虾青素保护视网膜色素上皮细胞免受蓝光发光二极管诱导的氧化应激损伤

目的：探究虾青素对蓝光发光二极管（light-emitting diodes,LED）诱导ARPE-19细胞氧化应激损伤的保护作用及其机制。方法：采用不同浓度的虾青素预处理细胞1 h后,蓝光LED下光氧化损伤诱导24 h。噻唑蓝法测定细胞活力,乳酸脱氢酶检测法分析细胞毒性,2’,7’-二氯二氢荧光素二乙酸酯荧光探针法测定细胞内活性氧（reactive oxygen species,ROS）的水平,JC-1荧光探针法测定细胞内线粒体膜电位的变化,利用酶学相关试剂盒测定细胞内源性抗氧化酶活力,实时荧光定量聚合酶链式反应法测定细胞内II相解毒基因的转录表达水平,Western blot法测定细胞内核因子E2相关因子2（nuclear factor erythroid-2-related factor 2,Nrf2）的核蛋白表达水平。结果：虾青素（5、10 μmol/L和20 μmol/L）预处理以浓度依赖的方式抑制蓝光LED诱导的ARPE-19细胞活力降低,缓解细胞毒性;虾青素预处理能够减少细胞内ROS的产生,稳定线粒体膜电位,提高内源性抗氧化酶活力。此外,虾青素诱导了Nrf2的核转位,增加了抗氧化酶和II相解毒基因的表达,从而保护ARPE-19细胞免受蓝光LED诱导的氧化应激损伤。结论：虾青素通过诱导Nrf2的核转位,促进抗氧化酶和II相解毒基因的表达水平升高从而保护ARPE-19细胞免受蓝光LED诱导的氧化应激损伤。     

Metabolism of anthocyanins and consequent effects on the gut microbiota

Abstract

Anthocyanins are natural water-soluble polyphenols present in fruits and vegetables. Health-promoting effects attributed to anthocyanins are mainly associated with oxidative stress inhibition and gut microbiota modulation. Dietary anthocyanins undergo a complex metabolism after ingestion and interact with endogenous and microbial enzymes, leading to the production of a large number of circulating and excreted anthocyanin metabolites and catabolic products. To date, the bioavailability and health benefits of anthocyanins have been widely documented. Although there are several papers that illustrated the metabolism of anthocyanins, the effects of dietary anthocyanins on the modulation of the gut microbial ecology and on the growth of certain microbial species are still poorly understood. The present paper summarizes the recent data on the absorption of anthocyanins in the upper gastrointestine and the metabolism of anthocyanins by gut microbiota. The modulatory effects of anthocyanins from different sources on gut microbiota are also discussed.     

Impact of botanical source and processing conditions on physicochemical properties and antioxidant activity of honey in the northern part of Thailand

Phenolics, melissopalynological analysis, and selected physicochemical characteristics could differentiate floral honey origin. Botanical sources (longan, multifloral and Manuka) had more pronounced effect on honey properties than processing conditions. The conductivity was related to ash content and colour of honey. Total sugar, fructose and glucose content in all samples were not significantly different. Melissopalynological analysis was used to verify the botanical source of honey samples. Predominant pollen was identified. Results characterising antioxidant properties (DPPH radicals, hydroxyl radicals, and carbon-centred radicals scavenging activity) were confirmed via both Electron Spinning Resonance and oxygen radical absorbance capacity (ORAC). They showed that only hydroxyl radicals scavenging activity and ORAC were significantly different. Type and amount of phenolics in honey samples identified using HPLC could differentiate botanical source. Gallic acid and kaempferol were potential marker phenolics for longan honey. Multivariate statistical analysis allowed discrimination of honey from different botanical sources based on their phenolic profiles.     

