Kinetic analysis of antioxidant capacity of wine

A competition kinetics procedure for measuring total antioxidant capacity in wine is described. This procedure is based on the "crocin bleaching test" [28] as modified for analyzing the antioxidant capacity of complex mixtures [24]. The antioxidant capacity of white wines ranged from 0.08 to 1.2 mM equivalents of the reference antioxidant (Trolox C), while for red wines values ranging from 6.4 to 41.9 mM have been obtained. Although a correlation exists between antioxidant capacity and total phenol content of wines, due to the variable reactivity of different phenol groups, the analysis of the phenol content provides only a crude indication of the actual antioxidant capacity. The analysis of antioxidant capacity on different polyphenol classes, separated by solid phase extraction, indicated that anthocyanins are the major antioxidants of young red wines, and tannins of old red wines and white wines. Several vintages of the same grape have been analyzed and the expected decrease of antioxidant capacity upon ageing was not observed, although spectrophotometric analysis clearly demonstrated the shift from anthocyanin monomers to polymers. Artificial ageing by stirring under air produced a rapid decrease (30 min) of antioxidant capacity followed by an increase (up to two weeks), but not any significant modification of the spectrophotometric chemical age factor. Since neither natural nor artificial ageing present a clear-cut relationship with a decrease of antioxidant capacity, we could conclude that the a priori assumption that an old wine contains less antioxidant capacity, although popular, is not fully correct.     

The antioxidant status of patients subjected to total body irradiation.

BACKGROUND AND PURPOSE: Total body irradiation (TBI) is a routine preconditioning procedure for the treatment of leukemia and aplastic anemia, prior to bone marrow transplantation (BMT). Ionizing radiation generates reactive oxygen derived species (ROS) that can be removed by antioxidants. Our purpose is to determine the antioxidant status of patients undergoing TBI by evaluating the oxidant stress and their antioxidant capacity. MATERIAL AND METHODS: We evaluated by cyclic voltammetry (CV) the total antioxidant capacity (TAC) in plasma of 14 patients undergoing TBI prior to BMT. The levels of the antioxidants, ascorbic acid (AA) and uric acid (UA) were determined by HPLC-ECD. The oxidant stress level was calculated by the ratio [dehydro ascorbic acid]/total ascorbic acid]. RESULTS: TAC was reduced by 36% (p < 0.02) but after 4 months recovered to a level 22% higher than before the treatment (p < 0.05). Both, AA and UA, decreased following irradiation by 84% (p < 0.02) and 24% (p < 0.05) respectively, but returned to a level of 21% and 320% after 4 months compared to baseline values. The changes in [UA] were affected by Allopurinol (xanthine oxidase inhibitor), given as a routine pretransplant therapy until day -1. The [dehydroascorcbic acid]/[total ascorbic acid] (%) was 45% (range of normal controls = 13.2 +/- 1.5%) and increased by 69% following TBI. In order to obtain a decrease in the TAC of plasma in vitro, comparable to that in vivo, a 1000 fold higher dose of irradiation was required. CONCLUSIONS: TBI caused a pronounced decrease in antioxidant capacity and an excessive increase in oxidant stress. We assume that TBI alters antioxidant homeostasis greatly enhancing the stress damage. CV measurements may lead to a better understanding of the balance between oxidant stress and antioxidant utilization, and to a reconsideration of the routine use of Allopurinol as pretreatment for TBI, and antioxidant support before and/or after TBI.     

