Association of dietary isoflavone consumption with subclinical cardiovascular disease in middle-aged and elderly Chinese people

Background and aimsThe association between isoflavone (ISF) consumption and cardiovascular disease (CVD) remains controversial because of limited evidence. Carotid atherosclerosis is an established indicator of subclinical CVD. The study aimed to investigate the relationship between dietary ISF intake and subclinical CVD in middle-aged and elderly adults.Methods and resultsA total of 873 subjects aged 40–70 years without CVD were enrolled in this cross-sectional study. A restricted cubic spline was used to investigate the association between ISF intake and subclinical CVD risk. The odds ratio (OR) and 95% confidence interval of the risk of subclinical CVD for ISF were estimated by two-segmented logistic regression analysis. In Model 2, there was a non-linear association between ISF intake and the risk of subclinical CVD among women (P_non-linear = 0.002), with an inverse association below the change point. The nadir for the risk of subclinical CVD among women was 7.26 mg/day (energy-adjusted). Below the change point, an increase of 1 mg ISF/day reduced the risk of subclinical CVD by 15%. There was no significant association between ISF intake and subclinical CVD risk above the change point (OR = 1.01 [0.99, 1.04]). ISF intake was not associated with subclinical CVD risk in men (Model 2: P_non-linear = 0.224).ConclusionsBelow the change point (7.26 mg/day), women with a higher intake of ISF had a significantly lower risk of subclinical CVD. Encouraging the consumption of ISF-rich foods may help to lower CVD risk in middle-aged and elderly women.Trial registrationThis study is registered at http://www.chictr.org.cn (ChiCTR 1900022445).     

Role of phytoestrogens in prevention and management of type 2 diabetes

Type 2 diabetes(T2D)has become a major public health threat across the globe.It has been widely acknowledged that diet plays an important role in the development and management of T2D.Phytoestrogens are polyphenols that are structurally similar to endogenous estrogen and have weak estrogenic properties.Emerging evidence from pre-clinical models has suggested that phytoestrogens may have anti-diabetic function via both estrogendependent and estrogen-independent pathways.In the current review,we have summarized the evidence linking two major types of phytoestrogens,isoflavones and lignans,and T2D from epidemiological studies and clinical trials.The cross-sectional and prospective cohort studies have reported inconsistent results,which may due to the large variations in different populations and measurement errors in dietary intakes.Long-term intervention studies using isoflavone supplements have reported potential beneficial effects on glycemic parameters in postmenopausal women,while results from short-term smallsize clinical trials are conflicting.Taken together,the current evidence from different study designs is complex and inconsistent.Although the widespread use of phytoestrogens could not be recommended yet,habitual consumption of phytoestrogens,particularly their intact food sources like soy and whole flaxseed,could be considered as a component of overall healthy dietary pattern for prevention and management of T2D.     

淡豆豉与黑豆提取物抗癌细胞增殖作用及4种异黄酮成分的含量测定

目的:探讨淡豆豉和黑豆提取物对乳腺癌MCF-7细胞增殖的调节作用,并检测提取物中4种异黄酮成分的含量。方法:MTT法观察淡豆豉和黑豆提取物对乳腺癌细胞株MCF-7细胞增殖率的影响,Annexin/PI法流式细胞仪分析检测细胞的早期凋亡,高效液相色谱法检测淡豆豉和黑豆提取物中4种异黄酮成分大豆苷、染料木苷、大豆苷元和染料木素的含量变化。结果:淡豆豉和黑豆提取物对MCF-7细胞的增殖均有抑制作用且诱发癌细胞凋亡,但高浓度淡豆豉提取物的抑制癌细胞增殖作用明显高于黑豆(P0.05)。淡豆豉提取物中大豆苷、大豆苷元和染料木素的含量显著高于黑豆提取物(P0.01),但染料木苷的含量未见明显变化。结论:淡豆豉提取物与黑豆相比具有较强的抑制癌细胞增殖作用,淡豆豉中含量较高的异黄酮成分大豆苷、大豆苷元和染料木素,可能是其较强的抗癌细胞增殖作用的物质基础。     

近十年葛根防治骨质疏松症的研究进展

葛根是一种药食同源植物,含有大量异黄酮。实验研究表明葛根及相关提取物在体内外实验中有增加骨量、改善骨代谢的功能。临床研究发现葛根能改善骨质疏松症病人的骨代谢生化指标,并改善患者的临床症状,一些防治骨质疏松症的中药复方也开始加入葛根,说明葛根治疗骨质疏松症已得到认可并应用于临床。本文对近十年来葛根防治骨质疏松症的研究进展作一综述,并对未来做出展望。     

Kudzu extract treatment does not increase the intoxicating effects of acute alcohol in human volunteers

