Isoflavone Mixture Research Articles

Long-Term Exposure to Isoflavones Alters the Hormonal Steroid Homeostasis-Impairing Reproductive Function in Adult Male Wistar Rats

The consumption of isoflavones is gaining popularity worldwide due to their beneficial effects on health. However, isoflavones are considered to be endocrine disruptors and cause deleterious effects on hormone-sensitive organs, especially in males. Therefore, this study aimed to determine if a continuous and prolonged exposure to isoflavones in adult males altered the endocrine axis effect of testicular function. For this purpose, seventy-five adult male rats were administered with low and high mixtures of isoflavones (genistein and daidzein) for 5 months. The determination of steroid hormones (progesterone, androstenedione, dehydroepiandrosterone, testosterone, dihydrotestosterone, 17β-estradiol, and estrone sulphate) was carried out in serum and testicular homogenate samples. Sperm quality parameters and testicular histology were also determined. The results revealed that low and high doses of isoflavones promote a hormonal imbalance in androgen and estrogen production, resulting in a decrease in circulating and testicular androgen levels and an increase in estrogen levels. These results are associated with a reduction in the sperm quality parameters and a reduction in the testicular weight, both in the diameter of the seminiferous tubules and the height of the germinal epithelium. Altogether, these results suggest that a continuous exposure to isoflavones in adult male rats causes a hormonal imbalance in the testes that disrupts the endocrine axis, causing defects in testicular function.

The role of isoflavones in augmenting the effects of radiotherapy.

Cancer is one of the major health problems and the second cause of death worldwide behind heart disease. The traditional soy diet containing isoflavones, consumed by the Asian population in China and Japan has been identified as a protective factor from hormone-related cancers. Over the years the research focus has shifted from emphasizing the preventive effect of isoflavones from cancer initiation and promotion to their efficacy against established tumors along with chemo- and radiopotentiating effects. Studies performed in mouse models and results of clinical trials emphasize that genistein or a mixture of isoflavones, containing in traditional soy diet, could be utilized to both potentiate the response of cancer cells to radiotherapy and reduce radiation-induced toxicity in normal tissues. Currently ongoing clinical research explores a potential of another significant isoflavone, idronoxil, also known as phenoxodiol, as radiation enhancing agent. In the light of the recent clinical findings, this article reviews the accumulated evidence which support the clinically desirable interactions of soy isoflavones with radiation therapy resulting in improved tumor treatment. This review discusses important aspects of the development of isoflavones as anticancer agents, and mechanisms potentially relevant to their activity in combination with radiation therapy of cancer. It gives a critical overview of studies characterizing isoflavone targets such as topoisomerases, ENOX2/PMET, tyrosine kinases and ER receptor signaling, and cellular effects on the cell cycle, DNA damage, cell death, and immune responses.

Investigation of isoflavone constituents from tuber of Apios americana Medik and its protective effect against oxidative damage on RIN-m5F cells

In our previous study, AI-3, a mixture of isoflavones, was obtained from Apios Americana Medik tuber and showed strong protective ability on oxidative damaged RIN-m5F cells. This study aimed to identify the main compounds of AI-3 and elucidate their activities and underlying mechanism. In results, eleven compounds were purified from AI-3. Among them, Compound 8 (2′-Hydroxy, 5-methoxy genistein-7-O-glucoside, HMG) was the most effective compound against H2O2-induced injury in RIN-m5F cells (stronger than positive control α-LA). Further RNA-seq analysis found that compared with H2O2 group, 388 differentially expressed genes (DEGs) were identified in HMG group. The enrichment analyses revealed fluid shear stress and atherosclerosis pathway and hepatocellular carcinoma pathway enriched the most DEGs, in which HOX-1, GST, NQO1, SQSTM, TrxR1 were significantly up-regulated. The finding indicated Keap1-Nrf2-ARE signaling pathway may play essential role in the protective effect of HMG on oxidative damaged RIN-m5F cells.

Isoflavones and their metabolites influence the milk production ability of bovine mammary epithelial cells in a type-specific manner.

