Sparing effect of procyanidins from Vitis vinifera on vitamin E: in vitro studies

The Lipid-Lowering Efficacy of a Nutraceutical Combination Including Leucoselect Phytosome, Red Yeast Rice, Policosanol and Folic Acid in Dyslipidaemia Patients: Real-World Insights

BACKGROUND

Cardiovascular disease is a global health concern and reducing plasma LDL-C levels is a major goal in cardiovascular prevention. Our study aimed to evaluate the effectiveness of a nutraceutical formulation including leucoselect® phytosome®, red yeast rice, policosanol and folic acid on LDL-c levels in patients at low cardiovascular risk with dyslipidemia.

MATERIALS AND METHODS

We prospectively enrolled all consecutive patients with dyslipidemia at low cardiovascular risk who were unresponsive to diet and physical activity. Clinical assessments and laboratory analyses, encompassing lipid profile, hepatic function, and CPK levels, were performed at baseline prior to initiating treatment and repeated at the 12-week mark following administration of the study nutraceutical.

RESULTS

Sixty (60) consecutive patients (mean age 48.02 ± 10.1 years; 60% male) were included. At the 12-week follow-up, a statistically significant reduction in Total Cholesterol (13.1%) and LDL-c serum level (20.4%) was observed. Hepatic and muscular function remain stable over the time. The adherence to therapy was 99% and the persistence was maximum.

CONCLUSIONS

The nutraceutical formulation including leucoselect® phytosome® red yeast rice, policosanol and folic acid significantly reduced the LDL-c plasma levels, consistent with previous research showing that the bioactive component in red yeast rice-lovastatin-is effective in addressing problems with lipid metabolism. Importantly, it was safe and well-tolerated among patients with dyslipidemia in a real-world setting.

Condensed Tannins as Antioxidants in Ruminants-Effectiveness and Action Mechanisms to Improve Animal Antioxidant Status and Oxidative Stability of Products

Condensed tannins (CTs) are widely distributed in plants, and due to their recognized antioxidant activity are considered as possible natural antioxidants for application in ruminant diets. A wide range of CT-rich sources has been tested in ruminant diets, and their effects on animal antioxidant status and oxidative stability of their products are reviewed in the present work. Possible mechanisms underlying the CT antioxidant effects in ruminants are also discussed, and the CT chemical structure is briefly presented. Utilization of CT-rich sources in ruminant feeding can improve the animals' antioxidant status and oxidative stability of their products. However, the results are still inconsistent. Although poorly understood, the evidence suggests that CTs can induce an antioxidant effect in living animals and in their products through direct and indirect mechanisms, which can occur by an integrated and synergic way involving: (i) absorption of CTs with low molecular weight or metabolites, despite CTs' poor bioavailability; (ii) antioxidant action on the gastrointestinal tract; and (iii) interaction with other antioxidant agents. Condensed tannins are alternative dietary antioxidants for ruminants, but further studies should be carried out to elucidate the mechanism underlying the antioxidant activity of each CT source to design effective antioxidant strategies based on the use of CTs in ruminant diets.

Anti-inflammatory effect of Centella asiatica phytosome in a mouse model of phthalic anhydride-induced atopic dermatitis

BACKGROUND

Centella asiatica phytosome (CA phytosome) has potent antioxidant and anti-inflammatory properties. However, its anti-dermatitic effect has not yet been reported.

PURPOSE

We investigated the effects of CA phytosome on inflammatory reponses by macrophages in an atopic dermatitis (AD) mouse model.

STUDY DESIGN

The effects of CA phytosome on atopic dermatitis were examined by using phthalic anhydride (PA)-induced AD mouse model and RAW 264.7 murine macrophages.

METHODS

An AD-like lesion was induced by a topical application of 5% phthalic anhydride (PA) to the dorsal skin or ear of HR-1 mice. After AD induction, 100 µl (20 µl/cm²) of 0.2% and 0.4% CA phytosome was spread on the dorsal skin and ear of the mice three times a week for four weeks. We evaluated histopathological changes and changes in protein expression by Western blotting for iNOS and COX-2; NF-κB activity was determined by EMSA. We also measured TNF-α, IL-1β, and IgE concentration in the blood of AD mice by ELISA.

RESULTS

Histological analysis showed that CA phytosome inhibited infiltration of inflammatory cells. CA phytosome treatment inhibited the expression of iNOS and COX-2, activity of NF-κB, and release of TNF-α, IL-1β, and IgE. In addition, CA phytosome (5, 10, and 20 µg/ml) potently inhibited LPS (1 µg/ml)-induced NO production as well as iNOS and COX-2 expression in RAW 264.7 macrophage. Furthermore, CA phytosome inhibited LPS-induced DNA binding activities of NF-κB, and this was associated with the discontinuation of IκBα degradation and subsequent decreases in the translocation of p65 and p50 into the nucleus.

