Cyanidin 3-O-beta-D-glucoside attenuates the hepatic ischemia-reperfusion injury through a decrease in the neutrophil chemoattractant production in rats

New Labeling Rules for Wine: Wine Alcohol-Derived Calories and Polyphenol Consumption on Health

Alcohol content, proanthocyanins and anthocyanins influence wine quality. The composition of wine depends on the type of cultivar, location, environmental conditions, and management practices. Phenolic compounds have attracted considerable research interest due to their antioxidant properties and potential beneficial effects on human health. However, the low bioavailability of anthocyanins creates a major bottleneck in their ability to exert beneficial effects. Despite extensive research on the effects of wine on human health, no clear evidence has been obtained on the benefits of wine quality or geographic area of production on health conditions, such as metabolic syndrome. Five climatically and geologically distinct wines were evaluated. Based on recent studies, meta-analyses, and pooled analyses of wine composition, along with the predicted low bioavailability of polyphenol compounds, we estimated the efficacy of five geographically distinct wines according to gastrointestinal absorption and the effects of alcohol intake on both men and women, with a view to ascertaining whether geographical origin influences the antioxidant serum composition of wine. Data on the estimated consumption of wine suggest that the polyphenol contents are similar regardless of choice of wine/area, while different alcohol compositions affect the level of alcohol and calorie intake. Thus, moderate wine drinkers should be advised to control the habit, but without exceeding the dose considered a healthy threshold (up to 30-40 g of alcohol/day in men and 10-20 g of alcohol/day in women), given no medical contraindications are present. These results will add value to the framework of the last reform of the Common Agricultural Policy (CAP) adopted in December 2021, where the European Parliament and the Council introduced new labeling rules for the wine sector and aromatized wine products.

Cornus mas L. (cornelian cherry), an important European and Asian traditional food and medicine: Ethnomedicine, phytochemistry and pharmacology for its commercial utilization in drug industry

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus mas L. (cornelian cherry) fruits have been used for centuries as traditional cuisine and folk medicine in various countries of Europe and Asia. In folk medicines, the fruits and other parts of the plant have been used for prevention and treatment of a wide range of diseases such as diabetes, diarrhea, gastrointestinal disorders, fevers, rheumatic pain, skin and urinary tract infections, kidney and liver diseases, sunstroke, among others. This review provides a systematic and constructive overview of ethnomedicinal uses, chemical constituents and pharmacological activities of this plant as well as future research need for its commercial utilization as nutraceutical food supplement and medicine.

MATERIALS AND METHODS

This review is based on available literature on ethnomedicinal uses, phytochemical, pharmacological, toxicity and clinical studies on Cornus mas L. (cornelian cherry) fruits and other organs that was collected from electronic (SciFinder, PubMed, Science Direct and ACS among others) and library searches of books and journals.

RESULTS

Versatile ethnomedicinal uses of the plant in different European and Asian countries have been reported. Phytochemical investigations on different parts of this plant have resulted in the identification of 101 compounds, among which anthocyanins, flavonoids and iridoids are the predominant groups. The crude extracts of fruits and other parts of the plant and their pure isolates exhibit a broad spectrum of pharmacological activities such as anti-microbial, anti-diabetic, anti-atherosclerotic, cyto-, hepato-, neuro- and renalprotective, antiplatelet and antiglaucomic activities. Anthocyanins, flavonoids, iridoids and vitamin C are the major bioactive constituents of the fruits. Fruits are non-toxic and safe food on acute toxicity studies in rat and human models. Clinical trials in diabetic type2 and hyperlipidemic patients showed significant trends of amelioration in sugar level, insulin secretion in diabetic patients and amelioration of lipid profile, apolipoprotein status and vascular inflammation in hyperlipidemic patients.

CONCLUSION

Based on our review, Cornus mas L. (cornelian cherry) fruits and leaves can be used mainly in the treatment of diabetes, obesity, atherosclerosis, skin diseases, gastrointestinal and rheumatic problems. Some indications from ethnomedicines have been validated by pharmacological activities of the fruits and its extracts/pure isolates. The reported data reveal that the fruits are a potential source for treatment of diabetes, obesity, hyperlipidemia and gastrointestinal disorders. Unfortunately, the pharmacological studies in these areas are still insufficient to substantiate these preventive effects in confirmatory trials on the mass-scale clinical settings. Future studies on mechanisms of action, bioavailability, pharmacokinetics and adverse effects of the extracts and their bioactive constituents as well as their effective doses and long term toxic effects in humans are needed for commercial applications of these extracts/isolates in modern medicines. The available literature showed that most of the activities of the extracts are due to their constituents, anthocyanins, flavonoids and other phenolics, iridoids and vitamins for their antioxidant and other properties.

