Cytoprotective effects of anthocyanins and other phenolic fractions of Boysenberry and blackcurrant on dopamine and amyloid β‐induced oxidative stress in transfected COS‐7 cells

There is growing interest both from consumers and researchers in the role that berries play in human health. In the experiments reported here, we assessed the ability of anthocyanins and phenolic fractions of Boysenberry and blackcurrant to ameliorate the deleterious effect of the amyloid β_25–35 (100 µmol L^?1, 24 h) and dopamine (1 mmol L^?1, 4 h) on calcium buffering (recovery) of M1 muscarinic receptor‐transfected COS‐7 cells. Cell viability was also studied. Our results demonstrate that extracts of Boysenberry and blackcurrant showed significant protective effect and restored the calcium buffering ability of cells that had been subjected to oxidative stress induced by dopamine and the amyloid β_25–35. Blackcurrant polyphenolics showed slightly higher protective effect against dopamine, whereas Boysenberry polyphenolics had a higher effect against the amyloid β_25–35. In viability studies, all extracts showed significant protective effects against dopamine and amyloid β_25–35‐induced cytotoxicity. Our results provide further evidence for the protective effects of berries against the neurotoxic effect of dopamine and amyloid β_25–35 in brain cells. Copyright © 2007 Society of Chemical Industry     

Bolus ingestion of white and green tea increases the concentration of several flavan‐3‐ols in plasma,but does not affect markers of oxidative stress in healthy non‐smokers

White tea (WT) is rich in flavan‐3‐ols as green tea (GT) and might provide health protective effects due to the strong antioxidant properties of flavan‐3‐ols. Since intervention studies with WT are lacking, we evaluated the effects of WT consumption on antioxidant status, antioxidant capacity and biomarkers of oxidative stress compared to water and GT. After an overnight fast, 70 healthy non‐smokers were randomized to consume 600 mL of WT, GT or water (control). Plasma (epi‐)catechin and epi(gallo)catechingallate, antioxidant capacity (Folin assay, trolox equivalent antioxidant capacity test), 8‐iso‐prostaglandin F_2α, ascorbic acid and uric acid were determined before and several times within 8 h after consumption. DNA strand breaks were measured in vivo and ex vivo (H₂O₂ stimulation) in leukocytes. Plasma flavan‐3‐ols significantly increased after WT and GT ingestion. Trolox equivalent antioxidant capacity was lower after 5 h in controls versus WT (p=0.031) and GT (p=0.005). Folin‐Ciocalteu reducing capacity, ascorbic and uric acid as well as markers of oxidative stress (8‐iso‐prostaglandin‐F_2α, DNA strand breaks) were not affected by the beverages. A short‐term increase of catechins does not change plasma antioxidant capacity in healthy subjects. Conclusions with respect to health protective effects of WT and GT on the basis of these biomarkers can, thus, not be drawn.     

美国浆果博伊森莓(boysenberry)的研究概况

博伊森莓(boysenberry)是由树莓(raspberry)、黑莓(blackberry)以及罗甘莓(loganberry)杂交而成的一种美国浆果,其富含花青素、叶酸等物质,具有抗氧化性,能够降低癌症风险,具有独特的保健功能。boysenberry的果实在国外用途很广,除可鲜食外还可以加工成果汁、果酱、蜜饯、冷饮等各种制品。目前国内已经引进种植boysenberry,但尚没有基于该水果的产品开发。本文对该浆果的种植历史、营养成分、功能、生物学特征等进行了概述。     

Fruit‐based functional foods II: the process for identifying potential ingredients

Developing functional food products requires a structured approach for screening potential ingredients. Using the development of a product with antioxidant properties as a model, eight fruit juice concentrates were screened, including New Zealand fruits. The total phenolic content and the antioxidant capacity, using chemical‐based assays (ferric reducing antioxidant power and oxygen radical absorbance capacity assays), were determined. The potential to protect against oxidative stress in Jurkat cells was also determined. Results indicate that the total phenolic content and antioxidant capacity in chemical‐based assays were strongly correlated. However, the total phenolic content did not dictate the level of protection from oxidative stress in this cell‐based model, suggesting that the type of phenolic compounds present and interactions between them may be important, although the activity of other compounds, such as vitamin C or carotenoids, may also be implicated. This model for screening ingredients may be used to design synergistic combinations of ingredients, and results may provide supportive evidence in the development of functional foods for this and other health targets.     