CONCLUSION

From our data, CA phytosome application, which operates via NF-κB signaling inhibition, seems to be a promising AD treatment. Herein, we investigated the effects of Centella asiatica phytosome (CA phytosome) on inflammatory responses by macrophages in an atopic dermatitis (AD) mouse model. An AD-like lesion was induced by the topical application of 5% phthalic anhydride (PA) to the dorsal skin or ear of HR-1 mice. After AD induction, 100 µl (20 µl/cm²) of 0.2% and 0.4% CA phytosome was spread on the dorsal skin and ear of the mice three times a week for four weeks. We evaluated dermatitis severity, histopathological changes, and changes in protein expression by Western blotting for iNOS and COX-2; NF-κB activity was determined by gel electromobility shift assay (EMSA). We also measured TNF-α, IL-1β, and IgE concentration in the blood of AD mice by enzyme-linked immunosorbent assay (ELISA). CA phytosome attenuated the development of PA-induced AD. Histological analysis showed that CA phytosome inhibited hyperkeratosis, proliferation of mast cells, and infiltration of inflammatory cells. Furthermore, CA phytosome treatment inhibited the expression of iNOS and COX-2, activity of NF-κB, and release of TNF-α, IL-1β, and IgE. In addition, CA phytosome (5, 10, and 20 µg/ml) potently inhibited lipopolysaccharide (LPS) (1 µg/ml)-induced NO production as well as iNOS and COX-2 expression in RAW 264.7 macrophage cells. Furthermore, CA phytosome inhibited LPS-induced DNA binding activities of NF-κB, and this was associated with the discontinuation of IκBα degradation and subsequent decreases in the translocation of p65 and p50 into the nucleus. From our data, CA phytosome application, which operates via NF-κB signaling inhibition, seems to be a promising AD treatment.

Fractionation, enzyme inhibitory and cellular antioxidant activity of bioactives from purple sweet potato (Ipomoea batatas)

Sweet potato (Ipomoea batatas L.) is mainly cultivated in Asia. The deep purple color of purple sweet potato (PSP) is due to the high content of acylated anthocyanins. In the present study, PSP-derived polyphenols were identified using HPLC-PDA and HPLC-ESI-MSⁿ analyses. After concentration of the polyphenols from PSP, preparative separation into two fractions, designated anthocyanins (AF) and copigments (CF), was carried out using adsorptive membrane chromatography. In enzyme inhibitory assays, all PSP samples inhibited the enzymes α-amylase, α-glucosidase and xanthine oxidase. Additionally, the cell signaling cellular antioxidant properties of the PSP extracts were investigated in cultured cells. PSP induced the transcription factor Nrf2, which regulates the expression of genes encoding heme oxygenase 1 (Hmox1), glutamate-cysteine ligase catalytic subunit (Gclc) and paraoxonase 1 (PON1). Furthermore, PSP enhanced cellular glutathione concentrations and decreased lipid peroxidation in cultured hepatocytes. Overall, these results suggest that PSP extracts exhibit enzyme inhibitory and cellular antioxidant properties, especially PSP CF.

RETRACTED: Cadmium induced cardiac oxidative stress in rats and its attenuation by GSP through the activation of Nrf2 signaling pathway

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Western Blots from Figures 8B and 9A appear similar to Blots from Figure 4A of the article previously published by the authors in Biochemistry and Cell Biology 93 (2015) 210-226 https://doi.org/10.1139/bcb-2014-0114 and Figures 12 and 14 of the article previously published by the corresponding author et al in Biomedicine & Preventive Nutrition 4 (2014) 561-577 https://doi.org/10.1016/j.bionut.2014.08.003, although the Western Blots purportedly described different samples. Also, sections within the panels from Figures 10 and 11D appear unusually similar to each other. The explanation provided by the corresponding author was not satisfactory and the Editor decided to retract the article.

Oxidative stress induced by cadmium in the plasma, erythrocytes and lymphocytes of rats: Attenuation by grape seed proanthocyanidins

The present study has been designed to investigate the ameliorative effect of grape seed proanthocyanidins (GSP) on cadmium (Cd)-induced oxidative damage in rat erythrocytes. Twenty four male Wistar rats were divided into four groups: control, GSP-treated group (100 mg kg(-1) body weight (BW)), Cd-treated group (cadmium chloride, 5 mg kg(-1) BW), and GSP + Cd-treated group in which GSP was orally pre-administered 90 min before Cd intoxication for 4 weeks. At the end of the experimental period, blood samples were collected by cardiac puncture and were processed for various biochemical estimations. The extent of oxidative damage in isolated rat erythrocyte membrane was assessed by measuring lipid peroxidation, enzymatic and non-enzymatic content, calcium ion (Ca(2+))/magnesium ion (Mg(2+))-ATPase and sodium ion (Na(+))/potassium ion (K(+))-ATPase activities, free iron, calcium, hydrogen peroxide (H2O2) concentration, and osmotic fragility. Our results unveiled that Cd intoxication significantly increased the erythrocyte lipid peroxidation markers and decreased the activity of enzymatic and non-enzymatic markers in erythrocytes. Conversely, GSP pretreatment significantly prevented the decrease in the activities of antioxidant enzymes and membrane-bound ATPases. GSP also restored the levels of iron, calcium, and H2O2 in Cd-treated rats. Conformational changes in erythrocytes of various groups were also determined using morphological and ultrastructural electron microscopic analysis. The findings of our study clearly revealed that GSP affords superior protection against Cd-induced reactive oxygen species generation, lipid peroxidation, and free radical generation in Cd-treated rats, which presumably reflects the ability of this flavonoid to protect erythrocytes and lymphocytes of rats from the toxic effects of Cd.