Cytoprotective and Cytotoxic Effects of Rice Bran Extracts in Rat H9c2(2-1) Cardiomyocytes

This study was aimed at preliminarily assessing the cytoprotective and antioxidative effects of rice bran extracts (RBEs) from a Sarawak local rice variety (local name: "BJLN") and a commercial rice variety, "MR219," on oxidative stress in rat H9c2(2-1) cardiomyocytes. The cardiomyocytes were incubated with different concentrations of RBE and hydrogen peroxide (H2O2), respectively, to identify their respective IC50 values and safe dose ranges. Two nonlethal and close-to-IC50 doses of RBE were selected to evaluate their respective effects on H2O2 induced oxidative stress in cardiomyocytes. Both RBEs showed dose-dependent cytotoxicity effects on cardiomyocytes. H2O2 induction of cardiomyocytes pretreated with RBE further revealed the dose-dependent cytoprotective and antioxidative effects of RBE via an increase in IC50 values of H2O2. Preliminary analyses of induction effects of RBE and H2O2 on cellular antioxidant enzyme, catalase (CAT), also revealed their potential in regulating these activities and expression profile of related gene on oxidative stress in cardiomyocytes. Pretreated cardiomyocytes significantly upregulated the enzymatic activity and expression level of CAT under the exposure of H2O2 induced oxidative stress. This preliminary study has demonstrated the potential antioxidant effects of RBE in alleviating H2O2-mediated oxidative injuries via upregulation in enzymatic activities and expression levels of CAT.

Current knowledge on oxidative stress in hepatic ischemia/reperfusion

Ischemia/reperfusion (I/R) injury associated with hepatic resections and liver transplantation remains a serious complication in clinical practice, despite several attempts to solve the problem. The redox balance, which is pivotal for normal function and integrity of tissues, is dysregulated during I/R, leading to an accumulation of reactive oxygen species (ROS). Formation of ROS and oxidant stress are the disease mechanisms most commonly invoked in hepatic I/R injury. The present review examines published results regarding possible sources of ROS and their effects in the context of I/R injury. We also review the effect of oxidative stress on marginal livers, which are more vulnerable to I/R-induced oxidative stress. Strategies to improve the viability of marginal livers could reduce the risk of dysfunction after surgery and increase the number of organs suitable for transplantation. The review also considers the therapeutic strategies developed in recent years to reduce the oxidative stress induced by hepatic I/R, and we seek to explain why some of them have not been applied clinically. New antioxidant strategies that have yielded promising results for hepatic I/R injury are discussed.

Anthocyanin kinetics are dependent on anthocyanin structure

The kinetics of anthocyanin metabolism was investigated in a human feeding trial. Volunteers (n 12) consumed purple carrots containing five anthocyanin forms: cyanidin-3-(xylose-glucose-galactoside), cyanidin-3-(xylose-galactoside), cyanidin-3-(xylose-sinapoyl-glucose-galactoside), cyanidin-3-(xylose-feruloyl-glucose-galactoside) and cyanidin-3-(xylose-coumuroyl-glucose-galactoside). The purple carrots were served as three different treatments in a crossover design with a 3-week washout between treatments. Purple carrot treatments were 250 g raw carrots, 250 g cooked carrots and 500 g cooked carrots. Serial blood and urine samples were collected for 8 and 24 h after the dose, respectively, and analysed for anthocyanins. Of the anthocyanin forms ingested, four were detected in plasma and urine: cyanidin-3-(xylose-glucose-galactoside), cyanidin-3-(xylose-galactoside), cyanidin-3-(xylose-sinapoyl-glucose-galactoside) and cyanidin-3-(xylose-feruloyl-glucose-galactoside). The time courses of plasma and urine anthocyanin contents were evaluated with compartmental modelling. Results showed that absorption, gastrointestinal transit and plasma elimination are dependent on anthocyanin structure. Absorption efficiencies of acylated compounds (cyanidin-3-(xylose-sinapoyl-glucose-galactoside) and cyanidin-3-(xylose-feruloyl-glucose-galactoside)) were less than those for non-acylated anthocyanins (cyanidin-3-(xylose-glucose-galactoside) and cyanidin-3-(xylose-galactoside)). The acylated anthocyanins exhibited a shorter half-life for gastrointestinal absorption than the non-acylated anthocyanins. Fractional elimination of non-acylated compounds was slower than that for acylated anthocyanins. These results provide the first information about the kinetics of individual anthocyanins in human beings.

