Isoflavones in food supplements: chemical profile, label accordance and permeability study in Caco-2 cells

Biochanin A: Disrupting the inflammatory vicious cycle for dry eye disease

Dry eye disease (DED) is a complex disorder driven by several factors like reduced tear production, increased evaporation, or poor tear quality. Oxidative stress plays a key role by exacerbating the inflammatory cycle. Previous studies explored antioxidants for DED treatment due to the link between oxidative damage and inflammation. Biochanin A (BCA) is a bioisoflavone from red clover with potent anti-inflammatory effects. This study investigated BCA's therapeutic potential for DED. Human corneal epithelial cells were cultured under hyperosmotic conditions to mimic DED. BCA treatment increased cell viability and decreased apoptosis and inflammatory cytokine expression. A DED mouse model was developed using female C57BL/6 mice in a controlled low-humidity environment combined with scopolamine injections. Mice received eye drops containing phosphate-buffered saline, low-dose BCA, or high-dose BCA. The effectiveness was evaluated by measuring tear volume, fluorescein staining, eye-closing ratio, corneal sensitivity and PAS staining. The levels of inflammatory components in corneas and conjunctiva were measured to assess DED severity. Maturation of antigen-presenting cells in cervical lymph nodes was analyzed by flow cytometry. BCA eye drops effectively reduced inflammation associated with DED in mice. BCA also decreased oxidative stress levels by reducing reactive oxygen species and enhancing the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2). These findings demonstrate that BCA ameliorates oxidative stress and ocular surface inflammation, indicating potential as a DED treatment by relieving oxidative damage and mitigating inflammation.

Phytochemical Composition of Different Red Clover Genotypes Based on Plant Part and Genetic Traits

Red clover (Trifolium pratense L.) is an important legume that is also known as a rich source of isoflavones, which are compounds with mild estrogenic activity. Therefore, this plant is often used as a raw material in the production of dietary supplements recommended in menopause. Many factors can influence isoflavone content, but those genetically related are considered to be the most important. Therefore, the aim of this study was to evaluate the phytochemical profile of different plant parts of 30 red clover genotypes grouped according to ploidy and country of seed origin by analyzing the content of dominant isoflavones, total phenolic content (TPC) and antioxidant activity. It was found that there are significant differences in the examined traits among plant parts. Red clover leaves had the highest total isoflavone content, with biochanin A as the dominant compound, while flower extracts had the highest TPC and antioxidant activity. Diploid and tetraploid genotypes were significantly different concerning the content of daidzein, genistein, formononetin and TPC with higher quantities in tetraploid samples. On the other hand, seed origin was not a useful separating factor for the analyzed samples. The results of this research indicate that ploidy, as a previously poorly studied factor, could influence isoflavone content in red clover.

Chemical and Biological Properties of Biochanin A and Its Pharmaceutical Applications

Biochanin A (BCA), an isoflavone derived from various plants such as chickpea, red clover and soybean, is attracting increasing attention and is considered to have applications in the development of pharmaceuticals and nutraceuticals due to its anti-inflammatory, anti-oxidant, anti-cancer and neuroprotective properties. To design optimised and targeted BCA formulations, on one hand there is a need for more in-depth studies on the biological functions of BCA. On the other hand, further studies on the chemical conformation, metabolic composition and bioavailability of BCA need to be conducted. This review highlights the various biological functions, extraction methods, metabolism, bioavailability, and application prospects of BCA. It is hoped that this review will provide a basis for understanding the mechanism, safety and toxicity of BCA and implementing the development of BCA formulations.

Natural isoflavone formononetin inhibits IgE-mediated mast cell activation and allergic inflammation by increasing IgE receptor degradation

Immunoglobulin (Ig)E-associated mast cell (MC) activation triggers pro-inflammatory signals that underlie type I allergic diseases. Here, we examined the effects of the natural isoflavone formononetin (FNT) on IgE-mediated MC activation and associated mechanisms of high-affinity IgE receptor (FcεRI) signal inhibition. The effects of FNT on the mRNA expression of inflammatory factors, release of histamine and β-hexosaminidase (β-hex), and expression of signaling proteins and ubiquitin (Ub)-specific proteases (USPs) were analyzed in two sensitized/stimulated MC lines. FcεRIγ-USP interactions were detected by co-immunoprecipitation (IP). FNT dose-dependently inhibited β-hex activity, histamine release, and inflammatory cytokine expression in FcεRI-activated MCs. FNT suppressed IgE-induced NF-κB and MAPK activity in MCs. The oral administration of FNT attenuated passive cutaneous anaphylaxis (PCA) reactions and ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) reactions in mice. FNT reduced the FcεRIγ chain expression, via increased proteasome-mediated degradation, and induced FcεRIγ ubiquitination by inhibiting USP5 and/or USP13. FNT and USP inhibition may be useful for suppressing IgE-mediated allergic diseases.