Grape seed proanthocyanidins ameliorates cadmium-induced renal injury and oxidative stress in experimental rats through the up-regulation of nuclear related factor 2 and antioxidant responsive elements

Cadmium (Cd) preferentially accumulates in the kidney, the major target for Cd-related toxicity. Cd-induced reactive oxygen species (ROS) have been considered crucial mediators for renal injury. The biologically significant ionic form of cadmium (Cd+) binds to many bio-molecules, and these interactions underlie the toxicity mechanisms of Cd. The present study was hypothesized to explore the protective effect of grape seed proanthocyanidins (GSP) on Cd-induced renal toxicity and to elucidate the potential mechanism. Male Wistar rats were treated with Cd as cadmium chloride (CdCl2, 5 mg·kg−1 bw, orally) and orally pre-administered with GSP (100 mg·kg−1 bw) 90 min before Cd intoxication for 4 weeks to evaluate renal damage of Cd and antioxidant potential of GSP. Serum renal function parameters (blood urea nitrogen and creatinine) levels in serum and urine, renal oxidative stress (lipid peroxidation, protein carbonylation, enzymatic, and non-enzymatic antioxidants), inflammatory (NF-κB p65, NO, TNF-α, IL-6), apoptotic (caspase-3, caspase-9, Bax, Bcl-2), membrane bound ATPases, and Nrf2 (HO-1, keap1, γ-GCS, and μ-GST) markers were evaluated in Cd-treated rats. Pretreatment with GSP revealed a significant improvement in renal oxidative stress markers in kidneys of Cd-treated rats. In addition, GSP treatment decreases the amount of iNOS, NF-κB, TNF-α, caspase-3, and Bax and increases the levels Bcl-2 protein expression. Similarly, mRNA and protein analyses substantiated that GSP treatment notably normalizes the renal expression of Nrf2/Keap1 and its downstream regulatory proteins in the Cd-treated rats. Histopathological and ultra-structural observations also demonstrated that GSP effectively protects the kidney from Cd-induced oxidative damage. These findings suggest that GSP ameliorates renal dysfunction and oxidative stress through the activation of Nrf2 pathway in Cd-intoxicated rats.

Supplements for exotic pets

The use of supplements has become commonplace in an effort to complement traditional therapy and as part of long-term preventive health plans. This article discusses historical and present uses of antioxidants, vitamins, and herbs. By complementing traditional medicine with holistic and alternative nutrition and supplements, the overall health and wellness of exotic pets can be enhanced and balanced. Further research is needed for understanding the strengths and uses of supplements in exotic species. Going back to the animals' origin and roots bring clinicians closer to nature and its healing powers.

Investigation of antioxidant interactions between Radix Astragali and Cimicifuga foetida and identification of synergistic antioxidant compounds

The medicinal plants of Huang-qi (Radix Astragali) and Sheng-ma (Cimicifuga foetida) demonstrate significantly better antioxidant effects when used in combination than when used alone. However, the bioactive components and interactional mechanism underlying this synergistic action are still not well understood. In the present study, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay was employed to investigate the antioxidant capacity of single herbs and their combination with the purpose of screening synergistic antioxidant compounds from them. Chromatographic isolation was performed on silica gel, Sephadex LH-20 columns and HPLC, and consequently to yield formononetin, calycosin, ferulic acid and isoferulic acid, which were identified by their retention time, UV λ_max, MS and MS/MS data. The combination of isoferulic acid and calycosin at a dose ratio of 1∶1 resulted in significant synergy in scavenging DPPH radicals and ferric reducing antioxidant power (FRAP) assay. Furthermore, the protective effects of these four potential synergistic compounds were examined using H₂O₂-induced HepG2 Cells bioassay. Results revealed that the similar synergy was observed in the combination of isoferulic acid and calycosin. These findings might provide some theoretical basis for the purported synergistic efficiency of Huang-qi and Sheng-ma as functional foods, dietary supplements and medicinal drugs.

Proanthocyanidins produce significant attenuation of doxorubicin-induced mutagenicity via suppression of oxidative stress

This study has been initiated to determine whether proanthocyanidins can protect against doxorubicin-induced mutagenicity in mice and to elucidate the potential mechanism of this protection. Pretreatment of mice with proanthocyanidins (100 mg/kg/day, orally) for 7 days and simultaneously with doxorubicin (12 mg/kg, i.p.) for another day, significantly reduced the frequency of bone marrow DNA strand breaks and micronucleated polychromatic erythrocytes compared to doxorubicin-treated mice alone. Furthermore, proanthocyanidins caused a reduction in bone marrow suppression induced by doxorubicin treatment. In male germline, orally administration of proanthocyanidins (100 mg/kg/day, orally) for 7 consecutive days before and 7 consecutive days after treatment with doxorubicin (12 mg/kg, i.p.), significantly elevated the levels of sperm count and motility reduced by doxorubicin treatment. Furthermore, proanthocyanidins significantly decreased the elevated levels of spermatogonial and spermatocyte chromosomal aberrations and sperm head abnormality induced by doxorubicin. Prior administration of proanthocyanidins ahead of doxorubicin reduced the doxorubicin induced testicular lipid peroxidation and prevented the reduction in testicular non-protein sulfhydryl significantly. Conclusively, this study provides for the first time that proanthocyanidins have a protective role in the abatement of doxorubicin-induced mutagenesis and cell proliferation changes in germinal cells of mice that reside, at least in part, in their radical scavenger activity. Therefore, proanthocyanidins can be a promising chemopreventive agent to avert secondary malignancy and abnormal reproductive outcomes risks in cancer patients receiving doxorubicin-involved treatment.

