Showing papers on "Ascorbic acid published in 2003"
TL;DR: Factors which possibly affect the effectiveness of antioxidant protection under oxygen deprivation as well as under other environmental stresses are presented.
3,562 citations
TL;DR: Results obtained from available animal studies suggest that the compound is protective, and further studies are needed to better understand the cellular effects of this essential, but potentially toxic, trace mineral and its functional interaction with other nutrients.
1,722 citations
TL;DR: Dose concentration studies of vitamin C in healthy people showed a sigmoidal relationship between oral dose and plasma and tissue vitamin C concentrations, so optimal dosing is critical to intervention studies using vitamin C.
Abstract: Vitamin C in humans must be ingested for survival. Vitamin C is an electron donor, and this property accounts for all its known functions. As an electron donor, vitamin C is a potent water-soluble antioxidant in humans. Antioxidant effects of vitamin C have been demonstrated in many experiments in vitro. Human diseases such as atherosclerosis and cancer might occur in part from oxidant damage to tissues. Oxidation of lipids, proteins and DNA results in specific oxidation products that can be measured in the laboratory. While these biomarkers of oxidation have been measured in humans, such assays have not yet been validated or standardized, and the relationship of oxidant markers to human disease conditions is not clear. Epidemiological studies show that diets high in fruits and vegetables are associated with lower risk of cardiovascular disease, stroke and cancer, and with increased longevity. Whether these protective effects are directly attributable to vitamin C is not known. Intervention studies with vitamin C have shown no change in markers of oxidation or clinical benefit. Dose concentration studies of vitamin C in healthy people showed a sigmoidal relationship between oral dose and plasma and tissue vitamin C concentrations. Hence, optimal dosing is critical to intervention studies using vitamin C. Ideally, future studies of antioxidant actions of vitamin C should target selected patient groups. These groups should be known to have increased oxidative damage as assessed by a reliable biomarker or should have high morbidity and mortality due to diseases thought to be caused or exacerbated by oxidant damage.
1,684 citations
TL;DR: In this article, the authors investigated the impact of various agricultural practices on levels of secondary plant metabolites, and found that higher levels of TPs were consistently found in organically and sustainably grown foods as compared to those produced by conventional agricultural practices.
Abstract: Secondary phenolic metabolites play an important role in plant defense mechanisms, and increasing evidence indicates that many are important in human health. To date, few studies have investigated the impact of various agricultural practices on levels of secondary plant metabolites. To address this issue, the total phenolic (TP) content of marionberries, strawberries, and corn grown by sustainable, organic, or conventional cultural practices were measured. Additionally, the effects of three common postharvest processing treatments (freezing, freeze-drying, and air-drying) on the TP content of these agricultural products were also investigated. Statistically higher levels of TPs were consistently found in organically and sustainably grown foods as compared to those produced by conventional agricultural practices. In all samples, freeze-drying preserved higher levels of TPs in comparison with air-drying.
945 citations
TL;DR: A review of the state-of-the-art on tomato antioxidant properties can be found in this paper, with a focus on the effect of temperature on the synthesis of other antioxidants.
Abstract: Antioxidants are believed to be important in the prevention of diseases such as cancer and cardiovascular disease. Lycopene is one of the main antioxidants to be found in fresh tomatoes and processed tomato products. The lycopene content also accounts for the redness of the fruit, which is one of the main qualities for which industry and consumers now look. Other carotenes (such as β-carotene), vitamin C, vitamin E and various phenolic compounds are also thought to be health-promoting factors with antioxidant properties. Since the antioxidant content of tomatoes may depend on genetic factors, the choice of variety cultivated may affect the results at harvest. To be able to control the antioxidant content of tomatoes at the field level when growing a given variety, it is necessary to know the effects of both environmental factors and the agricultural techniques used. Temperatures below 12 °C strongly inhibit lycopene biosynthesis and temperatures above 32 °C stop this process altogether. The effects of the temperature on the synthesis of other antioxidants have not yet been properly assessed. The effects of light have been studied more thoroughly, apart from those on vitamin E. The effects of water availability, mineral nutrients (nitrogen, phosphorus, potassium and calcium) and plant growth regulators have been studied, but results are sometimes contradictory and the data often incomplete. During the ripening period, lycopene content of tomatoes increases sharply from the pink stage onwards, but no sufficient attempts have been made so far to assess the changes in the other antioxidants present in the fruit. This paper reviews the present state of the art. Copyright © 2003 Society of Chemical Industry
752 citations
TL;DR: The Panel on dietary antioxidants and related compounds stated that the in vivo data do not clearly show a relationship between excess ascorbic acid intake and kidney stone formation, pro-oxidant effects, excess iron absorption, and a number of clinical and epidemiological studies on anti-carcinogenic effects of ascorBic acid in humans did not show any conclusive beneficial effects on various types of cancer except gastric cancer.
