Molecular targets of dietary polyphenols with anti-inflammatory properties

There is persuasive epidemiological and experimental evidence that dietary polyphenols have anti-inflammatory activity. Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) have long been used to combat inflammation. Recently, cyclooxygenase (COX) inhibitors have been developed and recommended for treatment of rheumatoid arthritis (RA) and osteoarthritis (OA). However, two COX inhibitors have been withdrawn from the market due to unexpected side effects. Because conventional therapeutic and surgical approaches have not been able to fully control the incidence and outcome of many inflammatory diseases, there is an urgent need to find safer compounds and to develop mechanism-based approaches for the management of these diseases. Polyphenols are found in many dietary plant products, including fruits, vegetables, beverages, herbs, and spices. Several of these compounds have been found to inhibit the inflammation process as well as tumorigenesis in experimental animals; they can also exhibit potent biological properties. In addition, epidemiological studies have indicated that populations who consume foods rich in specific polyphenols have lower incidences of inflammatory disease. This paper provides an overview of the research approaches that can be used to unravel the biology and health effects of polyphenols. Polyphenols have diverse biological effects, however, this review will focus on some of the pivotal molecular targets that directly affect the inflammation process.     

A polyphenol-assisted IL-10 mRNA delivery system for ulcerative colitis

With the development of synthesis technology, modified messenger RNA (mRNA) has emerged as a novel category of therapeutic agents for a broad of diseases. However, effective intracellular delivery of mRNA remains challenging, especially for its sensitivity to enzymatic degradation. Here, we propose a polyphenol-assisted handy delivery strategy for efficient in vivo delivery of IL-10 mRNA. IL-10 mRNA binds to polyphenol ellagic acid through supramolecular binding to yield a negatively charged core, followed by complexing with linear polyetherimide and coating with bilirubin-modified hyaluronic acid to obtain a layer-by-layer nanostructure. The nanostructure specifically up-regulated the level of IL-10, effectively inhibited the expression of inflammatory factors, promoted mucosal repair, protected colonic epithelial cells against apoptosis, and exerted potent therapeutic efficacy in dextran sulfate sodium salt-induced acute and chronic murine models of colitis. The designed delivery system without systemic toxicity has the potential to facilitate the development of a promising platform for mRNA delivery in ulcerative colitis treatment.     

Polyphenols,methylxanthines, and antioxidant capacity of chocolates produced in Serbia

Different kinds of chocolates produced in Serbia were analyzed regarding total polyphenol, flavonoid and proanthocyanidin content using spectrophotometric methods. Flavan-3ols and methylxanthines in all samples were determined with RP-HPLC. DPPH, FRAP, ABTS and ORAC assays were applied for measuring antioxidant capacity. The average of all four antioxidant tests for each cocoa product was used for calculating antioxidant potency composite index (ACI). Obtained results for all four assays have shown that antioxidant capacity of analyzed chocolate/cocoa extracts followed cocoa, polyphenol, flavonoid, and proanthocyanidin contents. Although the addition of raspberries to dark chocolates had no significant influence on their total polyphenol, flavonoid and proanthocyanidin contents, statistical analysis showed that there was significant increase in the antioxidant capacity of dark chocolates with raspberry compared to plain dark chocolates (p = 0.007). Overall range for theobromine content varied from 5.5 to 22.3 mg/g depending on the product type, while the content of caffeine was 13–30 times lower in all analyzed cocoa products. In addition, correlation between antioxidant potency composite index and declared percentage of cocoa was high (R² = 0.798, p < 0.05) and indicated that declared cocoa content was a reliable indication for antioxidant capacity of chocolates produced in Serbia.     

Molecular interaction of tea catechin with bovine β-lactoglobulin: A spectroscopic and in silico studies

Polyphenols has attained pronounced attention due to their beneficial values of health and found to prevent several chronic diseases. Here, we elucidated binding mechanism between frequently consumed polyphenol “tea catechin” and milk protein bovine beta-lactoglobulin (β-Lg). We investigated the conformational changes of β-Lg due to interaction with catechin using spectroscopic and in silico studies. Fluorescence quenching data (Stern-Volmer quenching constant) revealed that β-Lg interacted with catechin via dynamic quenching. Thermodynamic data revealed that the interaction between β-Lg and catechin is endothermic and spontaneously interacted mainly through hydrophobic interactions. The UV-Vis absorption and far-UV circular dichroism (CD) spectroscopy exhibited that the tertiary as well as secondary structure of β-Lg distorted after interaction with catechin. Molecular docking and simulation studies also confirm that catechin binds at the central cavity of β-Lg with high affinity (~10⁵ M⁻¹) and hydrophobic interactions play significant role in the formation of a stable β-Lg-catechin complex.     