Dairy cows feed on isoflavones as physiologically active substances present in legumes. However, the influences of isoflavones (biochanin A, genistein, formononetin, and daidzein) and their metabolites (p-ethylphenol and equol) on milk components production, tight junctions (TJs), and their regulatory pathways are unclear in bovine mammary epithelial cells (BMECs). In this study, we investigated the influences of isoflavones and their metabolites in BMECs using an in vitro culture model. The influences of isoflavones on milk components production, TJ proteins, and STAT5/STAT3 signaling pathways were different in a type-specific manner. Biochanin A decreased the mRNA expression and secretion of both β-casein and lactoferrin while a decrease in activated STAT5 and an increase in activated STAT3. In contrast, equol increased claudin-3, which is the main components for less-permeable TJs in lactation, while an increase in activated STAT5. In addition, a mixture of multiple isoflavones based on the intake of red clover increased secretion of lactoferrin, mRNA expression of β-casein, and amount of claudin-3, but a mixture based on soy did not affect the BMECs. Thus, these results indicate that isoflavones in legumes and the metabolic activity of isoflavones in dairy cows when feeding legumes may affect the milk production ability in BMECs.

Effect of a diet containing a mixture of soybean isoflavones and soyasaponins on contact hypersensitivity and gut microbiota in mice

AbstractDietary soybean isoflavones (SIs) and soyasaponins (SSs) individually exert inhibitory effects on contact hypersensitivity (CHS), which is an animal model of allergic contact dermatitis (ACD); however, the beneficial effects of diets containing a mixture of SIs and SSs on CHS remain unclear. Here, we investigated the CHS‐suppressive effects of diets containing a mixture of SIs and SSs at physiologically relevant doses, and the role of the gut microbiota. The diets attenuated ear swelling and reduced the number of Gr‐1‐positive cells infiltrating the auricle tissues. Ear swelling was inhibited in the SI‐ and SS‐treated mice compared to the SI‐treated mice. Compared to the CHS controls, the levels of chemokine (C‐X‐C motif) ligand 2 and triggering receptor expressed on myeloid cells‐1 (TREM‐1) were lower in the auricle tissues of SI‐ and SS‐treated mice, whereas TREM‐1 production was not suppressed in SI‐ or SS‐treated mice. In addition, vancomycin treatment had little effect on the CHS‐inhibitory activity of SI and SS diets, whereas ciprofloxacin and metronidazole treatments blocked the effects of SI and SS diets. These antibiotics exhibited differing effects on the microbiota composition deduced from the bacterial 16S ribosomal RNA gene sequences. Therefore, consuming a mixture of SIs and SSs has ACD‐preventive effects and is affected by the gut microbiota.

Effects of Soybean Isoflavone and Astragalus Polysaccharide Mixture on Colostrum Components, Serum Antioxidant, Immune and Hormone Levels of Lactating Sows

Simple SummaryThe reproductive performance of sows plays an important role in the development of the pig industry. The health status during gestation and lactation capacity of sows determines the healthy development and later growth status of piglets. This study aimed to investigate the effects of soybean isoflavone and astragalus polysaccharide mixture on the colostrum components, and serum antioxidant activities, immune function, and hormone levels of lactating sows. Results showed that the soybean isoflavone and astragalus polysaccharide mixture increased the total lactation yield in the lactating phase, and improved the antioxidant, immune and hormone levels in the serum of lactating sows. In conclusion, the soybean isoflavone and astragalus polysaccharide mixture can improve the average daily feed intake, lactation yield, serum antioxidant activity, immune function, and the hormone levels of lactating sows, and the optimum dosage in this study was 200 mg/kg. This study provides a theoretical basis for the application of the soybean isoflavone and astragalus polysaccharide mixture application in the production of lactating sows and a reference basis for the development of green feed additives.The objectives of this study were to investigate the effects of soybean isoflavone (SI) and astragalus polysaccharide (APS) mixture on the colostrum components, serum antioxidant, immune and hormone levels of lactating sows. A total of 72 healthy Yorkshire × Landrace lactating sows, were randomly divided into four treatments with six replicates and three lactating sows for each replicate. The control group was fed the basal diet, while the experimental groups were fed the basal diet with 100, 200 and 300 mg/kg SI and APS mixture in the form of powder, respectively. Compared with the control group, (a) the total lactation yield of the 200 mg/kg group was significantly higher (p < 0.05) at 21 days, (b) there was no significant difference in colostrum composition, (c) TG, CHO and MDA content in each treatment group were significantly decreased (p < 0.05), (d) IgA, GH, IGF-1, TNF-α and SOD contents in the 200 mg/kg group were significantly increased (p < 0.05). The SI and APS mixture could improve the average daily feed intake, lactation yield, serum antioxidant activities, immune function, and hormone levels of lactating sows, and the optimum dosage in this study was 200 mg/kg.