Abstract: Ascorbic acid is one of the important water soluble vitamins. It is essential for collagen, carnitine and neurotransmitters biosynthesis. Most plants and animals synthesize ascorbic acid for their own requirement. However, apes and humans can not synthesize ascorbic acid due to lack of an enzyme gulonolactone oxidase. Hence, ascorbic acid has to be supplemented mainly through fruits, vegetables and tablets. The current US recommended daily allowance (RDA) for ascorbic acid ranges between 100–120 mg/per day for adults. Many health benefits have been attributed to ascorbic acid such as antioxidant, anti-atherogenic, anti-carcinogenic, immunomodulator and prevents cold etc. However, lately the health benefits of ascorbic acid has been the subject of debate and controversies viz., Danger of mega doses of ascorbic acid? Does ascorbic acid act as a antioxidant or pro-oxidant ? Does ascorbic acid cause cancer or may interfere with cancer therapy? However, the Panel on dietary antioxidants and related compounds stated that the in vivo data do not clearly show a relationship between excess ascorbic acid intake and kidney stone formation, pro-oxidant effects, excess iron absorption. A number of clinical and epidemiological studies on anti-carcinogenic effects of ascorbic acid in humans did not show any conclusive beneficial effects on various types of cancer except gastric cancer. Recently, a few derivatives of ascorbic acid were tested on cancer cells, among them ascorbic acid esters showed promising anticancer activity compared to ascorbic acid. Ascorbyl stearate was found to inhibit proliferation of human cancer cells by interfering with cell cycle progression, induced apoptosis by modulation of signal transduction pathways. However, more mechanistic and human in vivo studies are needed to understand and elucidate the molecular mechanism underlying the anti-carcinogenic property of ascorbic acid. Thus, though ascorbic acid was discovered in 17th century, the exact role of this vitamin/nutraceutical in human biology and health is still a mystery in view of many beneficial claims and controversies.
702 citations
TL;DR: It is confirmed that ONOO– uncouples eNOS by oxidation of tetrahydrobiopterin and that ascorbate does not fully protect BH4 from oxidation but recycles its radical, and that the BH 4 reaction rate constant exceeds those of thiols or asCorbate.
672 citations
TL;DR: Antioxidant activity of betalain pigments from plants of the family Amaranthaceae was evaluated using the modified DPPH(*) (1,1-diphenyl-2-picrylhydrazyl) method and the relationship between the chemical structure and the activity of the betalains was investigated and discussed.
Abstract: Antioxidant activity of betalain pigments (seven pure compounds and four combined fractions) from plants of the family Amaranthaceae was evaluated using the modified DPPH(*) (1,1-diphenyl-2-picrylhydrazyl) method. All tested betalains exhibited strong antioxidant activity. Their EC(50) values ranged from 3.4 to 8.4 microM. Gomphrenin type betacyanins (mean = 3.7 microM) and betaxanthins (mean = 4.2 microM) demonstrated the strongest antioxidant activity, 3-4-fold stronger than ascorbic acid (13.9 microM) and also stronger than rutin (6.1 microM) and catechin (7.2 microM). Antioxidant activity of the tested betalains decreased in the following order: simple gomphrenins > acylated gomphrenins > dopamine-betaxanthin > (S)-tryptophan-betaxanthin > 3-methoxytyramine-betaxanthin > betanin/isobetanin > celosianins > iresinins > amaranthine/isoamaranthine. This study also investigated and discussed the relationship between the chemical structure and the activity of the betalains. The free radical scavenging activity of the betalains usually increased with the numbers of hydroxyl/imino groups and, moreover, depended on the position of hydroxyl groups and glycosylation of aglycones in the betalain molecules.
