JOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2010
MANEEWAN SUKSOMTIP
Methanolic extracts from the seed coats of five major tamarinds (Srichomphu, Sithong-nak, Sithong-bao, Priao-yak and Khanti) cultivated in Thailand were investigated for their content of phenolic compounds and their antioxidative properties. Antioxidative properties were evaluated by various different methods: scavenging effect on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical, anti-lipid peroxidation and reducing power assay. The phenolic compound contents were determined by spectrophotometric methods. Extract of Priao-yak with the highest tannin content showed the strongest reducing power, while extract of Khanti with the highest proanthocyanidin content revealed high scavenging ability on both DPPH and hydroxyl radicals. Stronger antioxidative activity measured by most assays was noted for the extract of Sithong-bao with a high content of total phenols, proanthocyanidin and tannins. The results suggest that specific phenolic constituents in the extract could be responsible for the different antioxidant properties observed in different cultivars. Furthermore, seed coat extract of Sithong-bao may be a potential source of natural antioxidant to be developed into nutraceuticals. PRACTICAL APPLICATIONS Components of Tamarindus indica L., a tree indigenous to India and South-East Asia, have long been used as a spice, food component and traditional medicine. According To traditional medicine, the tamarind pulp is used as a digestive, carminative, laxative, expectorant and blood tonic; the seeds are used as an anthelmintic, antidiarrheal and emetic. In addition, the seed coat is used to treat burns and aid wound healing as well as as an antidysenteric. Recent studies have demonstrated polyphenolic constituents with more potent antioxidant and anti-inflammatory activities of T. indica seed coat extract. Therefore, seed coat extracts of T. indica have economic potential for development into health promotion products as well as natural preservatives to increase the shelf life of food by preventing lipid peroxidation. [source]

ANTIOXIDANT AND ANTIMICROBIAL ACTIVITY OF DIFFERENT FLORAL ORIGIN HONEYS FROM TURKIYE

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2010
ESRA ULUSOY
ABSTRACT The bioactivities of phenolic extracts of nine Turkish honeys from different floral sources were investigated. The antioxidant properties of the extracts were assessed by ferric reducing/antioxidant power (FRAP) assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and cupric reducing antioxidant capacity (CUPRAC) assay. The total phenolic contents measured by Folin,Ciocalteau method varied from 66 to 223 mg/g extract as gallic acid equivalent. The antioxidant activities found with CUPRAC, expressed as trolox equivalent antioxidant capacity, ranged from 124.8 to 532 µmol/g, those determined with DPPH· expressed as IC50 ranged from 84 to 296 µg/mL, and those determined with FRAP expressed as trolox equivalent were in 33,166 µmol/g range. The antioxidant activities showed a marked correlation with total phenolics. In the antimicrobial tests using six bacteria and a yeast, Escherichia coli was moderately sensitive to each extract. There was no correlation between antimicrobial activity and total phenolic contents. PRACTICAL APPLICATIONS Honey has functional properties and promotes human health, and such properties depend largely on the floral source. Although studies on screening the antimicrobial and antioxidant activity of raw honey samples have been done densely, studies on phenolic compounds of honey are very limited. The present study demonstrates that honey phenolic compounds are partially responsible for honey antioxidant activity, displaying the relevance of honey as both healthy foodstuff and source of antioxidant. [source]

UBIQUINONE-10 AS AN ANTIOXIDANT,

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2008
DAVID PETILLO
ABSTRACT Ubiquinol, the reduced form of coenzyme Q, is known as a lipid antioxidant. Its fully oxidized form, ubiquinone, would theoretically not have this activity. However, we report that ubiquinone-10, the oxidized form of coenzyme Q, demonstrated antioxidant activity in model studies against a lipid-soluble free radical generator, 2,2,-azobis(2,4-dimethylvaleronitrile). This was demonstrated at both 1:100 and 1:1,000 ratios of ubiquinone-10 to lipid (for both methyl linoleate and methyl linolenate). Ubiquinone-10 should therefore not be discounted as a possible antioxidant in more complex systems such as food. PRACTICAL APPLICATIONS Coenzyme Q (ubiquinol/ubiquinone) is an important component of electron transport in biological tissues and is also classified as a potent antioxidant. It is generally believed that the form that is active as an antioxidant is the reduced ubiquinol. In evaluating the loss of antioxidants in mackerel light and dark muscle tissues, it was observed that the oxidized form, ubiquinone, comprised over 87% of the total coenzyme Q in light muscle and over 93% in dark muscle and this observation did not change under anaerobic conditions. This study was done to determine if the oxidized form of coenzyme Q, ubiquinone, was capable of acting as an antioxidant. In this study, it is shown that it can function in this manner. [source]

