膳食多酚改善炎症性肠病的作用机制研究进展

文章概述了膳食多酚通过调节氧化应激、保护肠黏膜屏障、调节肠道菌群及代谢物改善炎症性肠病的作用机制,重点阐述了膳食多酚对炎症性肠病炎症信号通路的调节作用,并展望了膳食多酚在炎症性肠病等疾病营养干预领域的研究方向。     

膳食多酚的糖稳态调节作用

机体糖稳态是维持正常生命活动的重要基础,膳食多酚通过抑制碳水化合物消化酶活性、抑制葡萄糖转运和调节胰岛素抵抗等多种方式参与糖稳态调节的相关研究已经引起学界广泛关注。文章在查阅文献的基础上,对膳食多酚的种类和分布、调节糖代谢功效及作用机制进行了综述,并对膳食多酚调节糖稳态的未来发展方向进行了展望。     

The role of dietary polyphenols in the moderation of the inflammatory response in early stage colorectal cancer

Current focus in colorectal cancer (CRC) management is on reducing overall mortality by increasing the number of early-stage cancers diagnosed and treated with curative intent. Despite the success of screening programs in down-staging CRC, interval cancer rates are substantial and other strategies are desirable. Sporadic CRC is largely associated with lifestyle factors including diet. Polyphenols are phytochemicals ingested as part of a normal diet, which are abundant in plant foods including fruits/berries and vegetables. These may exert their anti-carcinogenic effects via the modulation of inflammatory pathways. Key signal transduction pathways are fundamental to the association of inflammation and disease progression including those mediated by NF-κB and STAT, PI3K and COX. Our aim was to examine the evidence for the effect of dietary polyphenols intake on tumor and host inflammatory responses to determine if polyphenols may be effective as part of a dietary intervention. There is good epidemiological evidence of a reduction in CRC risk from case-control and cohort studies assessing polyphenol intake. It would be premature to suggest a major public health intervention to promote their consumption; however, dietary change is safe and feasible, emphasizing the need for further investigation of polyphenols and CRC risk.     

Nonextractable polyphenols,usually ignored,are the major part of dietary polyphenols: A study on the Spanish diet

Scope: Dietary polyphenols (PP) can be divided into two groups: extractable polyphenols (EPP) or compounds solubilized by aqueous organic solvents, and nonextractable polyphenols (NEPP) or compounds that remain in their corresponding extraction residues. Most studies on food polyphenols and dietary intakes address exclusively EPP. The objective of this work was to determine the actual amount of PP, including NEPP, in food and in a whole diet. Methods and results: HPLC‐MS analyses were performed to identify EPP in methanol–acetone extracts and NEPP in the acidic hydrolyzates of their extraction residues in cereals, fruits, vegetables, nuts, and legumes. NEPP contents, estimated as hydrolyzable PP plus nonextractable proanthocyanidins (PA), ranged from 880 mg/100 g dry weight in fruits to 210 mg/100 g in cereals and were substantially higher than the contents of EPP. NEPP intake (day/person) in the Spanish diet (942 mg) is higher than EPP intake (258 mg) fruits and vegetables (746 mg) are the major contributors to the total PP intake (1201 mg). Conclusion: Non extractable polyphenols are the major part of dietary polyphenols. The knowledge of intakes and physiological properties of NEPP may be useful for a better understanding of the potential health effects of dietary PP.     

不同渥堆工艺对浏阳豆豉多酚抗氧化及免疫活性的影响

目的 探究不同渥堆工艺对浏阳豆豉多酚抗氧化及免疫活性的影响,确定最佳工艺条件。方法 测定不同渥堆盐度(0、3%、5%)、水分(35%、42%、50%)浏阳豆豉多酚的组成、抗氧化能力及免疫活性差异。并利用超高效液相色谱-串联质谱法进一步分析活性最佳工艺豆豉的多酚组分。结果 渥堆期间多酚含量变化明显,且随着渥堆水分的增加,豆豉的多酚及黄酮含量越高。体外抗氧化实验结果显示高水分、低盐度渥堆有助于提升豆豉对2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐阳离子自由基、1,1-二苯基-2-三硝基苯肼自由基的清除能力,其中以50%水分无盐渥堆豆豉的抗氧化活性最强。细胞实验表明,各样品组均呈剂量依赖性抑制经脂多糖刺激的RAW264.7细胞释放NO,免疫活性最佳为42%水分、5%盐度渥堆的豆豉样品。42%水分下无盐渥堆豆豉与5%盐渥堆豆豉的酚类差异代谢物共筛选出多酚及其衍生物(6)、黄酮类(13)以及异黄酮类(6) 25种,相关性分析发现其中雌马酚、槲皮素与浏阳豆豉的抗氧化活性呈显著正相关,而木犀草素、山奈酚、川陈皮素等与其免疫活性呈显著正相关。结论 50%水分无盐渥堆豆豉多酚表现出较强的抗...     