黄酒多酚诱导沉默调节蛋白3表达减轻阿霉素心肌损伤研究

背景 阿霉素（DOX）是一种常见的强效蒽环类抗肿瘤药物,被广泛应用于各类肿瘤尤其是实体性肿瘤的治疗中。然而,DOX有较强的心脏毒性,临床表现为不可逆性心肌病和充血性心力衰竭。黄酒多酚（YWPC）是从绍兴黄酒中提取的多酚类物质,具有抗炎、抗氧化等生理活性,对DOX所致心肌损伤有一定缓解作用,但其作用机制还不明晰。 目的 通过体内外实验探讨YWPC减轻DOX心肌损伤的作用机制。 方法 动物实验：使用SD大鼠建立DOX心肌损伤模型,分为对照组、YWPC组、DOX组与DOX+YWPC组;取心脏组织进行MASSON染色、原位末端标记（TUNEL）染色及免疫组织化学染色,取血清测定乳酸脱氢酶（LDH）水平,并用动物组织蛋白、Western Blot法检测凋亡水平〔B淋巴细胞瘤-2蛋白（Bcl-2）、Bcl-2相关X蛋白（Bax）〕及沉默调节蛋白3（SIRT3）表达水平变化。体外实验：通过1 μmol/L DOX干预H9C2细胞24 h建立DOX诱导H9C2细胞损伤模型,先将一批H9C2细胞分为对照组、DOX组、DOX+YWPC（1 mg/L）组、DOX+YWPC（10 mg/L）与DOX+YWPC（100 mg/L）5组,采用CCK-8法检测H9C2细胞活力,通过Western Blot法检测凋亡水平及SIRT3表达水平变化;之后将另一批H9C2细胞分为对照组、DOX组、DOX+YWPC组、DOX+SIRT3抑制剂（3-TYP）组及DOX+YWPC+3-TYP组,通过3-TYP抑制SIRT3蛋白活性,通过Western Blot法检测凋亡水平及SIRT3表达水平变化,进一步明确SIRT3在YWPC减轻DOX心肌损伤中的作用。 结果 动物实验中,大鼠心肌切片通过MASSON染色后可见：DOX组大鼠心肌纤维排列紊乱,大量蓝色胶原纤维贯穿心肌纤维;DOX+YWPC组大鼠心肌切片纹理部分恢复,蓝色胶原纤维减少。DOX组胶原纤维占比、血清LDH水平高于对照组、DOX+YWPC组（P<0.05）。DOX组Bcl-2/Bax比值、SIRT3表达水平低于对照组、DOX+YWPC组（P<0.05）;DOX组大鼠心肌切片中代表凋亡的绿色亮点明显增多,呈片状分布,而经YWPC治疗后凋亡亮点减少。体外实验中,DOX组吸光度值、Bcl-2/Bax比值、SIRT3表达水平低于对照组、DOX+YWPC（1 mg/L）组、DOX+YWPC（10 mg/L）组、DOX+YWPC（100 mg/L）组（P<0.05）,DOX组、DOX+3-TYP组Bcl-2/Bax比值、SIRT3表达水平低于对照组（P<0.05）;DOX+YWPC+3-TYP组Bcl-2/Bax比值低于DOX+YWPC组（P<0.05）,DOX+YWPC组与DOX+YWPC+3-TYP组SIRT3表达水平比较,差异无统计学意义（P>0.05）。 结论 YWPC可以通过调节SIRT3表达水平减轻DOX心肌损伤,抑制SIRT3会降低YWPC的作用。     

人参红皮病发病部位同工酶的研究

利用聚丙烯酰胺凝胶电泳和薄层扫描,定量研究人参红皮病发病部位同工酶组份和活力变化表明:受到侵染的各类样品中酯酶活力平均比无病白皮参增加100％,多酚氧化酶活力增加60～30％;且在侵染早期出现了新的同工酶谱带。     

白蔹多酚类化学成分的研究(Ⅱ)

对百蔹(Ampelopsis japonica)多酚类化学成分的进一步研究分离得到了7个多酚类化合物,经波谱分析及化学方法鉴定它们为二聚没食子酸,1,4,6—三氧—没食子酰基—β—D—吡喃葡萄糖,2,4,6—三氧—没食子酰基—D—吡喃葡萄糖,2,3,4,6—四氧—没食子酰基—D—吡喃葡萄糖,6—氧—二聚没食子酰基—1,2,3—三氧—没食子酰基—β—D—吡喃葡萄糖,槲皮素—3—O—α—L—吡喃鼠李糖,槲皮素—3—O—(2—O—没食子酰基)—α—L—吡喃鼠李糖。以上7个化合物均为首次从该属植物中分离得到。     