Genistein and daidzein reduced chlorpyrifos induced damage in PC12 cell

The present study preliminarily evaluated neurotoxicity injuries induced by chlorpyrifos in PC12 ​cell, which were used as a model for nervous cell system. In cultured PC12 ​cell, application of soy isoflavones (genistein, daidzein, monomer and mixture) significantly reduced chlorpyrifos induced toxicity, a widely used pesticide, and resulted in a better cell survival rate. Treatments with isoflavones reduced malondialdehyde content, reactive oxygengeneration and acetylcholine level in medium, and maintained mitochondrial membrane potential integrity. Daidzein enhanced endogenous antioxidant system in PC12 ​cell with an increasing in superoxide dismutase per-unit activity. Genistein reduced acetylcholine content in the medium. Daidzein and genistein showed different effects, and their combined effect were greater than individual. In conclusion, soy isoflavones as an antioxidant and neuroprotectant, enhanced choline metabolism, which effectively mitigated disadvantageous influence of PC12 ​cell caused by chlorpyrifos.

Co-solubilisation of a binary mixture of isoflavones in a water micellar solution of sodium cholate or cetyltrimethylammonium bromide: Influence of micelle structure

During co-solubilisation of a binary mixture of daizdein (D) and genistein (G) in a micelle water solution of sodium cholate (SC), G synergistically affects the solubilisation of D, while D antagonistically affects the solubilisation of G. In SC micellar binary mixtures of isoflavones, the interaction parameter (coefficient of activity) of molecule D is <1, while for G it is >1, i.e. D molecules are thermodynamically more stable than in the micellar pseudophase without G. It is assumed that formation of SC secondary micelles have a role in the thermodynamic stabilisation of D, especially when the content of the micellar binary mixture of isoflavones leads to a molar fraction of 1. In micellar co-solubilisation of the same binary mixtures with cetyltrimethylammonium bromide (CTAB), a mutual antagonistic effect occurs between components of the mixture related to their solubilisation. This is probably the result of competition between D and G for micelle binding sites.

Isoflavin-β modifies muscle oxidative stress and prevents a thyrotoxicosis-induced loss of muscle mass in rats.

We sought to verify whether isoflavin-beta (Iso-β), a mixture of isoflavones with antioxidant properties, could prevent thyrotoxicosis-induced loss of muscle mass and the participation of oxidative stress (OS) in the mechanisms of this prevention. Two experimental periods of thyrotoxicosis induction were used in Wistar rats: 3 and 5 days to assess Iso-β effects before and after thyrotoxicosis-induced muscle wasting. After euthanasia, peritoneal fat and gastrocnemius muscle were collected, weighed, and muscle OS was assessed. Iso-β prevented the loss of gastrocnemius mass in thyrotoxic rats through the prevention of muscle OS generation during thyrotoxicosis, increasing muscle total antioxidant capacity and decreasing mitochondrial cytochrome c oxidase activity, lipid peroxidation, and protein carbonyl content. Iso-β decreased oxidative modification of proteins, which is known to exert a major role during proteolysis induction and is present in thyrotoxic myopathy, highlighting the potential action of Iso-β in this complication of the disease. Muscle Nerve 56: 975-981, 2017.

Quantification of isoflavones in coffee by using solid phase extraction (SPE) and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