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.     

Effect of different light transmittance paper bags on fruit quality and antioxidant capacity in loquat

BACKGROUND: Bagging has been widely used to improve the commercial value of fruit. The purpose of this study was to evaluate the effects of different light transmittance paper bags on the quality and antioxidant capacity of loquat fruit. Two loquat cultivars, Baiyu and Ninghaibai (Eriobotrya japonica Lindl.), were used for materials. One‐layered white paper bags (OWPB) with ～50% light transmittance and two‐layered paper bags with a black inner layer and a grey outer layer (TGDPB) with ～0% light transmittance were used as treatments and unbagged fruits were used as the control (CK) in this experiment. Fruit quality was determined by physicochemical characteristics, the quantity of sugar, total phenolic, flavonoid, carotenoid and vitamin C. The antioxidant capacities of the methanol extracted from the pulp were tested using three different assays. RESULTS: The results showed that bagging decreased the weight of fruit but promoted the appearance of loquat fruits. The total sugar content in the fruit bagged with OWPB was higher than in controls and in fruit bagged with TGDPB. The total phenolic and flavonoid contents were decreased by both bagging treatments, with the lowest occurring in the fruit bagged with TGDPB. Bagging also decreased the total antioxidant capacity of the fruit pulp, which was again lower in TGDPB‐treated fruits than in those bagged using OWPB. Correlation analysis showed a linear relationship between total antioxidant capacity and the content of total phenolic and flavonoid. CONCLUSION: The results showed that different light transmittance bags had different effects on fruit quality and antioxidant capacity. In particular, bags with low light transmittance (TGDPB) decreased the inner quality and total antioxidant capacity of loquat fruit. All results indicated that bagging with OWPB was more suitable for maintaining the quality of the loquat fruit than bagging with TGDPB. Copyright © 2010 Society of Chemical Industry     

Thermal treatments affect the polyphenol profile and increase antioxidant capacity in five varieties of edible bean milks

We investigated the influence of two thermal treatments, steaming and boiling, on polyphenol profile and antioxidant capacity in milks from five edible bean varieties, including green mung bean milk, yellow and black soya bean milk, rice bean milk and white cow gram milk. The two thermal treatments had different influences on polyphenol profile and antioxidant capacity with steaming better than boiling in increasing total phenolic content (TPC) and antioxidant capacity in edible bean milks. In particular, steaming substantially increased soya bean isoflavone glucosides in the two soya bean milks. Bioconversion between polyphenols, the release of bound polyphenols and the induction of Maillard reaction products could contribute to the increase in TPC and antioxidant capacity in some edible bean milks. Therefore, it is recommended to steam edible bean milk for consumption, and edible bean milk containing antioxidant polyphenols can be developed into functional drinks with potential health benefits.     

响应面法优化超声波辅助提取黑加仑多酚工艺及其抗氧化活性分析

为提高黑加仑多酚的提取效率,采用乙醇溶液作为提取溶剂,超声波辅助对黑加仑果中多酚进行提取。通过单因素实验考察了乙醇体积分数、超声波功率、提取时间、料液比对黑加仑果多酚提取量的影响。在单因素实验的基础上,结合响应面试验优化提取工艺,并对黑加仑果多酚的抗氧化活性进行分析。结果表明:响应面法得到的黑加仑果多酚最佳提取工艺为:乙醇体积分数50%,超声波功率300 W,提取时间20 min,料液比1:10 g/mL。在上述提取条件下,黑加仑果多酚提取量为538.00 mg/100 g。抗氧化活性表明,黑加仑果多酚对DPPH自由基、羟自由基和ABTS+自由基清除率的IC₅₀值分别为7.97、7.92和5.26 mg/mL,表明黑加仑果多酚具有较好的抗氧化活性。该结果可为黑加仑果多酚的工业化生产提供参考。     

