Bioavailability of Isoflavone Metabolites After Korean Fermented Soybean Paste (Doenjang) Ingestion in Estrogen‐Deficient Rats

Doenjang (DJ), a fermented soybean product used in soups, stews, and sauces, contains high quality proteins, fats, vitamins, minerals, and other functional ingredients, including isoflavones and saponins. This study investigated whether DJ improves the bioavailability of isoflavones compared to boiled soybean (BS) in sham‐operated or ovariectomized (OVX) rats. We also examined the effects of ovariectomy on the differences in bioavailability of isoflavones. BS and DJ were administered in sham‐operated and OVX rats, and blood samples were collected. Twenty‐six isoflavone‐derived metabolites were identified. Pharmacokinetic analysis revealed that T_1/2 values of the individual isoflavone metabolites were most different in sham and OVX rats, even after the same sample treatment; however, T_max values were significant different in a few metabolites such as daidzein 4′‐glucuronide, daidzein 4′‐sulfate, 2‐(4‐hydroxyphenyl)propionic acid, and benzoic acid. For most of the individual metabolites, C_max was higher in both sham and OVX rats administered BS than those administered DJ. The AUC was generally lower in OVX rats than in sham rats. The AUC of daidzein and genistein in BS‐fed sham rats was approximately 1.7‐fold higher than those administered DJ, whereas glycitein was detected only in the DJ group. No significant differences in AUC of daidzein and genistein were observed between BS and DJ administration in OVX rats, although the total isoflavone content of DJ was lower; thus, DJ‐mediated isoflavone bioavailability was more effective in OVX rats. Similar tendencies were observed for phase II and gut‐mediated metabolites. These results suggested that DJ enhanced isoflavone bioavailability under estrogen deficiency, even when the total isoflavone content was decreased by fermentation.     

纤维素载体固定化β-葡萄糖苷酶及其在大豆异黄酮水解中的应用

建立纤维素载体固定化β-葡萄糖苷酶系统,用于黑豆浆中大豆异黄酮去糖基化反应,并对该催化系统进行了可行性评价。结果表明,在40 cm3纤维素颗粒上可结合超过40 mgβ-葡萄糖苷酶,并且能有效将4-硝基苯-β-D-葡糖苷酸水解成对硝基苯酚,其反应最适温度为50℃。经动力学测试后可得其米氏常数Km值为(1.38±0.20)mmol/L。将该固定化酶系统用于黑豆浆中大豆异黄酮去糖基化,通过高效液相色谱检测其转化效率,表明该系统可以在30 min内利用40 cm~3含酶载体将50 mL黑豆浆中的异黄酮全部转化为去糖基化形式。该固定化酶催化系统连续化催化稳定性实验表明,在经过15次反应以及15 d之后,该固定化酶系统仍然可维持其60%的催化活性。     

大豆异黄酮对AD大鼠海马PS-1表达的影响

目的：探讨大豆异黄酮(SIF)对AD大鼠海马PS-1表达的影响。方法：采用β-淀粉样蛋白(Aβ)单侧海马注射建立阿尔茨海默病(AD)大鼠模型,给予相应药物后,利用跳台实验观察AD大鼠学习记忆能力的变化,免疫组化检测AD大鼠海马早老素(PS-1)表达。结果：大豆异黄酮可改善AD大鼠的学习记忆能力(P＜0.01),显著性降低AD大鼠PS-1表达(P＜0.01)。结论：大豆异黄酮显著降低AD大鼠海马组织PS-1表达,从而改善AD大鼠学习记忆能力。     

微生物发酵产大豆异黄酮苷元的连续超声波提取工艺及其定量分析研究

选取浅玫瑰链霉菌、红色糖多孢菌及黑曲霉为发酵菌种,采用Plackett-Burman设计及正交试验,对影响微生物发酵法产大豆异黄酮苷元(染料木黄酮、黄豆苷元、黄豆黄素)的连续超声波提取工艺的主要试验因素进行系统优化。以浅玫瑰链霉菌为发酵菌种的实验结果表明：各主要试验因素对3种异黄酮苷元提取率影响程度大小为：抽提溶剂组分、超声波时间、淋洗液体积。而温度、溶剂流速两个因素与提取效率负相关。连续超声波作用时间及抽提溶剂组分为影响异黄酮苷元提取工艺的两个主要影响因素。当两因素的最优值分别为7min及70%时,总异黄酮苷元提取率为(98.7±1.23)%。通过固相萃取(SPE)可有效去除发酵提取液中杂质对HPLC定量分析的干扰,并使3种异黄酮苷元含量浓缩10倍以上,从而使HPLC方法的检测限达到10-3μg/mL,样品总分析时间小于10min,样品回收率为96.2%～103.4%,RSD值小于2.34%。上述结果表明,该方法可满足微生物发酵法产大豆异黄酮苷元的高效提取纯化及快速定量分析。     

大豆异黄酮影响类风湿性关节炎模型大鼠FLS凋亡

采用完全弗氏佐剂制备类风湿性关节炎(Rheumatoid arthritis,RA)模型对照大鼠,模型对照大鼠采用大豆异黄酮(Soybean isoflavone,SBI)灌胃治疗后,分离大鼠滑膜组织,原代培养大鼠(Fibroblast like synoviocytes,FLS),real time qPCR分别检测SBI各剂量灌胃治疗对模型对照组大鼠FLS细胞凋亡相关基因和RA相关基因表达的影响。结果发现,经SBI 50 mg/kg体重、100 mg/kg体重和150 mg/kg体重3个剂量灌胃治疗后,细胞凋亡因子caspase 3、促凋亡基因Bax表达显著升高,抗凋亡基因Bcl-2表达显著降低,MMP3和fibronectin表达同样显著降低。SBI可能通过促进FLS凋亡影响模型对照组大鼠滑膜增值和关节炎症。     

