原花青素的生物活性

原花青素是一种聚多酚类混合物,有着极强的抗氧化及清除自由基活性,还有调节脂质代谢、抗肿瘤、降血压、治疗眼科疾病、免疫调节等作用。综述了原花青素生理活性的研究进展,探讨了目前仍存在的一些问题,并对原花青素的发展前景进行了展望。     

蓝莓原花青素的提取与检测方法

花青素属于酚类化合物中的类黄酮类,花青素广泛存在于自然界中,多达三百多种。具有极强的抗氧化作用,可以抵御自由基对人体的损伤,具有延缓衰老、抗辐射的功效。在医药保健、化妆品、食品添加等方面被广泛应用。本文阐述了蓝莓原花青素的提取方法及测定技术。     

原花青素对乙二醇所致大鼠肾结石的影响

目的:探究肾结石大鼠在原花青素的干预下,其相关血液指标、肾内结晶及肾小管损伤情况,为预防肾结石提供思路。方法:40只健康雄性SD大鼠随机分为空白组(A)、成石组(B)、低、高剂量原花青素干预组(C、D)各10只。除空白组外,均采用1.25%乙二醇合1%氯化铵灌胃法制作肾结石大鼠模型,C、D组分别用原花青素5 mg/kg、10 mg/kg灌胃。实验结束时检测大鼠血肌酐、尿素氮浓度及肾组织中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量并观察大鼠肾内结晶情况及肾小管氧化应激程度。结果:成石组与空白组比较,大鼠肌酐、尿素氮及MDA含量增加,SOD活性降低(P0.01);低、高剂量原花青素干预组大鼠经不同浓度原花青素处理后与成石组比较,大鼠肌酐、尿素氮及MDA含量降低,SOD活性增加(P0.05)。经原花青素干预后,肾小管内形成晶体数量减少,且以高剂量原花青素(10 mg/kg)灌胃后减少更明显,且肾小管炎性反应减轻更明显。结论:肾结石大鼠在原花青素的干预下,肾内氧化应激水平降低,肾功能转好,肾内结晶数量减少,证明原花青素对预防大鼠肾结石及保护肾功能有积极作用。     

葡萄籽中提取原花青素的研究

用常规溶剂提取青、红两种葡萄籽中的原花青素。研究了葡萄籽品种、操作温度、提取剂种类和提取剂浓度对原花青素提取效果的影响。结果表明,最优工艺参数为青、红两种葡萄籽分别用搅拌方式提取,料液比1∶20,提取2h,50℃,青葡萄籽提取剂为丙酮,浓度60%～80%,产物纯度和提取率达67.35%和7.86%;红葡萄籽提取剂为乙醇,浓度80%,产物纯度和提取率达55.20%和5.36%。     

原花青素微胶囊释放动力学的研究

研究了原花青素微胶囊释放动力学及释放机制.测定了原花青素微胶囊在不同介质中的释放曲线,并用3种模型方程-零级动力学方程、一级动力学方程、Higuchi模型方程对原花青素微胶囊在正己烷与无水乙醇中的释放曲线进行线性拟合.结果表明,原花青素微胶囊在正己烷与无水乙醇中的释放动力学拟合结果的优劣顺序均为:Higuchi模型方程、一级动力学方程、零级动力学方程.原花青素微胶囊在正己烷与无水乙醇中的释放遵从Higuchi模型方程,为骨架扩散机制.     

