrated that elevated levels of plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) are the major risk factors for coronary heart disease (CHD), whereas high concentrations of plasma high-density lipoprotein cholesterol (HDL-C) and a low ratio of TC to HDL-C are protective against CHD. A relationship between plasma TC and the risk of CHD is well established at concentrations above 240 mg/dL. In addition to the use of three main classes of cholesterol-lowering medications, including HMG-CoA reductase inhibitors, anion-exchange resins, and fibrates, a nutritionally balanced diet that reduces saturated fat and cholesterol intake has traditionally been the first goal of dietary therapy in lowering plasma TC. In recent years, nutraceuticals and functional foods have attracted much interest as possible alternative therapies for lowering plasma TC, especially for hypercholesterolemia patients, whose blood cholesterol level is marginally high (200-240 mg/dL) but not high enough to warrant the prescription of cholesterol-lowering medications. This review summarizes the findings of recent studies on the production, application, efficacy, and mechanisms of popular cholesterol-lowering nutraceuticals and functional foods.

The effects of soy isoflavones on obesity

Over the last decades, the prevalence of obesity and related diseases has increased rapidly in the Western world. Obesity is a disorder of energy balance and is associated with hyper-insulinemia, insulin resistance, and abnormalities in lipid metabolism, and it is one of the most important risk factors in the development of Type II diabetes, cardiovascular disease, atherosclerosis, and certain cancers. Because of the lower frequency of these diseases in Asian countries, attention has been turned toward the Asian diet, which consists highly of soy and soy-based products. The health benefits associated with soy consumption have been linked to the content of isoflavones, the main class of the phytoestrogens. As a result of their structural similarities to endogenous estrogens, isoflavones elicit weak estrogenic effects by competing with 17beta-estradiol (E2) for binding to the intranuclear estrogen receptors (ERs) and exert estrogenic or antiestrogenic effects in various tissues. The estrogenic activities of soy isoflavones are thought to play an important role in their health-enhancing properties. Additionally, the isoflavones have been proved to exert non-ER-mediated effects through numerous other pathways. Genistein, daidzein, and glycitein are the principal isoflavones in soy. Genistein is the most thoroughly examined of these, because it is the most prevalent isoflavone in soy and the most active of these compounds, because of its higher binding affinity for the ER. Genistein and daidzein can be obtained in high levels in humans under certain nutritional conditions, and epidemiologic and laboratory data suggest that these compounds could have health benefits in human obesity. This review will focus on the latest results of research on isoflavones and their effect on obesity in cell cultures, rodents, and humans.