噪声刺激后豚鼠耳蜗抗氧化能力的变化和α-硫辛酸对声损伤的保护作用

实验探讨了声刺激后豚鼠血清总抗氧化能力(total antioxidant capacity,TAC)和耳蜗组织一氧化氮(nitricoxide,NO)含量的变化及α-硫辛酸的抗氧化和对声损伤的保护作用。将豚鼠(350-400 g)随机分为无噪声对照组(n=20)、噪声+生理盐水组(n=20)和噪声+α-硫辛酸组(n=20)。噪声刺激(4.kHz倍频程,115 dB SPL 5 h)结束后立即测试脑于诱发电位(auditory brainstem responses,ABRs),取血清测TAC,制备耳蜗组织匀浆测NO的水平。所得结果如下:(1)无噪声对照组,动物听阈无明显变化;噪声刺激后生理盐水组,听阈上升的幅度明显高于α-硫辛酸组(P<0.05)。(2)噪声+生理盐水组,TAlC明显低于无噪声对照组(P<0.05);噪声+α-硫辛酸组同噪声+生理盐水组相比,TAC明显升高(P<0.05),同无噪声对照组相比,无显著性差异(P>0.05)。(3)噪声+生理盐水组,NO含量高于无噪声对照组(P<0.05);噪声+α-硫辛酸组同噪声+生理盐水组相比,NO含量明显减少(P<0.05),同无噪声对照组相比,差异无显著性(P>0.05)。上述结果提示,噪声刺激后血清TAC降低,耳蜗组织内NO含量增加;α-硫辛酸可通过抗氧化机制对噪声性听力损伤(noise induced hearing loss,NIHL)发挥保护作用。     

Influence of <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> strains on wine total antioxidant capacity evaluated by photochemiluminescence

A preliminary investigation on 20 Aglianico del Vulture commercial wines from the Basilicata region proved the existence of a significant variability in total antioxidant capacity which can exert a potential impact on wine quality. Nineteen Saccharomyces cerevisiae strains were tested in Aglianico del Vulture on pilot scale fermentation and the experimental wines obtained were evaluated for the antioxidant capacity, ethanol and total polyphenols. At the ninth day of fermentation the experimental wines had an antioxidant capacity, measured by photochemiluminescence, between 2.88 and 6.25 mM of ascorbic acid equivalent, ethanol concentration, measured by GC, between 5.49% and 10.99% and total polyphenols, determined by Folin Ciocalteau reagent, from 1153 to 1867 mg catechins/l. After 12 days the total antioxidant capacity was increased in most wines but decreased in some wines. These results, statistically analysed by principal component analysis, revealed a significant influence of S. cerevisiae strain on total antioxidant capacity and total polyphenols content of wine.     

The total antioxidant capacity of blood plasma during cardiovasculary bypass surgery in patients with coronary heart disease

We studied he effect of ischemia and reperfusion on the total antioxidant capacity (TAC) of blood plasma during cardiopulmonary bypass surgery employing the modified St. Thomas Hospital cardioplegic solution. TAC was determined using the FRAP method. TAC decreased during surgery, but no further decrease in TAC was observed during reperfusion, indicating that it is a relatively stable parameter of the antioxidative barrier of the body.     

Postprandial increases in serum antioxidant capacity in older women.

Eight women were recruited for studying the effects of a meal on overall antioxidant status. Subjects resided in a metabolic research unit for two 36-h periods. During period A, subjects fasted overnight (12 h) and were then given a breakfast, a lunch, a snack, and a dinner. During period B, subjects fasted for 23 h and were then given a dinner. These meals were designed to contain negligible antioxidants. Blood samples were collected for analyzing total antioxidant capacity (TAC) and individual antioxidants. The results showed that serum TAC significantly increased by up to 23% after the consumption of the lunch and dinner during period A. Serum TAC did not increase until after the consumption of the dinner during period B. Among the antioxidants (vitamin C, alpha-tocopherol, bilirubin, and uric acid) examined, serum uric acid was the only one that showed a significant postprandial increase, which was also parallel to the postprandial response in serum TAC. These results indicate that food intake, even if low in antioxidants, can increase the serum total antioxidant activity.     

Effect of histidine on autotaxin activity in experimentally induced liver fibrosis