Carotenoid and anthocyanin contents of grains of Brazilian maize landraces

BACKGROUND

Carotenoid and anthocyanin contents of 26 maize landraces cultivated in southern Brazil were determined to evaluate their potential as natural colorants or functional food ingredients.

RESULTS

The major carotenoids detected in the whole grain flour were zeaxanthin and lutein. Anthocyanins of landraces with purple starchy endosperm (Lingua de Papagaio and Mato Grosso Palha Roxa) were more extractable in methanol-HCl (1%, v/v), exhibiting 2.45 and 0.94 g kg(-1) of whole grains flour, respectively. In contrast, butanol-HCl (30%, v/v) was more effective for the extraction of anthocyanins from the purple-colored landraces Roxo 29 and Roxo 41; genotypes with pigments localized in the outer parts (pericarp) of grains (2.60 and 2.19 g kg(-1)). The Roxo 41 landrace showed the highest concentration of pigments, e.g. 11.72 10(-3) g kg(-1) of total carotenoids and 2.16 g kg(-1) of total anthocyanins. Similarly, the yellow-colored MPA 1 and the purple-colored Roxo 29 landraces showed prominent amounts of carotenoids (10.86 10(-3) g kg(-1)) and anthocyanins (2.60 g kg(-1)), respectively.

CONCLUSION

Our findings suggest that the colored grains of maize landraces studied may hold promise for the development of grain-based functional foods or natural colorants regarding their carotenoid and anthocyanin contents and as genetic resource in breeding programs.

Detection of lipid-lysine amide-type adduct as a marker of PUFA oxidation and its applications

Research into lipid peroxidation-induced protein modification has been ongoing for many years. Recent studies on lipo-oxidation shows the occurrence of another type of protein modification, amide-type adduct formation by lipid hydroperoxide, as well as classical aldehyde-derived protein modifications. The amide-type modifications can be either classified as alkylamide and carboxyalkylamide according to the formed structures. As an alkylamide-type adduct, Nepsilon-(hexanoyl)lysine can be formed by the reaction of peroxidized n-6 fatty acid with lysine. Nepsilon-(propanoyl)lysine is considered to be generated from oxidation of n-3 fatty acid with lysine. The generation pattern of both might be useful for classification of which fatty acids are more involved in oxidation in vivo. Since the alkylamide type-adducts are relatively stable and detectable from biological specimens like urine, these adducts, especially Nepsilon-(hexanoyl)lysine, are used as reliable markers for not only oxidative stress evaluation but also development of functional food.

Current status of oxidative stress in pediatric liver transplantation

Generation of free radicals in children after liver transplantation is multifactorial from ischemia-reperfusion injury, immunosuppression and post-transplant complications. Thus, this group is at higher risk of oxidative imbalance with molecular and clinical consequences. We discuss pathogenesis and ways of action against oxidative stress in liver transplant recipients.

Nitric oxide and redox regulation in the liver: part II. Redox biology in pathologic hepatocytes and implications for intervention

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are created in normal hepatocytes and are critical for normal physiologic processes, including oxidative respiration, growth, regeneration, apoptosis, and microsomal defense. When the levels of oxidation products exceed the capacity of normal antioxidant systems, oxidative stress occurs. This type of stress, in the form of ROS and RNS, can be damaging to all liver cells, including hepatocytes, Kupffer cells, stellate cells, and endothelial cells, through induction of inflammation, ischemia, fibrosis, necrosis, apoptosis, or through malignant transformation by damaging lipids, proteins, and/or DNA. In Part I of this review, we will discuss basic redox biology in the liver, including a review of ROS, RNS, and antioxidants, with a focus on nitric oxide as a common source of RNS. We will then review the evidence for oxidative stress as a mechanism of liver injury in hepatitis (alcoholic, viral, nonalcoholic). In Part II of this review, we will review oxidative stress in common pathophysiologic conditions, including ischemia/reperfusion injury, fibrosis, hepatocellular carcinoma, iron overload, Wilson's disease, sepsis, and acetaminophen overdose. Finally, biomarkers, proteomic, and antioxidant therapies will be discussed as areas for future therapeutic interventions.