A double-blind, randomized, vehicle-controlled clinical study to evaluate the efficacy and safety of MAS063DP (ATOPICLAIR) in the management of atopic dermatitis in paediatric patients

A multicenter, randomized, double-blind, vehicle-controlled clinical study was conducted to evaluate the efficacy and safety of MAS063DP in 60 paediatric patients affected by atopic dermatitis (AD), aged between 2 and 17 years. Using the Investigator's Global Assessment (IGA) score for AD, patients with a score of 2 (mild) or 3 (moderate) were enrolled in the study. Patients were randomly selected to receive MAS063DP (20 patients), MAS060 (20 patients, a similar formulation with lower key ingredients' concentration and no preservatives) or vehicle (20 patients).The study consisted in a treatment period of 43 days, with clinical evaluations at baseline (day 1), days 8, 15, 22, 29 and 43, at which time the treatment was stopped. MAS063DP showed nearly 80% improvement in IGA score at day 22, compared with 16.6% and 26.3% with the MAS060 and vehicle respectively. A statistically significant difference was found by comparing MAS063DP with MAS060 (p < 0.0001); a similar result was evidenced comparing MAS063DP and vehicle (p = 0.001). By contrast, no significant difference was found between MAS060 and vehicle. A statistically significant difference was sustained until the end of the study. MAS063DP may therefore be considered as one of the available regimens effective in the treatment of mild-to-moderate AD in children and adolescents.

Antioxidant Status of Faeces of Captive Black Rhinoceros (Diceros bicornis) in Relation to Dietary Tannin Supplementation

In context with the frequent observations of excessive iron (Fe) storage in captive black rhinoceroses (Diceros bicornis), it has been suggested that both an excessive dietary Fe content and a lack of dietary Fe-chelating substances, such as tannins, is the underlying cause. Therefore, studies on the effects of tannin supplementation to captive diet are warranted. Six captive rhinoceroses were fed their normal zoo diet (N), and a similar diet supplemented with either tannic acid (T, hydrolysable tannin) or quebracho (Q, condensed tannins), and the total antioxidant capacity (TAC) was measured as mmol Trolox equivalents per kg fresh faeces. The TAC values on diets N (1.24 +/- 0.39 mmol/kg fresh faeces) and T (1.34 +/- 0.33 mmol/kg fresh faeces) were similar, but significantly higher on diet Q (2.32 +/- 0.61 mmol/kg fresh faeces). In contrast to expectations, faecal TAC increased with increasing faecal Fe, possibly as a result of the fact that the faecal Fe content was positively correlated to the proportion of concentrate feeds in the diet, which also contain antioxidants, such as vitamin E, in addition to Fe. Increased antioxidant status caused by the use of tannin substances could have a beneficial effect on animal health, but if tannins should be incorporated in designed diets, other tannin sources, such as grape pomace should be tested.

Effects of Low-Carbohydrate Diet and Pycnogenol®Treatment on Retinal Antioxidant Enzymes in Normal and Diabetic Rats

Because chronic hyperglycemia of uncontrolled diabetes mellitus may lead to increased reactive oxygen species and decreased enzymatic antioxidant defenses responsible for pathological processes in diabetic retinopathy, this study examined the hypothesis that a low-carbohydrate, high-fat diet, either alone or in combination with Pinus maritima can reduce hyperglycemia, restoring a more balanced, oxidative condition. Normal and streptozotocininduced diabetic rats were fed either a regular or low-carbohydrate diet for 30 or 90 d. In addition, normal and diabetic rats on the chronic (90-d) low-carbohydrate diet were treated with daily intraperitoneal Pinus maritima doses (10 mg/kg) for 14 consecutive days. Retinas were fractionated to assay activities of glutathione peroxidase, glutathione reductase, and gamma-glutamyl transferase. After 30 d, the low-carbohydrate diet reduced glycemic parameters and normalized aspartate aminotransferase activity in diabetic animals, suggesting less organ damage. No differences were observed between males and females in any measured glycemic parameters. Whereas all diabetic control animals developed cataracts bilaterally, no treated diabetic animals developed cataracts. There were no deleterious effects on retinal antioxidant defenses with either a 30-d or chronic low-carbohydrate diet. When diet was combined with Pinus maritima treatment, both retinal glutathione peroxidase and glutathione reductase activities increased, suggesting that a low-carbohydrate diet plus Pinus maritima may be an effective antioxidant and antihyperglycemic therapy, reducing the risk of diabetic retinopathy and cataract formation.

Antioxidant activity of polyphenols from solid olive residues of c.v. Coratina

The antioxidant profile of extracts from solid olive residue (SOR) of c.v. Coratina, a cultivar widely diffused in the south of Italy, using both cell-free and cell-based experimental models, was investigated. A total hydroalcoholic extract (polyphenols content 19.7%) and a purified extract (Oleaselecttrade mark) (polyphenols content 35.1%) were tested for their ability to quench the stable free radical DPPH, the peroxyl radicals (ORAC assay), by monitoring the loss in fluorescence of R-phycoerythrin induced by the peroxyl radical generator AAPH and their ability to inhibit the cumene hydroperoxide-induced lysis of rat red blood cells (RBC). The total hydroalcoholic extract showed IC(50) 26.96+/-1.53 microg/ml in the DPPH assay, that 10 microg/ml were equivalent to 2.11+/-0.12 microg/ml Trolox (ORAC assay) and IC(50) 1.7+/-0.20 microg/ml in the RBC hemolysis. The Oleaselect extract was 4 to 5 folds more active than the hydroalcoholic extract in all the experimental models, with IC(50) values of 7.36+/-0.38 microg/ml in the DPPH test and of 0.38+/-0.03 microg/ml in RBC; the antioxidant activity in the ORAC assay was slightly greater than that of Trolox (10 microg/ml equivalent to 11.45+/-0.40 microg/ml). The scavenging effect of the extract in the ORAC assay was compared to that of verbascoside (the main polyphenol component) and of caffeic acid (the basic constituent of verbascoside): the results indicate that caffeic acid (10 microg/ml equivalent to 35.70+/-2.95 microg/ml Trolox) is more potent than verbascoside (10 microg/ml equivalent to 15.42+/-1.21 microg/ml Trolox) in entrapping peroxyl radicals. Finally the antioxidant activity of the Oleaselect extract was confirmed in human umbilical endothelial cells (EC) exposed to the site-specific peroxyl radical inducer AAPH, where a massive lipid peroxidation process (marker the fluorescence probe BODIPY) takes place, paralleled by a marked loss of cell viability (calcein assay). The purified extract (1-20 microg/ml) pre-incubated with EC for 1 h dose-dependently inhibited both the lipid-peroxidation damage and cell death. Taking into account the total polyphenol content, these results clearly indicate a greater antioxidant activity for the purified extract, due to a cooperative antioxidant interaction among its polyphenol constituents.