EFFECT OF VARIOUS ANTIOXIDANTS ON THE OXIDATIVE STABILITY OF ACID AND ALKALI SOLUBILIZED MUSCLE PROTEIN ISOLATES

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2009
SIVAKUMAR RAGHAVAN
ABSTRACT Protein isolates prepared from cod (Gadus morhua) myofibrillar proteins using acid or alkali solubilization are susceptible to oxidative rancidity. Oxidation could be delayed by the exogenous addition of antioxidants. The objective of this research was to compare the efficacy of antioxidants such as ,-tocopherol, butylated hydroxyanisole (BHA) and propyl gallate, to inhibit oxidation in acid- and alkali- solubilized cod protein isolates. Oxidation was catalyzed using cod hemolysate. Oxidation of lipids was monitored by the measurement of thiobarbituric acid reactive substances and painty odor. Results showed that protein isolates prepared using the acid process was significantly (P < 0.05) more susceptible to lipid oxidation than alkali-solubilized protein isolates. Regardless of pH treatments, the efficacy of various antioxidants decreased in the order propyl gallate > BHA > ,-tocopherol. PRACTICAL APPLICATIONS Research has shown that seafood available for human consumption is rapidly getting depleted and that many fish species may become extinct in the next half-century or so. Acid and alkali solubilization methods are recent but well-known techniques used for preparing protein isolates from under-utilized aquatic species and the by-products of seafood industry. Although numerous researchers have studied the use of acid and alkali processes on several sources of seafood, almost no research has been done on the use of antioxidants to protect protein isolates from lipid oxidation. In our research, we have studied the effect of various antioxidants on the oxidative stability of acid- and alkali-solubilized fish myofibrillar proteins. The results from this work will enable the seafood industry to properly identify the process and the type of antioxidants required for making muscle food products with increased oxidative stability. [source]

EFFECTS OF COOKED TEMPERATURES AND ADDITION OF ANTIOXIDANTS ON FORMATION OF HETEROCYCLIC AROMATIC AMINES IN PORK FLOSS

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2009
GUOZHOU LIAO
ABSTRACT Heterocyclic aromatic amines (HAAs) are an important class of food mutagens and carcinogens produced in meats cooked at high temperature. The formation of HAAs in pork floss during processing and the effect of vitamin C and vitamin E on HAAs formation in pork floss were studied. Pork floss was prepared by steaming of raw pork, followed by pressing, tearing, adding various additives, and then the cooked pork was subjected to stir frying. The various HAAs in pork floss were isolated by solid phase extraction and analyzed by high-performance liquid chromatography (HPLC). Results showed that the type and level of HAAs increased with increasing processing temperature. Up to seven HAAs, 9H-pyrido[4,3-b]indole (Norharman), 1-methyl-9H-pyrido[4,3-b]indole (Harman), 2-amino-1- methyl-6-phenylimidazo[4,5-f]pyridine (PhIP), 2-amino-dipyrido[1,2-a: 3,,2,-d]imidazole (Glu-P-2), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-9H-pyrido[2,3-b]indole (AaC) and 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAaC) were detected in pork floss when stir fried at 150C. Color development increased with cooking temperatures, and was correlated with HAAs formation. The addition of vitamin C at various levels was not effective toward HAAs inhibition. However, the incorporation of 0.1% vitamin E reduced Norharman, PhIP, AaC and MeAaC concentrations in the pork floss. PRACTICAL APPLICATION The formation of heterocyclic aromatic amines (HAAs) is one of the most unfavorable changes during the cooking of food. Since the connection between the consumption of dietary carcinogens and cancer risks in human has been established, interest in this matter has been growing. However, the processing methods and conditions of Chinese traditional food are different from Western, and to date, little is known about HAAs content in the traditional meat products of China. The information derived from this study serves as an essential base of knowledge from a public health standpoint, and contributes to a repository of HAAs information relevant to Chinese cooking; it also can provide clues to understanding the factors that affect HAAs formation and can indicate means of reducing or eliminating these compounds. [source]

LIPID OXIDATION OF FISH LIVER OIL AS AFFECTED BY LIGHT, ANTIOXIDANTS AND TEMPERATURE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2004
WEIGUO SANG
Crude and refined Mackerel liver oil with or without antioxidants were stored in artificial light or in darkness to assess the effects of photo-oxidative stress on the stability of oils and the antioxidant activity of butylated hydroxy-anisole (BHA) and tert-butylhydroquinone (TBHQ) on those oils. Changes in peroxide value (PV) and thiobarbituric acid value (TBA) were monitored over 18 days at 5C and 40C. The results showed that visible light exposure played the most critical role in the acceleration of fish liver oil oxidation. The addition of antioxidants showed a significant effect in retarding oxidation with TBHQ more effective than BHA. The oxidation rate of the oils decreased in the following order: control with light > control + BHA with light > control without light > control + TBHQ with light > control + BHA without light > control + TBHQ without light. Higher PV and TBA values were observed in refined oils versus crude oils. Increasing storage temperature accelerated the oxidation of only refined oils in light. [source]