Topical treatment with black raspberry extract reduces cutaneous UVB-induced carcinogenesis and inflammation

Light in the UVB spectrum (280-320 nm) induces a number of changes in the epidermis and dermis of mice and humans, resulting in a robust inflammatory response. A standardized black raspberry extract (BRE) has been effective in reducing signaling pathways commonly initiated by inflammatory stimuli. In this study, we determined whether this extract could reduce cutaneous UVB-induced inflammation and carcinogenesis. In our carcinogenesis model, female SKH-1 hairless mice were exposed to one minimal erythemal dose of UVB thrice weekly on nonconsecutive days for 25 weeks. Immediately after each exposure, the mice were treated topically with either BRE dissolved in vehicle or with vehicle only. Beginning on week 19, mice treated with BRE had a significant reduction in tumor number and in average tumor size. This reduction correlated with a significant reduction in tumor-infiltrating CD3(+)foxp3(+) regulatory T-cells. In the acute model, mice were exposed to a single minimal erythemal dose of UVB and treated topically with BRE or with vehicle. At 48 hours post-UVB exposure, topical BRE treatment significantly reduced edema, p53 protein levels, oxidative DNA damage, and neutrophil activation. The ability of topical BRE to reduce acute UVB-induced inflammation and to decrease tumor development in a long-term model provides compelling evidence to explore the clinical efficacy of BRE in the prevention of human skin cancers.

Corn husk as a potential source of anthocyanins

Anthocyanin pigments are extracted from various plants and used for diverse purposes. The overall goal of this study was to develop high-anthocyanin corn to enhance the economic efficiency of anthocyanin production. We determined and compared the anthocyanin contents from the different parts of purple corn in various breeding lines. Our results revealed that purple corn produced the anthocyanin pigment throughout the plant, especially high in the husk and cob regions, although anthocyanin levels varied significantly among different plant parts. We analyzed the 295 selected lines from the 2006 breeding population, and it showed that anthocyanin levels of husks ranged from 17.3% to 18.9% of dry weight, roughly 10 times more than the standard current purple corn kernel content, 1.78%. LC-MS/MS analysis demonstrated that the main components of purple corn husk anthocyanin were cyanidin derivatives, and the most prevalent constituents were cyanidin-3-glucoside, cyanidin-3-succinylglucoside and pelargonidin-3-(6''-malonylglucoside). The results suggested that high-anthocyanin corn will boost the purple corn pigment production far more than its current level.

Gene expression microarray analysis of the effects of grape anthocyanins in mice: a test of a hypothesis-generating paradigm

The mechanism(s) through which fruits, vegetables, and whole grains favorably affect health is not well established. Using an anthocyanin-rich grape as a model, we examined the ability of an agnostic analytical approach using gene expression microarrays to generate novel testable hypotheses regarding the mechanisms of action of potentially healthful foods and food components. C57BL/6 mice were divided into 2 groups and fed a proatherogenic diet with or without a semipurified anthocyanin extract (70% anthocyanins) incorporated at a level of 0.1 mg/mL into the drinking water. After 6 weeks, compared with control mice, mice supplemented with anthocyanins tended to gain more weight and have increased adipose tissue mass, although these effects did not achieve statistical significance. Anthocyanin-supplemented mice had significantly reduced relative liver weights and heart weights. Serum lipids and inflammatory cytokines were not different between the groups. Gene expression microarray analysis of the liver and skeletal muscle identified a number of molecular pathways significantly affected by anthocyanin treatment. Two distinct clusters emerged. The first cluster included down-regulated pathways in both muscle and liver involving cellular defense, whereas the second included hepatic genes involved in energy metabolism. From these data, 3 hypotheses were developed for future investigation.

