Current knowledge and future direction of research on soy isoflavones as a therapeutic agents

Soy Protein Concentrate Diets Inversely Affect LPS-Binding Protein Expression in Colon and Liver, Reduce Liver Inflammation, and Increase Fecal LPS Excretion in Obese Zucker Rats

Dietary soy protein and soy isoflavones have anti-inflammatory properties. Previously, we reported that feeding soy protein concentrate diet (SPC) with low or high isoflavone (LIF or HIF) to young (seven-week-old) obese (fa/fa) Zucker rats inhibits lipopolysaccharide (LPS) translocation and decreases liver inflammation compared to a casein control (CAS) diet. The current study investigated whether SPC-LIF and SPC-HIF diets would reduce liver inflammation in adult obese Zucker rats fed a CAS diet. A total of 21 six-week-old male obese (fa/fa) Zucker rats were given CAS diet for 8 weeks to develop obesity then randomly assigned to CAS, SPC-LIF, or SPC-HIF (seven rats/group) diet for an additional 10 weeks. The expression of LPS-translocation, inflammation, and intestinal permeability markers were quantified by qPCR in liver, visceral adipose tissue (VAT), and colon. LPS concentration was determined in both the colon content and fecal samples by a Limulus amebocyte lysate (LAL) test. SPC-LIF and SPC-HIF diets significantly decreased liver LPS-binding protein (LBP) expression compared to CAS diet (p < 0.01 and p < 0.05, respectively). SPC-HIF diet also significantly decreased liver MCP-1 and TNF-α expression (p < 0.05) and had a trend to decrease liver iNOS expression (p = 0.06). In the colon, SPC-HIF diet significantly increased LBP expression compared to CAS diet (p < 0.05). When samples from all three groups were combined, there was a negative correlation between colon LBP expression and liver LBP expression (p = 0.046). SPC diets did not alter the expression of intestinal permeability markers (i.e., occludin, claudin 3, and zonula occludens-1) in the colon or inflammation markers (i.e., TNF-α and iNOS) in VAT or the colon. LPS levels in the colon content did not differ between any groups. Fecal LPS levels were significantly higher in the SPC-LIF and SPC-HIF groups compared to the CAS group (p < 0.01). In conclusion, SPC, particularly SPC with HIF, reduces liver LBP expression and inflammation makers (i.e., TNF-α and MCP-1 expression) in adult obese Zucker rats, likely by reducing LPS translocation.

Royal Jelly and Fermented Soy Extracts-A Holistic Approach to Menopausal Symptoms That Increase the Quality of Life in Pre- and Post-menopausal Women: An Observational Study

BACKGROUND

The objective of this study was to determine the effects of royal jelly and fermented soy extracts on menopausal symptoms and on quality of life in pre- and post-menopausal women.

MATERIALS AND METHOD

This prospective observational study was carried out in a Clinical Hospital of Brasov, Romania, during June 2020 and December 2021. Eighty pre- and post-menopausal women, aged between 45 and 60 years, were included in two groups. The first group (40 women) received a dietary supplement with fermented soy extract twice a day for eight weeks and the second group (40 women) received the same dietary supplement with fermented soy extracts and 1500 mg of royal jelly capsules for eight weeks. After the treatment, the MENQOL score, DASS-21 score, and the mean number and intensity of daily hot flushes were recorded and compared with baseline values.

RESULTS

After eight weeks of treatment, the score of the MENQOL questionnaire and all its domains' scores decreased in comparison with the baseline in both groups (p < 0.001). Also, the DASS-21 score (p < 0.001), depression score (p < 0.001), anxiety score (p < 0.001), and stress score (p < 0.001) improved. The mean number and the intensity of hot flushes decreased in both groups (p < 0.001). Comparing these variables after the treatment in both groups, we observed that the women who received dietary supplements with fermented soy extracts and royal jelly capsules recorded better scores for MENQOL (vasomotor, physical, and psychosocial domains) and a more reduced mean number of daily hot flushes.

CONCLUSIONS

This observational study suggests that both dietary fermented soy supplements and royal jelly capsules possess beneficial effects against menopausal symptoms, increase the quality of life in pre- and post-menopausal women, and that the effects might be significantly improved if those dietary supplements are administered in association.

The Role of Isoflavones in the Prevention of Breast Cancer and Prostate Cancer

This narrative review summarizes epidemiological studies on breast cancer and prostate cancer with an overview of their global incidence distribution to investigate the relationship between these diseases and diet. The biological properties, mechanisms of action, and available data supporting the potential role of isoflavones in the prevention of breast cancer and prostate cancer are discussed. Studies evaluating the effects of isoflavones in tissue cultures of normal and malignant breast and prostate cells, as well as the current body of research regarding the effects of isoflavones attained through multiple modifications of cellular molecular signaling pathways and control of oxidative stress, are summarized. Furthermore, this review compiles literature sources reporting on the following: (1) levels of estrogen in breast and prostate tissue; (2) levels of isoflavones in the normal and malignant tissue of these organs in European and Asian populations; (3) average concentrations of isoflavones in the secretion of these organs (milk and semen). Finally, particular emphasis is placed on studies investigating the effect of isoflavones on tissues via estrogen receptors (ER).

Effect of soy isoflavones supplementation on migraine characteristics, mental status and calcitonin gene-related peptide (CGRP) levels in women with migraine: results of randomised controlled trial

Background

Literature suggests a relationship between estrogen levels and migraine headache pathogenesis. However, the effect of soy isoflavones on migraine characteristic remains unclear. This study aimed to investigate the effect of soy isoflavones on migraine characteristics and calcitonin gene-related peptide (CGRP) levels in women with migraine.

