Modulation of aromatase activity by diet polyphenolic compounds

Red Wine and Sexual Function in Men: An Original Point of View

Red wine is a rich source of nutrients whose biological properties have inspired numerous scientific studies. Indeed, it has been widely reported that there is a correlation between the positive health effects of moderate consumption of red wine and its phenolic content, which, due to its antioxidant activity, has proved to be useful in the improvement of various diseases, such as cardiovascular diseases, metabolic syndrome, cognitive disorders, depression, and cancer. It is a common opinion that the antioxidant activity of red wine is to be ascribed to its entire content of polyphenols, which act synergistically and not as a single component. Furthermore, this health-promoting effect of red wine can also be linked to its ethanol content, which has shown a wide array of biological properties. Beyond this evidence, very little is known about a possible correlation between moderate consumption of red wine and male sexual function. This brief review aimed to evaluate the effects of moderate consumption of red wine on erectile function. To accomplish this, Pubmed and Google Scholar databases were searched to retrieve the most relevant studies on this topic. The evidence so far collected has shown that red wine, if consumed in moderation, can be potentially beneficial for patients with erectile dysfunction as well as can positively influence reproductive function through mechanisms that depend on the vasorelaxant properties of red wine and its antioxidant properties.

The Effects of Diet and Exercise on Endogenous Estrogens and Subsequent Breast Cancer Risk in Postmenopausal Women

Endogenous estrogens have been associated with overall breast cancer risk, particularly for postmenopausal women, and ways to reduce these estrogens have served as a primary means to decrease overall risk. This narrative review of clinical studies details how various nutritional and exercise lifestyle interventions have been used to modify estrogen levels and metabolism to provide a protective impact against breast cancer incidence. We also summarized the evidence supporting the efficacy of interventions, outcomes of interest and identified emerging research themes. A systematic PubMed MEDLINE search identified scholarly articles or reviews published between 2000-2020 that contained either a cohort, cross-sectional, or interventional study design and focused on the relationships between diet and/or exercise and overall levels of different forms of estrogen and breast cancer risk and occurrence. Screening and data extraction was undertaken by two researchers. Data synthesis was narrative due to the heterogeneous nature of studies. A total of 1625 titles/abstracts were screened, 198 full texts reviewed; and 43 met eligibility criteria. Of the 43 studies, 28 were randomized controlled trials, and 15 were observational studies. Overall, studies that incorporated both diet and exercise interventions demonstrated better control of detrimental estrogen forms and levels and thus likely represent the best strategies for preventing breast cancer development for postmenopausal women. Some of the strongest associations included weight loss via diet and diet + exercise interventions, reducing alcohol consumption, and consuming a varied dietary pattern, similar to the Mediterranean diet. More research should be done on the effects of specific nutritional components on endogenous estrogen levels to understand the effect that the components have on their own and in combination within the diet.

The protective effect of epigallocatechin-3-gallate on testicular oxidative stress in lead-induced toxicity mediated by Cyp19 gene / estradiol level

Exposure to heavy metals contributes to most of the unexplained male infertility. Lead (Pb) is a well- known heavy metal, which disrupt the male reproductive system. This study was conducted to investigate the therapeutic and protective effects of green tea active principle, epigallocatechin gallate (EGCG), on the lead toxicity-induced infertility in male rats. Male albino rats receiving lead acetate (PbAc, 50 mg/l) once a daily in drinking water showed reduction of spermatozoa count and motility, diminishing the weights of testes, seminal vesicle and epididymis, low level of serum testosterone and 17β-estradiol (E2), and degenerative changes in seminiferous tubules. Additionally, the Pb exposure caused a testicular oxidative stress with a decrease in the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) enzymes, a remarkable rising in malondialdehyde (MDA) levels, as well as a downregulation in P450 aromatase gene expression (Cyp19) in the rats' testicular tissues. These adverse effects of Pb were ameliorated by EGCG treatment, which increased testosterone, E2 serum level, and aromatase P450 gene expression, and improved testicular architecture and semen picture. Additionally, EGCG decreased the tissue levels of MDA and retained the levels of antioxidative enzymes. In conclusion, EGCG administration can provide a significant protection against testicular toxicity caused by pb, indicating the beneficial roles of EGCG on the male reproductive system.