594 citations
TL;DR: Results indicate that flavonoids such as quercetin, epicatechin, and procyanidin B(2) rather than vitamin C contribute significantly to the total antioxidant activity of apples.
Abstract: The contribution of each phytochemical to the total antioxidant capacity of apples was determined. Major phenolic phytochemicals of six apple cultivars were identified and quantified, and their contributions to total antioxidant activity of apples were determined using a 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay and expressed as vitamin C equivalent antioxidant capacity (VCEAC). Average concentrations of major phenolics and vitamin C in six apple cultivars were as follows (mg/100 g of fresh weight of apples): quercetin glycosides, 13.20; procyanidin B(2), 9.35; chlorogenic acid, 9.02; epicatechin, 8.65; phloretin glycosides, 5.59; vitamin C, 12.80. A highly linear relationship (r (2) > 0.97) was attained between concentrations and total antioxidant capacity of phenolics and vitamin C. Relative VCEAC values of these compounds were in the order quercetin (3.06) > epicatechin (2.67) > procyanidin B(2) (2.36) > phloretin (1.63) > vitamin C (1.00) > chlorogenic acid (0.97). Therefore, the estimated contribution of major phenolics and vitamin C to the total antioxidant capacity of 100 g of fresh apples is as follows: quercetin (40.39 VCEAC) > epicatechin (23.10) > procyanidin B(2) (22.07) > vitamin C (12.80) > phloretin (9.11) > chlorogenic acid (8.75). These results indicate that flavonoids such as quercetin, epicatechin, and procyanidin B(2) rather than vitamin C contribute significantly to the total antioxidant activity of apples.
580 citations
TL;DR: Evidence that the biosynthesis of L-ascorbic acid in strawberry fruit occurs through D-galacturonic acid, a principal component of cell wall pectins is provided, demonstrating the feasibility of engineering increased vitamin C levels in plants using this gene.
Abstract: L-Ascorbic acid (vitamin C) in fruits and vegetables is an essential component of human nutrition. Surprisingly, only limited information is available about the pathway(s) leading to its biosynthesis in plants. Here, we report the isolation and characterization of GalUR, a gene from strawberry that encodes an NADPH-dependent D-galacturonate reductase. We provide evidence that the biosynthesis of L-ascorbic acid in strawberry fruit occurs through D-galacturonic acid, a principal component of cell wall pectins. Expression of GalUR correlated with changing ascorbic acid content in strawberry fruit during ripening and with variations in ascorbic acid content in fruit of different species of the genus Fragaria. Reduced pectin solubilization in cell walls of transgenic strawberry fruit with decreased expression of an endogenous pectate lyase gene resulted in lower ascorbic acid content. Overexpression of GalUR in Arabidopsis thaliana enhanced vitamin C content two- to threefold, demonstrating the feasibility of engineering increased vitamin C levels in plants using this gene.
522 citations
TL;DR: This study demonstrates the potential for chemically modifying the cardiac differentiation program of ES cells in a developmentally controlled manner and demonstrates the effect of ascorbic acid on cardiac differentiation.
Abstract: Background— Embryonic stem (ES) cells are capable of self-renewal and differentiation into cellular derivatives of all 3 germ layers. In appropriate culture conditions, ES cells can differentiate into specialized cells, including cardiac myocytes, but the efficiency is typically low and the process is incompletely understood. Methods and Results— We evaluated a chemical library for its potential to induce cardiac differentiation of ES cells in the absence of embryoid body formation. Using ES cells stably transfected with cardiac-specific α-cardiac myosin heavy chain (MHC) promoter-driven enhanced green fluorescent protein (EGFP), 880 compounds approved for human use were screened for their ability to induce cardiac differentiation. Treatment with ascorbic acid, also known as vitamin C, markedly increased the number of EGFP-positive cells, which displayed spontaneous and rhythmic contractile activity and stained positively for sarcomeric myosin and α-actinin. Furthermore, ascorbic acid induced the expressi...