Background: Isoflavone administration in the form of a purified extract from the herbal medication kudzu root has been shown to reduce, but not eliminate, alcohol consumption in alcohol‐abusing and alcohol‐dependent men. The precise mechanism of this action is unknown, but 1 possible explanation for these results is that the isoflavones in kudzu might actually increase the intensity or duration of alcohol’s effects and thus delay the desire for subsequent drinks. This study was designed to test this hypothesis. Methods: Twelve (12) healthy adult men and women (27.5 ± 1.89 years old) who consumed moderate amounts of alcohol (7.8 ± 0.63 drinks/wk) participated in a double‐blinded, placebo‐controlled crossover study in which they were treated with either kudzu extract (total isoflavone dose of 750 mg/d) or matched placebo for 9 days. On days 8 and 9, participants received an acute challenge of ethyl alcohol (either 0.35 or 0.7 g/kg alcohol). During the challenges, the following measures were collected: subjective effects, psychomotor (body sway), cognitive performance (vigilance/reaction time), physiological measures (heart rate and skin temperature), and plasma ethanol concentration. Results: Alcohol resulted in a dose‐related alteration in subjective measures of intoxication, impairment of stance stability, and vigilance/reaction time. Kudzu extract did not alter participants’ subjective responses to the alcohol challenge or to alcohol’s effects on stance stability or vigilance/reaction time. However, individuals treated with kudzu extract experienced a slightly more rapid rise in plasma ethanol levels, but only after the 0.7 g/kg dose. This transient effect during the first 30 minutes of the ascending plasma alcohol curve lasted only 10–15 minutes; there were no differences in peak plasma alcohol levels or alcohol elimination kinetics. Additionally, kudzu pretreatment enhanced the effects of the 0.7 g/kg dose of alcohol on heart rate and skin temperature. Conclusions: These data suggest that individuals who drink alcohol while being treated with kudzu extract experience no adverse consequences, and furthermore the reported reductions in alcohol intake after kudzu extract treatment are not related to an alteration in alcohol’s subjective or psychomotor effects.     

ESI-IT-TOF-MS~n方法对11个异黄酮的裂解规律研究

本文对选定的11个异黄酮化合物在ESI-IT-TOF-MS n的裂解规律进行研究。文章采用ESI-IT-TOF-MS n仪对样品进行高分辨质谱测定,正负离子多级切换,通过对质谱碎片离子进行预测,并根据结构对其质谱可能的裂解规律进行总结研究。由于在正离子模式下信号较强,采用正离子模式对11个异黄酮多级碎片离子分析,发现异黄酮苷的裂解主是优先断裂糖苷键？C环4位羰基易于中性丢失CO（–28）,而C环经过RDA裂解形成的A^1,3＋则能够比较A环与B环上的羟基取代位置？A环上有相邻羟基存在时,也易中性丢失CO（–28）或H2O（–18）？B环有甲氧基取代时中性丢失CH4（–16）、自由基（CH3）或CH3OH（–32）为常见,但A环与B环有单独羟基时也偶见中性丢失CO（–28）。通过ESI-IT-TOF-MS n方法,选定多级正离子模式下对异黄酮的裂解进行了总结,有利于了解异黄酮在质谱中的裂解行为,对于异黄酮类化合物相关的结构推测有重要意义。     

PAMPA permeability, plasma protein binding, blood partition, pharmacokinetics and metabolism of formononetin, a methoxylated isoflavone

Formononetin (FMN) is a methoxylated isoflavone which is the major constituent in red clover and in commercially available extracts of this plant. In this study, we investigated the parallel artificial membrane permeability assay (PAMPA) permeability, protein binding, blood uptake characteristics, pharmacokinetics and metabolism of FMN. The permeability study samples were analyzed by HPLC-PDA method; whereas the pharmacokinetic study, protein binding and whole blood partitioning samples were analyzed by LC-MS/MS method. The PAMPA permeability of FMN was found to be high at pH 4.0 and 7.0. Plasma protein binding of FMN was found to be 93.61 ± 0.44% and 96.14 ± 0.15% at the tested concentration of 50 and 150 ng/mL, respectively. FMN reached equilibrium fast between red blood cells (RBCs) and plasma, and the partition coefficients between RBCs and plasma (K_RBC/PL) were independent of the initial rat blood concentrations of FMN. The bioavailability of unchanged/free FMN was found to be poor, i.e. approximately 3%. FMN was found to have a high clearance (5.13 L/h/kg) and a large apparent volume of distribution (14.16 L/kg). Circulating conjugates (glucuronides/sulfates) of FMN and daidzein (DZN) were quantified using enzymatic hydrolysis of plasma samples. The levels of isoflavone glucuronides/sulfates were found to be much greater than that of the corresponding aglycones.     

Rapid characterization of metabolites in soybean using ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) and screening for α-glucosidase inhibitory and antioxidant properties through different solvent systems

This work was the first to investigate on the simultaneous characterization of metabolite profiles in soybean using UPLC-ESI-Q-TOF-MS/MS. Twenty two compositions were observed within 14 min from the methanol extract and confirmed as twelve isoflavones of three types and ten soyasaponins (Ab, Af, I–III, αg, βg, βa, γg, and γa). Moreover, the patterns of two chemicals showed considerable differences in seven solvent systems by HPLC analysis and their optimal extraction was achieved by 70% methanol (isoflavone: 4102.69 μg/g; soyasaponin: ten peaks). The second abundant isoflavones were detected in 50% methanol (4054.39 μg/g), followed by 30% methanol, 100% methanol, 10% methanol, CH₂Cl₂, and acetone extracts with 3134.03, 2979.49, 1681.33, 366.19, and 119.00 μg/g, respectively. Soyasaponins exhibited similar tendencies as those of isoflavones. The highest total phenolic was found as 2.10 ± 0.05 mg GAE/g in 70% methanol with remarkable differences by comparing other extracts. Specifically, this extract showed potent α-glucosidase inhibitory (81%) and antioxidant capacities (DPPH: 93% and ABTS: 95%) at a concentration of 1.0 mg/mL. Our results may be contributed to enhancing the value to functional foods and evaluating the secondary metabolites concern to antioxidant properties using solvent system in soybean.