EFFECTS OF ANTIOXIDANTS ON IRRADIATED BEEF COLOR

JOURNAL OF FOOD QUALITY, Issue 3 2010
LAKSHMANAN RAMAMOORTHI
ABSTRACT Fresh beef was dipped into ascorbic acid (AA; 500 ppm), butylated hydroxyanisole (BHA, 150 ppm), butylated hydroxytoluene (BHT, 100 ppm) or propyl gallate (PG; 100 ppm); control samples were dipped in deionized water. Samples were vacuum packaged, then irradiated (0, 1.25 or 2.50 kGy). After irradiation, samples were stored (0, 7 or 14 days) at 4C. Color was assessed instrumentally (L*, a*, b*values, hue angles, chroma) and visually. All antioxidants increased L*value by two units (lighter); however, irradiation dose had no effect. Irradiation increased wet dog and rancid odors of beef; however, it decreased sour odor, a*value, chroma and hue angle, and increased visual green and brown colors, indicating that it reduced redness and color intensity. Antioxidants reduced L*(decreased lightening) and a*values (redness) compared to controls. BHA had the greatest effect on a*value. AA decreased visual green color the most; however, BHA and BHT were also effective. Antioxidants had inconsistent effects on b*value, chroma and hue angle. Storage decreased L*and a*values, and chroma. BHA and PG were most effective at maintaining low thiobarbituric acid-reactive substances when samples were irradiated. PRACTICAL APPLICATIONS Irradiation has the potential to reduce microbial load, increasing both the safety and shelf life of red meat products; however, it has the potential to damage fresh meat color, resulting in unacceptable discoloration. Irradiation can increase off-odors (wet dog, rancid) of beef; however, it can decrease sour odor, instrumental measures of red color, and increase visual green and brown colors. Use of antioxidants including ascorbic acid, butylated hydroxytoluene, butylated hydroxyanisole and propyl gallate can help maintain the color of irradiated beef held in refrigerated storage for up to 2 weeks. [source]

CONSUMER EXPECTATIONS AND PERCEPTION OF CHOCOLATE MILK DESSERTS ENRICHED WITH ANTIOXIDANTS

JOURNAL OF SENSORY STUDIES, Issue 2010
GASTÓN ARES
ABSTRACT A study was carried out to identify consumers' previous expectations of chocolate milk desserts enriched with antioxidants and to determine if these expectations affected product perception. Seventy-five consumers participated in the study and were asked to complete a word association task before the evaluation. Then, consumers tried six milk desserts with different polyphenolic concentration, scored their overall liking and willingness to purchase and provided up to four words to describe each of the samples. Cluster analysis performed on consumer-elicited terms in the word association task allowed the identification of three consumer segments with different expectations and motivations toward chocolate milk desserts enriched with antioxidants. These groups also differed in their evaluation of the desserts when tasting them, showing different overall liking, willingness to purchase and sensory description of the samples. This suggests that consumers' prior expectations and motivations significantly affected their response when tasting the desserts. PRACTICAL APPLICATIONS Word association was used to get an insight on consumer expectations of chocolate milk desserts enriched with antioxidants, proving to be a useful methodology. This approach could be a simple technique to understand consumer expectations before tasting a product, and to study how these expectations affect their response after tasting the product, particularly interesting when novel products are considered. Consumer segmentation based on their previous thoughts about a product could help to assure that a product meets consumer expectations appropriately, leading to a higher satisfaction. [source]

Antioxidant and antimutagenic effects of the crude foliar extract and the alkaloid brachycerine of Psychotria brachyceras

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 9 2007
Naíla Cannes do Nascimento
Abstract The monoterpene indole alkaloid brachycerine from Psychotria brachyceras has been shown to be induced by UV and to have in vitro antioxidant activity, indicating a possible protective role against the secondary effects of this radiation. In this work, we have studied the antioxidant properties of brachycerine and a crude foliar extract from P. brachyceras by using Saccharomyces cerevisiae strains proficient and deficient in antioxidant defenses. The mutagenic and antimutagenic potential of these substances were assayed in S.cerevisiae N123 strain in the presence and absence of H2O2. In addition, we tested the antioxidant capacity of brachycerine and a crude foliar extract from P. brachyceras on hydroxyl radicals (OH,) using the hypoxanthine/xanthine oxidase assay. The results show that brachycerine and the crude foliar extract of P. brachyceras have antioxidant and antimutagenic effects in yeast and probably this action is mainly due to the scavenging of OH, radicals. Environ. Mol. Mutagen., 2007. © 2007 Wiley-Liss, Inc. [source]

Antioxidant and inflammatory responses of healthy horses and horses affected by recurrent airway obstruction to inhaled ozone

EQUINE VETERINARY JOURNAL, Issue 3 2005
C. M. DEATON
Summary Reasons for performing study: Inhaled ozone can induce oxidative injury and airway inflammation. Horses affected by recurrent airway obstruction (RAO) have a decreased pulmonary antioxidant capacity, which may render them more susceptible to oxidative challenge. It is currently unknown whether RAO-affected horses are more susceptible to oxidative stress than those unaffected by RAO. Objectives: To determine whether ozone exposure induces greater oxidative stress and airway inflammation in RAO-affected horses in remission than in healthy horses. Methods: Seven healthy control horses and 7 RAO-affected horses were exposed to 0.8 ppm ozone for 2 h at rest. Results: At baseline, bronchoalveolar lavage fluid (BALF) ascorbic acid concentrations were lower in RAO-affected horses than healthy controls. Ozone appeared to preferentially oxidise glutathione rather than ascorbic acid 6 h after exposure. Individual healthy and RAO-affected horses demonstrated oxidation of BALF glutathione after ozone exposure. Overall, RAO-affected horses did not demonstrate increased oxidative stress following ozone exposure, compared with healthy horses. Ozone did not induce significant airway inflammation in either group. Conclusions: RAO-affected horses in remission are not more sensitive to ozone despite a decreased pulmonary antioxidant capacity. Sensitivity to ozone appears to be independent of initial pulmonary antioxidant status. Potential relevance: Horses with high susceptibility to oxidative stress may benefit from antioxidant supplementation. [source]