Methods

Eighty-three participants completed a randomized double-blind controlled trial, receiving 50 mg per day soy isoflavones or placebo supplementation for 8 weeks. Migraine severity, migraine days per month, frequency and duration of attacks, mental status, quality of life and serum CGRP levels were measured at baseline and the end of the intervention. Bivariate comparison and intention-to-treat (ITT) were used for analysis.

Results

Soy isoflavones intake resulted in a significant decrease in mean frequency (-2.36 vs -0.43, P < 0.001), duration (-2.50 vs -0.02, P < 0.001) of migraine attacks and CGRP level (-12.18 ng/l vs -8.62, P = 0.002) in compared to placebo group. Also, a significant improvement was found in quality of life (16.76 vs 2.52, P < 0.001). Although, reduction in the migraine severity and mental status did not reach a statistically significant level (P > 0.05).

Conclusion

soy isoflavones supplementation may be considered as a complementary treatment for women with migraine to improve migraine characteristics and reduce the burden of disease.

Cellular and molecular mechanisms of genistein in prevention and treatment of diseases: An overview

Genistein is the simplest secondary metabolite in soybeans and belongs to a group of compounds called isoflavones. It is a phytoestrogen and it makes up more than 60% of soy isoflavones. Studies have shown the anti-inflammatory, anti-apoptotic, and anti-angiogenic effects of genistein in addition to its modulatory effects on steroidal hormone receptors. In this review, we discuss the pharmacologic and therapeutic effects of genistein on various diseases. PRACTICAL APPLICATIONS: In this review, we have discussed the therapeutic effects of genistein as the main constituent of soybeans on health conditions. Its antioxidant, anti-inflammatory, anti-apoptotic and, anti-angiogenic effects need more attention. The pharmacological properties of genistein make this natural isoflavone a potential treatment for various diseases such as postmenopausal symptoms, cancer, bone, brain, and heart diseases. Special emphasis should be given to it, resulting in using it in clinical as a safe, potent, and bioactive molecule.

Neonatal exposure to genistein affects reproductive physiology and behavior in female and male Long-Evans rats

The present study was designed to examine the effects of neonatal genistein exposure on measures of reproductive physiology and behavior. Approximately 24 h after birth, female and male Long-Evans rat pups were injected daily with genistein (150 µg, subcutaneous; n = 29) or olive oil (n = 23) between postnatal days 1 and 5. After weaning, we examined all subjects daily until they reached puberty (i.e. vaginal opening in female rats and preputial separation in male rats). For all female subjects, we also examined vaginal cytology. After monitoring estrous cyclicity, the female subjects were given the opportunity to interact with a gonadally intact male or a sexually receptive female rat on the day of behavioral estrus to assess sexual motivation (i.e. partner-preference test with and without physical contact), which has never been evaluated before. For all male subjects, we assessed the development of copulatory behavior and sexual motivation (partner-preference test without physical contact). Consistent with previous findings, we found that neonatal exposure to genistein did not affect puberty onset in female or male rats. However, female rats exposed to genistein displayed significantly more irregular estrous cycles than controls. Neonatal genistein exposure also altered the development of male copulatory behavior, as indicated by an increase in mount frequency and intromission frequency and shorter interintromission intervals. We extended previous findings confirming that neither female nor male sexual motivation was affected by neonatal genistein. The results of the present study have important implications for the development of reproductive physiology and behavior in human neonates exposed to genistein in soy-based baby formula.

Controlled release of soy isoflavones from multifunctional 3D printed bone tissue engineering scaffolds

Recent challenges in post-surgical bone tumor management have elucidated the need for a multifunctional scaffold, which can be used for residual tumor-cell suppression, defect repair, and simultaneous bone regeneration. In this perspective, 3D printing allows to create a wide variety of patient-specific implant with complex porous architecture and compatible mechanical strength to that of cancellous bone. Here, a multifunctional bone graft substitute is designed by incorporating the three primary soy isoflavones: genistein, daidzein, and glycitein onto a 3D printed (3DP) tricalcium phosphate (TCP) scaffolds with designed pores, endowing them with in vitro chemopreventive, bone-cell proliferating and immune-modulatory potential. The interconnected porosity and biodegradability of 3DP TCP ceramics have allowed controlled release kinetics of genistein, daidzein and glycitein in acidic and physiological buffer medium for 16 days, which is fitted with Korsmeyer-Peppas model. Presence of genistein, a well-known natural biomolecule shows a 90% reduction in vitro osteosarcoma (MG-63) cell viability and proliferation after 11 days. Meanwhile, daidzein, the other primary isoflavone, promotes in vitro cellular attachment and enhances viability and proliferation of human fetal osteoblast cell (hFOB). Furthermore, controlled release of genistein, daidzein, and glycitein from 3DP TCP scaffold demonstrates improved hFOB cell proliferation, viability, and differentiation in a dynamic flow-perfusion bioreactor, which is utilized to better simulate the clinical microenvironment. Finally, in vivo H&E staining confirms controlled co-delivery of genistein-daidzein-glycitein from 3DP scaffold carefully modulated neutrophil recruitment to the surgery site after 24 h of implantation in a rat distal femur model. These results advance our understanding towards multipronged therapeutic approaches utilizing synthetic bone graft substitutes as a drug delivery vehicle, and more importantly, demonstrate the feasibility of localized tumor cell suppression and bone cell proliferation for post-surgical defect repair application. STATEMENT OF SIGNIFICANCE: Designed multimodal porosity of 3D printed TCP scaffold allows a controlled and sustained release of soy isoflavones, genistein, daidzein and glycitein in both physiological and acidic pH. Presence of genistein shows 90% reduction in vitro bone cancer cell viability and proliferation. Meanwhile, controlled release of genistein, daidzein, and glycitein from 3DP TCP scaffolds demonstrate improved osteoblast cell proliferation, viability, and differentiation in static and dynamic flow-perfusion bioreactor. Furthermore, H&E staining at 24 h post-surgical specimens from rat distal femur model shows neutrophil recruitment at the surgery site is significantly decreased, suggesting the anti-inflammatory property of soy isoflavones. This work provides deeper understanding on the design of a multifunctional 3D printed patient-specific scaffold with enhanced in vitro chemopreventive, osteogenic and in vivo anti-inflammatory ability.