罗布麻叶中多酚的提取工艺和抗氧化活性的研究

目的确定罗布麻叶中多酚的最佳提取工艺,并分析其抗氧化活性。方法以乙醇为溶剂利用正交实验法优化提取多酚的条件,并通过清除羟自由基、DPPH.自由基和超氧阴离子自由基以及还原力实验来评价罗布麻叶中多酚体外抗氧化能力,并与VC进行了比较。结果乙醇浓度为50%、料液比为1∶20、提取时间为2 h、提取温度为50℃时罗布麻叶多酚的提取率最高,其含量达4.09%。罗布麻叶多酚具有一定的还原力,其还原力比VC的稍强。罗布麻叶多酚对.OH,DPPH.和O2-.都有一定清除能力,其IC50值分别为0.08,0.004和0.048 mg/ml,而VC的分别为0.13,0.027和0.023 mg/ml。结论罗布麻叶中多酚的最佳提取工艺为A1B1C2D1,在实验条件下,罗布麻叶多酚具有一定的抗氧化作用。     

Emerging food allergens: Identification of polyphenol oxidase as an important allergen in eggplant (Solanum melongena L.)

Although many allergens have been detected in eggplant (Solanum melongena L.), their identity have not been elucidated. The aim of this study was to investigate whether polyphenol oxidase (PPO), an important eggplant enzyme, acts as an allergen. The proteins of eggplant peel extract were separated on phenyl-Sepharose (PS), and analyzed by skin prick test (SPT), ELISA and IgE-immunoblotting; the components were analyzed for PPO activity, presence of protein–bound copper, and recognition by rabbit polyclonal anti-sweet potato PPO antiserum. LC–MS/MS and in silico analysis were employed to identify the separated allergens and prediction of IgE epitopes. Eggplant allergens were separated into 5 components (PS1–PS5), of which component PS2 exhibited high specific PPO activity. SPT and ELISA with PPO-rich pool (PS2) were positive in all 6 eggplant-allergic subjects; the 43, 64 and 71 kDa proteins displayed strong IgE-binding ability. The 64 and 71 kDa IgE-binding proteins show PPO activity, presence of copper, and recognition by anti-sweet potato PPO antiserum, clearly identifying them as PPOs; the 43 kDa protein appears to be a degradation product of the 64 or 71 kDa proteins based on enzymic activity and recognition by PPO antiserum. The 64 kDa protein upon further resolution by SDS-PAGE displayed two components (identified as eggplant PPO1 and PPO4 by LC–MS/MS). Based on bioinformatics approaches, PPO4 has been identified as an allergen since it harbors an IgE epitope. This study clearly demonstrates that the 64 and 71 kDa allergens in eggplant peel are PPOs based on enzymic activity and recognition by PPO antiserum; the 64 kDa copper-containing protein is identified as one of the several eggplant allergens (Sola m PPO4). This is the first instance of polyphenol oxidase being identified as a new food allergen.     

The use of a novel tobacco treatment process to reduce toxicant yields in cigarette smoke

The US Institute of Medicine has encouraged the pursuit and development of potential reduced-exposure products (PREPs) - tobacco products that substantially reduce exposure to one or more tobacco toxicants and can reasonably be expected to reduce the risk of one or more specific diseases or other adverse health effects. One potential approach is to reduce levels of some smoke toxicant precursors, such as proteins and polyphenols, in tobacco. We describe a treatment process involving aqueous tobacco extraction and treatment with protease; filtration of the extract to remove peptides, amino acids and polyphenols, and recombination of extract and treated tobacco. The process reduced levels of protein nitrogen (59%), polyphenols (33-78%) and nicotine (12%) while sugars increased 16%. ISO mainstream smoke yields of 43 toxicants were measured from cigarettes containing treated tobaccos; lower yields of tar, nicotine, carbon monoxide (16-20%), acrylonitrile, ammonia, aromatic amines, pyridine, quinolene and hydrogen cyanide (33-51%), tobacco specific nitrosamines (25-32%); phenolics (24-56%), benzene (16%), toluene (25%) and cadmium (34%) were obtained. There were significantly increased yields of formaldehyde (49%) and isoprene (17%). Reductions in sidestream yields of nitrogenous smoke toxicants and increases in sidestream yields of several carbonyls, benzo(a)pyrene and isoprene were also observed.