Effect of grape antioxidant dietary fibre on the prevention of lipid oxidation in minced fish: Evaluation by different methodologies

The effect of grape antioxidant dietary fibre (GADF) addition to minced fish muscle (MFM) on lipid stability during frozen storage (6 months) was studied. Concentrations of 0%, 2%, and 4% GADF were added to MFM samples. Analyses were carried out immediately after preparation of samples and during and after storage at −20 °C. GADF was characterized in terms of dietary fibre, total polyphenols and antioxidant capacity, and multifunctional antioxidant assays were carried out on all the MFM samples. The addition of red grape fibre considerably delayed lipid oxidation in minced horse mackerel muscle during the first 3 months of frozen storage.     

不同方法提取荷花蜂花粉可溶性膳食纤维的多酚含量及对微生物生长的影响

以纤维素酶酶解提取、酸溶液提取、碱溶液提取3种方法提取的荷花蜂花粉可溶性膳食纤维(bee pollen soluble dietary fiber,BPSDF)为研究对象,探究提取方法对BPSDF多酚含量及常见致病菌、有益菌生长的影响。结果表明,BPSDF中多酚主要以游离态的形式存在,纤维素酶酶解提取、酸溶液提取、碱溶液提取的游离酚分别占其总酚的81.16%,80.34%,69.59%;纤维素酶解提取的游离酚、总酚含量相对较高;碱溶液提取的结合酚含量相对较高。提取方法不同BPSDF游离酚、结合酚和总酚含量均差异显著,但对BPSDF中游离酚、结合酚的多酚组分影响较小。3种方法提取的BPSDF对大肠杆菌、金黄色葡萄球菌、白色念珠球菌均有较好的抑制作用,相对来说纤维素酶酶解提取的BPSDF的抑菌作用最好;3种方法提取的BPSDF对双歧杆菌和嗜酸乳杆菌有一定的促进作用,且对供试有害菌的抑制作用优于对供试有益菌的促进作用。     

Epigenetic effects of natural polyphenols: A focus on SIRT1‐mediated mechanisms

Polyphenols are a class of natural compounds widely distributed in fruits, vegetables, and plants. They have been reported to possess a wide range of activities in prevention and alleviation of various diseases like cancer, neuroinflammation, diabetes, and aging. Polyphenols are effective against chronic diseases and recent reports indicated strong epigenetic effects of polyphenols. Most of the studies investigating epigenetic effects of natural polyphenols have focused on their beneficial effects in cancer treatment. However, epigenetic defects have been demonstrated in many other diseases as well, and application of polyphenols to modulate the epigenome is becoming an interesting field of research. This review summarizes the effects of natural polyphenols in modulating epigenetic‐related enzymes as well as their effect in prevention and treatment of chronic diseases with a focus on SIRT1 modulation. We have also discussed the relation between the structure and function of epigenetic‐modifying polyphenols.     

多酚-膳食纤维相互作用及其影响多酚生物利用率研究进展

多酚广泛存在于植物源食品中,具有潜在的促进人体健康作用。天然多酚绝大多数以结合态存在,并且多酚与膳食纤维结合的比例要显著高于其他基质。多酚和膳食纤维的相互作用在食品加工和机体消化等环节会受到不同因素的影响,从而发生复杂的变化。近年来,多酚-膳食纤维相互作用对多酚生物利用率的影响已经受到了越来越多的关注。本文首先分析了多酚与膳食纤维的不同结合方式,随后总结了影响多酚与膳食纤维相互作用的主要因素,最后探讨了两者相互作用对于多酚生物利用率的影响,可为改善多酚食品的营养健康品质以及提高多酚的生物利用率提供一定的理论参考。     

植物多酚抗肿瘤活性及其机制研究进展

癌症是世界第二常见疾病,发病率逐年增加。尽管各种针对性的治疗手段快速发展,但癌症死亡率仍保持在一个惊人的水平。因此,攻克癌症需要寻求更有效的手段。现代研究表明,植物多酚在预防和治疗癌症方面都表现出了良好的生物学活性。本文就近年来国内外对植物多酚的抗肿瘤活性和机制研究进展进行综述,以期为植物多酚的充分利用提供参考。      