TL;DR: The results reveal that antioxidant defenses are markedly decreased in osteoporotic women, and the mechanisms underlying antioxidant depletion and its relevance to the pathogenesis of osteoporeosis deserve further investigation.
Abstract: Although recent epidemiological studies found a positive correlation between dietary vitamin C intake and bone mineral density, data on plasma levels of vitamin C or other antioxidants in osteoporotic subjects are scanty. The aim of this study was to evaluate whether antioxidant defenses are decreased in elderly osteoporotic women and, if this is the case, to understand whether osteoporosis is a condition characterized by increased oxidative stress. To answer these questions, plasma vitamins C, E, and A; uric acid; and the enzymatic activities of superoxide dismutase in plasma and erythrocytes and of glutathione peroxidase in plasma were measured in 75 subjects with osteoporosis and 75 controls. Dietary and endogenous antioxidants were consistently lower in osteoporotic than in control subjects. On the other hand, plasma levels of malondialdehyde, a byproduct of lipid peroxidation, did not differ between groups. Our results reveal that antioxidant defenses are markedly decreased in osteoporotic women. The mechanisms underlying antioxidant depletion and its relevance to the pathogenesis of osteoporosis deserve further investigation.
TL;DR: It is demonstrated that the vitamin C content of plants can be elevated by increasing expression of the enzyme responsible for recycling ascorbate.
Abstract: Vitamin C (ascorbic acid) is essential to prevent disease associated with connective tissue (e.g., scurvy), improves cardiovascular and immune cell functions, and is used to regenerate α-tocopherol (vitamin E). In contrast to most animals, humans lack the ability to synthesize ascorbic acid as a result of a mutation in the last enzyme required for ascorbate biosynthesis. Vitamin C, therefore, must be obtained from dietary sources and, because it cannot be stored in the body, it must be obtained regularly. Once used, ascorbic acid can be regenerated from its oxidized form in a reaction catalyzed by dehydroascorbate reductase (DHAR). To examine whether overexpression of DHAR in plants would increase the level of ascorbic acid through improved ascorbate recycling, a DHAR cDNA from wheat was isolated and expressed in tobacco and maize, where DHAR expression was increased up to 32- and 100-fold, respectively. The increase in DHAR expression increased foliar and kernel ascorbic acid levels 2- to 4-fold and significantly increased the ascorbate redox state in both tobacco and maize. In addition, the level of glutathione, the reductant used by DHAR, also increased, as did its redox state. These results demonstrate that the vitamin C content of plants can be elevated by increasing expression of the enzyme responsible for recycling ascorbate.
TL;DR: Further information is needed regarding the potential involvement of oxygen radicals in Cr genotoxicity, the specific DNA repair pathways activated by Cr and the complex signaling mechanisms involved in the cellular response to Cr(VI).