Quality Assessment of Commercial Dietary Antioxidant Products From Vitis vinifera L. Grape Seeds

Phenolic preparations from Vitis vinifera L. grape seeds are products commonly used in the formulation of dietary antioxidant supplements. In this article, we used a methodology (the oxygen radical absorbance capacity, ORAC) to evaluate the in vitro antioxidant capacity of commercial dietary grape seed products and studied the relationship of the antioxidant capacity with the phenolic composition of these products. The ORAC value of the different brands of commercial products studied (n = 16) varied from 2.71 to 26.4 micromol Trolox equivalents/mg (approximately equal to 10-fold difference). For four of these products, the batch-to-batch ORAC variation, expressed as a coefficient of variation of the mean, was 10.5% (n = 6), 13.1% (n = 3), 19.4% (n = 4), and 7.8% (n = 4). Analysis of monomeric and oligomeric flavan-3-ols by liquid chromatography-diode array detection (LC-DAD)/electrospray-mass spectrometry and procyanidins by thiolysis-LC-DAD also revealed large differences among the commercial grape seed products. Moreover, the ORAC value could be fitted to a regression model using variables from contents of individual phenolic compounds and procyanidins. The product-to-product and batch-to-batch variation in ORAC values and flavan-3-ol composition found among the commercial products studied demonstrated that they are poorly standardized, resulting in inconsistent composition and biological activity.

Effects of pycnogenol treatment on oxidative stress in streptozotocin-induced diabetic rats

Free radicals and oxidative stress have been implicated in the etiology of diabetes and its complications. This in vivo study has examined whether subacute administration of pycnogenol, a French pine bark extract containing procyanidins that have strong antioxidant potential, alters biomarkers of oxidative stress in normal and diabetic rats. Diabetes was induced in female Sprague-Dawley rats by a single injection of streptozotocin (90 mg/kg body weight, ip), resulting (after 30 days) in subnormal body weight, increased serum glucose concentrations, and an increase in liver weight, liver/body weight ratios, total and glycated hemoglobin, and serum aspartate aminotransferase activity. Normal and diabetic rats were treated with pycnogenol (10 mg/kg body weight/day, ip) for 14 days. Pycnogenol treatment significantly reduced blood glucose concentrations in diabetic rats. Biochemical markers for oxidative stress were assessed in the liver, kidney, and heart. Elevated hepatic catalase activity in diabetic rats was restored to normal levels after pycnogenol treatment. Additionally, diabetic rats treated with pycnogenol had significantly elevated levels of reduced glutathione and glutathione redox enzyme activities. The results demonstrate that pycnogenol alters intracellular antioxidant defense mechanisms in streptozotocin-induced diabetic rats.

Procyanidins from grape seeds protect endothelial cells from peroxynitrite damage and enhance endothelium-dependent relaxation in human artery: new evidences for cardio-protection

The peroxynitrite scavenging ability of Procyanidins from Vitis vinifera L. seeds was studied in homogeneous solution and in human umbilical endothelial cells (EA.hy926 cell line) using 3-morpholinosydnonimine (SIN-1) as peroxynitrite generator. In homogeneous phase procyanidins dose-dependently inhibited 2',7'-dichloro-dihydrofluorescein (DCFH) oxidation induced by SIN-1 with an IC50 value of 0.28 microM. When endothelial cells (EC) were exposed to 5 mM SIN-1, marked morphological alterations indicating a necrotic cell death (cell viability reduced to 16 +/- 2.5%) were observed. Cell damage was suppressed by procyanidins, with a minimal effective concentration of 1 microM (cell morphology and integrity completely recovered at 20 microM). Cellular localization of procyanidins in EC was confirmed using a new staining procedure and site-specific peroxyl radical inducers: AAPH and cumene hydroperoxide (CuOOH). Endothelial cells (EC) pre-incubated with procyanidins (20 microM) and exposed to FeCl3/K3Fe(CN)6 showed a characteristic blue staining, index of a site-specific binding of procyanidins to EC. Procyanidins dose-dependently inhibit the AAPH induced lipid oxidation and reverse the consequent loss of cell viability, but were ineffective when oxidation was driven at intracellular level (CuOOH). This demonstrates that the protective effect is due to their specific binding to the outer surface of EC thus to quench exogenous harmful radicals. Procyanidins dose-dependently relaxed human internal mammary aortic (IMA) rings (with intact endothelium) pre-contracted with norepinephrine (NE), showing a maximal vasorelaxant effect (85 +/- 9%) at 50 microM (catechin: 18 +/- 2% relaxation at 50 microM). This effect was completely abolished when IMA-rings were de-endothelized and when IMA-rings with intact endothelium were pretreated with L-NMMA or with the soluble guanylate cyclase inhibitor, ODQ. Pre-incubation with indomethacin reduces (by almost 50%) the vasodilating effect of procyanidins, indicating the involvement also of a COX-dependent mechanism. This was confirmed in another set of experiments, where procyanidins dose-dependently stimulate the prostacyclin (PGI2) release, reaching a plateau between 25 and 50 microM. Finally, pre-incubation of IMA-rings with procyanidins (from 6.25 to 25 microM) resulted in a dose-dependent prevention of the endothelin-1 (ET-1) vasoconstriction. The ability of procyanidins to prevent peroxynitrite attack to vascular cells, by layering on the surface of coronary EC, and to enhance endothelial NO-synthase-mediated relaxation in IMA rings provide further insight into the molecular mechanisms through which they exert cardioprotective activity in ischemia/reperfusion injury in vivo.