Analysis of Flavonoid Metabolites in Chaenomeles Petals Using UPLC-ESI-MS/MS

Chaenomeles species are used for both ornamental decoration and medicinal purposes. In order to have a better understanding of the flavonoid profile of Chaenomeles, the petals of four Chaenomeles species, including Chaenomeles japonica (RB), Chaenomeles speciose (ZP), Chaenomeles sinensis (GP), and Chaenomeles cathayensis (MY), were selected as experimental material. The total flavonoid content of GP was found to be the highest, followed by MY, ZP, and RB. In total, 179 flavonoid metabolites (including 49 flavonols, 46 flavonoids, 19 flavone C-glycosides, 17 procyanidins, 15 anthocyanins, 10 flavanols, 10 dihydroflavonoids, 6 isoflavones, 5 dihydroflavonols, and 2 chalcones) were identified by Ultra-Performance Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry. Screening of differential flavonoid metabolites showed that GP had higher levels of metabolites when compared with the other three Chaenomeles species. Annotation and enrichment analysis of flavonoid metabolites revealed that cyanidin 3,5-diglucoside and pelargonidin-3,5-diglucoside anthocyanins are likely responsible for the color differences of the four Chaenomeles petals. Additionally, a large number of flavonoids, flavonols, and isoflavones were enriched in the petals of GP. This study provides new insights into the development and utilization of Chaenomeles petals and provides a basis for future investigations into their utilization.

Phenolic Compounds of Soybean Seeds from Two European Countries and Their Antioxidant Properties

There is only a small acreage of planted soybeans in northern Europe, as the global production of this crop is mainly dictated by the warmer temperatures needed for bountiful yields. The defense response of soybean plants to a cold climate entails the secretion of specific compounds which help mitigate oxidative stress, i.e., antioxidants, including phenolic compounds. The objective of this study was to examine differences in the concentrations of phenolic compounds, their antioxidant properties, and the concentration of key isoflavones (namely genistein, daidzein, malonyl daidzein, malonyl genistein, and daidzin) in the seeds of six soybean cultivars from two different regions of Europe, namely Poland and France. The total phenolic contents, isoflavone levels, and in vitro antioxidant capacities of soybean seeds from most of the investigated cultivars of northeast Europe were found to be greater than those from southwest Europe. The phenolic compounds of seed extracts are primarily responsible for the free-radical scavenging of soybeans. Factors regulating the production of phenolic compounds in the seeds have not been thoroughly elucidated. Hence, the results presented in this paper can be useful in the selection of soybean cultivars with higher levels of seed phenolics, because of their beneficial impact on human health and on the soybean's defense mechanism against plant stresses.

Flavonoids and Other Polyphenols Act as Epigenetic Modifiers in Breast Cancer

Breast cancer is a common cancer that occurs due to different epigenetic alterations and genetic mutations. Various epidemiological studies have demonstrated an inverse correlation between breast cancer incidence and flavonoid intake. The anti-cancer action of flavonoids, a class of polyphenolic compounds that are present in plants, as secondary metabolites has been a major topic of research for many years. Our review analysis demonstrates that flavonoids exhibit anti-cancer activity against breast cancer occurring in different ethnic populations. Breast cancer subtype and menopausal status are the key factors in inducing the flavonoid's anti-cancer action in breast cancer. The dose is another key factor, with research showing that approximately 10 mg/day of isoflavones is required to inhibit breast cancer occurrence. In addition, flavonoids also influence the epigenetic machinery in breast cancer, with research demonstrating that epigallocatechin, genistein, and resveratrol all inhibited DNA methyltransferase and altered chromatin modification in breast cancer. These flavonoids can induce the expression of different tumor suppressor genes that may contribute to decreasing breast cancer progression and metastasis. Additional studies are required to confirm the contribution of epigenetic modifications by flavonoids to breast cancer prevention.

Seeds

A wide variety of plant species provide edible seeds. Seeds are the dominant source of human calories and protein. The most important and popular seed food sources are cereals, followed by legumes and nuts. Their nutritional content of fiber, protein, and monounsaturated/polyunsaturated fats make them extremely nutritious. They are important additions to our daily food consumption. When consumed as part of a healthy diet, seeds can help reduce blood sugar, cholesterol, and blood pressure.

Therapeutic effects of isoflavone-aglycone fraction from soybean (Glycine max L. Merrill) in rats with estradiol valerate-induced polycystic ovary syndrome as an inflammatory state

Polycystic ovary syndrome (PCOS) is a proinflammatory/oxidative state resulting in metabolic dysregulation and ovarian dysfunction. Isoflavones in soybean seed possess anti-inflammatory/antioxidant properties. So, in this study, the effects of soybean isoflavone-aglycones on tissue inflammation, oxidative status, and ovarian histology in an animal model of PCOS were considered to achieve a novel therapeutic agent. Thirty-two female Wistar rats were divided into four groups (n = 8): a control group receiving the vehicle (CON-); a group with PCOS receiving no treatment (PCOS); and two groups of PCOS rats treated with soybean isoflavone-aglycone fraction (SISAF) at 50 and 100 mg/kg (SISAF50 and SISAF100). PCOS was induced by injecting a single dose of estradiol valerate (4 mg/kg, IM) dissolved in 0.2 ml of sesame oil following 60 days for the full development of polycystic ovaries. The SISAF treatments were administered orally once a day for 21 days. Then, the ovaries were harvested for the assessment of oxidative/antioxidative parameters, interleukin (IL)-6, and tumor necrosis factor (TNF)-α levels concomitant with histological studies. Treatment with SISAF reduced the number of cystic follicles and thickness of the theca layer, as well as increasing the number of corpora lutea and granulosa cells in PCOS rats. Also, SISAF treatment significantly decreased ovarian tissue IL-6 and TNF-α levels, and improved total oxidative/antioxidative status compared to the PCOS group. Isoflavones may provide therapeutic effects in PCOS owing to the antioxidant and anti-inflammatory properties.

