抗菌肽抗菌机制及研究热点

文题释义： 抗菌肽：是一类具有广谱抗菌性的宿主防御多肽,由所有形式的生命体中的不同组织、细胞中产生,具有广谱抗菌、抗病毒、抗真菌、抗肿瘤、促进机体组织愈合及调节体内免疫系统等活性,其在宿主的天然免疫防御系统中发挥着重要的防御屏障作用。 抗菌肽的抗菌机制：由于抗菌肽在组成成分、结构和功能上存在差异性,因此其具有不同的抗菌机制;而抗菌肽的结构在很大程度上影响了抗菌肽的功能,由此决定了抗菌肽多种功能和作用模式,其中最为让人认可的是膜透化机制和非膜靶向机制。 背景：抗菌肽作为一种可从自然来源提取并用于对抗抗生素耐药细菌的潜在候选物,引起了科学家们的广泛关注,熟悉抗菌肽的抗菌机制有利于将抗菌肽的临床应用。 目的：综述近年来对抗菌肽抗菌机制的研究进展。 方法：由第一作者应用计算机检索PubMed、Springerlink、Web of Science、ScienceDirect等数据库2013年1 月至2019年3月发表的文献,选择与抗菌肽抗菌机制及其研究进展相关的文献。 结果与结论：抗菌肽是一类特殊的分子,为具有广谱抗菌性的宿主防御多肽,在一些生物体中其被认为是先天免疫系统的重要组成部分。抗菌肽的抗菌机制从作用模式上可以分为直接致死和免疫调节2类主要的模式,直接致死作用机制可进一步分为膜靶向和非膜靶向。与此同时基于抗菌肽的广泛应用,预计在葡萄球菌、口腔细菌(包括链球菌)和肠道细菌(包括沙门氏菌)等微生物环境中已发展出许多抵抗策略,主要分为被动抵抗和诱导或适应性抵抗机制。在未来的研究和应用中,阳离子肽是解决多重耐药性日益增多的一个有效选择,除了应设计新的方法来对抗细菌对抗菌肽的耐药性外,也应该预防由常规抗生素产生的耐药性。 ORCID: 0000-0002-7481-2832(张溪) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

Influence of the Mediterranean diet on carotid intima–media thickness in hypercholesterolaemic children: A 12-month intervention study

Background and aimsThe Mediterranean diet has been recognised as having a protective role on the cardiovascular system due to its low lipid and high antioxidant content. Lipid profile and oxidant status represent two important risk factors related to endothelial dysfunction, even at early stages of cardiovascular diseases. The aim of the study was to evaluate the influence of a 12-month Mediterranean diet on the variation of lipid profile and carotid intima–media thickness (cIMT) in pre-pubertal hypercholesterolaemic children.Methods and resultsWe performed a cross-sectional study comparing lipid profile and cIMT in a group of 68 pre-pubertal children (36 with hypercholesterolaemia and 32 controls). In addition, in the hypercholesterolaemic children a 12-month intervention programme with a Mediterranean diet was started to evaluate the variation of lipid profile and cIMT. At baseline, hypercholesterolaemic children showed a significantly higher cIMT (both right and left carotid artery) compared to controls (both p < 0.05). After 12 months of diet intervention, a significant reduction of total cholesterol, LDL-cholesterol and cIMT was documented (all p < 0.05). Furthermore, at the end of follow-up, delta body mass index-Standard Deviation score and delta LDL-cholesterol were significantly and independently related to the changes of cIMT (both p < 0.05).ConclusionThe Mediterranean diet represents a valid approach in the treatment of hypercholesterolaemia even during childhood.     

Determination of the antioxidative capacity of an antioxidant complex and idebenone: an in vitro rapid and sensitive method

Background/aims  The goal of this study was to determine the ability of two putative antioxidant solutions to suppress the formation of superoxide anion radicals created by optical excitation of a photosensitizer and measured by highly sensitive luminometric detection.
Methods/results  Solutions containing 3% antioxidant complex and 1% idebenone were tested.* The antioxidant complex is an aqueous combination of botanical extracts rich in ferulic acid, caffeic acid, and other polyphenols. Idebenone is a lower molecular weight analog of coenzyme Q₁₀ (a potent antioxidant). Each was dissolved in lipid soluble reagents (solutions) and run through a Photochem^® (photochemiluminometer system) device. Their antioxidant capacity was expressed as nmol equivalents of synthetic vitamin E. Nine aliquots of each compound were measured. The mean antioxidant capacities for the 3% antioxidant complex and 1% idebenone were 525 ± 23 and 213 ± 14 nmol, respectively, with a statistically significant difference between the two compounds ( P  < 0.001).
Conclusion  The 3% antioxidant solution possesses a significant antioxidative capacity, which was 2.5 times greater than the known antioxidant idebenone in a 1% solution as shown by the quenching of superoxide anion radicals measured by photochemiluminescence. This method provides rapid, accurate, and sensitive measurement of the antioxidant properties of lipid-soluble compounds.     

Advances in the research of plant-derived natural products against retinoblastoma

Retinoblastoma (RB) is a highly aggressive ocular tumor, and due to socioeconomic and medical constraints, many children receive treatment only in the metaphase and advanced clinical stages, resulting in high rates of blindness and disability. Although several approaches exist in the treatment of RB, some children with the disease do not have satisfactory results because of various factors. Plant-derived natural products have shown definite therapeutic effects in the treatment of various tumors and are also widely used in the study of RB. We review plant-derived natural products used in the study of anti-RB to provide ideas for the clinical application of these drugs and the development of new therapeutic drugs.     