Effect of a standardized grape seed extract on low-density lipoprotein susceptibility to oxidation in heavy smokers

The aim of our study was to evaluate the effect of a standardized formulation of a polyphenolic extract of grapes (Leucoselect-Phytosome [LP]) on low-density lipoprotein (LDL) susceptibility to oxidation in a group of heavy smokers. A randomized, double-blind, crossover study was undertaken in 24 healthy male heavy smokers, aged > or = 50 years. Enrolled subjects were given 2 capsules twice daily for 4 weeks (phase 1). Each capsule contained 75 mg of a grape procyanidin extracts and soy-phosphatidlcholine or placebo consisiting of 75 mg lactose and soy-phosphatidlcholine. A wash out period of 3 weeks was then followed by 4 weeks of the opposite treatment (phase 2). Blood samples were taken at baseline and at the end of each phase and assayed for plasma lipids and LDL susceptibility to oxidation. Compliance was good, and no adverse effects were recorded. Subjects did not show significant modification of total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C) and LDL-C during LP treatment. Among oxidative indices, thiobarbituric acid reactive substances (TBARS) concentration was significantly reduced in subjects taking LP (-14.7% +/- 21.1% v +5.0% +/- 18.1%, P <.01), and the lag phase prolonged (+15.4% +/- 24.4% v -0.1% +/- 16.0%, P <.05) compared with placebo and basal values. The antioxidant potential of grape seed extract polyphenols may prove effective in a model of oxidative stress (smoking); however more investigational data are needed before use in wider clinical settings.

Determination of the antioxidant capacity of samples of different types of tea, or of beverages based on tea or other herbal products, using a superoxide dismutase biosensor

Research was performed to experimentally evaluate the antioxidant capacity of different plant products sold by herbalists (ginger, dog rose, ginseng and camomile) and of several types of tea (ordinary tea, green tea, detheinated tea, lemon and peach flavoured tea) using a superoxide dismutase (SOD) biosensor recently developed by the present authors. Measurements were carried out by comparing biosensor response to the superoxide radical produced in solution using the xanthine-xanthine oxidase system, both in the presence and absence of the antioxidant sample considered. Precision of antioxidant capacity measures for herbal products and for non diluted samples was good, generally with a R.S.D.%< or =10% and a LOD value about 0.1 for relative antioxidant capacity. Also a "pool" of polyphenols from different tea samples was measured using a tyrosinase biosensor (LOD approximately 2 microM).

Mass spectrometry in grape and wine chemistry. Part I: polyphenols

Mass spectrometry, had and still has, a very important role for research and quality control in the viticulture and enology field, and its analytical power is relevant for structural studies on aroma and polyphenolic compounds. Polyphenols are responsible for the taste and color of wine, and confer astringency and structure to the beverage. The knowledge of the anthocyanic structure is very important to predict the aging attitude of wine, and to attempt to resolve problems about color stability. Moreover, polyphenols are the main compounds related to the benefits of wine consumption in the diet, because of their properties in the treatment of circulatory disorders such as capillary fragility, peripheral chronic venous insufficiency, and microangiopathy of the retina. Liquid Chromatography-Mass Spectrometry (LC-MS) techniques are nowadays the best analytical approach to study polyphenols in grape extracts and wine, and are the most effective tool in the study of the structure of anthocyanins. The MS/MS approach is a very powerful tool that permits anthocyanin aglycone and sugar moiety characterization. LC-MS allows the characterization of complex structures of grape polyphenols, such as procyanidins, proanthocyanidins, prodelphinidins, and tannins, and provides experimental evidence for structures that were previously only hypothesized. The matrix-assisted-laser-desorption-ionization-time-of-flight (MALDI-TOF) technique is suitable to determine the presence of molecules of higher molecular weight with high accuracy, and it has been applied with success to study procyanidin oligomers up to heptamers in the reflectron mode, and up to nonamers in the linear mode. The levels of resveratrol in wine, an important polyphenol well-known for its beneficial effects, have been determined by SPME and LC-MS, and the former approach led to the best results in terms of sensitivity.