The aim of this study was to explain whether serum autotaxin (ATX) activity might be a target for regulation of liver fibrosis and to evaluate the hepatoprotective and antifibrotic effects of histidine in thioacetamide (TAA)-induced liver fibrosis in rats. This study was carried out on 100 Wistar Albino rats, classified into five groups, each containing 20 rats: Group I (control group), Group II: rats were given histidine intraperitoneally, Group III: rats were injected intraperitoneally with TAA, Group IV: rats were injected with L-histidine together with TAA, and Group V: rats were injected with TAA for 1 month then treated with intraperitoneal injection of L-histidine for another month. At the end of experiment, blood and liver were collected for determination of some liver enzymes, plasma total antioxidant capacity (TAC), serum ATX activity, and liver tissue hydroxyproline. Thioacetamide treatment caused significant increases in liver enzymes, ATX activities, and liver hydroxyproline, but a significant decrease in plasma's TAC. Upon treatment with histidine, a significant decrease in liver enzymes, ATX activities, and liver hydroxyproline was observed with a significant increase in plasma TAC in Group IV and a significant decrease in Group V. Histidine as an antioxidant has a protective effect on TAA-induced liver fibrosis; it is beneficial in rats not only by inhibition of collagen synthesis and increasing TAC but also by inhibition of ATX activities thus reducing its capacity to produce lysophosphatidic acid, which has a role in liver fibrosis.     

Comparison of the contents of the main biochemical compounds and the antioxidant activity of some Spanish olive oils as determined by four different radical scavenging tests

The aim of this study was to compare the contents of the main biochemical compounds and the antioxidant capacity of five Spanish olive oils by four different antioxidant tests and to find out the most valuable oil for disease preventing diets. Fatty acids, sterols and individual antioxidant compounds in Arbequina, Hojiblanca, Extra Virgin, Picual and Lampante Spanish olive oils were determined. Antioxidant activities were done as well using different radical scavenging activities: total radical-trapping antioxidative potential by ABAP (TRAP-ABAP), radical scavenging activity by DPPH (RSA-DPPH), antioxidant assay by beta-carotene-linoleate model system (AA-beta-carotene) and total antioxidant status by ABTS (TAA-ABTS). The highest content of all studied antioxidant compounds (353; 329; 4.6 and 2.7 mg/kg for tocopherols, tocotrienols, polyphenols and o-diphenols, respectively) was found in Extra Virgin oil. Also the highest antioxidant capacity was observed in Extra Virgin oil (668 nM/ml; 29.4%; 40.4% and 2.64 mM TE/kg for TRAP-ABAP, RSA-DPPH, AA- beta-carotene and TAA-ABTS, respectively). The correlation between total phenols and antioxidant capacities measured by four methods was very high, but the highest for the beta-carotene (R = 0.9958). In conclusion, the best method for determination of the antioxidant capacity of olive oils is the beta-carotene test. Extra Virgin olive oil has high organoleptic properties and the highest antioxidant activity. The above-mentioned makes this oil a preferable choice for diseases preventing diets.     

The interaction between follicular fluid total antioxidant capacity,infertility and early reproductive outcomes during in vitro fertilization

Abstract

Introduction: The objective of this study was to determine whether the relationship between antioxidant capacity of follicular fluid and early reproductive outcomes is influenced by the cause of infertility, polycystic ovarian morphology, age and smoking.

Patients and methods: This was a prospective, cross-sectional study performed in an assisted conception unit and a teaching hospital. The study cohort was 34 women undergoing IVF treatment. Interventions included total antioxidant capacity (TAC) measured using ferric reducing/antioxidant power assay in 303 follicular fluid samples. The main outcome measures were follicular fluid TAC, percentage TAC loss after 72 h and early reproductive outcomes.

Results: Follicular TAC was elevated in women with infertility of 'unexplained' (UE) or tubal factor (TF) aetiology, relative to those with male factor (MF) infertility, when reproductive outcomes were positive but not when they were negative. In the TF and UE groups, low TAC was associated with ovum fertilization incompetence, whereas TAC was comparable irrespective of embryo viability. Unexplained infertility was associated with significantly elevated follicular TAC. Among women with polycystic ovaries, fertilization incompetence was associated with elevated TAC; the opposite was true in women with normal ovaries. Follicular fluid 72-h TAC consumption > 20% was associated with poorer reproductive performance.

Conclusions: The follicular fluid pro-oxidant-antioxidant balance required for conception in women undergoing IVF is related to the aetiology of infertility, age, the presence of polycystic ovary morphology and smoking.     