Neuroprotective effect of caffeoylquinic acids from Artemisia princeps Pampanini against oxidative stress-induced toxicity in PC-12 cells

Abstract: Phenolics in dry Artemisia princeps Pampanini, an herbal plant traditionally consumed as food ingredients in Korea was extracted, fractionated, and quantified as well as evaluated for its neuroprotection for PC‐12 cells. Whole extract had 5,852 mg gallic acid equivalents/100 g of total phenolics and 6,274 mg and 9,698 mg vitamin C equivalents/100 g of antioxidant capacities assayed by DPPH and ABTS radicals, respectively. The fraction extracted with n‐butanol had the highest levels of total phenolics and antioxidant capacity than the other fractions (n‐hexane, chloroform, ethyl acetate, and water). Using a reversed‐phase HPLC system, caffeoylquinic acid (CQA) and its derivatives such as 3‐CQA, 4‐CQA, 5‐CQA, 1,5‐diCQA, 3,4‐diCQA, 3,5‐diCQA, and 4,5‐diCQA were isolated and quantified. The whole extract and its n‐butanol fraction yielded 3,5‐diCQA with the highest amount, which consisted of approximately 36.8% and 33.5%, respectively. The whole extract, the n‐butanol fraction, and 3,5‐diCQA showed neuroprotective effect on PC‐12 cells under the insult of amyloid ß peptide in a dose‐dependent manner. Treatments of the whole extract and the n‐butanol fraction for PC‐12 cells under oxidative stress increased approximately 1.6 and 2.4 times higher cell viability, compared with the control without treatments. For PC‐12 cells treated with 3,5‐diCQA, intracellular oxidative stress decreased by 51.3% and cell viability increased up to 2.8 times compared to the control with oxidative insult of amyloid ß peptide only. These results indicate that phenolics from A. princeps Pampanini alleviated the oxidative stress and enhanced the viability of PC‐12 cells, suggesting that it may be applied as a dietary antineurodegenerative agent in functional foods.     

Aqueous extract from the vegetative portion of Spanish black radish (Raphanus sativus L. var. niger) induces detoxification enzyme expression in HepG2 cells

The vegetative, or above ground, portion of radishes are not typically consumed and have not been characterized in terms of their phytochemical content or biological activity. The antioxidant capacity of the freeze-dried vegetative portion of mature Spanish black radishes (harvested 2 months after planting) was 3.7-, 3.6- and 2.9-fold greater than freeze-dried roots as assayed by ferric ion reducing antioxidant power (FRAP), total phenolics and oxygen radical absorbance capacity (ORAC), respectively. No carotenoids were detected in the roots, however the vegetative portion contained 905.0 and 421.2 μg/g of lutein and β-carotene, respectively. Despite differences in glucosinolate composition, a class of compounds related to the induction of detoxification enzymes, the aqueous extracts of roots and the vegetative portion similarly induced quinone reductase activity and the expression of multiple phase I and II detoxification enzymes in the HepG2 human hepatoma cell line. When juiced, the resulting freeze-dried juice and pulp of the vegetative portion maintained the ability to induce detoxification enzymes, although there were some differences in the phytochemical contents of these two dried materials. These data demonstrate that the ability of the vegetative portion of Spanish black radish, which has significantly greater antioxidant potential than roots, to induce detoxification enzyme expression was similar to that of the roots.     

Effect of ethylene on total phenolics, antioxidant activity, and the activity of metabolic enzymes in mung bean sprouts

Mung bean sprouts are a well-known healthy food and their nutritional enhancement has become an important area of research due to the rapid expansion of the industry and their importance to human health. The purpose of this study was to investigate the effect of ethephon treatment at different concentrations on total phenolics metabolism and free radical scavenging-linked antioxidant activity. Mung bean sprouts treated with 100 mg/L of ethephon gave the highest total phenolics content of 0.594 mg/g FW, which was approximately 31 % higher than that of the control on the second day of germination. Total phenolics content in mung bean sprouts increased significantly by increasing glucose-6-phosphate dehydrogenase activity to resist oxidative stress caused by ethylene during early-stage germination. Total phenolics synthesis was greater than polymerization at this time. In contrast, polymerization of total phenolics gradually increased with the decrease in oxidative stress during late-stage germination. Total phenolics were polymerized to lignin because of the increase in guaiacol peroxidase activity. These results indicated that ethylene could improve the nutritional value of mung bean sprouts, and harmless stress factors could be used to enhance health-promoting compounds in the sprouts.     