Determination of antioxidant properties of aromatic herbs, olives and fresh fruit using an enzymatic sensor

The aim was to experimentally evaluate the antioxidant capacity of different fresh aromatic herbs (field balm, marjoram, parsley, rosemary, sage, sweet basil), several varieties of olives from Central Italy ('Carboncello', 'Rosciolo', 'Olivastro', 'Coratello', 'Leccino', 'Frantoio') and several types of fresh fruit (apple, apricot, banana, cherry, fig, grape, medlar, melon, peach, pear, pineapple, plum, water melon, yellow plum) using a superoxide dismutase (SOD) biosensor developed by the present authors. Measurements were carried out by comparing the biosensor response to the concentration of superoxide radical produced in solution using a xanthine/xanthine oxidase system in the presence and absence of the antioxidant sample considered. Tests carried out on different samples of fruit and aromatic herbs showed that the homogenised samples had better antioxidant properties than the centrifuged ones (obtained by centrifuging the homogenate), which sometimes gave extremely low antioxidant capacity values. The reliability of the proposed method was checked by comparing the trend of some experimental results found using the SOD biosensor with those reported in the literature obtained using the classic (ORAC) method. The precision of this method of analysis was found to be good for samples of aromatic herbs (RSD% <or=8%), acceptable for homogenised fruit samples (RSD% <or=13%) and less good for homogenised and centrifuged samples (RSD% <or=20%).

Cocoa procyanidin chain length does not determine ability to protect LDL from oxidation when monomer units are controlled

Cocoa flavan-3-ols (catechin, epicatechin and oligomeric procyanidins) were tested for their ability to decrease LDL oxidative susceptibility and spare alpha-tocopherol (alpha-toc) in vitro. Physiologic concentration (0.10-0.50 &mgr;M) of flavanols were used. The flavanols increased LDL conjugated diene lag times dose-dependently from 23-207% and 15-143% in response to copper and AAPH oxidation, respectively, and delayed alpha-toc consumption. Sparing of LDL alpha-toc represents a possible mechanism for flavanols to enhance the resistance of plasma and LDL to oxidative stress. Procyanidins decreased LDL oxidative susceptibility with increasing chain length. However, when based on equivalent amounts of monomeric units, they inhibited LDL oxidation to a similar extent. This suggests that antioxidant activity of procyanidins with biologic substrates is not attributable to chain length or charge delocalization through polymeric linkages, but primarily to ring structures and catechol groups. Additionally, human plasma was analyzed for the presence of oligomeric procyanidins following consumption of a flavanol-rich cocoa product. Procyanidin dimers were detected in plasma concordant with the appearance of monomeric flavanols, with a peak of 0.08 +/- 0.01 &mgr;mol/L (n = 6) at two hours after consumption. Thus, this paper confirms the occurrence of procyanidins in human plasma, and extends previous structure-function observations regarding flavanoid protection of LDL.

Select flavonoids and whole juice from purple grapes inhibit platelet function and enhance nitric oxide release

BACKGROUND

Moderate red wine consumption is inversely associated with coronary ischemia, and both red wine and purple grape juice (PGJ) contain flavonoids with antioxidant and antiplatelet properties believed to be protective against cardiovascular events. Acute cardiac events are also associated with decreased platelet-derived nitric oxide (NO) release. In this study, the effects of PGJ and PGJ-derived flavonoids on platelet function and platelet NO production were determined.

METHODS AND RESULTS

Incubation of platelets with dilute PGJ led to inhibition of aggregation, enhanced release of platelet-derived NO, and decreased superoxide production. To confirm the in vivo relevance of these findings, 20 healthy subjects consumed 7 mL. kg(-1). d(-1) of PGJ for 14 days. Platelet aggregation was inhibited after PGJ supplementation, platelet-derived NO production increased from 3.5+/-1.2 to 6.0+/-1.5 pmol/10(8) platelets, and superoxide release decreased from 29.5+/-5.0 to 19.2+/-3.1 arbitrary units (P<0.007 and P<0.05, respectively). alpha-Tocopherol levels increased significantly after PGJ consumption (from 15.6+/-0.7 to 17.6+/-0.9 micromol/L; P<0.009), and the plasma protein-independent antioxidant activity increased by 50.0% (P<0.05). Last, incubation of platelets with select flavonoid fractions isolated from PGJ consistently attenuated superoxide levels but had variable effects on whole-blood aggregation, platelet aggregation, and NO release.

CONCLUSIONS

Both in vitro incubation and oral supplementation with PGJ decrease platelet aggregation, increase platelet-derived NO release, and decrease superoxide production. These findings may be a result of antioxidant-sparing and/or direct effects of select flavonoids found in PGJ. The suppression of platelet-mediated thrombosis represents a potential mechanism for the beneficial effects of purple grape products, independent of alcohol consumption, in cardiovascular disease.

Fluorescent probes as markers of oxidative stress in keratinocyte cell lines following UVB exposure

In this work we describe the development of specific markers for determination of both the membrane and intracellular damage induced by free radicals generated by UVB radiation (5-150 mJ/cm2) in cultured keratinocytes. This using simple, specific and sensitive fluorescent probes: cis-parinaric acid (PNA) to monitor membrane lipid peroxidation and 2',7'-dichloro-dihydrofluorescein diacetate (DCFH-DA) to evaluate the intracellular redox status, in parallel to the fluorimetric determination of the main intracellular antioxidant glutathione. To validate the methodologies, the changes in the intracellular oxidative status following exposure to low doses UVB were measured in both control and N-acetylcysteine-protected cells, in parallel with morphological analyses. UVB induces an early reduction of GSH inside the cell correlated with an increase in the intracellular peroxide content. The effects were time- and dose-dependent. In addition, using a sensitive fluorescent method, we quantitated the release of proteases, a family of proteolytic enzymes greatly involved in the onset/perpetuation of the free radical-induced skin damage from keratinocytes exposed to suberythemal UVB doses (5-15 mJ/cm2). The use of these fluorescent probes provides a reliable tool to detect the early signs of damage in keratinocyte cultures (when the apoptotic phenomenon has not yet been triggered) useful for future screening of protective molecules.