原花青素微胶囊化工艺的研究

为扩大原花青素在食品工业中的应用,以原花青素为心材,对其微胶囊化工艺进行了研究。通过单因素实验确定微胶囊化工艺的最佳壁材组合为：乙基纤维素、阿拉伯胶、麦芽糊精;原花青素占复合壁材的最佳质量百分数为15％;乳化剂占原花青素的质量百分数为0．6％。通过混料实验确定复合壁材的最佳配比为：乙基纤维素25％,阿拉伯胶33．33％,麦芽糊精41．67％,包埋率可达88．1％。原花青素微胶囊在正己烷中的溶解度为87．1mg／g,而未包埋的原花青素溶解度仅为43．5mg/g。     

柳树叶中原花青素的提取与含量测定

以乙醇提取柳树叶的原花青素,考察了乙醇浓度、料液比、提取时间和提取温度等对提取率的影响。结果表明,乙醇浓度70%,料液比1∶20,提取温度70℃,提取时间120 min为最佳提取条件。运用香草醛-盐酸显色法,对最佳提取条件下提取的柳树叶中原花青素含量进行测定,测得绥化地产柳树叶中原花青素含量为10.77 mg/g。     

锁阳原花青素的HPLC-MS分析

采用反相液相色谱-电喷雾质谱(RP-HPLC/ESI-MS)分析法对锁阳提取液中原花青素的组成进行了分析.建立了采用RP-HPLC/ESI-MS对锁阳提取物中原花青素低聚体进行分析的方法.通过ESI-得到准分子离子[M-H]检测其单体和低聚体.研究结果发现:提取液中可检测出原花青素,初步检测出2个单体,6个二聚体,5个三聚体,但未检测出没食子酸单酯及其聚合体.建立的本方法不仅可以定性检测锁阳中含原花青素,且为非酯性原花青素.     

肉桂原花青素的片段化研究

采用食物来源的茶多酚为亲核试剂对肉桂中原花青素多聚体(PPC)进行片段化反应,采用大孔吸附树脂HP-20对片段化反应产物进行分级处理,使低聚体从片段化反应产物中分离出来。以反应后低聚体含量和低聚体中原花青素含量为考察指标,通过单因素试验、正交试验考察了片段化反应时间、反应温度、盐酸体积分数和多聚体与茶多酚物料比对反应的影响。结果表明,各因素对反应的影响次序为:盐酸体积分数 > 多聚体与茶多酚物料比 > 反应温度 > 反应时间,片段化反应最佳条件为:反应温度为50 ℃、反应时间为60 min、盐酸体积分数为1%、多聚体与茶多酚物料比为1:1,在此条件下,得到片段化反应后低聚体含量为65.26%,低聚体中原花青素含量为75.28%。     

葡萄籽中原花青素的精制与纯化

采以葡萄籽为原料,用乙醇提取葡萄籽中的原花青素,用大孔树脂进行纯化,探讨不同树脂的吸附和解吸性能,同时研究了上样速率、上样体积,洗脱剂种类及洗脱剂浓度等因素的影响,并对粗产品和纯化物进行红外表征。结果表明,H2MGL大孔树脂对葡萄籽原花青素的吸附效果最好,在树脂体积为27 m L,上样量为120 m L,上样速率为1.2 m L/min,洗脱剂为45%的乙醇时纯化效果最好,解吸率达到94.65%,此条件下得到的固体纯度为91.48%,说明用H2MGL大孔树脂纯化的方法可行。     

Effects of rice bran oil on the intestinal microbiota and metabolism of isoflavones in adult mice

This study examined the effects of rice bran oil (RBO) on mouse intestinal microbiota and urinary isoflavonoids. Dietary RBO affects intestinal cholesterol absorption. Intestinal microbiota seem to play an important role in isoflavone metabolism. We hypothesized that dietary RBO changes the metabolism of isoflavonoids and intestinal microbiota in mice. Male mice were randomly divided into two groups: those fed a 0.05% daidzein with 10% RBO diet (RO group) and those fed a 0.05% daidzein with 10% lard control diet (LO group) for 30 days. Urinary amounts of daidzein and dihydrodaidzein were significantly lower in the RO group than in the LO group. The ratio of equol/daidzein was significantly higher in the RO group (p < 0.01) than in the LO group. The amount of fecal bile acids was significantly greater in the RO group than in the LO group. The composition of cecal microbiota differed between the RO and LO groups. The occupation ratios of Lactobacillales were significantly higher in the RO group (p < 0.05). Significant positive correlation (r = 0.591) was observed between the occupation ratios of Lactobacillales and fecal bile acid content of two dietary groups. This study suggests that dietary rice bran oil has the potential to affect the metabolism of daidzein by altering the metabolic activity of intestinal microbiota.     