Botanicals and the metabolic syndrome

Metabolic syndrome describes the human condition characterized by the presence of coexisting traditional risk factors for cardiovascular disease, such as hypertension, dyslipidemia, glucose intolerance, and obesity, in addition to nontraditional cardiovascular disease risk factors, such as inflammatory processes and abnormalities of the blood coagulation system. Although the specific etiology for metabolic syndrome is not known, insulin resistance--a clinical state in which a normal or elevated insulin concentration reflects an impaired biological response--is present and is considered a key pathophysiologic abnormality. As such, metabolic syndrome can be considered to be a prediabetic state and contributes greatly to increased morbidity and mortality in humans. Given the public health significance of metabolic syndrome, successful strategies are direly needed to intervene in its development. As such, nutritional supplementation with botanicals that effectively address pathogenic mechanisms, combined with the acceptance and widespread use of botanical supplements by the general public, represents an attractive, novel, and potentially effective approach to the problem. Thus, the overall goal of our botanical research center is to comprehensively evaluate botanicals in addressing the pathophysiologic mechanisms that lead to the development of insulin resistance and metabolic syndrome. Currently, each of the 3 research projects evaluates a specific botanical [Russian tarragon (Artemisia dracunculus L), shilianhua (Sinocrassula indica), and grape (Vitus vinifera) anthocyanins] and assesses the effect on pathogenic mechanisms leading to the development of insulin resistance. With the completion of our research, we anticipate a better understanding of the cellular mechanisms by which insulin resistance develops and the role of botanicals in modulating the progression to metabolic syndrome.

Cyanidin 3-glucoside ameliorates hyperglycemia and insulin sensitivity due to downregulation of retinol binding protein 4 expression in diabetic mice

Adipocyte dysfunction is strongly associated with the development of obesity and insulin resistance. It is accepted that the regulation of adipocytokine expression is one of the most important targets for the prevention of obesity and improvement of insulin sensitivity. In this study, we have demonstrated that anthocyanin (cyanidin 3-glucoside; C3G) which is a pigment widespread in the plant kingdom, ameliorates hyperglycemia and insulin sensitivity due to the reduction of retinol binding protein 4 (RBP4) expression in type 2 diabetic mice. KK-A(y) mice were fed control or control +0.2% of a C3G diet for 5 weeks. Dietary C3G significantly reduced blood glucose concentration and enhanced insulin sensitivity. The adiponectin and its receptors expression were not responsible for this amelioration. C3G significantly upregulated the glucose transporter 4 (Glut4) and downregulated RBP4 in the white adipose tissue, which is accompanied by downregulation of the inflammatory adipocytokines (monocyte chemoattractant protein-1 and tumor necrosis factor-alpha) in the white adipose tissue of the C3G group. These findings indicate that C3G has significant potency in an anti-diabetic effect through the regulation of Glut4-RBP4 system and the related inflammatory adipocytokines.

Nephroprotective and hepatoprotective effects of curcuminoids

Curcumin (U1) has a wide spectrum of therapeutic effects such as antitumor and anti-inflammatory effects, including antibacterial, antiviral, antifungal, and antispasmodic activities. By comparison of the structure-activity relationship, tetrahydrocurcumin (THU1), one of the major metabolites, showed the highest antioxidative activity in both in vitro and in vivo systems. U1 has been reported to have the nephroprotective effect to improve creatinine and urea clearance and also protected the chronic renal allograft nephropathy. These beneficial effects have been explained by the protection of oxidative stress and the induction of antioxidative enzymes. The protective effect of THU1 against ferric nitrilotriacetate (Fe-NTA)-induced oxidative renal damage using male ddY mice was greater than that of U1, by monitoring not only radical scavenging activity measured by ESR, and TBARS, 4-HNE-modified protein and 8-OHdG formation but also induction of anioxidative enzymes and detoxification enzymes. THU1 was also expected to improve redox regulation through glutathione and suppress the oxidative stress in diabetic nephropathy and neuropathy. Earlier studies reported that U1 reduced the iron-induced hepatic damage, aflatoxin- and benzo[a]pyrene- induced mutagenicity and hepatocarcinogenecity and also the formation of the DNA adduct by inhibiting cytochrome P450 in the liver. The hepatoprotective role of U1 has been examined using carbone terachloride-induced liver damage in rats and alcoholic liver disease model rats, but not examined using THU1. Our recent data suggests that THU1 is a more promising hepatprotective agent because of its strong induction activity of antioxidant and phase 2-metabolizing enzymes in liver compared to kidney, although more detaied examinations are required.