A new method for extracting isoflavones from espresso coffee (EC) was coupled with high-performance liquid chromatography-tandem mass spectrometry (MS/MS) for the first time to analyse five isoflavones, which included both a glycosilated form, genistin and the aglycons daidzein, genistein, formononetin and biochanin A. Isoflavones were extracted from coffee samples using methanol, stored in a freezer overnight to precipitate proteic or lipidic residues and purified on SPE C18 cartridges before high-performance liquid chromatography-MS/MS analysis. The recovery percentages obtained by spiking the matrix at concentrations of 10 and 100 µg l(-1) with a standard mixture of isoflavones were in the range of 70 to 104%. The limits of detection and limits of quantification were in the range of 0.015-0.3 µg l(-1) and 0.05-1 µg l(-1) , respectively. Once validated, the method was used to analyze the concentrations of isoflavones in six ECs and ten ground coffee samples. Only formononetin and biochanin A were found, and their respective concentrations ranged from 0.36 to 0.41 µg l(-1) and from 0.58 to 3.26 µg l(-1) in ECs and from 0.36 to 4.27 µg kg(-1) and from 0.71 to 3.95 µg kg(-1) in ground coffees. This method confirms the high specificity and selectivity of MS/MS systems for detecting bioactives in complex matrices such as coffee.Copyright © 2016 John Wiley & Sons, Ltd.

Treatment with soy isoflavones during early adulthood improves metabolism in early postnatally overfed rats

Purpose: The incidences of obesity and related diseases have reached epidemic proportions, and new therapeutic approaches are needed. Soy isoflavones have been identified as an important dietary factor for preventing and treating metabolic dysfunction. This study examined the effects of high doses of isoflavone on glucose and fat metabolism in a model of programmed obesity and evaluated its effects on the autonomic nervous system.Methods: Litters of Wistar rats were standardized at nine pups per dam in normal litters (NL) or reduced to three pups per dam at the third day of life (P3) in small litters (SL) to induce postnatal overfeeding. Gavage with a soy bean isoflavone mixture (1 g/day) diluted in water was started at P60 and continued for 30 days. The control animals received vehicle gavage. At P90, biometric and metabolic parameters as well as direct autonomic nerve activity were measured.Results: Increases in glycaemia and insulinaemia observed in SL rats were reduced by isoflavone treatment, which also caused lower glucose-induced insulin secretion by pancreatic islets. Sympathetic activity in the major splanchnic nerve was increased, while vagus nerve activity was reduced by isoflavone treatment. The dyslipidaemia induced by overfeeding in SL rats was restored by isoflavone treatment.Conclusion: The present study shows that treatment with isoflavone reduces adiposity and improves glucose and lipid metabolism. Collectively, these effects may depend on autonomic changes.

Pharmacokinetics of isoflavones from soy infant formula in neonatal and adult rhesus monkeys

Consumption of soy infant formula represents a unique exposure scenario in which developing children ingest a mixture of endocrine-active isoflavones along with a substantial portion of daily nutrition. Genistein and daidzein were administered as glucoside conjugates to neonatal rhesus monkeys in a fortified commercial soy formula at 5, 35, and 70 days after birth. A single gavage dosing with 10 mg/kg bw genistein and 6 mg/kg bw daidzein was chosen to represent the upper range of typical daily consumption and to facilitate complete pharmacokinetic measurements for aglycone and total isoflavones and equol. Adult monkeys were also gavaged with the same formula solution at 2.8 and 1.6 mg/kg bw genistein and daidzein, respectively, and by IV injection with isoflavone aglycones (5.2 and 3.2 mg/kg bw, respectively) to determine absolute bioavailability. Significant differences in internal exposure were observed between neonatal and adult monkeys, with higher values for dose-adjusted AUC and Cmax of the active aglycone isoflavones in neonates. The magnitude and frequency of equol production by the gut microbiome were also significantly greater in adults. These findings are consistent with immaturity of metabolic and/or physiological systems in developing non-human primates that reduces total clearance of soy isoflavones from the body.

Intake of Genistein and Daidzein Ameliorates Adiposity and Metabolic Syndrome in High Fat Fed C57BL/6J Mice