Isoflavones enhance the plasma cholesterol-lowering activity of 7S protein in hypercholesterolemic hamsters

Previous studies have shown that 7S protein is the active ingredient responsible for the plasma cholesterol-lowering activity of soybean. It is hypothesized that isoflavones in soybean could enhance the blood cholesterol-lowering activity of 7S protein. Forty-eight hamsters were divided into six groups and fed a non-cholesterol diet or one of the five high-cholesterol diets containing 12.1% 7S protein with 0-15.62 mg g-1 isoflavones. The results showed that addition of isoflavones in diets dose-dependently enhanced the plasma total cholesterol-lowering activity of 7S protein. Addition of isoflavones in 7S protein-based diets significantly reduced hepatic cholesterol accumulation by 12.6-26.1%, compared with the high cholesterol control diet. Isoflavones could also facilitate excretion of neutral sterols in a dose-dependent manner. Supplementation of isoflavones in diets favourably modulated mRNA expression and the protein mass of HMG-CoA reductase. It was concluded that the enhancing effect of isoflavones on the blood cholesterol-lowering activity of 7S protein was mediated by inhibiting the cholesterol absorption and de novo cholesterol synthesis in hypercholesterolemic hamsters.

Biological Effect of Soy Isoflavones in the Prevention of Civilization Diseases

Scientific advancements in recent years have shed new light on the relationship between diet and human health. Nutrients play an important role in the prevention of many civilization diseases, such as osteoporosis, type II diabetes, hypercholesterolemia, and cardiovascular diseases. The biological activity of natural plant components allows their use in the treatment of various diseases, especially civilization diseases, to be speculated. Special attention is paid to phenolic compounds that have numerous health-promoting properties. Isoflavones, phenolic compounds, are commonly found in legumes, especially in soybeans. Their structural similarity to 17-β-estradiol (E2), the main female sex hormone, allows them to induce estrogenic and antiestrogenic effects by binding to estrogen receptors, and their consumption has been associated with a decreased risk of hormone-related cancers. In addition, numerous epidemiological studies and related meta-analyses suggest that soy consumption may be associated with a lower incidence of certain diseases. However, there are some doubts about the potential effects on health, such as the effectiveness of cardiovascular risk reduction or breast cancer-promoting properties. The purpose of this review is to present the current knowledge on the potential effects of soy isoflavone consumption with regard to civilization diseases.

Protease technology for obtaining a soy pulp extract enriched in bioactive compounds: isoflavones and peptides

This work presents a new bioprocess process for the extraction of bioactive components from soy pulp by-product (okara) using an enzymatic technology that was compared to a conventional water extraction. Okara is rich in fiber, fat, protein, and bioactive compounds such as isoflavones but its low solubility hampers the use in food and fertilizer industry. After the enzymatic attack with endoproteases half of the original insoluble proteins were converted into soluble peptides. Linked to this process occured the solubilization of isoflavones trapped in the insoluble protein matrix. We were able to extract up to 62.5% of the total isoflavones content, specially aglycones, the more bioactive isoflavone forms, whose values rose 9.12 times. This was probably due to the increased solubilization and interconversion from the original isoflavones. In conclusion, our process resulted in the formulation of a new functional product rich in aglycones and bioactive peptides with higher antioxidant potency than the original source. Therefore, we propose that the enzymatic extraction of okara bioactive compounds is an advantageous tool to replace conventional extraction.

Glycitein induces reactive oxygen species-dependent apoptosis and G0/G1 cell cycle arrest through the MAPK/STAT3/NF-κB pathway in human gastric cancer cells

Glycitein is an isoflavone that reportedly inhibits the proliferation of human breast cancer and prostate cancer cells. However, its anti-cancer molecular mechanisms in human gastric cancer remain to be defined. This study evaluated the antitumor effects of glycitein on human gastric cancer cells and investigated the underlying mechanisms. We used MTT assay, flow cytometry and western blotting to investigate its molecular mechanisms with focus on reactive oxygen species (ROS) production. Our results showed that glycitein had significant cytotoxic effects on human gastric cancer cells. Glycitein markedly decreased mitochondrial transmembrane potential (ΔΨm) and increased AGS cells mitochondrial-related apoptosis, and caused G0/G1 cell cycle arrest by regulating cycle-related protein. Mechanistically, accompanying ROS, glycitein can activate mitogen-activated protein kinase (MAPK) and inhibited the signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappaB (NF-κB) signaling pathways. Furthermore, the MAPK signaling pathway regulated the expression levels of STAT3 and NF-κB upon treatment with MAPK inhibitor and N-acetyl-L-cysteine (NAC). These findings suggested that glycitein induced AGS cell apoptosis and G0/G1 phase cell cycle arrest via ROS-related MAPK/STAT3/NF-κB signaling pathways. Thus, glycitein has the potential to a novel targeted therapeutic agent for human gastric cancer.

Synthesis and biological evaluation of 3-arylcoumarin derivatives as potential anti-diabetic agents

A variety of substituted 3-arylcoumarin derivatives were synthesised through microwave radiation heating. The method has characteristics of environmental friendliness, economy, simple separation, and purification process, less by-products and high reaction yield. Those 3-arylcoumarin derivatives were screened for antioxidant, α-glucosidase inhibitory and advanced glycation end-products (AGEs) formation inhibitory. Most compounds exhibited significant antioxidant and AGEs formation inhibitory activities. Anti-diabetic activity studies showed that compounds 11 and 17 were equipotent to the standard drug glibenclamide in vivo. According to the experimental results, the target compound 35 can be used as a lead compound for the development of new anti-diabetic drugs. The whole experiment showed that anti-diabetic activity is prevalent in 3-arylcoumarins, which added a new natural skeleton to the development of anti-diabetic active drugs.