Antioxidant activity of different phenolics fractions isolated in must from Pedro Ximenez grapes at different stages of the off-vine drying process

The evolution of total phenolics, flavonoids and flavonols in the white grapes of Pedro Ximénez were determined during the off-vine drying process. Phenolics compounds determined, browning index and total antioxidant activity increased during the off-vine drying process. The analysis by gel filtration chromatography showed that compounds of high molecular weight are formed during the off-vine process and are partially responsible for the antioxidant activity and browning of grapes. Musts were separated by solid phase extraction in four fractions (I–IV) and the phenolics and antioxidant activity determined. Fraction III containing catechins and procyanidins, and fraction IV containing polymeric procyanidins were greatly enhanced during the off-vine drying process. Lastly, ethanolic extracts from grape pomaces at different drying stages were fractionated and analysed. The antioxidant activity showed similar values to those obtained in musts at the end of the drying process; however total phenolics and the browning index showed a 30% and 50% reduction, respectively, in comparison to those observed in the corresponding musts. This indicates that the ethanolic extracts could be used as a source of phenolic compounds without enhancing browning and as a way to increase the antioxidant activity of wines from dried grapes.     

The etiology of oxidative stress in the various species of animals,a review

Oxidative stress is the consequence of an imbalance of pro‐oxidants and antioxidants leading to cell damage and tissue injury. The exhaustion of antioxidant systems is one of the reasons for the occurrence of oxidative stress, which results in avalanche production of reactive oxygen species (ROS) or free radicals. High oxidative stress is common in organs and tissues with high metabolic and energy demands, including skeletal and heart muscle, liver and blood cells. Stress arises in animals in response to unavoidable or adverse environmental conditions. In the external environment, which affects the body of the cow, there are four main groups of stressors: physical, chemical, biological and psychological. Physical stressors include fluctuations in ambient temperature as well as mechanical injuries. High ambient temperature is one of the factors affecting the productivity of cows. Biological stressors are conditioned by errors and irregularities in habits. Both of these phenomena have an adverse impact on both the resistance of animals and fertility and are the etiological agent of oxidative stress. Various mechanisms may be responsible for metal‐induced oxidative stress: direct or indirect generation of ROS, depletion of glutathione and inhibition of antioxidant enzymes are well known for all redox‐active and redox‐inactive metals. © 2014 Society of Chemical Industry     

Changes in Antioxidant Activity of Cyphomandra betacea (Cav.) Sendtn. Fruits During Maturation and Senescence

Antioxidants are extremely important substances that possess the ability to protect the body from damage caused by free radical induced oxidative stress. Antioxidants are derived from dietary sources, such as fruits, vegetables, and beverages. In this study, the antioxidant activity of different maturity stages of two varieties of Cyphomandra betacea fruits of Darjeeling was evaluated in vitro. The radical scavenging properties on 2,2-diphenyl-1-picrylhydrazyl, superoxide anion, hydroxyl radical, lipid peroxidation, nitric oxide, and reducing power as well as the flavonoids, phenolics, lycopene, and total carotene contents of methanolic extracts of the fruits were determined. All fruit extracts, mainly the mature red fruit of purple-red variety exhibited strong scavenging activity towards all radicals tested due to the presence of relatively high total phenol, flavonoids, and lycopene as well as total carotene contents. The findings suggest that purple red variety of C. betacea fruit is endowed with antioxidant phytochemicals, which could provide protection against oxidative stress induced diseases.     