Green Tea Catechin Extract Supplementation Does Not Influence Circulating Sex Hormones and Insulin-Like Growth Factor Axis Proteins in a Randomized Controlled Trial of Postmenopausal Women at High Risk of Breast Cancer

BACKGROUND

Consumption of green tea has been associated with reduced risk of breast cancer. Hormonal modulation has been suggested as one of the potential underlying mechanisms; however, it has yet to be fully elucidated in large, long-term human clinical trials.

OBJECTIVE

We investigated the effects of decaffeinated green tea extract (GTE) on circulating sex hormones and insulin-like growth factor (IGF) proteins.

METHODS

We conducted a placebo-controlled double-blind randomized clinical trial recruiting from 8 clinical centers in Minnesota. Participants were 538 healthy postmenopausal women randomly assigned to the GTE group (463 completed the study; mean age = 60.0 y) and 537 to the placebo group (474 completed; mean age = 59.7 y). Women in the GTE group orally took 4 decaffeinated capsules containing 1315 mg total catechins including 843 mg epigallocatechin-3-gallate daily for 1 y, whereas women in the placebo group took similar capsules containing no tea catechins. Blood sex hormones (estrone, estradiol, androstenedione, testosterone, and sex hormone-binding globulin) and IGF proteins (IGF-1 and IGF binding protein-3) were quantified at baseline and months 6 (for IGF proteins only) and 12, and were assessed as secondary outcomes of the study using a mixed-effect repeated-measures ANOVA model.

RESULTS

Women in the GTE group had significantly higher blood total estradiol (16%; P = 0.02) and bioavailable estradiol (21%; P = 0.03) than in the placebo group at month 12. There was a statistically significant interaction between GTE supplementation and duration of treatment on estradiol and bioavailable estradiol (both Ps for interaction = 0.001). The catechol-O-methyltransferase genotype did not influence blood sex hormones before or after GTE supplementation. The circulating concentrations of IGF proteins were comparable between GTE and placebo groups at all 3 time points.

CONCLUSION

These results suggest that a 12-mo GTE supplementation significantly increases circulating estradiol concentrations in healthy postmenopausal women. This trial was registered at clinicaltrials.gov as NCT00917735.

Alcoholic Beverage Consumption and Chronic Diseases

Epidemiological and experimental studies have consistently linked alcoholic beverage consumption with the development of several chronic disorders, such as cancer, cardiovascular diseases, diabetes mellitus and obesity. The impact of drinking is usually dose-dependent, and light to moderate drinking tends to lower risks of certain diseases, while heavy drinking tends to increase the risks. Besides, other factors such as drinking frequency, genetic susceptibility, smoking, diet, and hormone status can modify the association. The amount of ethanol in alcoholic beverages is the determining factor in most cases, and beverage types could also make an influence. This review summarizes recent studies on alcoholic beverage consumption and several chronic diseases, trying to assess the effects of different drinking patterns, beverage types, interaction with other risk factors, and provide mechanistic explanations.

The effect of red wine consumption on hormonal reproductive parameters and total antioxidant status in young adult male rats