Consuming Genistein Improves Survival Rates in the Absence of Laxative in ΔF508-CF Female Mice

Genistein is a naturally occurring isoflavone found in soy. Genistein has been shown to increase the open probability of the most common cystic fibrosis (CF) disease-associated mutation, ∆F508-CFTR. Mice homozygous for the ∆F508 mutation are characterized with severe intestinal disease and require constant laxative treatment for survival. This pathology mimics the intestinal obstruction (meconium ileus) seen in some cystic fibrosis patients. This study tested whether dietary supplementation with genistein would reduce the dependence of the ∆F508 CF mouse model on laxatives for survival, thereby improving mortality rates. At weaning (21 days), homozygous ∆F508 mice were maintained on one of three diet regimens for a period of up to 65 days: normal diet, normal diet plus colyte, or genistein diet. Survival rates for males were as follows: standard diet (38%, n = 21), standard diet plus colyte (83%, n = 42) and genistein diet (60%, n = 15). Survival rates for females were as follows: standard diet (47%, n = 19), standard diet plus colyte (71%, n = 38), and genistein diet (87%, n = 15). Average weight of male mice fed genistein diet increased by ~2.5 g more (p = 0.006) compared to those with colyte treatment. Genistein diet did not change final body weight of females. Expression of intestinal SGLT-1 increased 2-fold (p = 0.0005) with genistein diet in females (no change in males, p = 0.722). Expression of GLUT2 and GLUT5 was comparable between all diet groups. Genistein diet reduced the number of goblet cells per micrometer of crypt depth in female (p = 0.0483), yet was without effect in males (p = 0.7267). The results from this study demonstrate that supplementation of diet with genistein for ~45 days increases the survival rate of female ∆F508-CF mice (precluding the requirement for laxatives), and genistein only improves weight gain in males.

Dietary soya protein improves intra-myocardial lipid deposition and altered glucose metabolism in a hypertensive, dyslipidaemic, insulin-resistant rat model

This study investigates the effects of replacing dietary casein by soya protein on the underlying mechanisms involved in the impaired metabolic fate of glucose and lipid metabolisms in the heart of dyslipidaemic rats chronically fed (8 months) a sucrose-rich (62·5 %) diet (SRD). To test this hypothesis, Wistar rats were fed an SRD for 4 months. From months 4 to 8, half the animals continued with the SRD and the other half were fed an SRD in which casein was substituted by soya. The control group received a diet with maize starch as the carbohydrate source. Compared with the SRD-fed group, the following results were obtained. First, soya protein significantly (P<0·001) reduced the plasma NEFA levels and normalised dyslipidaemia and glucose homoeostasis, improving insulin resistance. The protein levels of fatty acid translocase at basal state and under insulin stimulation and the protein levels and activity of muscle-type carnitine palmitoyltransferase 1 were normalised. Second, a significant (P<0·001) reduction of TAG, long-chain acyl CoA and diacylglycerol levels was observed in the heart muscle. Third, soya protein significantly increased (P<0·01) GLUT4 protein level under insulin stimulation and normalised glucose phosphorylation and oxidation. A reduction of phosphorylated AMP protein kinase protein level was recorded without changes in uncoupling protein 2 and PPARα. Fourth, hydroxyproline concentration decreased in the left ventricle and hypertension was normalised. The new information provided shows the beneficial effects of soya protein upon the altered pathways of glucose and lipid metabolism in the heart muscle of this rat model.

TMF and glycitin act synergistically on keratinocytes and fibroblasts to promote wound healing and anti-scarring activity

Keratinocyte-fibroblast interactions are critical for skin repair after injury. During the proliferative phase of wound healing, proliferation, migration and differentiation of these cells are the major mechanisms leading to tissue remodeling. We have previously reported that glycitin, a major soy isoflavone, stimulates dermal fibroblast proliferation; and the phytochemical, 4′,6,7-trimethoxyisoflavone (TMF), induces migration of HaCaT keratinocyte cells. We therefore investigated whether these compounds display synergistic effects on skin cells during wound healing in vitro and in vivo. Co-treatment with TMF and glycitin synergistically promotes the proliferation and migration of both keratinocytes and dermal fibroblasts, with a 1:1 ratio of these compounds showing the greatest efficacy in our co-culture system. This keratinocyte-fibroblast interaction occurred via the secretion of TGF-β, and the induction of differentiation and proliferation was confirmed in both indirect and direct co-culture assays. In an excisional and burn wound animal model, mice treated with a 1:1 ratio of TMF and glycitin showed faster wound closure, regeneration and scar reduction than even the positive control drug. These data indicate that two isoflavones, TMF and glycitin, act synergistically to promote wound healing and anti-scarring and could potentially be developed together as a bioactive therapeutic for wound treatment.

Health Risks and Benefits of Chickpea (Cicer arietinum) Consumption

Chickpeas (CPs) are one of the most commonly consumed legumes, especially in the Mediterranean area as well as in the Western world. Being one of the most nutritional elements of the human diet, CP toxicity and allergy have raised health concerns. CPs may contain various antinutritional compounds, including protease inhibitors, phytic acid, lectins, oligosaccharides, and some phenolic compounds that may impair the utilization of the nutrients by people. Also, high consumption rates of CPs have enhanced the allergic problems in sensitive individuals as they contain many allergens. On the other hand, beneficial health aspects of CP consumption have received attention from researchers recently. Phytic acid, lectins, sterols, saponins, dietary fibers, resistant starch, oligosaccharides, unsaturated fatty acids, amylase inhibitors, and certain bioactive compounds such as carotenoids and isoflavones have shown the capability of lowering the clinical complications associated with various human diseases. The aim of this paper is to unravel the health risks as well as health-promoting aspects of CP consumption and to try to fill the gaps that currently exist. The present review also focuses on various prevention strategies to avoid health risks of CP consumption using simple but promising ways.