9-Demethoxy-medicarpin: A potential bone health supplement for the management of protein deficiency-induced bone loss in growing rats

Human skeleton requires an adequate supply of many different nutritional factors for optimal growth and development. The role of nutrition in bone growth has piqued interest in recent years, especially in relation to maximizing peak bone mass and reducing the risk of osteoporosis. Protein deficiency-induced bone loss was induced in female growing rats. All experimental rodent diets were prepared as per recommendations for growing animals. 9-Demethoxy-medicarpin (DMM) treatment was given to growing Sprague Dawley (SD) rats at 1 mg and 10 mg dose orally for 30 days. Bones were collected for bone mineral density (BMD). Bone marrow cells were isolated from femur for calcium nodule formation. Serum samples were collected for biochemical parameters. We found that DMM treatment speeds up the recovery of musculoskeletal weakness by replenishing nutrients in proven rodent model. DMM supplementation for four weeks showed significantly increased vertebral, femur and tibial BMD compared with the untreated PD group. Albumin levels were significantly enhanced in treatment groups, in which 10 mg dose imparted a better effect. We conclude that DMM treatment led to increased BMD and biochemical parameters in protein deficient condition in growing rats and has potential as a bone growth supplement.

Estrogens and phytoestrogens in body functions

Estrogens are the hormones of reproduction in women as well as of many other important functions in the male and female body. They undergo significant changes in the different phases of life, e.g. during puberty, pregnancy or at menopause/andropause. Phytoestrogens are natural non-steroidal phenolic plant compounds that can mimic the activity of estrogens and their beneficial effects in women and in men. This narrative review summarizes the literature on the physiological role of estrogens and the several potential health benefits of phytoestrogens, with particular attention given to the possible role of phytoestrogens in aging.

Plant isoflavones can affect accumulation and impact of silver and titania nanoparticles on ovarian cells

Objectives. The application of nanoparticles is experiencing a rapid growth, but it faces a problem of their toxicity, especially adverse effects on female reproduction. Food and medicinal plants and their isoflavones can be protectors against environmental stressors, but their ability to abate the adverse effects of nanoparticles has not been studied yet. In the present study, we examined the effect of silver (AgNPs) and titanium dioxide (titania, TiO2NPs) nanoparticles alone or in combination with plant phytoestrogens/antioxidants (resveratrol, diosgenin, and quercetin) on accumulation of nanoparticles, and progesterone release by cultured porcine ovarian granulosa cells.Methods. Porcine granulosa cells were incubated in the presence of AgNPs or TiO2NPs (0.1, 1, 10 or 100 µg/ml) alone or in combination with resveratrol, diosgenin or quercetin (10 µg/ml) for 48 h. The accumulation of tested nanoparticles by granulosa cells was assessed under light microscope. Progesterone concentration in culture media was measured by ELISA kit.Results. Cells accumulated both AgNPs and TiO2NPs in a dose-dependent manner. AgNPs, but not TiO2NPs, at highest dose (100 µg/ml) resulted in a destruction of cell monolayer. Both Ag-NPs and TiO2NPs reduced progesterone release. Resveratrol, diosgenin, and quercetin promoted accumulation of both AgNPs and TiO2NPs in ovarian cells and inhibited the progesterone output. Furthermore, resveratrol and diosgenin, but not quercetin, prevented the suppressive action of both AgNPs, and TiO2NPs on progesterone release.Conclusions. These observations (1) demonstrate accumulation of AgNPs and TiO2NPs in ovarian cells, (2) confirm the toxic impact of AgNPs, and TiO2NPs on these cells, (3) confirm the inhibitory effects of plant polyphenols/phytoestrogens on ovarian steroidogenesis, (4) show the ability of these isoflavones to increase the accumulation of AgNPs and TiO2NPs, and (5) show their ability to reduce the suppressive effect of AgNPs and TiO2NPs on ovarian progesterone release. The suppressive effect of AgNPs and TiO2NPs on ovarian functions should be taken into account by their exposition. However, these adverse effects could be mitigated by some plant isoflavones.