Very little is known about the effects of red wine consumption on male reproductive functions. Here we report the effect of regular drinking of different types of red wine on hormonal reproductive parameters and total antioxidant status in young adult male rats. Dry red wine (D-RW) exerted higher antioxidant activity and was characterized by higher concentration of phenolic compounds compared to semi-dry (SD-RW), sweet (S-RW) and semi-sweet (SS-RW) wines. No differences in total antioxidant status of rat plasma after six weeks of drinking of the wines were detected. Increased plasma follicle-stimulating hormone levels in S-RW versus control and D-RW (5.26 vs. 3.06 and 3.21 ng mL(-1)) groups were found. The plasma testosterone concentration was lower in D-RW compared to control, SD-RW, S-RW and SS-RW groups (0.25 vs. 1.12, 1.09, 1.54 and 1.25 ng mL(-1)). Higher plasma 17β-estradiol level in S-RW versus SD-RW and SS-RW (10.94 vs. 7.18 and 6.72 pg mL(-1)) group was stated. The prolactin level was higher in plasma of S-RW versus D-RW and SS-RW (17.35 vs. 9.74 and 8.59 ng mL(-1)) rats. The effects of red wine drinking on the hormonal regulation of the male reproductive system depend on the type and the dose of red wine. Chemical compounds naturally occurring in red wines (i.e. phenolics) may modulate the effects of ethyl alcohol, but also directly affect the male reproduction.

Green tea intake is associated with urinary estrogen profiles in Japanese-American women

Scope

Intake of green tea may reduce the risk of breast cancer; polyphenols in this drink can influence enzymes that metabolize estrogens, known causal factors in breast cancer etiology.

Methods and results

We examined the associations of green tea intake (<1 time/week, 1-6 times weekly, or 7+ times weekly) with urinary estrogens and estrogen metabolites (jointly EM) in a cross-sectional sample of healthy Japanese American women, including 119 premenopausal women in luteal phase and 72 postmenopausal women. We fit robust regression models to each log-transformed EM concentration (picomoles per mg creatinine), adjusting for age and study center. In premenopausal women, intake of green tea was associated with lower luteal total EM (P trend = 0.01) and lower urinary 16-pathway EM (P trend = 0.01). In postmenopausal women, urinary estrone and estradiol were approximately 20% and 40% lower (P trend = 0.01 and 0.05, respectively) in women drinking green tea daily compared to those drinking <1 time/week. Adjustment for potential confounders (age at menarche, parity/age at first birth, body mass index, Asian birthplace, soy) did not change these associations.

Conclusions

Findings suggest that intake of green tea may modify estrogen metabolism or conjugation and in this way may influence breast cancer risk.

Inhibitory effect of luteolin on estrogen biosynthesis in human ovarian granulosa cells by suppression of aromatase (CYP19)

Inhibition of aromatase, the key enzyme in estrogen biosynthesis, is an important strategy in the treatment of breast cancer. Several dietary flavonoids show aromatase inhibitory activity, but their tissue specificity and mechanism remain unclear. This study found that the dietary flavonoid luteolin potently inhibited estrogen biosynthesis in a dose- and time-dependent manner in KGN cells derived from human ovarian granulosa cells, the major source of estrogens in premenopausal women. Luteolin decreased aromatase mRNA and protein expression in KGN cells. Luteolin also promoted aromatase protein degradation and inhibited estrogen biosynthesis in aromatase-expressing HEK293A cells, but had no effect on recombinant expressed aromatase. Estrogen biosynthesis in KGN cells was inhibited with differing potencies by extracts of onion and bird chili and by four other dietary flavonoids: kaempferol, quercetin, myricetin, and isorhamnetin. The present study suggests that luteolin inhibits estrogen biosynthesis by decreasing aromatase expression and destabilizing aromatase protein, and it warrants further investigation as a potential treatment for estrogen-dependent cancers.

Novel flavonoids with antiproliferative activities against breast cancer cells

A series of flavone analogues were synthesized and evaluated for their antiproliferation activity against breast cancer cells. The IC(50) of compound 10 and 24 were determined to be at 5 μM. These compounds were used as baits to screen breast cancer cDNA expression phage display proteome library. DNA sequencing of the binding phages suggests that eEF1A1 is a target protein for 10 and 24. Further optimization of these compounds led to the discovery of 39 with higher cytotoxic potency (IC(50) = 1 μM) and binding to eEF1A2. Biological and biochemical data suggest that eEF1A2 might be a therapeutic target and that 39 is an excellent lead compound for further development.