Pharmacological Evaluation of Antidepressant-Like Effect of Genistein and Its Combination with Amitriptyline: An Acute and Chronic Study

The present study was designed to evaluate the acute and chronic antidepressant effect of genistein in combination with amitriptyline in mice. Animals were divided into six groups (n = 6) for treatment with water, genistein, or amitriptyline, either alone or in combination for ten days. Animals were subjected to locomotor activity testing; tail suspension test (TST); and forced swim test (FST) and immobility time was recorded on day one and day ten. Acute treatment of all treatment groups did not significantly reduce the immobility time (p > 0.05). Chronic treatment of combination of genistein (10 mg/kg) and amitriptyline (5 mg/kg and 10 mg/kg) significantly reduced the immobility time as compared to control group (p < 0.001) and was comparable to amitriptyline alone (10 mg/kg). However, no changes in anti-immobility activity in combination of subeffective doses of genistein (5 mg/kg) and amitriptyline (5 mg/kg) were observed. Genistein at its standard dose (10 mg/kg) rendered synergistic effects in combination with subeffective dose of amitriptyline (5 mg/kg) and additive effects in combination with therapeutic dose of amitriptyline (10 mg/kg).

Isoflavone Attenuates the Caspase-1 and Caspase-3 Level in Cell Model of Parkinsonism

The study has investigated the effect of isoflavone attenuates the caspase-1 and caspase-3 level in cell model of Parkinsonism. The subjects were PC12 cells. They were randomly divided into six groups: control, MPP(+) (250 μmol/L), isoflavone (10 μM), isoflavone (10 μM) + MPP(+) (250 μmol/L), Z-YVAD-CHO (10 nM) + MPP(+) group, and Z-DEVD-CHO (10 nM) + MPP(+) group. Cell viability was measured by MTT methods; the content of tyrosine hydroxylase was measured by immunocytochemistry method of avidinbiotin peroxidase complex; apoptosis ratio was measured by flow cytometry. The results showed that cell viability in the MPP(+) group was lower than in all other five groups. There was no difference in cell viability between isoflavone + MPP(+) and control group. Optical density of TH positive cells in isoflavone group was higher than in control, isoflavone + MPP(+), and MPP(+) only groups. The apoptosis ratio in the isoflavone + MPP(+) group and control group and the Z-YVAD-CHO + MPP(+) and Z-DEVD-CHO + MPP(+) group was similar, which was lower than in the MPP(+) group. The lowest apoptosis ratio was found in the isoflavone only group.

Membrane steroid receptor-mediated action of soy isoflavones: tip of the iceberg

Soy isoflavone's (genistein and daidzein in particular) biological significance has been thoroughly studied for decades, so we started from the premise that refreshed investigation approach in this field should consider identification of their new molecular targets. In addition to recently described epigenetic aspects of polyphenole action, the cell membrane constituents-mediated effects of soy isoflavones are worthy of special attention. Accordingly, the expanding concept of membrane steroid receptors and rapid signaling from the cell surface may include the prominent role of these steroid-like compounds. It was observed that daidzein strongly interacts with membrane estrogen receptors in adrenal medullary cells. At low doses, daidzein was found to stimulate catecholamine synthesis through extracellular signal-regulated kinase 1/2 or protein kinase A pathways, but at high doses, it inhibited catecholamine synthesis and secretion induced by acetylcholine. Keeping in mind that catecholamine excess can contribute to the cardiovascular pathologies and that catecholamine lack may lead to depression, daidzein application promises to have a wide range of therapeutic effects. On the other hand, it was shown in vitro that genistein inhibits LNCaP prostate cancer cells invasiveness by decreasing the membrane fluidity along with immobilization of the androgen receptor containing membrane lipid rafts, with down regulation of the androgen receptors and Akt signaling. These data are promising in development of the molecular pharmacotherapy pertinent to balanced soy isoflavone treatment of cardiovascular, psychiatric, and steroid-related malignant diseases.

The effects of Cordyceps sinensis phytoestrogen on estrogen deficiency-induced osteoporosis in ovariectomized rats

BACKGROUND

Isoflavones are naturally occurring plant chemicals belonging to the "phytoestrogen" class. The aim of the present study was to examine the effects of isoflavones obtained from Cordyceps sinensis (CSIF) on development of estrogen deficiency-induced osteoporosis in ovariectomized rats.

METHODS

After the rats were treated orally with CSIF, serum alkaline phosphatase (ALP), tartarate resistant acid phosphatase (TRAP), serum osteocalcin (OC), homocysteine (HCY), C-terminal crosslinked telopeptides of collagen type I (CTX), estradiol and interferonγ (IFN-γ) level were examined. At the same time, the urine calcium, plasma calcium, plasma phosphorus and the mass of uterus, thymus and body were also examined.

RESULTS

The beneficial effects of CSIF on improvement of osteoporosis in rats were attributable mainly to decrease ALP activity, TRAP activity, CTX level and IFN-γ level. At the same time, CSIF also increase the OC and estradiol level in ovariectomized osteopenic rats. The histological examination clearly showed that dietary CSIF can prevent bone loss caused by estrogen deficiency.

CONCLUSION

The significant estrogenic activity of CSIF demonstrated that CSIF has significant estrogenic effects in OVX rats.