IntroductionGenistein and daidzein are isoflavones abundant in soybean. These isoflavones have been shown to have a weak but significant estrogenic effect and other studies have shown isoflavones may impact cancer and metabolic disease. Our prior research (Luo et al. 2014) indicated metabolic improvements in male mice fed a high‐fat (HF) diet supplemented with Novasoy, a dietary supplement containing a mixture of soy isoflavones. With two related, but slightly different chemical structures, it is plausible that dietary genistein and daidzein influence metabolism differently.ObjectiveThe objective of the present study was to determine if diet supplementation with genistein (G) or daidzein (D) would have a differential impact on body weight, body composition, and other physiologic and metabolic parameters in high‐fat fed male C57BL/6J mice.MethodsC57BL/6J mice (n=8 per group) were provided either low‐fat diet (LF, 10% kcal fat), high‐fat diet (HF, 45% kcal fat), or HF plus ~0.2% of either G or D for 10 weeks. Dietary levels of isoflavones are equivalent to intake of dietary supplements in humans. Body weight was recorded weekly and food intake bi‐weekly.ResultsDietary supplementation with G or D led to decreased body weight compared to HF‐fed mice. Furthermore, body weight gain in G‐fed mice was profoundly impacted and lower in value vs. all groups including LF‐fed mice, weight gains were as follows: LF: 7.0 ± 0.6 g, HF: 18.6 ± 1.0 g, G: 2.9 ± 0.7 g, D: 11.9 ± 1.4 g. In glucose tolerance testing, both G and D intake were associated with a trend of decreased area under the curve (AUC), consistent with improved glucose sensitivity vs. HF‐fed mice. Serum insulin levels were consistent with this finding, with concentrations in G‐fed mice significantly lower than HF‐fed and equivalent to LF‐fed mice (P &lt; 0.01). Serum resistin concentrations showed a trend of lower levels vs. HF‐fed mice in G‐ and D‐fed mice (P &lt; 0.01). Serum MCP‐1 levels were measured by ELISA and G‐fed mice had trended to lower MCP‐1 levels compared to HF‐ and D‐fed mice (P &lt; 0.10). Liver tissue sections were evaluated for fat content and relative fat content was LF: 9.0 ± 1.7 %, HF: 30.8 ± 3.8 %, G: 15 ± 3.7 %, D: 30 ± 6.3 %. Hepatic gene expression levels were measured by RT‐PCR, and G‐fed mice had higher levels of several genes related to lipid metabolism including stearoyl‐CoA desaturase‐1 and sterol regulatory element‐binding protein 1a.ConclusionThe profound impact of genistein intake on weight gain was unanticipated and needs to be further explored to determine if it may be of use as a dietary supplement to help promote weight loss or to help improve glucose sensitivity.Support or Funding InformationOregon Agricultural Experiment Station

Soy isoflavones, inulin, calcium, and vitamin D3 in post-menopausal hot flushes: an observational study

To evaluate the effect of soy isoflavones and inulin (SII) on hot flushes (HF) and quality of life in a clinical setting, the authors conducted an observational study. The authors performed an observational, prospective, multicentric study on women in peri-/post-menopause treated or untreated with a product present on the Italian market, consisting in a mixture of calcium (500 mg), vitamin D3 (300 IU), inulin (3 g) and soy isoflavones (40 mg). A total of 135 patients, 75 (55.6%) in the SII group and 60 (44.4%) in the untreated group entered the study. After three months, the mean number of HF declined of 2.8 (SD 3.7) in the SII group and 0.0 in the untreated one. The corresponding values after six months were -3.7 (SD 2.7) in the SII group and -0.9 (SD 5.3) in the control group (p = 0.02). This observational trial suggests a possible beneficial effect of a dietary soy supplement containing 40 mg of isoflavone/day plus inulin in the management of menopausal symptoms such as hot flashes.

Dietary soy isoflavones increase metastasis to lungs in an experimental model of breast cancer with bone micro-tumors.

Bone is one of the most common sites for metastasis in breast cancer (BC). Micro-metastasis in bone marrow was detected in 30% of patients with stage I, II, or III BC at primary surgery and is a strong indicator of poor prognosis. The role dietary soy isoflavones play in BC with bone micro-metastasis is unclear. In this study, we examined the effects of genistein, daidzein, (-)-equol or a mixture of soy isoflavones on BC with bone micro-metastasis using an experimental model of murine mammary cancer 4T1 cells engineered with luciferase. A small number (1000) of 4T1 cells were injected into the tibia of female Balb/c mice to establish micro-tumors in bone. Soy isoflavones were supplemented in the AIN-93G diet at 750 mg/kg and were provided to mice from 3 weeks before to 3 weeks after cell injection. Bioluminescent imaging was conducted on day 2 (D2), D6, D8, D16 and D20 post cell injection and the results indicated dietary soy isoflavones enhanced the growth of bone micro-tumors on D8. Furthermore, dietary soy isoflavones stimulated metastatic tumor formation in lungs and increased Ki-67 protein expression in these metastasized tumors. In vitro, soy isoflavones (<10 µM) had limited effects on the growth, motility or invasion of 4T1 cells. Thus, the in vivo stimulatory effect could be likely due to systemic effects between the host, 4T1 tumors and soy isoflavones. In conclusion, soy isoflavones stimulate BC with bone micro-metastasis in mice and further investigations are needed regarding their consumption by BC survivors.