Plant-Derived Colorants for Food,Cosmetic and Textile Industries: A Review

This review provides a report on properties and recent research advances in the application of plant-derived colorants in food, cosmetics and textile materials. The following colorants are reviewed: Polyphenols (anthocyanins, flavonol-quercetin and curcumin), isoprenoids (iridoids, carotenoids and quinones), N-heterocyclic compounds (betalains and indigoids), melanins and tetrapyrroles with potential application in industry. Future aspects regarding applications of plant-derived colorants in the coloration of various materials are also discussed.     

Allergy to plant-derived fresh foods in a birch- and ragweed-free area

BACKGROUND: Allergy to plant-derived fresh foods has often been reported in geographical areas where birch or ragweed pollens are frequent and has been attributed to cross-reactivity to pollens. OBJECTIVE: The aim of this study has been to evaluate allergy to plant-derived fresh foods among pollen-allergic patients from a birch and ragweed-free area. METHODS: Ninety-five pollen-allergic patients took part in the study. The study consisted of a questionnaire, skin prick tests and challenge tests. Pollen skin tests to five grasses, eight trees and seven weeds were performed in duplicate. Prick tests (prick by prick) and challenge tests were carried out with the fresh foods. RESULTS: Most patients allergic to pollens were sensitized to grass (Lolium and Phleum; 97.9%), followed by tree (Olea; 82.1%) and weed pollens (Plantago; 64.2%). 35 of the 95 pollen-allergic patients had positive skin test responses to some plant-derived fresh foods, the highest percentage corresponding to several fruits in the Rosaceae family (peach and pear, 26.3%), followed by Cucurbitacea fruits (melon, 13.7%). The 21. 05% of the pollen-allergic patients were allergic to some type of plant-derived fresh food. Peach was the plant-derived fresh food which most frequently elicited allergy symptoms (12.6%), followed by melon (7.36%). The cluster of positive responses to Rosaceae fruits was higher for skin testing than for challenge testing. CONCLUSION: Peach was the most important allergy provoking fruit in a birch and ragweed free-area where apples were consumed at a rate of two times more than peaches and the patients allergic to pollen were principally sensitized to grass pollens.     

Comparative Assessment of the Acute Effects of Whey,Rice and Potato Protein Isolate Intake on Markers of Glycaemic Regulation and Appetite in Healthy Males Using a Randomised Study Design

Global protein consumption has been increasing for decades due to changes in demographics and consumer shifts towards higher protein intake to gain health benefits in performance nutrition and appetite regulation. Plant-derived proteins may provide a more environmentally sustainable alternative to animal-derived proteins. This study, therefore, aimed to investigate, for the first time, the acute effects on glycaemic indices, gut hormones, and subjective appetite ratings of two high-quality, plant-derived protein isolates (potato and rice), in comparison to a whey protein isolate in a single-blind, triple-crossover design study with nine male participants (30.8 ± 9.3 yrs). Following a 12 h overnight fast, participants consumed an equal volume of the three isocaloric protein shakes on different days, with at least a one-week washout period. Glycaemic indices and gut hormones were measured at baseline, then at 30, 60, 120, 180 min at each visit. Subjective palatability and appetite ratings were measured using visual analogue scales (VAS) over the 3 h, at each visit. This data showed significant differences in insulin secretion with an increase in whey (+141.8 ± 35.1 pmol/L; p = 0.011) and rice (−64.4 ± 20.9 pmol/L; p = 0.046) at 30 min compared to potato protein. A significantly larger total incremental area under the curve (iAUC) was observed with whey versus potato and rice with p < 0.001 and p = 0.010, respectively. There was no significant difference observed in average appetite perception between the different proteins. In conclusion, this study suggests that both plant-derived proteins had a lower insulinaemic response and improved glucose maintenance compared to whey protein.     

植物源烟水对白花丹参生物量和有效物质积累的影响

该文采用1：500,1：1000,1：2000浓度的烟水处理白花丹参,研究其对白花丹参生物量和有效物质积累的影响,测量指标包括地下部分鲜重、地下部分干重、分根数、最大根粗、平均根粗、平均根长、脂溶性成分（二氢丹参酮、隐丹参酮、丹参酮Ⅰ、丹参酮Ⅱ_A）和水溶性成分（迷迭香酸、丹酚酸B）含量。结果显示,1：500和1：1000浓度的烟水处理显著提高白花丹参地下部分鲜重和干重,分别达到98.01%,44.32%和85.71%,28.57%。1：500浓度的烟水处理显著提高白花丹参最大根粗（58.44%）和地下部分干重（85.71%）。烟水处理后白花丹参中丹参酮I和丹参酮Ⅱ_A含量显著提高,二氢丹参酮、隐丹参酮以及水溶性成分的积累未表现出显著性差异。研究表明烟水处理能有效提高白花丹参生物量和有效物质的积累,为白花丹参绿色生态种植提供新的思路。     

不同来源细胞外囊泡在中药组分高效递送领域中应用的研究进展

细胞外囊泡（extracellular vesicles,EVs）是内源性脂质双分子层纳米囊泡,由内溶酶体途径主动合成并分泌到细胞间隙或系统循环中,具有高生物相容性、低免疫原性及靶向性等特点。EVs不仅在细胞间通讯发挥重要作用,由于其复杂的组成及在健康和疾病中的作用,其作为治疗手段也越来越受到重视。中药活性成分具有明确的药理作用,然而其溶解度差、生物利用度低、存在不良反应等缺陷限制了其临床应用,利用EVs作为载体递送中药组分可提高其生物利用度等。通过对不同来源EVs的分泌、生物学功能、载药方式及其在多种疾病的药物递送及治疗中的重要应用进行综述,为EVs递送中药组分在临床中的应用提供依据。