Microarray profiling of gene expression in human adipocytes in response to anthocyanins

Adipocyte dysfunction is strongly associated with the development of obesity and insulin resistance. It is accepted that the regulation of adipocytokine secretion or the adipocyte specific gene expression is one of the most important targets for the prevention of obesity and amelioration of insulin sensitivity. Recently, we demonstrated that anthocyanins, which are pigments widespread in the plant kingdom, have the potency of anti-obesity in mice and the enhancement adipocytokine secretion and its gene expression in adipocytes. In this study, we have shown the gene expression profile in human adipocytes treated with anthocyanins (cyanidin 3-glucoside; C3G or cyanidin; Cy). The human adipocytes were treated with 100 microM C3G, Cy or vehicle for 24 h. The total RNA from the adipocytes was isolated and carried out GeneChip microarray analysis. Based on the gene expression profile, we demonstrated the significant changes of adipocytokine expression (up-regulation of adiponectin and down-regulation of plasminogen activator inhibitor-1 and interleukin-6). Some of lipid metabolism related genes (uncoupling protein2, acylCoA oxidase1 and perilipin) also significantly induced in both common the C3G or Cy treatment groups. These studies have provided an overview of the gene expression profiles in human adipocytes treated with anthocyanins and demonstrated that anthocyanins can regulate adipocytokine gene expression to ameliorate adipocyte function related with obesity and diabetes that merit further investigation.

Protective role of antioxidative food factors in oxidative stress caused by hyperglycemia

Hyperglycemia causes the autoxidation of glucose, glycation of proteins, and the activation of polyol metabolism. These changes accelerate generation of reactive oxygen species (ROS) and increases in oxidative chemical modification of lipids, DNA, and proteins in various tissues. Oxidative stress may play an important role in the development of complications in diabetes such as lens cataracts, nephropathy, and neuropathy. Glycation reactions, especially Maillard reactions, occur in vivo as well as in vitro and are associated with the chronic complications of diabetes mellitus and aging and age-related diseases by increases in oxidative chemical modification of lipids, DNA, and proteins. In particular, long-lived proteins such as lens crystallines, collagens, and hemoglobin may react with reducing sugars to form advanced glycation end products (AGEs). Recently, we found a novel type of AGE, named MRX, and we found that MRX is a good biomarker for detecting oxidative stress produced during Maillard reaction. We also examined in detail the role of lipid peroxidation reaction in hyperglycemia and found that hexanoyl modification formed by the reaction of oxidized lipids and proteins must be important for oxidative stress. Detailed analyses of the formation mechanism of hexanoyl lysine (HEL) moiety in proteins were conducted, and excretion of HEL into urine was quantified by using LC/MS/MS. Macrophages and neutrophils play an important role in oxidative stress during hyperglycemia, and we determined that oxidatively modified tyrosines are a good biomarker for formation of oxidative stress at an early stage. Immunochemical analyses by application of monoclonal antibodies specific to lipid hydroperoxide-modified proteins produced by polyunsaturated fatty acids including docosahexaenoic acid (DHA) in oxidative stress caused by hyperglycemia were conducted, and the relationship between glycation and lipid peroxidation reactions both by chemical and immunochemical approaches are discussed. Recently, we put much more focus on dietary antioxidants for prevention of diabetic complications. Curcuminoids, the main yellow pigments in Curcuma longa (turmeric), have been used widely and for a long time in the treatment of sprain and inflammation in indigenous medicine. Curcumin is the main component of turmeric, and two minor components are also present as the curcuminoids. Curcuminoids possess antioxidant activity. Protective effects of curcumin (U1) and one of its major metabolites, tetrahydrocurcumin (THU1), have been examined for development of diabetic cataract in 25% galactose-fed SD rats. Through detailed examination of protective mechanisms of THU1, it was found that THU1 showed that scavenger ROS not only formed during hyperglycemia, but also induced antioxidative enzymes including detoxification enzymes such as glutathine S-transferase. THU1 also showed significant increase of glutathione concentration in the cultured rat lens. Glutathione (gamma-glutamylcysteinyl glycine [GSH]) is thought to be an important factor in cellular function and defense against oxidative stress, and we found that dietary GSH suppresses oxidative stress in vivo in prevention of diabetic complications such as diabetic nephropathy and neuropathy.