Prevention of retinoic acid-induced osteoporosis in mice by isoflavone-enriched soy protein.

A novel soy protein aggregate enriched with isoflavones (SPA-IS), a mixture of soy protein and isoflavones (Mix), isoflavones (IS), and the soy protein were obtained to investigate the preventive effects on osteoporosis induced by retinoic acid in Kunming mice. The serum osteocalcin levels in the Mix and SPA-IS groups decreased compared with the model group (mice showing retinoic acid-induced osteoporosis) (P < 0.05). The trabecular analysis results showed an increased preventive effect of the SPA-IS group over the Mix group, the IS group, and the soy protein group. The results of both left tibial maximum load and the 4th lumbar structural strength differ between the IS and the SPA-IS groups. The SPA-IS exhibited obvious oestrogenic activities on retinoic acid-induced osteoporosis in Kunming mice compared to Mix, IS, and soy protein. The results suggest that there is a potential use for SPA-IS in the treatment of osteoporosis induced by intake of retinoic acid. The improvement of bone indicators might be attributed to the formation of aggregate particles and the improvement of IS solubility.

Anti-obese and anti-diabetic effects of a mixture of daidzin and glycitin on C57BL/6J mice fed with a high-fat diet.

We investigated the effects of a mixture of daidzin and glycitin, which are the glycoside-form isoflavones of daidzein and glycitein, respectively, on body weight, lipid levels, diabetic markers, and metabolism in a high-fat diet (HF) fed C57BL/6J mice for 92days. The mice were divided into basic diet group (CON), HF group, and HF companied with the isoflavone mixture group (HFISO). Results showed that mice in HFISO had a significantly lower body weight and adipose tissue compared to HF group. Blood glucose, serum HbA1c, and serum insulin also showed lower levels in HFISO group. In addition, higher hepatic GSH level and lower serum 8-hydroxy-2'-deoxyguanosine (8-OHdG) level were found in HFISO group mice. This suggests that the regulation of oxidative stress by daidzin and glycitin was closely related to the suppression of adipose tissue and the progression of diabetes.

Can Glycyrrhiza glabra L. Reduce Delirium after Coronary Artery Bypass Graft Surgery?