Molecular targets of dietary phytochemicals for possible prevention and therapy of uterine fibroids: Focus on fibrosis

Uterine fibroids (myomas or leiomyomas) are common benign tumors of reproductive aged women. Fibroids are clinically apparent in 20–50% of women, and cause abnormal uterine bleeding, abdominal pain and discomfort, pregnancy complications and infertility. Unfortunately, limited numbers of medical treatment are available but no effective preventive strategies exist. Moreover, the benefits of medical treatments are tempered by lack of efficacy or serious adverse side effects. Fibrosis has recently been recognized as a key pathological event in leiomyoma development and growth. It is defined by the excessive deposition of extracellular matrix (ECM). ECM plays important role in making bulk structure of leiomyoma, and ECM-rich rigid structure is believed to be a cause of abnormal bleeding and pelvic pain/pressure. Dietary phytochemicals are known to regulate fibrotic process in different biological systems, and being considered as potential tool to manage human health. At present, very few dietary phytochemicals have been studied in uterine leiomyoma, and they are mostly known for their antiproliferative effects. Therefore, in this review, our aim was to introduce some dietary phytochemicals that could target fibrotic processes in leiomyoma. Thus, this review could serve as useful resource to develop antifibrotic drugs for possible prevention and treatment of uterine fibroids.     

Effects of dietary fibre‐ and polyphenol‐rich grape products on lipidaemia and nutritional parameters in rats

The aim of this work was to evaluate the effects of three dietary fibre‐ and polyphenol‐rich materials obtained from grapes on serum cholesterol, lipoprotein and triglyceride concentrations as well as on body weight, fat and protein digestibility in adult Wistar rats fed on cholesterol‐free and 10 g kg⁻¹ cholesterol‐added diets. Dietary fibre content of materials ranged from 540 to 590 g kg⁻¹. Intake of grape products increased stool weight and the amount of fat and protein excreted in faeces, but did not affect negatively animal growth or protein efficiency of the diet in Wistar rats. Studied grape fractions lower serum total cholesterol and LDL cholesterol concentrations in hypercholesterolemic rats. These results could be taken into account in potential applications of these products as a food ingredient. © 2000 Society of Chemical Industry     

The role of altered immune function during the dry period in promoting the development of subclinical ketosis in early lactation

Subclinical ketosis (SCK) may impair white blood cell (WBC) function and thus contribute to the risk of disease postpartum. This preliminary study investigated changes occurring in the immune system before disease onset to elucidate their role in the occurrence of SCK. A group of 13 Holstein dairy cows were housed in tie-stalls and retrospectively divided into 2 groups based on their levels of β-hydroxybutyrate (BHB) measured in plasma between calving day and 35 d from calving (DFC). Levels of BHB <1.4 mmol/L were found in 7 cows (control cows, CTR group) and levels >1.4 mmol/L were found in 6 cows at ≥1 of 6 time points considered (cows with SCK, KET group). From ?48 to 35 DFC, body condition score, body weight, dry matter intake, rumination time, and milk yield were measured, and blood samples were collected regularly to assess the hematochemical profile and test the WBC function by ex vivo challenge assays. Data were submitted for ANOVA testing using a mixed model for repeated measurements that included health status and time and their interactions as fixed effects. Compared with CTR cows, KET cows had more pronounced activation of the immune system (higher plasma concentrations of proinflammatory cytokines, myeloperoxidase, and oxidant species, and greater IFN-γ responses to Mycobacterium avium), higher blood concentrations of γ-glutamyl transferase, and lower plasma concentrations of minerals before calving. Higher levels of nonesterified fatty acids, BHB, and glucose were detected in KET cows than in CTR cows during the dry period. The effect observed during the dry period was associated with a reduced dry matter intake, reduced plasma glucose, and increased fat mobilization (further increases in nonesterified fatty acids and BHB) during early lactation. A reduced milk yield was also detected in KET cows compared with CTR. The KET cows had an accentuated acute-phase response after calving (with greater concentrations of positive acute-phase proteins and lower concentrations of retinol than CTR cows) and impaired liver function (higher blood concentrations of glutamate–oxaloacetate transaminase and bilirubin). The WBC of the KET cows, compared with CTR cows, had a reduced response to an ex vivo stimulation assay, with lower production of proinflammatory cytokines and greater production of lactate. These alterations in the WBC could have been driven by the combined actions of metabolites related to the mobilization of lipids and the occurrence of a transient unresponsive state against stimulation aimed at preventing excessive inflammation. The associations identified here in a small number of cows in one herd should be investigated in larger studies.     