Characterization of Formononetin Sulfonation in SULT1A3 Overexpressing HKE293 Cells: Involvement of Multidrug Resistance-Associated Protein 4 in Excretion of Sulfate

Formononetin is one of the main active compounds of traditional Chinese herbal medicine Astragalus membranaceus. However, disposition of formononetin via sulfonation pathway remains undefined. Here, expression-activity correlation was performed to identify the contributing of SULT1A3 to formononetin metabolism. Then the sulfonation of formononetin and excretion of its sulfate were investigated in SULT1A3 overexpressing human embryonic kidney 293 cells (or HKE-SULT1A3 cells) with significant expression of breast cancer resistance protein (BCRP) and multidrug resistance-associated protein 4 (MRP4). As a result, formononetin sulfonation was significantly correlated with SULT1A3 protein levels (r = 0.728; p < 0.05) in a bank of individual human intestine S9 fractions (n = 9). HEK-SULT1A3 cells catalyzed formononetin formation of a monosulfate metabolite. Sulfate formation of formononetin in HEK-SULT1A3 cell lysate followed the Michaelis-Menten kinetics (V_max = 13.94 pmol/min/mg and K_m = 6.17 μM). Reduced activity of MRP4 by MK-571 caused significant decrease in the excretion rate (79.1%–94.6%) and efflux clearance (85.3%–98.0%) of formononetin sulfate, whereas the BCRP specific inhibitor Ko143 had no effect. Furthermore, silencing of MRP4 led to obvious decrease in sulfate excretion rates (>32.8%) and efflux clearance (>50.6%). It was worth noting that the fraction of dose metabolized (f_met), an indicator of the extent of drug sulfonation, was also decreased (maximal 26.7%) with the knockdown of MRP4. In conclusion, SULT1A3 was of great significance in determining sulfonation of formononetin. HEK-SULT1A3 cells catalyzed formononetin formation of a monosulfate. MRP4 mainly contributed to cellular excretion of formononetin sulfate and further mediated the intracellular sulfonation of formononetin.

Lactic acid fermentation of legume seed sprouts as a method of increasing the content of isoflavones and reducing microbial contamination

Legume seeds and sprouts are a rich source of phytoestrogens in the form of isoflavonoids. For the first time, lactic acid fermentation of four types of legume sprouts was used to increase the content of isoflavonoids and microbiological safety. After germination, the highest content of isoflavonoids was observed in the clover and chickpea sprouts, which amounted to 1.1 g/100 g dw., whereas the lactic acid fermentation allowed the increase to as much as 5.5 g/100 g dw. The most beneficial properties were shown by fermented chickpea sprouts germinated in blue light. During fermentation the number of lactic acid bacteria increased by 2 Log₁₀ CFU/mL (LU), whereas mold decreased by 1 LU, E. coli and Klebsiella sp. by 2 LU, Salmonella sp. and Shigella sp. did not occur after fermentation, similar to Staphylococcus epidermidis, while S. aureus and S. saprophyticus decreased by 3 LU and in some trials were not detected.

Isoflavones and bone health in perimenopausal and postmenopausal women

PURPOSE OF REVIEW

Isoflavones exert estrogenic activity distinct from estrogen, they have the potential to treat diseases and symptoms related to estrogen deficiency with minimal side effects and risks. Isoflavone supplementation, in general, is shown to exert beneficial effects against estrogen-deficient bone loss in women, however, some clinical trials still produce conflicting findings. The purpose of this review is to highlight and summarize the most recent and up-to-date research in the field and to bring attention to factors that play a major role in the outcomes of clinical trials that investigate phytoestrogens. Here, we also discuss the latest and most relevant data regarding the clinical safety of these substances.

RECENT FINDINGS

Isoflavones are naturally occurring secondary metabolites found in the Fabacaea plant family. Clinical data from isoflavone interventions support that aglycones (abundant in fermented products) exert enhanced beneficial effects against estrogen-deficient bone loss in women compared with isoflavone glycosides. Studies that employ methods to determine isoflavone content and form of treatments are more likely detect beneficial effects on bone. EFSA have confirmed the safety of isoflavones for women in the most comprehensive report to date.

SUMMARY

Isoflavone aglycones exert greater effects against bone loss than glycosides. Isoflavones show promise as a first-line prophylactic/treatment for bone loss in women.

The Castanea sativa bur as a new potential ingredient for nutraceutical and cosmetic outcomes: preliminary studies

Chestnuts are a common food product in Mediterranean countries, being recognized also for their beneficial effects on human health. Nevertheless, during processing, these fruits generate a large amount of food by-products, such as shells and burs. In the present work, the macronutrient composition, vitamin E profile and amino acid content of the burs were determined in samples from three different Portuguese regions (Minho, Trás-os-Montes and Beira-Alta). The nutritional composition was similar for all samples, being characterised by a high moisture content and low fat amounts. All essential amino acids were present in considerable amounts. Concerning vitamin E, the predominant vitamer was α-tocopherol for the Minho and Beira-Alta samples. The total phenolic compounds were quantified, and the antioxidant activity evaluated in different extracts using two biochemical assays (DPPH˙ and FRAP). All bur extracts showed a high total phenolic content, the highest obtained being that for the Beira-Alta samples. The chestnut bur from Minho showed the highest antioxidant activity in both assays. This study aims to demonstrate the potential of the Castanea sativa bur as a cosmetic and nutraceutical ingredient.