Hadi Darvishi Khezri, MSc Thalassemia Research Center Hemoglobinopathy Institute, Booali Sina Hospital Pasdaran Boulevard, Sari, Iran Hadidarvishi87@yahoo.com © 2014 S. Karger AG, Freiburg 1661–4119/14/0216–0418$39.50/0 Coronary artery bypass graft (CABG) surgery is one of the most commonly performed invasive procedures worldwide [1, 2]. Since the introduction of cardiopulmonary bypass (CPB), the neurological consequence of CABG surgery has been an important subject [2]. Delirium is a major problem after CABG surgery with the approximate reported incidence rate of 20–80% [2]. This complication is associated with increased mortality, longer hospital stay, increased hospital costs, and long-term care [2–4]. Regarding the high incidence of delirium in patients undergoing CABG surgery, prophylactic treatment is preferable. Hence, pharmacological neuroprotective strategies have been developed for these patients [3, 4]. A meta-analysis indicated that preoperative low-dose and shortterm administration of haloperidol or risperidone may modestly reduce delirium occurrence in high-risk patients that need intensive care unit (ICU) [4]. Other clinical trials have not reported any decreases in the incidence rate of delirium in patients receiving pharmacologic prophylactic (haloperidol, donepezil [5], citicoline [6], and rivastigmine) [7–9]. Acute inflammation and reduced serotonin neurotransmitter are the most important causes of delirium in these patients [10, 11]. In a meta-analysis, Peng et al. [12] showed the role of peripheral inflammatory markers, such as interleukin-6 and S-100 , in postoperative delirium [13]. Although some studies indicated that use of compounds with brain protective activities (such as propofol, aprotininand lidocaine) can prevent delirium after CABG surgery, no sufficient evidence was presented to make a change in standard clinical practice. Licorice (G. glabra, species: Leguminosae) is a worldwide popular herbal medicine. Just 3 out of the numerous species of licorice are usually used as commercial drugs, including G. glabra, Glycyrrhiza echinata L., and Glycyrrhiza uralensis Fisch. In traditional medicine, the roots and rhizomes (underground stems) of licorice are currently used as therapeutic compounds in many Asian and European countries. Licorice mainly consists of a mixture of glycyrrhizinic acid, glycyrrhizic acid, glycyrrhizin, isoflavones, isoliquiritigenin, hispaglabridin B, paratocarpin B, and glabiridin. Furthermore, this plant has been used as antidote and demulcent, expectorant, antioxidant, antiulcer, laxative, antipyretic, antimicrobial, and antiinflammation agent [14]. Glabridin, a major active flavonoid in licorice, has anti-atherosclerotic, anti-inflammatory, antinephritis, radical scavenging activities and antidepressant-like effects [15]. Moreover, this compound has been reported to be useful for renovascular and cardiovascular diseases [16]. Ojha et al. [16] evaluated the cardioprotective effect of licorice against ischemia-reperfusion injury induced by ligation of left anterior descending coronary artery in rats. Their results confirmed the cardioprotective activity of licorice by alleviating oxidative stress in myocardial ischemia-reperfusion injury [16]. Safe brain-protective agents, such as licorice, could be utilized to reduce the neuroinflammation and delirium caused by CPB in these patients. Muralidharan et al. [14] investigated the cerebroprotective effect of 250 and 500 mg/kg of licorice roots in hypoxic rats and indicated that licorice has a cerebro-

Effective clean-up and ultra high-performance liquid chromatography–tandem mass spectrometry for isoflavone determination in legumes

Legumes are an excellent source of macronutrients and phytochemicals as isoflavones. The aim of this work was to develop a new analytical method for determining five isoflavone compounds, three of which are aglycons, namely daidzein, genistein, biochanin A, and two of which, daidzin and genistin, are glycosilated, in lentils and other pulses, using an effective clean-up system and UHPLC–MS/MS (triple quadrupole) method.The recoveries obtained by spiking the lentil samples with a standard mixture of isoflavones at three levels of fortification (5, 25 and 100μgkg−1) were in the range of 54.4–111.1%, 68.6–91.1%, and 84.4–114%, respectively. The method was applied to analyse 48 lentil samples from central Italy and pulses for determining the isoflavone content, which was found to range from 1.1 to 95.6μgkg−1.

Glycation is regulated by isoflavones.

The effect of soy isoflavones on the Maillard reaction (MR) was investigated. Model systems composed of the soy protein glycinin (10 mg mL(-1)) and fructose (40 mg mL(-1)) under basic pH (∼12) conditions were employed for testing the anti-glycative effect of the major antioxidant soy isoflavones (genistin and genistein at 10 μg mL(-1)) and a soy isoflavone-rich extract. The contents of total phenols (TPCs) and total flavonoids (TFCs) of the isoflavone-rich extract were determined. Glycinin was pre-incubated with isoflavones for 1 h and 16 h at 60 °C prior to MR. The progress of MR was estimated by analysis of free amino groups by OPA assay; carbohydrate covalently bound to the protein backbone using phenol-sulfuric acid assay, protein-bound N(ε)-(carboxymethyl)lysine (CML) by UPLC-MS and spectral analysis of fluorescent protein-bound AGEs. Genistin (10 μg mL(-1), 23 μM) and its aglycone genistein (10 μg mL(-1), 37 μM) did not prevent protein glycation (p > 0.05). The soy isoflavone-rich extract containing 2.5 mg mL(-1) of TFC efficiently decreased the amount of carbohydrate bound to the protein skeleton (20%) (p < 0.05) and formation of advanced glycation end products (AGEs) (>80%) (p < 0.05). The anti-glycative mechanism of isoflavones may be related to its conjugation to glycation sites of the protein structure (free amino groups), their antioxidant character and trapping of dicarbonyl intermediates. Extracts based on mixtures of isoflavones may be useful for producing glycated conjugates avoiding the substantial formation of AGEs bound to protein.