The contemporary role of antioxidant therapy in attenuating liver ischemia-reperfusion injury: a review

Oxidative stress is an important factor in many pathological conditions such as inflammation, cancer, ageing and organ response to ischemia-reperfusion. Humans have developed a complex antioxidant system to eliminate or attenuate oxidative stress. Liver ischemia-reperfusion injury occurs in a number of clinical settings, including liver surgery, transplantation, and hemorrhagic shock with subsequent fluid resuscitation, leading to significant morbidity and mortality. It is characterized by significant oxidative stress but accompanied with depletion of endogenous antioxidants. This review has 2 aims: firstly, to highlight the clinical significance of liver ischemia-reperfusion injury, the underlying mechanisms and the main pathways by which the antioxidants function, and secondly, to describe the new developments that are ongoing in antioxidant therapy and to present the experimental and clinical evidence about the role of antioxidants in modulating hepatic ischemia-reperfusion injury.

Gene expression profile of isolated rat adipocytes treated with anthocyanins

Adipocyte dysfunction is strongly associated with the development of obesity and insulin resistance. It is accepted that the regulation of adipocytokine secretion or the adipocyte specific gene expression is one of the most important targets for the prevention of obesity and amelioration of insulin sensitivity. Recently, we demonstrated that anthocyanins, which are pigments widespread in the plant kingdom, have the potency of anti-obesity in mice and the enhancement adipocytokine secretion and adipocyte gene expression in adipocytes. In this study, we have shown for the first time the gene expression profile in isolated rat adipocytes treated with anthocyanins (cyanidin 3-glucoside; C3G or cyanidin; Cy). The rat adipocytes were treated with 100 muM C3G, Cy or vehicle for 24 h. The total RNA from the adipocytes was isolated and carried out GeneChip microarray analysis. A total of 633 or 427 genes was up-regulated (>1.5-fold) by the treatment of adipocytes with C3G or Cy, respectively. The up-regulated genes include lipid metabolism and signal transduction-related genes, however, the altered genes were partly different between the C3G- and Cy-treated groups. Based on the gene expression profile, we demonstrated the up-regulation of hormone sensitive lipase and enhancement of the lipolytic activity by the treatment of adipocytes with C3G or Cy. These data have provided an overview of the gene expression profiles in adipocytes treated with anthocyanins and identified new responsive genes with potentially important functions in adipocytes related with obesity and diabetes that merit further investigation.

Identification and quantification of N(epsilon)-(Hexanoyl)lysine in human urine by liquid chromatography/tandem mass spectrometry

The identification and quantification of N(epsilon)-(hexanoyl)lysine (N(epsilon)-HEL), which was found from the reactions between lipid hydroperoxide and lysine, from human urine was examined using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The N(epsilon)-HEL in the partially purified urine fraction was identified using LC/MS/MS by several approaches including precursor/product ion scans. The peak found by the multiple-reaction monitoring (MRM) of the collision-induced fragmentation of N(epsilon)-HEL was clearly observed in urine, and the elution position coincided with the synthetic standard N(epsilon)-HEL. The product, estimated N(epsilon)-HEL, was absorbed by a specific antibody to N(epsilon)-HEL. Moreover, N(alpha)-HEL, one of the plausible hexanoyl adducts from the reaction between the N(alpha) moiety of L-lysine and the peroxidized lipid, was hardly detected in urine samples, suggesting that the origin of the N(epsilon)-HEL is the peroxidized lipid-modified proteins but not artificial hexanoylated L-lysine. Using the MRM technique, the amount of urinary N(epsilon)-HEL from the control subjects (observed healthy) was estimated to be 1.58 +/- 0.23 mumol/mol of creatinine. A comparative study of the urinary N(epsilon)-HEL with an oxidative stress marker, 8-oxo-7,8-dihydro-2'-deoxyguanosine, showed a high correlation (r = 0.844) between the two biomarkers. Furthermore, the quantification of N(epsilon)-HEL in the control and diabetic urines revealed that the urinary N(epsilon)-HEL from diabetic subjects (3.21 +/- 0.65 mumol/mol of creatinine) was significantly higher than that from the control subjects.