Antioxidant and anti-inflammatory activities of melanocortin peptides

EXPERIMENTAL DERMATOLOGY, Issue 9 2004
J. W. Haycock
,-Melanocyte-stimulating hormone (,-MSH) has previously been identified as a potent anti-inflammatory agent in various tissues including the skin. It operates by binding to the melanocortin-1 receptor (MC-1R) which results in the elevation of cyclic AMP. ,-MSH opposes the action of several proinflammatory cytokines including tumour necrosis factor-, (TNF-,). We have shown that ,-MSH can inhibit TNF-,-stimulated activation of nuclear factor-,B (NF-,B) in human cultured melanocytes, melanoma cells, keratinocytes, fibroblasts, Schwann cells and olfactory ensheathing cells. It also inhibits TNF-,-stimulated upregulation of intercellular adhesion molecule-1 (ICAM-1) in many of these cells and can inhibit peroxide-stimulated activation of glutathione peroxidase, suggesting an antioxidant role. ,-MSH is also able to stimulate intracellular calcium release in keratinocytes and fibroblasts (which do not readily show detectible cyclic AMP elevation) but only in the presence of PIA (an adenosine agonist). The carboxyl terminal tripeptides KPV/KP-D-V are reported to be the minimal sequences necessary to convey anti-inflammatory potential, but evidence on how they act is not fully known. Stable transfection of Chinese hamster ovary cells with MC-1R suggests that the KPV peptides operate by this receptor, at least by elevating intracellular calcium. Elevation of cyclic AMP by these tripeptides has not been detected in any cell type studied; however, calcium elevation can inhibit TNF-,-stimulated NF-,B activity (as for cyclic AMP). In conclusion, the MSH peptides convey anti-inflammatory and antioxidant activity in many cell types in skin and nerve, by counteracting proinflammatory cytokine signalling. The KPV peptides appear to act functionally via the MC-1R and can also elevate intracellular calcium. [source]

Characterization of blond and Star Ruby (red) Jaffa grapefruits using antioxidant and electrophoretic methods

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2006
Shela Gorinstein
Summary Antioxidant and electrophoretic methods were used to characterize the quality differences between blond and Star Ruby (red) grapefruits. Dietary fibre, minerals and trace elements, total polyphenols, anthocyanins, flavonoids, phenolic and ascorbic acids were also determined. The antioxidant potential of red grapefruit was significantly higher than that of the blond fruit (P < 0.05) and correlated well with the total polyphenols (R2 from 0.8456 to 0.9711). In both the cultivars studied, thirty-two electrophoretic bands were detected [sodium dodecyl-polyacrylamide gel eletrophoresis (SDS-PAGE)]. The main electrophoretic bands occurred between 20 and 43 kDa in both grapefruits with few minor differences between the varieties. Our findings indicate the following (i) red grapefruit is preferable: it has a higher concentration of bioactive compounds and antioxidant potential than the blond; (ii) 1, 1-diphenyl-2-picrylhydrazyl (DPPH) test is a more sensitive method for the determination of antioxidant potential; (iii) there are some minor differences in electrophoretic patterns; (iv) antioxidant and electrophoretic methods are a good combination for characterization of differences of the same citrus fruits. [source]

Influence of Cultivation System on Bioactive Molecules Synthesis in Strawberries: Spin-off on Antioxidant and Antiproliferative Activity

JOURNAL OF FOOD SCIENCE, Issue 1 2010
L. D'Evoli
ABSTRACT:, Strawberries (Fragaria ananassa,L., cv. favette) were studied to investigate the influence of cultivation practices (biodynamic, conventional) on the synthesis of bioactive molecules (ascorbic acid, ellagic acid, anthocyanins, flavonols) and to evaluate their antioxidant activity. Additionally, the,in vitro,bioactivity, in terms of antioxidant and antiproliferative activity, of the same strawberry samples in human colon carcinoma (Caco-2) cells was also studied. Compared to conventional strawberries, biodynamic fruits had a significantly higher content of ascorbic acid (P,< 0.01), pelargonidin-3-glucoside (P,< 0.05), cyanidin-3-glucoside (P,< 0.01), ellagic acid (P,< 0.01), quercetin, and kaempferol (both,P,< 0.01). Antioxidant activity of biodynamic strawberry crude extract was significantly higher than that of the conventional one (P,< 0.05); in addition, while the antioxidant activity of water-soluble fraction was very similar in both biodynamic and conventional strawberries, that of water-insoluble fraction of biodynamic fruits was significantly higher (P,< 0.05). The same crude extract of biodynamic strawberry samples effectively corresponded to an increase of bioactivity, in terms of both cellular antioxidant activity and antiproliferative activity, in Caco-2 cells differentiated to normal intestinal epithelia and in undifferentiated Caco-2, respectively. Further studies are needed to confirm whether the practice of biodynamic agriculture is likely to increase the bioactivity of other varieties of fruits and vegetables. [source]

Reduction of Acrylamide and Its Kinetics by Addition of Antioxidant of Bamboo Leaves (AOB) and Extract of Green Tea (EGT) in Asparagine,Glucose Microwave Heating System