Abstract: Certain hexavalent chromium (Cr(VI))-containing compounds are recognized occupational human lung carcinogens and may pose an environmental health risk. The carcinogenicity of Cr(VI) is targeted to particulate forms of moderate to low solubility. Soluble Cr(VI) oxyanions in the immediate cellular microenvironment traverse the cell membrane by non-specific anionic transporters. Cr(VI) is reductively metabolized within cells by agents including ascorbic acid (Asc), glutathione (GSH) and cysteine (Cys). During Cr(VI) reduction, a diverse range of genetic lesions are generated including Cr-DNA binary (mono) adducts, Cr-DNA ternary adducts, DNA protein crosslinks (DPCs), bi-functional (DNA interstrand crosslinks (ICLs)) adducts, single-strand breaks (SSBs) and oxidized bases. Some forms of Cr damage, such as ICLs, present physical barriers to DNA replication/transcription and, thus, likely promote a terminal cell fate such as apoptosis or terminal growth arrest. Other lesions, such as ternary DNA adducts, are potentially pre-mutagenic. Cr(VI) exposure elicits a classical DNA damage response within cells including activation of the p53 signaling pathway and cell cycle arrest or apoptosis. Moreover, Cr(VI) also induces the ATM-dependent DNA damage response pathway which is paradoxically required for both apoptosis and survival after Cr(VI) insult. In yeast, moderately cytotoxic concentrations of Cr(VI) result in an initial G1 arrest and delayed S phase progression, whereas less toxic levels of Cr(VI) induce G2 arrest, which requires homologous recombination for exit and survival. The past several years has witnessed many important advances in our understanding of the genetic/cellular damage produced by exposure to Cr(VI). Further information is needed regarding the potential involvement of oxygen radicals in Cr genotoxicity, the specific DNA repair pathways activated by Cr and the complex signaling mechanisms involved in the cellular response to Cr(VI). These pertinent issues must be considered in relation to the potential role that each plays in the induction of human respiratory tract cancer by particulate Cr(VI) compounds.
TL;DR: It is proposed that a key function of the oxidative burst and of AO is to modify the apoplastic redox state in such a way as to modify receptor activity and signal transduction to regulate defence and growth.
TL;DR: In this paper, a method to deposit Cu metal onto surface-attached DNA, forming nanowire-like structures that are ∼3 nm tall, was developed, and the resulting nanostructures have been observed and characterized by atomic force microscopy.
Abstract: We have developed a method to deposit Cu metal onto surface-attached DNA, forming nanowirelike structures that are ∼3 nm tall. DNA is first aligned on a silicon surface and then treated with aqueous Cu(NO3)2. After the copper(II) has electrostatically associated with the DNA, it is reduced by ascorbic acid to form a metallic copper sheath around the DNA. The resulting nanostructures have been observed and characterized by atomic force microscopy. A more complete coating can be obtained by repeating the Cu(II) and ascorbic acid treatment. Control experiments involving treatments with aqueous solutions containing either NO3- or the divalent cation Mg2+ show no change in DNA height upon ascorbic acid exposure. These experiments indicate that copper nanowires, which may be valuable as interconnects in nanoscale integrated circuitry, can be readily generated from DNA molecules on surfaces.
TL;DR: The findings of the present investigation show that deltamethrin has oxidative-stress-inducing potential in fish, and gills are the most sensitive organs, and appropriate ecotoxicological risk assessment should be made in the areas where deltAMethrin is proposed to be used in pest control activities.
TL;DR: The immobilized GOD could electrocatalyze the reduction of dissolved oxygen and resulted in a great increase of the reduction peak current, which could be used for glucose detection with a high sensitivity and exclude the interference of commonly coex uric and ascorbic acid.
TL;DR: It is shown that concerted action of both enzymatic and non-enzymatic ROS scavenging machineries is vital to overcome salinity-induced oxidative stress in rice, and high levels of catalase activity indicate efficient scavenging of H 2 O 2.
01 Apr 2003
TL;DR: Stable concentrated aqueous dispersions of silver nanoparticles of narrow size distribution were prepared by reducing silver nitrate solutions with ascorbic acid in the presence of Daxad 19 (sodium salt of a high-molecular-weight naphthalene sulfonate formaldehyde condensate) as stabilizing agent.
Abstract: Stable concentrated aqueous dispersions of silver nanoparticles of narrow size distribution were prepared by reducing silver nitrate solutions with ascorbic acid in the presence of Daxad 19 (sodium salt of a high-molecular-weight naphthalene sulfonate formaldehyde condensate) as stabilizing agent. The latter has excellent ability to prevent the aggregation of nanosize silver at high ionic strength and high concentration of metal (up to 0.3 mol dm(-3)). The presence of the dispersing agent on the surface of silver particles was confirmed by ATR-FTIR spectroscopy and electrokinetic measurements, explaining both the negative charge over the entire pH range and the electrosteric effect responsible for their long-term stability. The other experimental conditions, i.e., the pH of the reacting solutions, the concentration of the stabilizing agent, and the metal/dispersant ratio, also have a significant impact on the size and stability of these dispersions. The final nanosize silver can be obtained as dried powder, and can be fully redispersed in deionized water by sonication.