Short Term High Fat Diet Induces Obesity-Enhancing Changes in Mouse Gut Microbiota That are Partially Reversed by Cessation of the High Fat Diet

The gut microbiota is proposed as a “metabolic organ” involved in energy utilization and is associated with obesity. Dietary intervention is one of the approaches for obesity management. Changes in dietary components have significant impacts on host metabolism and gut microbiota. In the present study, we examined the influence of dietary fat intervention on the modification of gut mucosa-associated microbiota profile along with body weight and metabolic parameter changes. Male C57BL/6J mice (6-week old) were fed a low fat diet (10% kcal fat) as a control or a high fat diet (HFD 60% kcal fat) for 7 weeks. In another group, mice were fed HFD for 5 weeks followed by low fat control diet for 2 weeks (HFD + Control). At 7 weeks, body weight gain, blood glucose and hepatic triacylglycerol levels of mice fed a HFD were significantly higher than that of the control group and the HFD + Control group. There were significant differences in the diversity and predicted functional properties of microbiota in the cecum and colon mucosa between the control group and the HFD group. HFD feeding reduced the ratio of Bacteroidetes to Firmicutes, a microbiota pattern often associated with obesity. The HFD + Control diet partially restored the diversity and composition of microbiota in the cecum to the pattern observed in mice fed a control diet. These results suggest that short-term high fat diet withdrawal can restore metabolic changes and prevent excess body weight gain, however, long-term dietary intervention may be required to optimize the restoration of gut microbiota in mouse.     

Influence of Myriophyllum spicatum-derived tannins on gut microbiota of its herbivore Acentria ephemerella

The submerged living larvae of Acentria ephemerella were fed in the laboratory with either M. spicatum or Potamogeton perfoliatus, two of their host plants. Larvae exhibited a reduced growth when fed M. spicatum, a freshwater angiosperm that contains high concentrations of tannins, secondary metabolites known for their herbivore-deterrent and antimicrobial properties. In this study, we investigated the influence of food-derived tannins on gut microbiota. Bacterial densities in the guts did not differ between the food regimes, ranging from 2.8 to 13.3 × 10⁶cells per gut. Gut bacteria were characterized with cultivation techniques and subsequent identification of the strains by molecular methods. We isolated 17 bacterial strains belonging to all subdivisions, i.e., we identified -, - and -proteobacteria, Cytophyaga/Flavobacteria (CF) and several Gram-positive bacteria. All except one Gram-positive strain were found in the guts of larvae fed with P. perfoliatus. Gram-positive bacteria and bacteria of the CF cluster were more sensitive to polyphenol-containing extracts of M. spicatum in an agar diffusion assay than strains of the - or -proteobacteria subdivision. Our results suggest an influence of food-derived tannins on gut microbiota in A. ephemerella.     

Antibiotics administration alleviates the high fat diet-induced obesity through altering the lipid metabolism in young mice

Currently, there is a global trend of rapid increase in obesity, especially among adolescents. The antibiotics cocktails (ABX) therapy is commonly used as an adjunctive treatment for gut microbiota related diseases, including obesity. However, the effects of broad-spectrum antibiotics alone on young obese hosts have rarely been reported. In the present study, the 3-week-old C57BL/6J male mice fed a high-fat diet (HFD) were intragastric administration with ampicillin, vancomycin, metronidazole or neomycin for 30 days. The lipid metabolites in plasma were assessed by biochemical assay kits, and genes related to lipid metabolite in the white adipose were assessed by qPCR. To further analyze the underlying mechanisms, the expression of genes related to lipid metabolism, inflammatory reactions and oxidative stress in the liver were determined by qPCR assay. In addition, the expression of oxidative damage-associated proteins in the liver were detected by western blot. The results showed that oral antibiotics exposure could reduce body weight and fat index in HFD-fed mice, concurrent with the increase of white adipose lipolysis genes and the decrease of hepatic lipogenic genes. Furthermore, antibiotics treatment could clearly reverse the HFD-induced elevation of oxidative damage-related proteins in the liver. Together, these findings will provide valuable clues into the effects of antibiotics on obesity.     