JOURNAL OF FOOD SCIENCE, Issue 2 2008
Yu Zhang
ABSTRACT:, This study investigated the effect of antioxidant of bamboo leaves (AOB) and extract of green tea (EGT) on the formation and kinetics of acrylamide in an equimolar asparagine,glucose model system. The substrates spiked with AOB and EGT were microwave-heated at 180 °C and the acrylamide content in final reaction products was quantified by ultra-performance liquid chromatography,tandem mass spectrometry (UPLC-MS/MS). The results showed that both AOB and EGT could effectively reduce the formation of acrylamide in an asparagine,glucose microwave heating model system and achieved a maximum reduction rate when the addition levels of AOB and EGT were both 10,6 mg/mL reaction solution. To describe the kinetic behavior of acrylamide, a simplified kinetic model was optimized and relative kinetic rate constants were evaluated under isothermal conditions. The results indicated that the reduction effect of AOB and EGT on the acrylamide formation may partly be ascribed to the decrease of the formation rate constant (kF) in both AOB and EGT-spiked systems (43.4% and 32.3% of decrease, respectively, P < 0.05). The kinetic parameter kE, which represents the elimination rate of acrylamide in both AOB and EGT-spiked systems, was not significantly different (6.9% of increase and 10.9% of decrease, respectively, P > 0.05). The results of the kinetic study indicated that addition of AOB and EGT could significantly reduce the formation rate constant (kF) of acrylamide, but could not significantly affect the elimination rate constant (kE) of acrylamide. [source]

Antioxidant and Antimutagenic Activity of Dietary Chlorophyll Derivatives Determined by Radical Scavenging and Bacterial Reverse Mutagenesis Assays

JOURNAL OF FOOD SCIENCE, Issue 7 2002
M.G. Ferruzzi
ABSTRACT: In vitro antioxidant and antimutagenic activity of dietary chlorophyll derivatives was assessed. Antioxidant activity was determined by the ability of each compound to scavenge the long-lived free radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2,-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS+). Antimutagenic activity was assayed with a modified microscreen bacterial reverse mutagenicity assay using Salmonella typhimurium TA100 and benzo[a]pyrene as the tester strain and mutagen respectively. Derivatives of chlorophyll a were found to be more effective radical quenchers than those of chlorophyll b. Furthermore, metal-free derivatives such as chlorins, pheophytins, and pyropheophytins exhibited significantly lower antiradical capacity than metallo-derivatives such as Mg-chlorophylls, Zn-pheophytins, Zn-pyropheophytins, Cu-pheophytina, andCu-chlorophyllins. Both metal-free and metallo-chlorophyll derivatives demonstrated similar dose-dependent inhibitory activity against B[a]P induced mutagenesis. These results demonstrate that dietary chlorophyll derivatives prevalent in both fresh and processed foods and dietary supplements have antioxidant and antimutagenic activities. [source]

In-vitro Antioxidant and In-vivo Photoprotective Effect of Three Lyophilized Extracts of Sedum telephium L. Leaves

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2000
FRANCESCO BONINA
Sedum telephium L. is a medicinal plant used in antiquity to cure many types of inflammatory skin diseases. The leaves (without the external cuticle), are used to promote healing and reduce skin inflammation and pain, and contain various components. We found two major components: flavonol glycosides and polysaccharides, with molecular weight between 13 000 and 13 500 Da. We evaluated the in-vitro antioxidant and in-vivo skin photoprotective effects of three lyophilized extracts obtained from the juice of S. telephium L. leaves: a total lyophilized juice, a lyophilized flavonolic fraction, and a lyophilized polysaccharidic fraction. Two in-vitro models were used: the bleaching of the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH*) radical, and the protective effect against UV-induced peroxidation on phosphatidylcholine multilamellar vesicles, as model membranes. The antioxidant/radical scavenging activity of each lyophilized extract was also assessed in-vivo by determining their ability to reduce UVB-induced skin erythema (monitored by reflectance spectrophotometry) in healthy human volunteers. The findings of the in-vitro experiments clearly demonstrated that, unlike the lyophilized polysaccharidic fraction, the lyophilized flavonolic fraction and total lyophilized juice possess strong antioxidant/free radical scavenging properties, which are likely due to phenolic compounds. Consistent with these findings, gel formulations of both the total lyophilized juice and, to a greater degree, the lyophilized flavonolic fraction appeared to possess a strong protective effect against UV-induced skin erythema in-vivo, whereas the lyophilized polysaccharidic fraction was completely ineffective. The in-vitro and in-vivo results suggest that, both the total lyophilized juice and, in particular, the lyophilized flavonolic fraction, but not the lyophilized polysaccharidic fraction of S. telephium L. leaves, have photoprotective effects against UVB-induced skin damage. [source]

Antimutagenic and antioxidant activities of cascalote (Caesalpinia cacalaco) phenolics

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2004
Rafael A Veloz-García
Abstract 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 [source]