Assay of the antioxidant capacity of foods using an iron(II)-catalysed lipid peroxidation model for greater nutritional relevance

The formation of free radicals by the iron-catalysed Fenton reaction is a major cause of oxidative damage in the body. Here a common assay of antioxidant capacity, inhibition of the β-carotene-linoleic acid model of lipid peroxidation, has been modified by the addition of ferrous iron (final concentration 36 μmol/l), which makes the rate of oxidation of the lipids occur 25 times faster. Such an assay can simulate the oxidative damage to membrane lipids and low density lipoproteins occurring in the body in the presence of free iron. It thus may be nutritionally more relevant than traditional chemical assays of antioxidant capacity, as it measures pre-emptive antioxidant activity, i.e. activity which prevents free radicals being formed in the first place. Pre-empting their formation is likely to be more protective than scavenging of free radicals. The relative antioxidant activity of some food products found using this new assay was very different from that found using a radical-scavenging assay. Vitamin C, at 280 mg/l, was found to be 60 times better than blackcurrant puree in scavenging free radicals, but only one eighth as good as the blackcurrant puree in preventing iron-catalysed lipid peroxidation.     

THE INFLUENCE OF ADDITION OF DEFATTED BLACKCURRANT SEEDS ON PRO‐HEALTH CONSTITUENTS AND TEXTURE OF CEREAL EXTRUDATES

ABSTRACT

Extrudates used in the study were prepared on the base of cornmeal (100%) – control, which was in 10, 30 and 50% replaced by defatted seeds of blackcurrant, which were a by‐product of supercritical fluid extraction, used for oil production. The aim of the study was to check the influence of the level of defatted blackcurrant seeds, on texture and chemical composition of the obtained extrudates. Special attention was paid to pro‐health constituents, i.e., dietary fiber, polyphenols, flavonoids and anthocyanins. The addition of defatted seeds resulted in an increase of polyphenol content, and antioxidant activity, and the rise in the level of flavonoids and soluble dietary fiber as compared with control. The enrichment of extrudates in pro‐health components, as well as improvement of sensory score, suggests that 10% addition of defatted blackcurrant seeds is a suitable level for preparation of extruded fruit‐cereal snacks.

PRACTICAL APPLICATIONS

The study demonstrates that defatted blackcurrant seeds could be a good, natural source of bioactive components in cereal snacks produced by extrusion. The suggested level of this component, optimal from sensory and dietary point of view, is 10%.

     

Consumption of Hibiscus sabdariffa L. aqueous extract and its impact on systemic antioxidant potential in healthy subjects

BACKGROUND: To evaluate health benefits attributed to Hibiscus sabdariffa L. a randomized, open‐label, two‐way crossover study was undertaken to compare the impact of an aqueous H. sabdariffa L. extract (HSE) on the systemic antioxidant potential (AOP; assayed by ferric reducing antioxidant power (FRAP)) with a reference treatment (water) in eight healthy volunteers. The biokinetic variables were the areas under the curve (AUC) of plasma FRAP, ascorbic acid and urate that are above the pre‐dose concentration, and the amounts excreted into urine within 24 h (Ae_0–24) of antioxidants as assayed by FRAP, ascorbic acid, uric acid, malondialdehyde (biomarker for oxidative stress), and hippuric acid (metabolite and potential biomarker for total polyphenol intake). RESULTS: HSE caused significantly higher plasma AUC of FRAP, an increase in Ae_0–24 of FRAP, ascorbic acid and hippuric acid, whereas malondialdehyde excretion was reduced. Furthermore, the main hibiscus anthocyanins as well as one glucuronide conjugate could be quantified in the volunteers' urine (0.02% of the administered dose). CONCLUSION: The aqueous HSE investigated in this study enhanced the systemic AOP and reduced the oxidative stress in humans. Furthermore, the increased urinary hippuric acid excretion after HSE consumption indicates a high biotransformation of the ingested HSE polyphenols, most likely caused by the colonic microbiota. Copyright © 2012 Society of Chemical Industry     