A microplate-based colorimetric assay of the total peroxyl radical trapping capability of human plasma

We developed a colorimetric assay estimating the radical-scavenging activity of human plasma. The test is based on a measure, in 96-well microplates at 450 nm, of the bleaching of carotenoid crocin by peroxyl radicals generated during thermal decomposition of 2, 2'-azobis-(2-amidinopopane) dihydrochloride (ABAP). The inhibition of this bleaching is a function of the antioxidant power of substances added to incubation mixture. We determined the optimal conditions for a sensitive, rapid, and reproducible assay of 50% inhibitory capacity (IC50) of a range of antioxidant substances and of plasma. Only a total of 200 microl of plasma is required in a complete dose-inhibition curve. The IC50 of normal human plasma resulted of 2.70 microl of plasma/250 microl assay volume. The total antioxidant capability (TAC) of plasma was defined as the reciprocal of IC50 and its value in a group of 19 healthy adults resulted in 0. 369 +/- 0.06. Intraassay and interassay coefficients of variation of plasma TAC were 6.13 and 4.80%, respectively. Measurement of samples with different uric acid concentration showed that antioxidant activity of uric acid accounts for approximately two-thirds of TAC.     

Isolation and clonal pre-selection of enological Saccharomyces

The aim of the present study was to perform a fast pre-selection from a great number of wine yeasts using a simple phenotypic-based methodology that allows many different strains to be simultaneously tested. A total of 150 elliptic yeasts, isolated from must and wine from black grapes of a distinctive Italian variety, were studied. Yeasts were identified to genus level by assessing their ability to ferment glucose and their production of spores on acetate agar. The Saccharomyces strains were seeded on BiGGY agar to determine their H(2)S production, on calcium carbonate agar to test their acetic acid production, and on grape-skin agar and on grape-seed agar to assess their interaction with phenolic compounds. The Saccharomyces strains were also examined for fermentative vigor after 2 d or 7 d both with and without the addition of 100 mg L(-1) of SO(2) in must at 20 degrees brix and pH 3.20. At the end of fermentation, the wines produced by the 18 best yeasts were analyzed and the strains were studied for additional biochemical and technological characteristics. The resistance of the strains to simultaneous acid-stress and osmotic-stress was studied carrying out in duplicate winemaking tests in must at 30 degrees brix and pH 2.60. A remarkable heterogeneity among the 150 autochthonous yeasts studied was demonstrated. The phenotypical biodiversity is particularly interesting for several technological characteristics useful in winemaking, such as fermentation vigor, acetic acid production and malic acid content of the wines. The vast majority of the elliptic wine yeasts isolated did not show suitable characteristics, so only 18 strains, 12% of the total, remained for the final tests. Many of the strains that had passed the preliminary screenings revealed some defects when they were studied for fermentation performance, both in standard winemaking and under stressors. Two strains exhibited particularly interesting performances: one strain for winemaking of normal musts and the other for winemaking of musts from dried grapes or under stressful conditions.     

Dietary Total Antioxidant Capacity and Colorectal Cancer in the Italian EPIC Cohort

Background

Colorectal cancer is the third most common cancer worldwide. Diet has been hypothesized as involved in colorectal cancer etiology, but few studies on the influence of total dietary antioxidant intake on colorectal cancer risk have been performed.

Methods

We investigated the association between colorectal cancer risk and the total antioxidant capacity (TAC) of the diet, and also of intake of selected antioxidants, in 45,194 persons enrolled in 5 centers (Florence, Naples, Ragusa, Turin and Varese) of the European Prospective Investigation into Cancer and Nutrition (EPIC) Italy study. TAC was estimated by the Trolox equivalent antioxidant capacity (TEAC) assay. Hazard ratios (HRs) for developing colorectal cancer, and colon and rectal cancers separately, adjusted for confounders, were estimated for tertiles of TAC by Cox modeling, stratifying by center.

Results

Four hundred thirty-six colorectal cancers were diagnosed over a mean follow-up of 11.28 years. No significant association between dietary TAC and colorectal cancer incidence was found. However for the highest category of TAC compared to the lowest, risk of developing colon cancer was lower (HR: 0.63; 95% CI: 0.44–0.89, P trend: 0.008). By contrast, increasing TAC intake was associated with significantly increasing risks of rectal cancer (2nd tertile HR: 2.09; 95%CI: 1.19–3.66; 3rd tertile 2.48 95%CI: 1.32–4.66; P trend 0.007). Intakes of vitamin C, vitamin E, and ß-carotene were not significantly associated with colorectal cancer risk.