Effects of genistein on stereological and hormonal characteristics of the pituitary somatotrophs in rats

The hypothalamic-pituitary somatotropic system plays a pivotal role in the regulation of physiological processes and metabolism, which is modulated by gonadal steroids. Considering that genistein belongs to the phytoestrogen family and acts via similar mechanisms to estrogens, the present study was designed to demonstrate whether genistein modulates the morphofunctional characteristic of somatotrophs [growth hormone (GH) cells] in adult rats in comparison with the effects of estradiol. In the study, the orchidectomized adult rats were used as an appropriate model system for testing the effects of this hormone-like substance. Changes in the pituitary somatotrophs were evaluated histologically and stereologically, while GH level was determined biochemically. Using immunolabelling and stereological methods, we showed that orchidectomy (Orx) provoked the decrease of GH cell volume density. After estradiol treatment of Orx rats, the most prominent change concerned the pituitary relative intensity of GH fluorescence and circulating GH level, which were elevated 77 % and 4.7-fold, respectively. Clearly, in contrast to orchidectomy, estradiol treatment enhanced the GH cells activity. Genistein treatment increased pituitary weight and volume, GH cell volume density, the total number of GH cells, and GH blood concentration (1.3-fold) in comparison to the Orx group. Although identical tendencies followed estradiol and genistein administration, the changes observed after genistein treatment were milder compared to estradiol treatment.

Soy isoflavones have antimutagenic activity on DNA damage induced by the antileishmanial Glucantime (meglumine antimoniate)

Isoflavones are phytoestrogens reported to be potent antioxidant agents. In contrast, the antileishmanial meglumine antimoniate has mutagenic activities. This study evaluated the ability of soy isoflavones to reduce DNA damage induced by meglumine antimoniate. Antimutagenic effects (by micronucleus test) were tested using Swiss mice divided into seven groups treated with meglumine antimoniate (425 mg/kg bw pentavalent antimony); cyclophosphamide (50 mg/kg bw); water (negative control); single isoflavones dose (1.6 mg/kg bw), and three groups received one dose of isoflavones via gavage (0.4 mg/kg bw, 0.8 mg/kg bw or 1.6 mg/kg bw) plus meglumine antimoniate via intraperitoneal, simultaneously. To evaluate antigenotoxicity (by Comet assay), each group with 10 animals received the above-mentioned control doses; single dose of isoflavones 0.8 mg/kg bw, and three groups received isoflavones (0.8 mg/kg bw) by gavage along with intraperitoneal meglumine antimoniate, which were treated with isoflavones 24 h before or after receiving meglumine antimoniate (pre-treatment and post-treatment, respectively) or simultaneously. Cells were harvested 24 h after the treatment, and the data were evaluated by ANOVA followed by Tukey's test (p < 0.05). The data from the simultaneous treatment by micronucleus test revealed that isoflavones (0.4 and 0.8 mg/kg) were able to reverse the mutagenic effect of Glucantime. Moreover, all regimes of the treatment with 0.8 mg/kg bw dose were able to reduce the genotoxicity caused by meglumine antimoniate. It is suggested that the protective effect of isoflavones against DNA damage is related to their ability to reduce oxidative stress caused by the trivalent Sb(III) metabolite of meglumine antimoniate.

Changes of growth hormone-releasing hormone and somatostatin neurons in the rat hypothalamus induced by genistein: a stereological study

OBJECTIVES

Genistein is a plant-derived estrogenic isoflavone commonly found in dietary and therapeutic supplements, due to its potential health benefits. Growth hormone-releasing hormone (GHRH) and somatostatin (SS) are neurosecretory peptides synthesized in neurons of the hypothalamus and regulate the growth hormone secretion. Early reports indicate that estrogens have highly involved in the regulation of GHRH and SS secretions. Since little is known about the potential effects of genistein on GHRH and SS neurons, we exposed rats to genistein.

METHODS

Genistein were administered to adult rats in dose of 30 mg/kg, for 3 weeks. The estradiol-dipropionate treatment was used as the adequate controls to genistein. Using applied stereology on histological sections of hypothalamus, we obtained the quantitative information on arcuate (Arc) and periventricular (Pe) nucleus volume and volume density of GHRH neurons and SS neurons. Image analyses were used to obtain GHRH and SS contents in the median eminence (ME).

RESULTS

Administration of estradiol-dipropionate caused the increase of Arc and Pe nucleus volume, SS neuron volume density, GHRH and SS staining intensity in the ME, when compared with control. Genistein treatment increased: Arc nucleus volume and the volume density of GHRH neurons (by 26%) and SS neurons (1.5 fold), accompanied by higher GHRH and SS staining intensity in the ME, when compared to the orhidectomized group.

DISCUSSION

These results suggest that genistein has a significant effect on hypothalamic region, involved in the regulation of somatotropic system function, and could contribute to the understanding of genistein as substance that alter the hormonal balance.

Soy isoflavones and cellular mechanics

Soy isoflavones are diphenolic compounds that are frequently used for alternative treatment of ageing symptoms in both genders. They operate at principally two hierarchical levels of functional organization - cellular and molecular, while these 'types' of action appear to have indefinite borders. Soy isoflavone action at the cellular level involves inter alia the effects on cell mechanics. This epigenetic and modular determinant of cell function and fate is defined by: the anchorage to extracellular matrix (ECM) and neighboring cells, cytoskeleton organization, membrane tension and vesicle trafficking. Soy isoflavones have been reported to: (i) generally fashion an inert cell phenotype in some cancers and enhance the cell anchorage in connective tissues, via the effects on ECM proteins, focal adhesion kinases-mediated events and matrix metalloproteinases inhibition; (ii) affect cytoskeleton integrity, the effects being related to Ca(2+) ions fluxes and involving cell retraction or differentiation/proliferation-related variations in mechanical status; (iii) increase, remain "silent" or decrease membrane tension/fluidity, which depends on polarity and a number and arrangement of functional groups in applied isoflavone; (iv) provoke inhibitory effects on vesicle trafficking and exo-/endocytosis, which are usually followed by changed cell morphology. Here we present and discuss the abundance of effects arising from cells' "encounter" with soy isoflavones, focusing on different morphofunctional definers of cell mechanics.