Effect of drying temperature on the sugars,organic acids,limonoids, phenolics,and antioxidant capacities of lemon slices

Changes in contents of sugars, organic acids, limonoids, phenolics contents, and antioxidant capacities of lemon slices dried at different temperatures were evaluated. Air drying (AD) promoted losses of sugars, citric acid, ascorbic acid, extractable phenolics (EPs), and non-extractable phenolics (NEPs), while it introduced an increase in limonoids. Phenolics of lemon were mainly presented in their extractable form. Hesperidin and eriocitrin were the main EPs; protocatechuic acid and poncirin were the predominant NEPs. The decrease in extractable phenolic acid, EP, and NEP content in lemon is lower at low drying temperatures, while the increase in non-extractable phenolic acid content is higher at high drying temperatures. The antioxidant capacity of EP was higher than that of NEP. Phenolics contributed to antioxidant capacities of lemon slices, and flavonoids were the main contributors among phenolics. Considering limonoids contents and the high levels of EP, NEP, and antioxidant capacities, AD at 60 °C could be an appreciate treatment for dehydrating lemon slices.     

The role of nutraceutical fruit drink on neurodegenerative diseases: a review

A changing lifestyle in food consumption due to the frequent taking of junk drinks based on the fast-food and ready-to-eat concept has brought about overloaded oxidative stress, thus weakening the body's defence mechanism to scavenge free oxygen radicals by destroying antioxidants. Oxidative stress occurs as a result of an imbalance between pro and antioxidant levels in favour of pro-oxidants resulting in the pathogenesis of neurodegenerative diseases. Though researches on the probable cure for neurodegenerative diseases are ongoing, fruits have been found to play an important dietetic role in preventing neurodegenerative diseases and other physiological disorders. Most fruits have their own valuable, unique active ingredients, having tremendous nutraceutical potentials and therapeutic implications. Therefore, people are required to make rational choices on the correct type of food for consumption to engender proper growth and development. The role of fruits or fruit juice in ameliorating neurodegenerative diseases has created a reawakening in nutrition and human health research.     

Olive oil and oxidative stress

Oxidative stress is defined as an imbalance between the oxidant and antioxidant systems of the body, in favor of the oxidants. Oxidative stress produced by free radicals has been linked to the development of several diseases such as cardiovascular, cancer, and neurodegenerative diseases Olive oil is the main source of fat of the Mediterranean diet which has been shown to be effective against oxidative stress associated diseases and also with ageing. Besides its richness in monounsaturated fatty acids, the oleic acid, olive oil contains minor components with antioxidant properties. In this review, we summarize the state of the art, and degree of evidence, of the body of knowledge concerning the protective role of the major and minor components of olive oil on oxidative stress.     

膳食多酚与肠道微生物相互作用研究进展

近年来膳食多酚与肠道微生物的相互作用逐渐成为食品科学、营养学和生物学的研究热点。多酚的抗衰老、抗肿瘤、预防心脑血管疾病的功能发挥主要依赖于肠道微生物对其的代谢;多酚的肠道微生物代谢产物又会通过影响肠道微生物菌相进而影响人体健康。本文在广泛查阅文献的基础上,综述肠道微生物对膳食结合态多酚的释放、代谢和影响因素以及多酚及其代谢产物对肠道微生物菌相和酶的影响,以期为膳食多酚和肠道菌群相互作用的深入研究提供一定参考依据。     

食品中亲电物质的最新研究进展

食品中的亲电物质是高效低毒的核转录因子NF-E2相关因子2(Nrf2)诱导剂,通过Keap1/Nrf2/ARE通路激活Ⅱ相酶和抗氧化酶的转录。Ⅱ相酶和抗氧化蛋白可发挥慢速、长效的抗氧化和解毒作用。目前已经发现食品中有9类亲电物质,它们具有相似的结构特征。研究和开发食品中的亲电物质,将成为功能性食品新的研究领域。     