Evaluation of commercial red fruit juice concentrates as ingredients for antioxidant functional juices

Phenolic profiles of nine red fruit commercial juice concentrates were characterised by means of high -performance liquid chromatography–diode array detection–mass spectrometry–mass spectrometry. Flavonoids such as anthocyanins, flavonols, hydroxycinnamic acid derivatives, stilbenoids, flavan 3-ols, ellagic acid derivatives, and other phenolic acids, were both identified and quantified in chokeberry, elderberry, blackcurrant and redcurrant, strawberry, red grape, cherry, plum, and raspberry commercial juice concentrates. Once the characterisation was carried out, the antioxidant capacity of each concentrate was assessed in vitro by means of two different methods: the 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (Trolox equivalent antioxidant capacity) method and the 2,2-diphenyl-1-picrylhydrazyl radical method. Elderberry, chokeberry and blackcurrant concentrates were the richest in total phenolics and they had the strongest antioxidant capacity; therefore, these three juices may have huge interest as ingredients in the design of functional juices.     

发酵酒的抗氧化活性研究进展

发酵酒是以粮谷、水果等为原料经发酵工艺酿制的低度酒,口感清冽,营养丰富,具有广阔的市场和发展前景.该文总结了黄酒、啤酒、葡萄酒和果酒这4种典型发酵酒的抗氧化能力和主要的抗氧化成分,为开发具抗氧化功能的发酵保健酒提供参考.     

Blueberry fruit polyphenolics suppress oxidative stress‐induced skeletal muscle cell damage in vitro

Skeletal muscle damage can result from disease and unaccustomed or excessive exercise. Muscle dysfunction occurs via an increased level of reactive oxygen species and hence there is potential in antioxidants as amelioration strategies. We explored the putative benefit of fruit polyphenolic extracts in reducing the susceptibility of skeletal muscle cells to oxidative stress. Muscle myotubes were simultaneously challenged with fruit extracts (1–50 μg/mL) and calcium ionophore (A23187), hydrogen peroxide, or 2,4‐dinitrophenol and damage monitored by release of cytosolic enzymes. A blueberry fruit extract displayed a potent and significant dose‐dependant protective capacity. Evaluation of the protective capacity of anthocyanin sub‐extracts of blueberry fruit and pure individual glycosides, with identification of extract polyphenolic components using MS, suggested that malvidin galactoside and/or glucoside were the active compounds. These in vitro data support the concept that blueberry fruits or derived foods rich in malvidin glycosides may be beneficial in alleviating muscle damage caused by oxidative stress. More research on the benefits of blueberry fruit consumption in human intervention studies is warranted.     

The antioxidant effect of a diet rich in Maillard reaction products is attenuated after consumption by healthy male adolescents. In vitro and in vivo comparative study

BACKGROUND: Maillard reaction products (MRPs) are widely consumed as a part of the human diet. A 2 week randomised two‐period crossover trial to determine whether MRP intake affects the antioxidant defence system in male adolescents (11–14 years, n = 18) was carried out using two diets rich and poor in MRPs (brown diet, BD, and white diet, WD, respectively). Fasting blood samples were collected after the dietary intervention periods to measure oxidative status. The in vitro antioxidant activity of the diets was also assessed. RESULTS: The BD had stronger in vitro antioxidant activity to scavenge free radicals and greater ability to reduce lipid peroxidation. However, in the in vivo assay, markers of oxidative damage (serum thiobarbituric acid‐reactive substances and erythrocyte hydroperoxides) and antioxidant defence parameters (serum antioxidants and enzymatic activities of catalase, superoxide dismutase and glutathione peroxidase) were unchanged after the dietary treatments. Only treatment of biological samples with external oxidants revealed higher values of the antioxidant capacity after consumption of the MRP‐rich diet. CONCLUSION: In spite of the higher antioxidant activity of the BD shown in vitro, consumption of diets rich in MRPs does not seem to modify oxidative status in healthy male adolescents. However, a protective effect against induced oxidation was shown. Copyright © 2008 Society of Chemical Industry     