Equol producers can have low leptin levels among prediabetic and diabetic females

OBJECTIVES

Soy isoflavones have received great attention for their beneficial effects on health and disease, i.e., in patients with diabetes. Equol is a biologically active isoflavone-related metabolite with interindividual differences in its production. The current study investigated the relationship between an equol-producing state and the levels of adipocytokine markers in a prediabetic and diabetic population.

SUBJECTS AND METHODS

A total of 79 subjects (34 males/45 females) in a prediabetic or diabetic state recruited from the general population were examined regarding their ability to produce equol using urine samples. Clinical data, such as age, smoking as well as anthropometric and biochemical variables, including body mass index (BMI), lipids, insulin, glucose, hemoglobin A1c, leptin and adiponectin, were recorded.

RESULTS

Equol producers exhibited lower leptin and leptin/BMI than non-producers among females. Simple correlation tests and stepwise multiple regression analyses revealed a significant inverse correlation between the leptin/BMI and equol-production. This relationship was not found in males.

CONCLUSIONS

Female equol producers can have favorable metabolic traits in relation to leptin metabolism in this population. Further studies are needed to confirm these results.

Phytoestrogens and the metabolic syndrome

Phytoestrogens are a diverse class of non-steroidal compounds that have an affinity for estrogen receptors α and β, for the peroxisome proliferator-activated receptor (PPAR) family and for the aryl hydrocarbon receptor. Examples of phytoestrogens include prenylated flavonoids, isoflavones, coumestans and lignans. Many phytoestrogens counteract the cellular derailments that are responsible for the development of metabolic syndrome. Here we propose a mechanism of action which is based on five pillars/principles. First, phytoestrogens are involved in the downregulation of pro-inflammatory cytokines, such as COX-2 and iNOS, by activating PPAR and by inhibiting IκB activation. Second, they increase reverse cholesterol transport, which is mediated by PPARγ. Third, phytoestrogens increase insulin sensitivity, which is mediated via PPARα. Fourth, they exert antioxidant effects by activating antioxidant genes through KEAP. Fifth, phytoestrogens increase energy expenditure by affecting AMP-activated kinase signaling cascades, which are responsible for the inhibition of adipogenesis. In addition to these effects, which have been demonstrated in vivo and in clinical trials, other effects, such as eNOS activation, may also be important. Some plant extracts from soy, red clover or licorice can be described as panPPAR activators. Fetal programming for metabolic syndrome has been hypothesized; thus, the consumption of dietary phytoestrogens during pregnancy may be relevant. Extracts from soy, red clover or licorice oil have potential as plant-derived medicines that could be used to treat polycystic ovary syndrome, a disease linked to hyperandrogenism and obesity, although clinical trials have not yet been conducted. Phytoestrogens may help prevent metabolic syndrome, although intervention studies will be always be ambiguous, because physical activity and reduced calorie consumption also have a significant impact. Nevertheless, extracts rich in phytoestrogens may be an alternative treatment or may complement conventional treatment for diseases linked with metabolic syndrome. This article is part of a Special Issue entitled 'Phytoestrogens'.

The inhibitory effect of black soybean on hepatic cholesterol accumulation in high cholesterol and high fat diet-induced non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is defined as excess of fat in the liver. We investigated the effects of black soybean on the cholesterol metabolism and insulin resistance of mice fed high cholesterol/fat diets. Mice were randomly allocated into four groups that were fed different diets: the normal cholesterol/fat diet; high cholesterol/fat diets (HCD); and HCD with 1%, and 4% black soybean powder (1B-HCD, and 4B-HCD). Liver total cholesterol and triglyceride concentrations were significantly lower in the black soybean-supplemented groups than that in the HCD group. PCR revealed significantly lower hepatic SREBP2 and HMG-CoA reductase mRNA levels of black soybean-supplemented mice. Real-time PCR revealed significantly higher hepatic ABCA1 mRNA level of black soybean-supplemented mice, which may increase cholesterol efflux. Liver bile acids concentration was significantly high in the 4B-HCD group. Black soybean stimulated secretion of adiponectin, activation of pAMPK, and eliminated free fatty acids in the liver. Black soybean supplementation decreased MDA and nitrate level. The activities of SOD, catalase, and GPx were restored by black soybean supplementation. Our data strongly indicate that black soybean influences the balance between oxidative and antioxidative stress. We suggest that black soybean improves cholesterol metabolism, insulin resistance, and alleviates oxidative damage in NAFLD.

Chemical reaction of soybean flavonoids with DNA: a computational study using the implicit solvent model

Genistein, daidzein, glycitein and quercetin are flavonoids present in soybean and other vegetables in high amounts. These flavonoids can be metabolically converted to more active forms, which may react with guanine in the DNA to form complexes and can lead to DNA depurination. We assumed two ultimate carcinogen forms of each of these flavonoids, diol epoxide form and diketone form. Density functional theory (DFT) and Hartree-Fock (HF) methods were used to study the reaction thermodynamics between active forms of flavonoids and DNA guanine. Solvent reaction field method of Tomasi and co-workers and the Langevin dipoles method of Florian and Warshel were used to calculate the hydration free energies. Activation free energy for each reaction was estimated using the linear free energy relation. Our calculations show that diol epoxide forms of flavonoids are more reactive than the corresponding diketone forms and are hence more likely flavonoid ultimate carcinogens. Genistein, daidzein and glycitein show comparable reactivity while quercetin is less reactive toward DNA.