Evaluation of estrogenic activity of red clover (Trifolium pratense L.) sprouts cultivated under different conditions by content of isoflavones, calorimetric study and molecular modelling

Isoflavones have an affinity for estrogen receptors (ERs) including beneficial affinity for ERβ. Widely used soy is a source of poorly absorbed isoflavones glycosides. Red clover contains mostly easily absorbed free aglycones. Red clover sprouts were cultivated under different conditions (white light, UVA or UVB for 12 or 24 h a day at 18 or 25 °C) to maximise the content of isoflavones, especially of high affinity for ERβ. The affinity of isoflavones to ERs was evaluated by molecular modelling and isothermal titration calorimetry (ITC). The richest source of isoflavones, especially formononetin were sprouts cultivated for 10 days under continuous white light and at 25 °C (562 mg/100 g of fresh mass). Formononetin and the above sprouts has been shown to have a high affinity for ERβ. Red clover sprouts can be considered as a source of phytoestrogens with high biological activity and as a dietary supplement reducing menopausal symptoms.

Soybean Milk Inhibits Absorption and Intestinal Transmembrane Transport of Gegen in Rats

Puerariae Lobatae Radix, known as Gegen in Chinese, is widely used to treat cardiovascular diseases, diabetes, and many other chronic illnesses. Flavonoids are the main active components in Gegen and are found in high concentrations in soybeans. Few studies, however, have focused on the effects of flavonoid-rich food on the absorption of Gegen. Here, we report an in vivo pharmacokinetic study on rats to explore the effects of soybean milk on the absorption of Gegen and an in vitro Ussing chamber study of puerarin intestinal transmembrane absorption. Area under the plasma concentration-time curve (AUC_0–t) and maximum plasma concentration (C_max) values of puerarin in rats were significantly decreased after drinking soybean milk, when taking Gegen decoction or a Gegen patent medicine (P < 0.01). In the Ussing chamber experiment, cumulative transmission (Qtn) after 2 h and apparent permeability coefficient (Papp) were lower in the puerarin-daidzin and puerarin-soybean milk solution groups than in the puerarin group. Daidzin in soybean milk inhibited the transmembrane transport of puerarin, resulting in decreased bioavailability of puerarin in Gegen. The results of this study strongly suggest that Gegen should not be taken with flavonoid-rich food, particularly soybean products.

Combined Red Clover isoflavones and probiotics potently reduce menopausal vasomotor symptoms

Background

Natural estrogen decline leads to vasomotor symptoms (VMS). Hormone therapy alleviates symptoms but increases cancer risk. Effective treatments against VMS with minimal cancer risks are needed. We investigate the effects of a highly bioavailable aglycone rich Red Clover isoflavone treatment to alleviate existing menopausal VMS, assessed for the first time by 24hour ambulatory skin conductance (SC)

Methods and results

We conducted a parallel, double blind, randomised control trial of 62 peri-menopausal women aged 40–65, reporting ≥ 5 hot flushes/day and follicle stimulating hormone ≥35 IU/L. Participants received either twice daily treatment with bioavailable RC extract (RCE), providing 34 mg/d isoflavones and probiotics, or masked placebo formulation for 12 weeks. The primary outcome was change in daily hot flush frequency (HFF) from baseline to 12 weeks using 24hr SC. Secondary outcomes were change in SC determined hot flush intensity (HFI), self-reported HFF (rHFF) and hot flush severity (rHFS), blood pressure and plasma lipids. A significant decrease in 24hr HFF (P < 0.01) and HFI (P<0.05) was found when comparing change from baseline to 12 months of the RCE (-4.3 HF/24hr, CI -6.8 to -2.3; -12956 μS s^-1, CI -20175 to -5737) with placebo (0.79 HF/24hr, CI -1.56 to 3.15; 515 μS s^-1, CI -5465 to 6496). rHFF was also significantly reduced (P <0.05)in the RCE (-2.97 HFs/d, CI -4.77 to -1.17) group compared to placebo (0.036 HFs/d, CI -2.42 to 2.49). Other parameters were non-significant. RCE was well tolerated.