TL;DR: This study indicates oxidative stress could be a mechanism of toxicity in fish exposed to pulp mill effluent and demonstrates the utility of TBARS in delineating zones of exposure to pulpmill effluent.
TL;DR: The effects of some nutritional components on skeletal development in larvae of a number of fish species are reviewed and it appears that dietary incorporation of 20 amino acid peptides or di- and tripeptides leads to a reduction of spinal malformations in sea bass.
TL;DR: Investigation of the relationship between AD and the intake of carotenes, vitamin C, and vitamin E in 980 elderly subjects in the Washington Heights-Inwood Columbia Aging Project found that intake of these vitamins was not associated with a decreased risk of AD.
Abstract: Background The generation of oxygen free radicals is involved in the pathogenesis of Alzheimer disease (AD). Objective To determine whether the intake of antioxidant vitamins decreases the risk of AD. Methods We investigated the relationship between AD and the intake of carotenes, vitamin C, and vitamin E in 980 elderly subjects in the Washington Heights-Inwood Columbia Aging Project who were free of dementia at baseline and were followed for a mean time of 4 years. Semiquantitative food frequency questionnaires were administered between baseline and the first follow-up visit. Cox proportional hazards regression models were conducted with quartiles of each vitamin intake as the exposure of interest and incident AD as the outcome, adjusted for age, level of education, sex, APOE ϵ4 status, ethnicity, and smoking. Results There were 242 incident cases of AD in 4023 person-years of follow-up (6 per 100 person-years). Intake of carotenes and vitamin C, or vitamin E in supplemental or dietary (nonsupplemental) form or in both forms, was not related to a decreased risk of AD. Trend tests for the association between quartiles of total intake of vitamins C and E also were not significant. Conclusion Neither dietary, supplemental, nor total intake of carotenes and vitamins C and E was associated with a decreased risk of AD in this study.
TL;DR: It is indicated that major depression is associated with increased levels of serum SOD, serum MDA and decreased levels of plasma ascorbic acid, and treatment with fluoxetine and citalopram reversed these biochemical parameters.
Abstract: There is evidence of derangement of oxidant and antioxidant defense systems in depression. The present study examined the effects of fluoxetine and citalopram, standard selective serotonin re-uptake inhibitors, on lipid peroxidation, superoxide dismutase (SOD) activity and ascorbic acid concentrations. For this, a prospective open-labeled, randomized design was utilized. Patients with major depression (n = 62) were compared with age- and sex-matched healthy volunteers (n = 40). There was a significant increase in serum SOD, serum MDA and decrease in plasma ascorbic acid levels in patients of major depression as compared to control subjects. The trend reversed significantly after treatment with fluoxetine and citalopram. Results indicate a greater reduction in oxidative stress with citalopram than fluoxetine. The Hamilton Rating Scale for Depression (HRSD) score also improved with fluoxetine and citalopram treatment. These findings indicate that major depression is associated with increased levels of serum SOD, serum MDA and decreased levels of plasma ascorbic acid. Treatment with fluoxetine and citalopram reversed these biochemical parameters. This study can be used as a predictor of drug response by fluoxetine and citalopram in major depression.
TL;DR: In this article, the performance of carbon nanotubes paste electrodes (CNTPE) prepared by dispersion of multi-wall carbon Nanotubes (MWNT) within mineral oil is described.
TL;DR: A number of mutants defective in different aspects of calcium oxalate crystal formation have been isolated Cellular and biochemical characterizations of the various mutants have revealed mutations affecting crystal nucleation, morphology, distribution, and/or amount such mutants will be useful tools in continued efforts to decipher the pathways of crystal formation and function in plants.