Berry anthocyanins: isolation, identification and antioxidant activities,

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2003
Marja P Kähkönen
Abstract Anthocyanins from bilberry, blackcurrant and cowberry were isolated for antioxidant evaluation. Individual compounds were identified and quantified using HPLC and HPLC/ESI,MS techniques. Antioxidant and radical-scavenging capacities of the isolates were studied in emulsified methyl linoleate and human low-density lipoprotein (LDL) in vitro and in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. The total anthocyanin contents in the phenolic extracts of bilberry, blackcurrant and cowberry were 6000, 2360 and 680 mg kg,1 fresh weight respectively. There were four dominant compounds in blackcurrant (glucosides and rutinosides of cyanidin and delphinidin), three in cowberry (monoglycosides of cyanidin) and 15 in bilberry (monoglycosides of cyanidin, delphinidin, malvidin, peonidin and petunidin). Quantification as cyanidin-3-glucoside equivalents gave markedly lower results regarding the total anthocyanin concentration and the content of individual delphinidin and malvidin compounds compared with quantification based on corresponding standard compounds. Berry anthocyanins were highly active radical scavengers in the DPPH test and effective antioxidants in emulsion and human LDL. Copyright © 2003 Society of Chemical Industry [source]

Antioxidant and antimicrobial activities of Polygonum cognatum Meissn extracts

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2003
Ali Y
Abstract The antioxidant activities, reducing powers, 2,2-diphenyl-l-picrylhydrazyl (DPPH) radical-scavenging activities, total phenolic compound contents and antimicrobial activities of ether, ethanol and hot water extracts of Polygonum cognatum Meissn were studied in vitro. The highest antioxidant activity was found in the water extract. However, there were no statistically significant differences among 15,µg,ml,1 extract-containing samples in linoleic acid emulsion (0.02,M, pH 7.0) during 120,h of incubation (P,>,0.05). The reducing power of the water extract was the highest, but its reducing power was markedly lower than that of ascorbic acid. The highest DPPH radical-scavenging activity was found in the water extract, with 50% DPPH radical scavenging at a concentration of 100,µg,ml,1 dried water extract, while at the same concentration of dried ethanol extract the value was 12%. Surprisingly, no DPPH radical-scavenging activity was observed in the ether extract. The concentrations of phenolic compounds found were 0.48, 0.50 and 0.01,µg,ml,1 gallic acid equivalent in 10,µg,ml,1 water, ethanol and ether extracts respectively. The ether and ethanol extracts showed antimicrobial activity against Staphylococcus aureus and Bacillus subtilis. The water extract did not show antimicrobial activity against the studied micro-organisms. © 2002 Society of Chemical Industry [source]

Interaction of Phytochemical-Quercetin with the Other Antioxidant, Ascorbic Acid and their Protective Effect in Tilapia after Ultraviolet Irradiation

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 5 2009
Gustavo A. Rodriguez-Montes De Oca
Semi-purified, casein-gelatin-based diets were prepared and supplemented with quercetin (Q) and/ or ascorbic acid (AA): control diet C,Q,(100 mg/kg AA), diet C ,Q+ (100 mg/kg AA + quercetin 10 g/kg), diet C +Q, (1000 mg/kg AA), and diet C +Q+ (1000 mg/kg AA + quercetin 10 g/kg). These diets were fed to tilapia for 19 wk and then fish were divided into controls and ultraviolet (UV) treatments. Fish were exposed to UV radiation. Control groups were protected with a MYLAR® polyester film and plexiglass. At week 20, the same fish were re-exposed to UV radiation. Control groups of fish were protected by a double layer of MYLAR® and the UV groups were exposed with no protection. Before UV exposure, 24 h after, and 7 d after the second treatment, fish liver and skin were dissected for Q and AA analyses. The proportion of oxidized ascorbate was significantly increased in fish from treatments C ,Q, and C ,Q+ . Q concentrations in fish after exposures were negligible in skin, whereas liver concentrations were significantly different among control (34 ± 10 ,g/g) and UV-irradiated fish (11 ± 6 ,g/g), respectively. The interaction between these two dietary antioxidants may change after chronic UV irradiation. [source]

Antioxidant and other biological activities of phenols from olives and olive oil

MEDICINAL RESEARCH REVIEWS, Issue 1 2002
Francesco Visioli
Abstract Olive oil is the principal source of fats in the Mediterranean diet, which has been associated with a lower incidence of coronary heart disease and certain cancers. Phenolic compounds, e.g., hydroxytyrosol and oleuropein, in extra-virgin olive oil are responsible for its peculiar pungent taste and for its high stability. Recent findings demonstrate that olive oil phenolics are powerful antioxidants, both in vitro and in vivo, and possess other potent biological activities that could partially account for the observed healthful effects of the Mediterranean diet. © 2001 John Wiley & Sons, Inc. Med Res Rev, 22, No. 1, 65,75, 2002 [source]

Antioxidant and Vasodilatory Effects of Heme Oxygenase on Mesenteric Vasoreactivity Following Chronic Hypoxia