Effect of the Lycium barbarum polysaccharides administration on blood lipid metabolism and oxidative stress of mice fed high-fat diet in vivo

Epidemiological and experimental studies have suggested that high dietary fat intake of mice is associated with many physically degenerative diseases. Since oxidative stress and abnormal lipid metabolism have been speculated to be critical mechanisms underlying degenerative diseases, we hypothesized that a high-fat (HF) diet might induce oxidative stress or lipid oxidation and subsequently contribute to the high risk of some diseases such as cardiovascular and cerebrovascular ones. To test this hypothesis, male kunming mice were placed on either a HF diet or a normal laboratory diet for 30 consecutive days. This investigation demonstrated that blood fat [low density lipoprotein (LDL), total cholesterol (TC), triacylglycerols (TAG), high density lipoprotein (HDL)], blood sugar (blood glucose and liver glycogen) and oxidative stress (activities of antioxidant enzymes and levels of non-enzymic antioxidants) of mice fed high-fat diet (group II) were significantly increased or decreased (P < 0.05, P < 0.01) when compared with the control group (I). The present study revealed that HF diet induced oxidative stress and provided novel evidence regarding the link between high dietary fat and increased risk of degenerative diseases. The administration of Lycium barbarum polysaccharides did not show any effect on the body weight of the experimental mice, but significantly decreased the levels of LDL, TC, TAG, blood glucose and thiobarbituric acid reactive substances (TBARS) or increased the activities of antioxidant enzymes (P < 0.05, P < 0.01) when compared with mice in HF group (II). These findings were further supported by significantly increased non-enzymic antioxidants levels (P < 0.05, P < 0.01), suggesting that L. barbarum polysaccharides showed a noticeable inhibition against lipid oxidation induced by free radicals caused by HF diet intake (groups III, IV, V) on the basis of their antioxidant activities.     

Antioxidant and antiproliferative capacities of phenolics purified from Phyllanthus emblica L. fruit

Phyllanthus emblica is a widely distributed tropical medicinal plant with good therapeutic properties. Gallic acid, ellagic acid, mucic acid 1,4-lactone 3-O-gallate, isocorilagin, chebulanin, chebulagic acid and mallotusinin were isolated and purified from this plant. The antioxidant activities of these compounds were evaluated by in vitro models of scavenging superoxide anion radicals, DPPH radicals and ABTS radicals, chelating ability of ferrous ion and inhibition capability of Fe (II)-induced lipid peroxidation, respectively. The results revealed that all the tested phenolics showed strong radical scavenging activity, good potency to chelate Fe²⁺ and good inhibition ability of lipid peroxidation. Amongst mallotusinin and mucic acid 1,4-lactone 3-O-gallate were reported for the first time to have antioxidant activity. In addition, the in vitro antiproliferative activities of those phenolics against MCF-7 breast cancer cell lines were assessed. Although the growth inhibition values induced by different phenolics on MCF-7 cell line yielded different effects, all the tested phenolics had apparent capacities of inhibiting the survival of MCF-7 human cancer cell line.     

Variation in Antioxidant Metabolites and Enzymes of ‘Red Fuji’ Apple Pulp and Peel During Cold Storage

Antioxidants are usually considered with regard to plant defense mechanisms due to the oxidative stress or their importance for human health or both. A comprehensive study in the present research was made to determine the variation in contents of antioxidants and their metabolites (such as ascorbate and glutathione) and enzymes activities of ‘Red Fuji’ apple pulp and peel tissue during cold storage (0 ± 1°C). Results showed that the majority of antioxidant metabolites were maintained in the reduced state, reduced ascorbate and glutathione, mainly localized in apple peel tissue. Strong or very strong correlations between hydrogen peroxide content and superoxide dismutase activity (r = 0.822 and 0.959), reduced/oxidized ascorbate ratio and monodehydroascorbate reductase activity (r = 0.966 and 0.984) as well as reduced/oxidized glutathione ratio and glutathione reductase activity (r = 0.969 and 0.924) were discovered. These results highlight that apple peel tissue could be selected to explore antioxidant mechanism and defense metabolism of apple fruit.     