TL;DR: The apple peel powder ingredient was characterized and had a strong antiproliferative effect on HepG(2) liver cancer cells with a median effective dose (EC(50)) of 1.88 +/- 0.01 mg/mL.
Abstract: There is some evidence that chronic diseases, such as cancer and cardiovascular disease, may occur as a result of oxidative stress. Apple peels have high concentrations of phenolic compounds and may assist in the prevention of chronic diseases. Millions of pounds of waste apple peels are generated in the production of applesauce and canned apples in New York State each year. We proposed that a valuable food ingredient could be made using the peels of these apples if they could be dried and ground to a powder without large losses of phytochemicals. Rome Beauty apple peels were treated with citric acid dips, ascorbic acid dips, and blanches before being oven-dried at 60 degrees C. Only blanching treatments greatly preserved the phenolic compounds, and peels blanched for 10 s had the highest total phenolic content. Rome Beauty apple peels were then blanched for 10 s and dried under various conditions (oven-dried at 40, 60, or 80 degrees C, air-dried, or freeze-dried). The air-dried and freeze-dried apple peels had the highest total phenolic, flavonoid, and anthocyanin contents. On a fresh weight basis, the total phenolic and flavonoid contents of these samples were similar to those of the fresh apple peels. Freeze-dried peels had a lower water activity than air-dried peels on a fresh weight basis. The optimal processing conditions for the ingredient were blanching for 10s and freeze-drying. The process was scaled up, and the apple peel powder ingredient was characterized. The total phenolic content was 3342 +/- 12 mg gallic acid equivalents/100 g dried peels, the flavonoid content was 2299 +/- 52 mg catechin equivalents/100 g dried peels, and the anthocyanin content was 169.7 +/- 1.6 mg cyanidin 3-glucoside equivalents/100 g dried peels. These phytochemical contents were a significantly higher than those of the fresh apple peels if calculated on a fresh weight basis (p 0.05). One gram of powder had an antioxidant activity equivalent to 220 mg of vitamin C. The freeze-dried apple peels also had a strong antiproliferative effect on HepG(2) liver cancer cells with a median effective dose (EC(50)) of 1.88 +/- 0.01 mg/mL. This was lower than the EC(50) exhibited by the fresh apple peels (p < 0.05). Apple peel powder may be used in a various food products to add phytochemicals and promote good health.
TL;DR: These data replicate the 3-year findings confirming that the supplementation with combination of vitamin E and slow-release vitamin C slows down atherosclerotic progression in hypercholesterolemic persons.
Abstract: Background— Self-selected supplementation of vitamin E has been associated with reduced coronary events and atherosclerotic progression, but the evidence from clinical trials is controversial. In the first 3 years of the ASAP trial, the supplementation with 136 IU of vitamin E plus 250 mg of slow-release vitamin C twice daily slowed down the progression of carotid atherosclerosis in men but not women. This article examines the 6-year effect of supplementation on common carotid artery (CCA) intima-media thickness (IMT). Methods and Results— The subjects were 520 smoking and nonsmoking men and postmenopausal women aged 45 to 69 years with serum cholesterol ≥5.0 mmol/L (193 mg/dL), 440 (84.6%) of whom completed the study. Atherosclerotic progression was assessed ultrasonographically. In covariance analysis in both sexes, supplementation reduced the main study outcome, the slope of mean CCA-IMT, by 26% (95% CI, 5 to 46, P=0.014), in men by 33% (95% CI, 4 to 62, P=0.024) and in women by 14% (not significant). ...
TL;DR: Cocoa flavanol and procyanidin supplementation for 28 d significantly increased plasma epicatechin and catechin concentrations and significantly decreased platelet function, which support the results of acute studies that used higher doses of cocoa flavanols and proCyanidins.
TL;DR: Data collectively support the hypothesis that cellular oxidative stress is a critical step in burn-mediated injury, and suggest that antioxidant strategies designed to either inhibit free radical formation or to scavage free radicals may provide organ protection in patients with burn injury.