Facile Synthesis of Chrysin-derivatives with Promising Activities as Aromatase Inhibitors†

Flavones such as chrysin show structural similarities to androgens, the substrates of human aromatase, which converts androgens to estrogens. Aromatase is a key target in the treatment of hormone-dependent tumors, including breast cancer. Flavone-based aromatase inhibitors are of growing interest, and chrysin in particular provides a (natural) lead structure. This paper reports multicomponent synthesis as a means for facile modification of the chrysin core structure in order to add functional elements. A Mannich-type reaction was used to synthesize a range of mono- and disubstituted chrysin derivatives, some of which are more effective aromatase inhibitors than the benchmark compound, aminoglutethimide. Similarly, the reaction of chrysin with various isonitriles and acetylene dicarboxylates results in a new class of flavone derivatives, tricyclic pyrano-flavones which also inhibit human aromatase. Multicomponent reactions involving flavones therefore enable the synthesis of a variety of derivatives, some of which may be useful as anticancer agents.

Red wine increases adipose tissue aromatase expression and regulates body weight and adipocyte size

OBJECTIVE

Obesity is an important component of the metabolic syndrome in constituting a risk factor for cardiovascular disease, diabetes, and cancer. Estrogens influence lipid accumulation in adipocytes, acting indirectly or directly on adipose tissue. In this study we aimed to investigate the influence of red wine ingestion on the expression of aromatase (estrogen synthase) in adipose tissue.

METHODS

Red wine or ethanol solution, in the concentration found in red wine, was provided to Wistar rats as the sole drinking fluid for 8 wk. Food and drink intakes and body weight were monitored throughout treatment and adipocyte size and aromatase expression in the adipose tissue were determined at the end of the experimental period.

RESULTS

Red wine and ethanol increased aromatase expression in the adipose tissue and red wine decreased adipocyte size (P < 0.05). In addition, animals treated with red wine or ethanol had significantly lower weight gain than controls, despite a similar energy intake.

CONCLUSION

Thus, the ingestion of red wine may alter the production of estrogens by adipose tissue, body weight gain, and adipocyte size. Some of these red wine effects are attributable to ethanol. This relation among estrogen availability, adipocyte biology, and weight gain is most interesting and deserves further study because it may lead to new strategies to reduce metabolic syndrome incidence.

Chronic green tea consumption decreases body mass, induces aromatase expression, and changes proliferation and apoptosis in adult male rat adipose tissue

Green tea (GT) and its components have been shown to possess antiobesity properties and the corresponding mechanisms of action are being investigated, given the epidemic proportions of obesity incidence. In the current work, we used 12-mo-old male Wistar rats to test the effect of 6 mo of treatment with GT as the sole drinking beverage (52.8 +/- 6.4 mL/d) on adipose tissue (AT). AT aromatase expression was determined by Western blotting, plasma concentrations of 17beta-estradiol and testosterone were determined by RIA, and adipocyte size determined by measuring diameter in tissue sections. Proliferation and apoptosis were also assessed by Ki67 immunostaining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling, respectively. Evaluations were made in subcutaneous (sc) AT and visceral (v) AT. Body weight increased over time in both groups (P < 0.001), but the increase was more pronounced in controls (P < 0.001) and food and fluid intake did not influence that effect. At the end of the experiment, aromatase expression increased in the AT (318.5 +/- 60.6% of control in scAT, P < 0.05, and 285.5 +/- 82.9% of control in vAT, P < 0.01). AT of GT-treated rats had a higher percentage of proliferating cells (204.1 +/- 19.5% of control in scAT, P < 0.01, and 246.6 +/- 50.2% of control in vAT, P < 0.01) and smaller adipocytes (78.3 +/- 1.7% of control in scAT, P < 0.001, and 87.9 +/- 3.2% of control in vAT, P < 0.05). GT also increased the number of apoptotic cells in vAT (320.4 +/- 21.9% of control; P < 0.001). These results suggest new mechanisms for GT on body weight and highlight its potential benefit to prevent or treat obesity and the metabolic syndrome.