纳豆发酵和体外模拟消化中活性物质含量及抗氧化活性的变化研究

本文研究了利用纳豆芽孢杆菌发酵纳豆过程中活性物质-总酚和异黄酮含量的变化,通过体外模拟消化实验,测定消化过程中总酚、异黄酮含量及抗氧化活性的变化规律。研究发现,由于发酵细菌及高温的作用,从干燥大豆到后熟24 h大豆,总酚含量提高了60.56%,异黄酮含量降低了63.30%。不同发酵阶段纳豆经过体外模拟消化处理,总酚的释放率为70.64%,异黄酮的残余率为21.79%。抗氧化活性测定采用了DPPH、ABTS和ORAC测定法。不同发酵阶段的纳豆经过体外模拟消化后,其DPPH自由基清除能力下降,ABTS和ORAC值有所提高;模拟胃消化阶段,后熟24 h大豆清除ABST自由基能力和ORAC值分别是干燥大豆的1.80和2.22倍;模拟肠消化阶段,后熟24 h大豆清除ABST自由基能力和ORAC值分别是干燥大豆的1.70和1.41倍。总体上来讲,经过发酵的纳豆抗氧化活性得到加强;在模拟消化过程中,胃消化阶段的纳豆具有更高的抗氧化活性。     

Self-Microemulsifying Drug Delivery Systems (SMEDDS) for Improving In Vitro Dissolution and Oral Absorption of Pueraria Lobata Isoflavone

The aim of our investigation was to develop and characterize self-microemulsifying drug delivery systems (SMEDDS) of Pueraria lobata isoflavone to improve its in vitro dissolution and oral absorption in beagle dogs. SMEDDS consisted of oil (ethyl oleate), a surfactant (Tween 80), and a cosurfactant (Transcutol P). In all the SMEDDS, the level of Pueraria lobata isoflavone was fixed at 20% w/w of the vehicle. The in vitro self-microemulsification properties and droplet size analysis of SMEDDS were studied following their addition to water under mild agitation. A pseudoternary phase diagram was constructed identifying the efficient self-microemulsification region. From these investigations, an optimized formulation was selected and its dissolution and bioavailability were compared with a tablet formulation in beagle dogs. The in vitro dissolution rate of puerarin from SMEDDS was more than threefold faster than that from Yufengningxin tablets (Pueraria lobata isoflavone tablets). A 2.5-fold increase in the relative bioavailability was observed for the SMEDDS compared with Yufengningxin tablets. The absolute bioavailability of the SMEDDS was 82.32 ± 15.51%, which was significantly improved compared with that of Yufengningxin tablets. These results demonstrate the potential of SMEDDS as an efficient way of improving the oral absorption of Pueraria lobata isoflavone.     

氧化石墨烯的制备及其催化水解大豆异黄酮

采用改良的Hummers法制备了负载有-SO3H、-COOH和-OH的氧化石墨烯,对其进行了结构表征。并首次以氧化石墨烯为催化剂,对天然产物大豆异黄酮糖苷水解反应进行了研究。实验结果显示氧化石墨烯在异黄酮糖苷水解反应中具有较好的催化活性,其最佳反应温度为105℃,此时3种大豆异黄酮糖苷的转化率分别达到94.3%,92.1%和88.8%,苷元的收率分别达到69.6%、60.6%和58.8%。其催化活性明显优于其他固体酸催化剂,如沸石HZSM-5和大孔树脂NKA-9,而与0.02 mol.L.1的硫酸相当。     

大豆异黄酮对阿尔茨海默病大鼠海马PKG和Raf-1的影响

目的:通过观察大豆异黄酮(SIF)对阿尔茨海默病(AD)大鼠海马组织蛋白激酶G(PKG)和Raf-1蛋白的影响,探讨大豆异黄酮治疗阿尔茨海默病作用机制。方法:采用β-淀粉样蛋白(Aβ)双侧海马注射建立AD大鼠模型,分组后给予不同剂量大豆异黄酮,Morris水迷宫实验观察大鼠学习记忆能力的变化,ELISA法测定大鼠海马组织PKG含量,免疫组化SP法观察大鼠海马组织Raf-1的表达。结果:大豆异黄酮可改善AD大鼠的学习记忆能力(P<0.05),显著降低AD大鼠海马组织PKG的含量(P<0.05),显著降低AD大鼠海马组织Raf-1的表达(P<0.05)。结论:大豆异黄酮可能通过降低AD大鼠海马PKG的含量和Raf-1的表达起到治疗AD的作用。     

超声波酸水解法提取豆渣中异黄酮条件优化

目的:对水酶法提取大豆油后的副产物进行研究,提取其生理活性物质大豆异黄酮。方法:采用超声方法和酸水解方法相结合对水酶法提取大豆油副产物进行异黄酮提取,在此基础上进行响应面优化,确定最佳提取工艺。结果:分析了影响异黄酮提取的各种因素,并予以优化。优化后工艺条件为:料液比为1:12.54,乙醇浓度为70.28%,盐酸浓度为2.6mol/L,水解提取时间为30min,提取温度为30℃。结论:超声波和酸水解的方法适用于水酶法提取油后豆渣中大豆异黄酮的提取,在加入酸水解后大豆异黄酮总提取量较单纯70%乙醇提取法提高42.55%。