Conclusion

Results suggest that moderate doses of RCE were more effective and superior to placebo in reducing physiological and self-reported VMS. Findings support that objective physiological symptom assessment methods should be used together with self-report measures in future studies on menopausal VMS.

Trial registration

ClinicalTrials.gov NCT02028702

Polymorphs of daidzein and intermolecular interaction effect on solution crystallization

Polymorphs of DAID with enhanced dissolution rates were discovered and the intermolecular interaction effect on crystallization behavior was investigated.

Assessment of Beneficial and Possible Toxic Effects of Two New Alfalfa-Derived Shelf Products

Aerial parts of Medicago sativa L. have been used as food and its consumption has been associated with health benefits, one among the most important being menopausal symptoms control. This work was aimed to explore possible pharmacological effects of two new alfalfa-derived products that have recently emerged as daily beverage preparations. In exploring their potential estrogenic effects, they produced no relevant alteration in the uterus. However, lowering glucose levels until normal values without causing further hypoglycemic effect were observed, when rats were treated with 1.5 g/kg/day samples. In vivo acute toxicity was not found when the alfalfa products were tested up to 3 g/kg rat weight. Furthermore, in vitro studies were conducted to assess their possible toxic effects. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase tests were carried out on the Caco-2 cell model to determine cell viability and membrane integrity. A concentration-dependent effect was observed, with a significant decrease in cell viability after exposure to concentrations of alfalfa product up to 100 mg/mL (after 3 h of incubation) and 50 mg/mL (after 24 h of treatment). Although in vitro level, the decrease in cell viability at these still low doses may underlie some toxicity, making necessary additional studies before any recommendation of a sustained consumption of these products by humans.

The isoflavone content of two new alfalfa-derived products for instant beverage preparation

The frequent use of plant-based products to promote health leads to the search for scientific information related to efficacy and safety of those products for human consumption. Two alfalfa-derived products (ADP), freeze-dried juice (FDJ) and dehydrated powder (DP), from alfalfa harvested in Mexico, are being developed as new possible nutraceuticals. To the best of our knowledge, any study reports the real composition of such products used to prepare instant beverages in what concerns isoflavone contents. Seven isoflavones (glycitein, formononetin, biochanin A, daidzein, genistein, daidzin and genistin) were assessed by HPLC-DAD analysis as well as its variation in five different batches of these products. Different solvents were tested in order to choose the best one to extract isoflavones. The results showed the presence of daidzein, genistein, genistin and daidzin in most samples while glycitein, formononetin and biochanin A were not detected. Significant differences between isoflavone contents were found with different solvent systems. Water was the best option to extract daidzein (0.40-1.08 mg per unit and 1.30-4.90 mg per unit for DP and FDJ, respectively) whereas the water-methanol-formic acid mixture was efficient to extract genistein (0.19-0.43 mg per unit and 0.15-0.72 mg per unit for DP and FDJ, respectively). In all cases, the total isoflavone content was higher in freeze-dried juices than in dehydrated powders. Genistein and daidzein were the more abundant isoflavones quantified. Further physiological and nutritional studies are needed to complete the validation of effectiveness and safety of these products.

Determination of the isoflavone composition and estrogenic activity of commercial dietary supplements based on soy or red clover

Dietary supplements high in isolated isoflavones are commercially available for human consumption primarily to alleviate menopausal symptoms in women. The isoflavone composition, quantity and importantly their estrogenic potency are poorly standardised and can vary considerably between different products. The aim of this study was to analyse the isoflavone composition of 11 dietary supplements based on soy or red clover using the HPLC/MS/MS technique. Furthermore, we investigated the transactivational potential of the supplements on the estrogen receptors (ER), ERα and ERβ, performing luciferase reporter gene assays. As expected, we found that the isoflavone composition varies between different products. The measured total isoflavone contents in various supplements were mostly comparable to those claimed by the manufacturers in their product information. However expressing the isoflavone content as isoflavone aglycone equivalents, soy-based supplements had a clearly lower quantity compared to the manufacturer information. All supplements transactivated more or less ERα and ERβ with a preference for ERβ. The transactivational efficiency exceeded partly the maximal 17β-estradiol induced ER activation. While the different soy-based supplements revealed similar transactivation potential to both ERs, red clover-based supplements differed considerably. We conclude that different commercial dietary supplements based on soy or red clover vary in their isoflavone composition and quantity. They are estrogenically active, although especially the red clover-based supplements show considerable differences in their estrogenic potential to ERα and ERβ. Thus, different isoflavone-rich products cannot be necessarily compared regarding possible biological effects.