Conclusions

Further prospective studies are needed to confirm the contrasting effects of high total antioxidant intake on risk of colon and rectal cancers.     

Degradation of biogenic amines by vineyard ecosystem fungi. Potential use in winemaking

Aims: To evaluate the ability of grapevine ecosystem fungi to degrade histamine, tyramine and putrescine in synthetic medium and in wines. Methods and Results: Grapevine and vineyard soil fungi were isolated from four locations of Spain and were subsequently identified by PCR. A total of 44 fungi were evaluated for in vitro amine degradation in a microfermentation system. Amine degradation by fungi was assayed by reversed‐phase (RP)‐HPLC. All fungi were able to degrade at least two different primary amines. Species of Pencillium citrinum, Alternaria sp., Phoma sp., Ulocladium chartarum and Epicoccum nigrum were found to exhibit the highest capacity for amine degradation. In a second experiment, cell‐free supernatants of P. citrinum CIAL‐274,760 (CECT 20782) grown in yeast carbon base with histamine, tyramine or putrescine, were tested for their ability to degrade amines in three different wines (red, white and synthetic). The highest levels of biogenic amine degradation were obtained with histamine‐induced enzymatic extract. Conclusion: The study highlighted the ability of grapevine ecosystem fungi to degrade biogenic amines and their potential application for biogenic amines removal in wine. Significance and Impact of Study: The fungi extracts described in this study may be useful in winemaking to reduce the biogenic amines content of wines, thereby preventing the possible adverse effects on health in sensitive individuals and the trade and export of wine.     

野生葡萄及葡萄酒抗氧化活性和抗菌性研究

选取广西、湖南等地野生葡萄,与经典酿酒葡萄比较,研究抗氧化活性和活性物质,同时监测葡萄酒发酵过程中各指标的动态变化,并对不同品种葡萄酒的抗菌性进行研究。结果表明:赤霞珠的酚类含量和抗氧化活性高于野生葡萄和玫瑰香葡萄,但野生葡萄酒的抗菌性能显著优于赤霞珠和玫瑰香葡萄酒。葡萄酒在发酵过程中其抗氧化活性和酚类物质含量均随发酵过程的进行而升高;总抗氧化活性与总酚含量、氧自由基清除能力与原花青素含量成显著正相关,相关系数均大于0.989;总花色苷含量在发酵初期上升,后期下降,葡萄酒颜色变浅。     

Reduction of diabetes-induced oxidative stress by phosphodiesterase inhibitors in rats

Increased oxidative stress has been suggested to be involved in the pathogenesis and progression of diabetic tissue damage. The aim of this study was to investigate the effect of different phosphodiesterase inhibitors on lipid peroxidation and total antioxidant capacity (TAC) of plasma in streptozotocin-induced diabetic rats (Rattus norvegicus). Rats became diabetic by a single administration of streptozotocin (STZ, 45 mg/kg). The effects of 15-days treatment by milrinone, sildenafil, and theophylline as cyclic-AMP and -GMP phosphodiesterase inhibitors (PDEIs) on diabetes-induced oxidative stress were studied. The levels of glucose, malonedialdehyde (MDA) the by product of lipid peroxides, and TAC (FRAP test) were estimated in plasma of control and experimental groups of rats. A significant increase in the levels of plasma glucose, and MDA and a concomitant decrease in the levels of TAC were observed in diabetic rats. These alterations were reverted back to near normal level after the treatment with PDEIs. Treatment of diabetic rats by PDEIs reduced MDA levels and increased TAC in the order of milrinone>sildenafil>theophylline. In conclusion, the present investigation show that PDIS possesses antioxidant activities, which may be attributed to their enhancing effect on cellular cyclic nucleotides contributing to the protection against oxidative stress in streptozotocin-induced diabetes. Exact mechanism of protective actions of cAMP- and cGMP-phosphodiesterase remains to be elucidated by further studies. This finding may suggest a place for PDEIs in maintaining health in diabetes.     