Effects of dietary l-carnitine supplementation on the response to an inflammatory challenge in mid-lactating dairy cows: Hepatic mRNA abundance of genes involved in fatty acid metabolism

This study aimed at characterizing the effects of dietary l-carnitine supplementation on hepatic fatty acid (FA) metabolism during inflammation in mid-lactating cows. Fifty-three pluriparous Holstein dairy cows were randomly assigned to either a control (CON, n = 26) or an l-carnitine supplemented (CAR; n = 27) group. The CAR cows received 125 g of a rumen-protected l-carnitine product per cow per day (corresponding to 25 g of l-carnitine/cow per day) from d 42 antepartum (AP) until the end of the trial on d 126 postpartum (PP). Aside from the supplementation, the same basal diets were fed in the dry period and during lactation to all cows. In mid lactation, each cow was immune-challenged by a single intravenous injection of 0.5 μg of LPS/kg of BW at d 111 PP. Blood samples were collected before and after LPS administration. The mRNA abundance of in total 39 genes related to FA metabolism was assessed in liver biopsies taken at d −11, 1, and 14 relative to LPS (d 111 PP) and also on d 42 AP as an individual covariate using microfluidics integrated fluidic circuit chips (96.96 dynamic arrays). In addition to the concentrations of 3 selected proteins related to FA metabolism, acetyl-CoA carboxylase α (ACACA), 5′ AMP-activated protein kinase (AMPK), and solute carrier family 25 member 20 (SLC25A20) were assessed by a capillary Western blot method in liver biopsies from d −11 and 1 relative to LPS from 11 cows each of CAR and CON. On d −11 relative to LPS, differences between the mRNA abundance in CON and CAR were limited to acyl-CoA dehydrogenase (ACAD) very-long-chain (ACADVL) with greater mRNA abundance in the CAR than in the CON group. The liver fat content decreased from d −11 to d 1 relative to the LPS injection and remained at the lower level until d 14 in both groups. One day after the LPS challenge, lower mRNA abundance of carnitine palmitoyltransferase 1 (CPT1), CPT2, ACADVL, ACAD short-chain (ACADS), and solute carrier family 22 member 5 (SLC22A5) were observed in the CAR group as compared with the CON group. However, the mRNA abundance of protein kinase AMP-activated noncatalytic subunit gamma 1 (PRKAG1), ACAD medium-chain (ACADM), ACACA, and FA binding protein 1 (FABP1) were greater in the CAR group than in the CON group on d 1 relative to LPS. Two weeks after the LPS challenge, differences between the groups were no longer detectable. The altered mRNA abundance before and 1 d after LPS pointed to increased transport of FA into hepatic mitochondria during systemic inflammation in both groups. The protein abundance of AMPK was lower in CAR than in CON before the LPS administration. The protein abundance of SLC25A20 was neither changing with time nor treatment and the ACACA protein abundance was only affected by time. In conclusion, l-carnitine supplementation temporally altered the hepatic mRNA abundance of some genes related to mitochondrial biogenesis and very-low-density lipoprotein export in response to an inflammatory challenge, but with largely lacking effects before and 2 wk after LPS.     

苹果多酚与甲醛的反应特性及在鱿鱼丝加工中的应用效果研究

通过苹果多酚与甲醛反应特性的研究,探讨苹果多酚作为甲醛捕获剂的可能性。研究了不同pH、反应温度、反应时间及苹果多酚浓度对苹果多酚与甲醛反应的影响,并将苹果多酚应用于鱿鱼丝加工中对其捕获效果进行了验证。结果表明:pH、反应温度、反应时间及苹果多酚浓度对甲醛减少率均具有显著性影响(p<0.05),碱性条件下苹果多酚与甲醛反应活性较高,随着反应温度的升高、反应时间的延长及苹果多酚浓度的增加,甲醛含量均显著减少。经苹果多酚处理的鱿鱼丝中甲醛初始含量及在30d贮藏期内甲醛含量增加量均显著(p<0.05)低于对照组。苹果多酚在实际生产中对鱿鱼丝中甲醛具有良好的捕获效果。