MICROCIRCULATION, Issue 2 2009
KAREN SWEAZEA
ABSTRACT Objective: Chronic hypoxia (CH) results in impaired vasoconstriction associated with increased expression of heme oxygenase (HO). We hypothesized that enhanced HO activity minimizes reactive oxygen species (ROS) in arteries from CH rats, thereby normalizing endothelium-dependent vasodilation and concurrently produces carbon monoxide (CO), resulting in tonic vasodilation. Methods: ROS were quantified in mesenteric arteries from control and CH Sprague-Dawley rats. Reactivity to the endothelium-dependent vasodilator, acetylcholine (ACh), and the vasoconstrictor, phenylephrine (PE), were also assessed. Results: Basal ROS levels did not differ between groups and were similarly increased by HO inhibition. In contrast, catalase inhibition increased ROS in CH rats only. Vasodilatory responses to ACh were not different between groups. Combined inhibition of catalase and HO impaired PE-induced vasoconstriction in both groups. CH-induced impairment of vasoconstriction was reversed by either catalase or HO inhibition supporting the protective roles of the HO and catalase pathways following CH. Increased vascular smooth muscle calcium was observed with inhibition in the CH group, suggesting that catalase and HO-derived CO elicit reduced calcium influx, leading to the impaired vasoconstriction. Conclusions: Our data suggest that although the HO pathway is an important antioxidant influence, impaired vasoconstriction following CH appears to be due to effects of ROS and HO-derived CO. [source]

Cover Picture , Mol.

MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2009
Nutr.
Regular issues provide a wide range of research and review articles covering all aspects of Molecular Nutrition & Food Research. Selected topics of issue 6 are: Quercetin-induced apoptotic cascade in cancer cells: Antioxidant versus estrogen receptor ,-dependent mechanisms. Bog blueberry anthocyanins alleviate photoaging in ultraviolet-B irradiation-induced human dermal fibroblasts Oxidative stress due to anesthesia and surgical trauma: Importance of early enteral nutrition [source]

Antioxidant and angiotension-converting enzyme inhibition capacities of various parts of Benincasa hispida (wax gourd)

MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 3 2004
Hui-Yu Huang
Abstract Vegetables and fruits have been shown to be good sources of antioxidants. Benincasa hispida (wax gourd) has been used in traditional Chinese medicine to treat hypertension and inflammation. The aims of this study were to investigate the abilities of antioxidation and inhibition of angiotensin-converting enzyme (ACE) activity of wax gourd pulp, core, seed, and peel prepared by different extraction methods. The fresh weights required to reach 50% inhibition of linoleic acid oxidation were higher in fresh extracts, compared to other extraction methods. Fresh weights required to reach 50% inhibition were the lowest in seed. The seed had the lowest Cu2+ -induced low-density lipoprotein (LDL) oxidation percentage and inhibition level of ACE activity among all parts. The higher antioxidant capacity of the seed may result from the higher total phenolics contents and superoxide dismutase activity. The abilities of antioxidation and ACE activity inhibition may provide protective effects against cardiovascular diseases and cancers. [source]

Update: Effects of Antioxidant and Non-Antioxidant Vitamin Supplementation on Immune Function

NUTRITION REVIEWS, Issue 5 2007
Aimee L. Webb PhD
The purpose of this manuscript is to review the impact of supplementation with vitamins E and C, carotenoids, and the B vitamins on parameters of innate and adaptive immune function as reported from clinical trials in humans. There is evidence to support causal effects of supplementation with vitamins E and C and the carotenoids singly and in combination on selected aspects of immunity, including the functional capacity of innate immune cells, lymphocyte proliferation, and the delayed-type hypersensitivity (DTH) response. Controlled intervention trials of B vitamin-containing multivitamin supplements suggest beneficial effects on immune parameters and clinical outcomes in HIV-positive individuals [source]

In Vitro Antioxidant and In Vivo Photoprotective Effects of an Association of Bioflavonoids with Liposoluble Vitamins

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2006
Patrícia M. B. G. Maia Campos
ABSTRACT A new tendency in cosmetic formulations is the association of botanical extracts and vitamins to improve skin conditions by synergic effects. The objective of this study was to determine the antioxidant activity of associated bioflavonoids, retinyl palmitate (RP), tocopheryl acetate (TA) and ascorbyl tetra-isopalmitate (ATIP), as well as their photoprotective effects in preventing increased erythema, transepidermal water loss (TEWL) and sunburn cell formation in hairless mouse skin. The antioxidant activity of solutions containing the association or each substance separately was evaluated in vitro by a chemiluminescence assay. The photoprotective effect was evaluated by means of in vivo tests. Dorsal skin of hairless mice was treated daily by topical applications for 5 days with formulations containing or not containing (vehicle) the flavonoid-vitamins association (5%). The skin was irradiated (UVA/B) 15 minutes after the last application. The results showed that bioflavonoids had in vitro antioxidant properties and also that when they were associated with vitamins their antioxidant activity was more pronounced. On the other hand, erythema and UV damage to the permeability barrier function (TEWL) was not significantly reduced by previous treatment with the flavonoid-vitamin-association formulations, when compared to the irradiated vehicle-treated area. However, the treatment protected the skin from UV damage because it reduced the number of sunburn cells, when compared to the vehicle-treated area. Finally, the association of vitamins and bioflavonoids added to a dermocosmetic formulation showed a relevant biological activity in terms of photoprotection, because the association of bioflavonoids and vitamins acted by different mechanisms, such as antioxidation and absorption of UV radiation, which suggests its use in antiaging and photoprotective products. [source]