Effects of sodium alginate elicitation on secondary metabolites and antioxidant activity of safflower genotypes under in vitro salinity stress

The present study was aimed at investigating the effects of different concentrations of sodium alginate (NaAlg) (0.075 and 0.15% (w/v)) on the production of secondary metabolites (SMs) and antioxidant activity of seven safflower genotypes under in vitro salinity stress. The results showed that total phenolic content (TPC), total flavonoids (TFD), total flavonols (TFL), anthocyanin (Ant), total antioxidant capacity (TAC), phenylalanine ammonia-lyase (PAL), catalase (CAT) activity, and lipid peroxidation significantly increased under salinity stress consisting of the concentration of 1.5% (w/v) of NaCl, but callus growth traits decreased. The highest amount of TPC, Ant, and callus growth traits was observed under the elicitation of the sample with the concentration of 0.075(%) NaAlg under salinity stress, but the highest amount for TFD, TFL, CAT, PAL, and TAC was observed under elicitation of the sample with the concentration of 0.15% of NaAlg under salinity stress. This indicated the superiority of NaAlg for elicitation to increase SMs in safflower under salinity stress. Overall, the results showed that genotypes of Mex.22-191 and GE₆₂₉₁₈ could be processed to produce SMs by eliciting NaCl in safflower as an important medicinal plant at cellular level. A positive and significant correlation between CAT and TPC was observed and indicates that phenolic compounds are the major contributors to the antioxidant potential in safflower. This new elicitor introduced new ways to select and exploit the best NaAlg concentration to develop SMs that are of tremendous importance in terms of commercial purposes along with medical features in safflower at cellular level.

     

Human urine: Epicatechin metabolites and antioxidant activity after cocoa beverage intake

Associations between cocoa consumption in humans, excreted metabolites and total antioxidant capacity (TAC) have been scarcely investigated. The aims of the study were to investigate the epicatechin (( ? )-Ec) metabolites excreted in urine samples after an intake of 40 g of cocoa powder along with the TAC of these urine samples and the relation between both the analyses. Each of the 21 volunteers received two interventions, one with a polyphenol-rich food (PRF) and one with a polyphenol-free food (PFF) in a randomized cross-over study. Urine samples were taken before and during 24 h at 0–6, 6–12 and 12–24 h periods after test intake. The excreted ( ? )-Ec metabolites and the TAC were determined in urine samples by LC-MS/MS and TEAC assay, respectively. The maximum excretion of ( ? )-Ec metabolites and the maximum TAC value were observed in urine samples excreted between 6 and 12 h after PRF consumption. Significance of TAC increase was found in urine samples excreted during 0–6 and 6–12 h (66.6 and 72.67%, respectively, with respect to the 0 h).     

Thiols are main determinants of total antioxidant capacity of cellular homogenates

While the total antioxidant capacity (TAC) of blood plasma is mainly accounted for by urate, TAC of cell interior can be expected to depend more on other antioxidants, especially glutathione and protein -SH groups. We studied TAC of homogenates of several lines of cultured cells subjected to the action of thiol-modifying agents. Comparison of changes of TAC of the homogenates and of the level of total thiols (determined with a biradical spin label) demonstrates that alterations in cellular thiol content is the main determinant of changes of TAC of cell homogenates. These results show that estimation of TAC of cell extracts may be a useful parameter of assessment of oxidative stress, primarily of oxidation of thiol groups, yielding information different than TAC of body fluids.     

Thiols are Main Determinants of Total Antioxidant Capacity of Cellular Homogenates

While the total antioxidant capacity (TAC) of blood plasma is mainly accounted for by urate, TAC of cell interior can be expected to depend more on other antioxidants, especially glutathione and protein -SH groups. We studied TAC of homogenates of several lines of cultured cells subjected to the action of thiol-modifying agents. Comparison of changes of TAC of the homogenates and of the level of total thiols (determined with a biradical spin label) demonstrates that alterations in cellular thiol content is the main determinant of changes of TAC of cell homogenates. These results show that estimation of TAC of cell extracts may be a useful parameter of assessment of oxidative stress, primarily of oxidation of thiol groups, yielding information different than TAC of body fluids.