Antimutagenic and antioxidant activities of cascalote (Caesalpinia cacalaco) phenolics

There is an increasing awareness and interest in the antioxidant behaviour and potential health benefits of phenolic acids. The identification of novel sources of phenolic acids has been also of scientific interest. Cascalote (Caesalpinia cacalaco) pods are known to be a good source of ‘tannins’, the name by which industry in Mexico recognizes phenolic extract. Phenolics were determined as gallic acid equivalents g^?1. The antimutagenic activity against aflatoxin B₁ and the antioxidant activity, using two different methods, of the extract were also evaluated. Gallic acid accounts for almost 90% of the phenolic extract of cascalote, the remaining 10% was tannic acid. Antimutagenic activity of cascalote phenolics was dose‐dependent, showing an inhibition level of 64.42% at the highest dose assayed. Antioxidant and antiradical activities were also dose‐dependent. The highest antioxidant activity showed by cascalote phenolics was 73.5%, higher than that of Trolox. The highest antiradical activity of cascalote phenolics was 75.3%, higher than that of BHT and Trolox. Cascalote pods are an outstanding source of gallic and tannic acids. Copyright © 2004 Society of Chemical Industry     

采前和采后贮藏对果蔬中抗氧化物质影响的研究进展

自由基是人体正常代谢的产物, 但自由基过量会引发一系列的疾病。越来越多的研究表明, 食用果蔬有助于预防由过量自由基引起的多种疾病, 这主要源于果蔬中富含的各种抗氧化物质。本文主要从采前和采后贮藏保鲜两个阶段对果蔬组织中的抗氧化物质(重点包括总酚、总黄酮、抗坏血酸、花青素)以及抗氧化能力的影响因素及其影响效果进行了较为全面的综述。     

Raphasatin is a more potent inducer of the detoxification enzymes than its degradation products

Abstract: The biological activity of cruciferous vegetables is hypothesized to be due to the metabolites of a class of phytochemicals called glucosinolates. The chemical properties of these metabolites, including isothiocyanates, determine the biological activity of these compounds and thus their effects on human health. The 2 primary radish (Raphanus sativus L.) glucosinolates, glucoraphasatin, and glucoraphenin, were isolated using solid phase extraction followed by preparative HPLC purification. In an aqueous environment, 77.6% of the maximum amount of sulforaphene produced by the metabolism of glucoraphenin was present after 24 h. Under the same conditions raphasatin, the isothiocyanate metabolite of glucoraphasatin and the oxidized counterpart of sulforaphene, was highly unstable with a half‐life of less than 30 min and no raphasatin was detectable after 24 h. In HepG2 cells, raphasatin‐induced quinone reductase activity and the RNA expression of several phase 1 and 2 detoxification enzymes by a significantly greater amount than the degradation products of raphasatin. Raphasatin, but not its degradation products, activated the antioxidant response element (ARE) in a stably‐transfected reporter cell line. Mice fed a diet consisting of 20% freeze dried radishes for 2 wk had significantly higher liver expression of cytochrome P450 (CYP) 1A1, 1A2, quinone reductase, microsomal epoxide hydrolase, and glutathione S‐transferase α2 than mice fed a nutritionally‐matched control diet. Practical Application: Glucoraphasatin, the primary glucosinolate in radishes, is metabolized into an isothiocyanate (raphasatin) that has biological activity but is also unstable in an aqueous environment. Despite the instability of raphasatin, dietary exposure to radishes produced significant induction of detoxification enzymes. Understanding the chemical properties of raphasatin, both in terms of biological activity and instability, could help develop processing methods to retain the most activity from radishes, glucoraphasatin, and raphasatin.