Flavonol content in the water extract of the mulberry (Morus alba L.) leaf and their antioxidant capacities

Abstract: The biological activities of the mulberry (Morus alba L.) leaf have been attributed to its flavonoid content. The water extract of the mulberry leaf (WEML) was prepared by autoclaving at 121 °C for 15 min, and the flavonol content of the WEML was determined by HPLC The WEML contained 4 flavonols in the following order: quercetin‐3‐β‐D‐glucose (QT‐G) > quercetin‐3‐O‐glucose‐6″‐acetate (QT‐GA) > rutin (RT) > quercetin (QT). In the oxygen radical absorbance capacity (ORAC) assay, QT had the highest peroxyl radical‐scavenging capacity and a similar hydroxyl radical‐scavenging capacity as its glycosides (QT‐G, QT‐GA, and RT). QT exhibited a stronger cellular antioxidant capacity (CAC) against 2,2′‐Azobis(2‐amidinopropane) dihydrochloride (AAPH)‐ and Cu²⁺‐induced oxidative stress in HepG2 cells compared to its glycosides, indicating that the intracellular antioxidant capacity of QT and its glycosides may depend upon both the permeability across the cell membrane and the peroxyl or hydroxyl radical‐scavenging capacity. Practical Application: The information presented might be used for developing mulberry leaf‐based functional foods.     

Mechanism of preventive action of Viburnum dilatatum Thunb (gamazumi) crude extract on oxidative damage in rats subjected to stress

The fruit of Viburnum dilatatum Thunb (gamazumi) has been shown to prevent oxidative injury induced by water immersion restraint stress (WIRS) in rats. In this study the effect of gamazumi crude extract (GCE) on antioxidant enzymatic activities in the plasma, liver and stomach of rats with WIRS was investigated to elucidate the mechanism of prevention of oxidative injury. Ulcer formation and lipid peroxidation were inhibited in rats supplied GCE for 2 weeks in comparison with rats supplied water. Although the activities of plasma, hepatic and gastric antioxidant enzymes in rats given water were decreased by WIRS, only slight changes were observed in rats given GCE. There was no difference in enzymatic activities between the water and GCE groups not subjected to WIRS. Furthermore, ferrous ascorbate‐induced oxidation in hepatic homogenate from rats given GCE was inhibited. These results suggest that ingestion of GCE does not induce antioxidant enzymes and that the absorbed antioxidant components of GCE have a direct effect on oxidative injury in the body. Copyright © 2003 Society of Chemical Industry     

Strawberry consumption improves plasma antioxidant status and erythrocyte resistance to oxidative haemolysis in humans

Significant increases in the plasma total antioxidant capacity (TAC) have already been reported after acute intake of strawberries. In addition, antihaemolitic effects of strawberry extracts have been recently demonstrated in vitro, revealing that part of the antioxidant properties of strawberry bioactive compounds could lie in their localisation within cell membranes. However, there is a lack of research evidence from in vivo protracted strawberry consumption studies. We carried out a 16-day pilot study where 12 healthy subjects ingested 500 g of antioxidants-rich strawberries daily, and we evaluated the potential effects of fruit consumption on biomarkers of plasma and cellular antioxidant status. A significant increase in fasting plasma TAC and in serum vitamin C concentrations were progressively observed during the period of strawberry supplementation. An enhanced resistance to haemolysis was also observed in both AAPH-treated and untreated erythrocytes, collected during and after the period of strawberry consumption. The results obtained in this work suggest that regular consumption of antioxidant-rich strawberries may exert an improvement on the plasma antioxidant status and an increase on the antihaemolitic defenses of human erythrocytes.