Characterization of proanthocyanidins from grape seeds

Leucoselect (grape seed selected proanthocyanidins) was analyzed. HPLC thermospray mass spectrometry (TSP-MS) allowed the detection of monomeric flavan-3-ols and dimeric proanthocyanidins. Fractionation over Sephadex LH-20 resin and analysis of the isolated fractions by gel permeation chromatography (GPC) and electrospray mass spectrometry (ESI-MS) led to the complete characterization of the proanthocyanidin constituents of Leucoselect. The analysis revealed the presence of approximately 15% of (+)-catechin (1) and (-)-epicatechin (2), 80% of (-)-epicatechin 3-O-gallate (3), dimers, trimers, tetramers and their gallates and 5% of pentamers, hexamers, heptamers and their gallates.

Anti-oxidant therapy for the treatment of coronary artery disease

Coronary artery disease is the most common cause of death in developed countries. It may present in many different ways, but most frequently as a myocardial infarction, sudden death, angina or heart failure. Preventive measures in relation to coronary artery disease are particularly important because of its high incidence, high mortality and because most patients die outside hospital. Since the oxidation of low density lipoprotein cholesterol (LDL-C) is a critical early step in the process of atheroma formation, taking anti-oxidants to prevent LDL-C oxidation may prove a very effective means of reducing coronary artery disease mortality. However, the role of anti-oxidants in coronary artery disease prevention needs to be evaluated as part of an overall strategy that includes pharmacological and non-pharmacological measures, which are described in this review. In addition, a more structured and scientific approach to anti-oxidant therapy needs to be adopted. This requires that evidence for oxidative stress in a particular condition is obtained, the nature and severity determined and an appropriate anti-oxidant is administered, in an effective dose, which can be shown to correct the oxidative stress. When this is achieved, meaningful clinical trials should be possible, which will determine the place of anti-oxidant therapy for the specified condition.

Diet enriched with procyanidins enhances antioxidant activity and reduces myocardial post-ischaemic damage in rats

Aim of this work was to study the efficacy of procyanidins from Vitis vinifera seeds, a standardized mixture of polyphenol antioxidants, on cardiac mechanics following ischemia/reperfusion stunning in the rat, after 3 weeks supplementation. Young and aged male rats were fed a diet enriched with procyanidins complexed (1:3 w/w) with soybean lecithin (2.4%); control animals (CTR-young and CTR-aged) received an equal amount of lecithin and 2 additional groups of animals the standard diet. At the end of the treatment, the total plasma antioxidant defense (TRAP), vitamin E, ascorbic acid and uric acid were determined in plasma and the hearts from all groups of animals subjected to moderate ischemia (flow reduction to 1 ml/min for 20 min) and reperfusion (15 ml/min for 30 min). In both young and aged rats supplemented with procyanidins the recovery of left ventricular developed pressure (LVDP) at the end of reperfusion was 93% (p < 0.01) and 74% (p < 0.01) of the preischemic values and the values of coronary perfusion pressure (CPP) were maintained close to those of the preischemic period. Also creatine kinase (CK) outflow was restrained to baseline levels, while a 2-fold increase in prostacyclin (6-keto-PGF1alpha) in the perfusate from hearts of young and aged rats was elicited during both ischemia and reperfusion. In parallel, procyanidins significantly increased the total antioxidant plasma capacity (by 40% in young and by 30% in aged rats) and the plasma levels of ascorbic acid, while tend to reduce vitamin E levels; no significant differences were observed in uric acid levels. The results of this study demonstrate that procyanidins supplementation in the rat (young and aged) makes the heart less susceptible to ischemia/reperfusion damage and that this is positively associated to an increase in plasma antioxidant activity.

An evaluation of the antioxidant activity of a standardized grape seed extract, Leucoselect

Coronary Artery Disease (CAD) remains the major cause of mortality and morbidity in the Western World. The oxidation of low-density lipoproteins (LDLs) by free radicals is associated with initiation of atherosclerosis and therefore, development of CAD. LDLs are protected from oxidation by antioxidants and in times of antioxidant deficiency are more likely to be oxidized. Hypercholesterolaemic patients are at a higher cardiovascular risk and may, therefore, require more antioxidant protection. Increased consumption of red wine containing antioxidants is thought to account for the lower incidence of CAD in Mediterranean countries. Red wine, although rich in antioxidants, is not suitable as routine therapy for prevention of CAD.

OBJECTIVE

To evaluate the effects of a capsule formulation of an antioxidant polyphenolic extract of grapes on serum total antioxidant activity and vitamin C and E levels.

METHOD

A single-blinded randomised, placebo-controlled cross-over study was undertaken in 20 young volunteers. Subjects were given two capsules containing 300 mg of grape procyanidin extracts (Leucoselect-phytosome) or placebo daily for 5 days. Blood samples were taken at the start of the study and end of the study and assayed for antioxidant activity and vitamins C and E levels. After a washout period of at least 2 weeks, the study was repeated with the second treatment.

RESULTS

The extract had no effect on serum vitamins C and E levels but increased serum total antioxidant activity (TAC). On day 5, TAC increased from 408.1+/-22.9 to 453.3+/-453.3 micromol/l trolox equivalents 1 hour postdose.

CONCLUSION

The capsules increased serum antioxidant activity but the longer-term clinical implications need to be assessed in further randomised clinical trials.