Copper treatment activates mitogen-activated protein kinase signalling in rice

PHYSIOLOGIA PLANTARUM, Issue 3 2003
Chuan-Ming Yeh
It is well known that mitogen-activated protein kinase (MAPK) pathways are modules involved in the transduction of extracellular signals to intracellular targets in all eukaryotes. In plants, it has been shown that MAPKs play a role in the signalling of biotic and abiotic stresses. To characterize signalling pathways involved in heavy metal-induced stress responses, we examine whether plant MAPKs are also involved in this process. The analyses of mRNA levels of OsMAPK genes have shown that only OsMAPK2 mRNA transcripts increased within 12 h upon CuCl2 treatment in suspension cells and roots. An in-gel kinase assay revealed that three protein kinases, approximate 42, 50, and 64-kDa, were activated by CuCl2 treatments. The approximate 42-kDa protein kinase displayed MAPK properties. Antioxidant, GSH, prevented copper-induced kinase activity. Furthermore, we found that rice roots underwent a rapid cell death upon this copper treatment. The copper-induced cell death of rice roots was partially blocked by MAPK kinase inhibitor, PD98059. These results suggest that the MAPK cascades may function in the plant heavy metal induced-signalling pathway. [source]

Antioxidant and cytoprotective properties of infusions from leaves and inflorescences of Achillea collina Becker ex Rchb.

PHYTOTHERAPY RESEARCH, Issue 4 2009
Annamaria Giorgi
Abstract Plants are the main source of molecules with antioxidant and radical scavenging properties that aid the natural defence systems of cells and may be involved in the preservation of human health, particularly preventing all the physiopathological conditions where oxidative damage is a hallmark. Achillea collina Becker ex Rchb. is a medicinal plant of the Achillea millefolium aggregate (yarrow) traditionally used, particularly in mountain areas, as an infusion or alcohol extract for its digestive, antiinflammatory, analgesic, antipyretic and wound healing properties. The aim of this study was to investigate the antioxidant capacity and cytoprotective activity against oxidative stress of infusions obtained from the leaves and inflorescences of Achillea collina Becker ex Rchb., assessed by chemical (free radical scavenging activity by DPPH and Folin Ciocalteu assay) and biological assays (in vitro model of cytotoxicity and lipid peroxidation in PC12 cells line). Infusions of leaves had the highest antioxidant properties and cytoprotective activity. The antioxidant capacity was significantly correlated with the total phenolic content but not with the cytoprotective profile. Achillea collina Becker ex Rchb. has good antioxidant and cytoprotective properties, suggesting further investigations on its chemical composition and potential health value, particularly for traditionally prepared infusions of leaves. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Antioxidant and antiinflammatory activities of Sideritis perfoliata subsp. perfoliata (Lamiaceae)

PHYTOTHERAPY RESEARCH, Issue 4 2008
Maria-Thiresia Charami
Abstract Sideritis perfoliata L. subsp. perfoliata is a plant widely used in folk medicine in Greece since antiquity because of its antiinflammatory, antirheumatic, antiulcer, digestive and vasoprotective properties. Phytochemical investigations of the polar extracts afforded four flavonoid glycosides, four phenylpropanoic glycosides, caffeic acid and one iridoid, ajugoside. Reactive oxygen species (ROS) are implicated in the aetiology of several inflammatory processes. In the present study polar fractions and isolated compounds from S. perfoliata subsp. perfoliata were evaluated for their antioxidant activity using DPPH spectrophotometric and TBA lipid peroxidation assays, as well as for their antiinflammatory activity using the soybean lipoxygenase bioassay. All extracts and isolated compounds showed significant antioxidant and inhibitory activity against soybean lipoxygenase. These findings give support to the ethnopharmacological use of the plant in the treatment of several inflammatory ailments. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Antioxidant and antiglycation properties of total saponins extracted from traditional Chinese medicine used to treat diabetes mellitus

PHYTOTHERAPY RESEARCH, Issue 2 2008
Miaomiao Xi
Abstract Eleven antidiabetic traditional Chinese medicine (TCM) extracts rich in saponins were examined for their antioxidant and antiglycation activities. The antioxidant activities of these extracts were evaluated by studying the inhibition of lipid peroxidation in rat liver microsomes induced by ascorbate/Fe2+, cumine hydroperoxide (CHP) or CCl4/reduced form of nicotinamide-adenine dinucleotide phosphate (NADPH). The antioxidant capacities were also evaluated by studying the scavenging of 2,2,-diphenyl-1-picrylhydrazyl (DPPH) free radical. The antiglycation activities of these extracts were evaluated by hemoglobin- , -gluconolactone (, -Glu) assay, bovine serum albumin (BSA)-glucose assay and N-acetyl-glycyl-lysine methyl ester (GK peptide)-ribose assay. Aralia taibaiensis outperformed other extracts in most of the assays except inhibition of early glycation products formation, where Acanthopanax senticosus showed higher activity. Aralia taibaiensis was particularly potent in inhibiting the late glycation and formation of advanced glycation end products (AGEs) on proteins. The antioxidant and antiglycation activities of most extracts were correlated with the saponin content. The results demonstrate that the antidiabetic activities of most extracts could be explained, at least in part, by their combined antioxidant and antiglycation properties. Copyright © 2007 John Wiley & Sons, Ltd. [source]