肠道微生物代谢产物参与动脉粥样硬化的研究进展

肠道微生物群像一个内分泌器官,能产生多种生物活性代谢物,影响宿主的健康.近来研究发现,肠道微生物的代谢组成变化在肥胖、高血压、慢性心脏和肾脏疾病中起重要作用.多项研究表明,肠道微生物衍生的许多代谢物与动脉粥样硬化事件密切相关,如三甲胺N-氧化物(trimethylamine N-oxide,TMAO)、胆汁酸(bile...     

Short‐Chain Fatty Acids Enhance the Lipid Accumulation of 3T3‐L1 Cells by Modulating the Expression of Enzymes of Fatty Acid Metabolism

Short‐chain fatty acids (SCFA) such as acetic acid, propionic acid, and butyric acid are produced by fermentation by gut microbiota. In this paper, we investigate the effects of SCFA on 3T3‐L1 cells and the underlying molecular mechanisms. The cells were treated with acetic acid, propionic acid, or butyric acid when cells were induced to differentiate into adipocytes. MTT assay was employed to detect the viability of 3T3‐L1 cells. Oil Red O staining was used to visualize the lipid content in 3T3‐L1 cells. A triglyceride assay kit was used to detect the triacylglycerol content in 3T3‐L1 cells. qRT‐PCR and Western blot were used to evaluate the expression of metabolic enzymes. MTT results showed that safe concentrations of acetic acid, propionic acid, and butyric acid were less than 6.4, 3.2, and 0.8 mM, respectively. Oil Red O staining and triacylglycerols detection results showed that treatment with acetic acid, propionic acid, and butyric acid accelerated the 3T3‐L1 adipocyte differentiation. qRT‐PCR and Western blot results showed that the expressions of lipoprotein lipase (LPL), adipocyte fatty acid binding protein 4 (FABP4), fatty acid transporter protein 4 (FATP4), and fatty acid synthase (FAS) were significantly increased by acetic acid, propionic acid, and butyric acid treatment during adipose differentiation (p < 0.05). In conclusion, SCFA promoted lipid accumulation by modulating the expression of enzymes of fatty acid metabolism.     

The Immune System through the Lens of Alcohol Intake and Gut Microbiota

The human gut is the largest organ with immune function in our body, responsible for regulating the homeostasis of the intestinal barrier. A diverse, complex and dynamic population of microorganisms, called microbiota, which exert a significant impact on the host during homeostasis and disease, supports this role. In fact, intestinal bacteria maintain immune and metabolic homeostasis, protecting our organism against pathogens. The development of numerous inflammatory disorders and infections has been linked to altered gut bacterial composition or dysbiosis. Multiple factors contribute to the establishment of the human gut microbiota. For instance, diet is considered as one of the many drivers in shaping the gut microbiota across the lifetime. By contrast, alcohol is one of the many factors that disrupt the proper functioning of the gut, leading to a disruption of the intestinal barrier integrity that increases the permeability of the mucosa, with the final result of a disrupted mucosal immunity. This damage to the permeability of the intestinal membrane allows bacteria and their components to enter the blood tissue, reaching other organs such as the liver or the brain. Although chronic heavy drinking has harmful effects on the immune system cells at the systemic level, this review focuses on the effect produced on gut, brain and liver, because of their significance in the link between alcohol consumption, gut microbiota and the immune system.