Cyanidins: metabolism and biological properties

Cyanidin and its glycosides belong to the anthocyanins, a widespread class of water-soluble plant compounds that are responsible for the brilliant color (red, orange, blue) of fruits and flowers. They are widely ingested by humans as it has been estimated a daily intake around 180 mg, mainly deriving from fruits and red wines. This paper reviews the literature on the biological activities, absorption and metabolism of cyanidins, with emphasis to the antioxidant, antimutagenic and other protective activities ascribed to these compounds. Their role in contrasting development of cancer and other pathologies is also reviewed. It is concluded that a great deal of work is still necessary to i) definitively clarify the metabolism of cyanidins in human beings; ii) assess the dietary burden and variations within and between populations; iii) evaluate the relationship between cyanidin glycosides-rich food consumption and incidence of given pathologies. The amount of work to be performed is even more significant when considering a possible therapeutic use of cyanidin glycosides-based drugs. With this aim, information on absorption, distribution, metabolism and excretion of cyanidin-glycosides administered by main possible routes are largely insufficient. However, consisting findings allow looking at cyanidins as dietary compounds with a potential beneficial role for human health.

Anthocyanin enhances adipocytokine secretion and adipocyte-specific gene expression in isolated rat adipocytes

Adipocyte dysfunction is strongly associated with the development of obesity and insulin resistance. It is accepted that the regulation of adipocytokine secretion or the adipocyte-specific gene expression is one of the most important targets for the prevention of obesity and amelioration of insulin sensitivity. In this study, we demonstrated that anthocyanins (cyanidin or cyanidin 3-glucoside) have the potency of a unique pharmacological function in isolated rat adipocytes. Treated adipocytes with anthocyanins enhanced adipocytokine (adiponectin and leptin) secretion and up-regulated the adipocyte specific gene expression without activation of PPARgamma in isolated rat adipocytes. The gene expression of adiponectin was also up-regulated in white adipose tissue in mice fed an anthocyanin supplemented diet. As one of the possible mechanisms, AMP-activated protein kinase activation would be associated with these changes, nevertheless, the AMP:ATP ratio was significantly decreased by administration of the anthocyanins. These data suggest that anthocyanins have a potency of unique therapeutic advantage and also have important implications for preventing obesity and diabetes.

Dietary cyanidin 3-O-beta-D-glucoside-rich purple corn color prevents obesity and ameliorates hyperglycemia in mice

Anthocyanins, which are used as a food coloring, are widely distributed in human diets, suggesting that we ingest large amounts of anthocyanins from plant-based foods. Mice were fed control, cyanidin 3-glucoside-rich purple corn color (PCC), high fat (HF) or HF + PCC diet for 12 wk. Dietary PCC significantly suppressed the HF diet-induced increase in body weight gain, and white and brown adipose tissue weights. Feeding the HF diet markedly induced hypertrophy of the adipocytes in the epididymal white adipose tissue compared with the control group. In contrast, the induction did not occur in the HF + PCC group. The HF diet induced hyperglycemia, hyperinsulinemia and hyperleptinemia. These perturbations were completely normalized in rats fed HF + PCC. An increase in the tumor necrosis factor (TNF)-alpha mRNA level occurred in the HF group and was normalized by dietary PCC. These results suggest that dietary PCC may ameliorate HF diet-induced insulin resistance in mice. PCC suppressed the mRNA levels of enzymes involved in fatty acid and triacylglycerol synthesis and lowered the sterol regulatory element binding protein-1 mRNA level in white adipose tissue. These down-regulations may contribute to triacylglycerol accumulation in white adipose tissue. Our findings provide a biochemical and nutritional basis for the use of PCC or anthocyanins as a functional food factor that may have benefits for the prevention of obesity and diabetes.

Inhibition of myeloperoxidase-catalyzed tyrosylation by phenolic antioxidants in vitro

We have developed an in vitro assay system for the evaluation of the inhibitory effects of phenolic antioxidants on myeloperoxidase (MPO) activity. The formation of dityrosine from the MPO/H2O2/L-tyrosine system was used as an indicator of the MPO activity. Because the buffer system used does not include chloride ion, this assay has the advantage of exclusion of direct reaction between an antioxidant and HOCl. In this assay, ferulic acid, gallic acid, and quercetin strongly inhibited the dityrosine formation, and curcumin and caffeic acid were also effective.