Cytoprotection by neutral fraction of tannat red wine against oxidative stress-induced cell death

Isorhamnetin Enhances the Radiosensitivity of A549 Cells Through Interleukin-13 and the NF-κB Signaling Pathway

Isorhamnetin (ISO), a naturally occurring plant flavonoid, is widely used as a phytomedicine. The major treatment modality for non-small-cell lung carcinoma (NSCLC) is radiotherapy. However, radiotherapy can induce radioresistance in cancer cells, thereby resulting in a poor response rate. Our results demonstrated that pretreatment with ISO induced radiosensitizing effect in A549 cells using colony formation, micronucleus, and γH2AX foci assays. In addition, ISO pretreatment significantly enhanced the radiation-induced incidence of apoptosis, the collapse of mitochondrial membrane potential, and the expressions of proteins associated with cellular apoptosis and suppressed the upregulation of NF-κBp65 induced by irradiation in A549 cells. Interestingly, the expression of interleukin-13 (IL-13), an anti-inflammatory cytokine, was positively correlated with the ISO-mediated radiosensitization of A549 cells. The knockdown of IL-13 expression by RNA interference decreased the IL-13 level and thus reduced ISO-mediated radiosensitivity in cells. We also found that the IR-induced NF-κB signaling activation was inhibited by ISO pretreatment, and it was abrogated in IL-13 silenced cells. We speculated that ISO may confer radiosensitivity on A549 cells via increasing the expression of IL-13 and inhibiting the activation of NF-κB. To our knowledge, this is the first report demonstrating the effects of ISO treatment on the responsiveness of lung cancer cells to irradiation through IL-13 and the NF-κB signaling pathway. In summary, ISO is a naturally occurring radiosensitizer with a potential application in adjuvant radiotherapy.

The Tannat genome: Unravelling its unique characteristics

Tannat (Vitis vinifera) is the most cultivated grapevine variety in Uruguay for the production of high quality red wines. Its berries have unusually high levels of polyphenolic compounds (anthocyanins and tannins), producing wines with intense purple colour and high antioxidant properties. Remarkably, more than 40% of its tannins are galloylated, which determines a greater antioxidant power. Technologies of massive sequencing allow the characterization of genomic variants between different clutivars. The Tannat genome was sequenced with a 134X coverage using the Illumina technology, and was annotated using transcriptomes (RNA-Seq) of different berry tissues. When comparing the genomes of Tannat with Pinot Noir PN40024 (reference genome) we found an expansion of the gene families related to the biosynthesis of polyphenols. A search base on the recently reported epicatechin galloyl transferase (ECGT) from tea leaves determined five putative genes encoding the ECGT in Tannat. Genetic analysis of one of the transcription factor that regulates the anthocyanin synthesis during berry ripening, VvMYBA1, shows the presence of Gret1 retrotransposon in one of the VvMYBA1 alleles in the Tannat clones analysed. This work makes original contributions about the molecular bases of the biosynthesis of anthocyanins and tannins during the development of the flagship grape of Uruguay.

A Mediterranean Diet Model in Australia: Strategies for Translating the Traditional Mediterranean Diet into a Multicultural Setting

Substantial evidence supports the effect of the Mediterranean Diet (MD) for managing chronic diseases, although trials have been primarily conducted in Mediterranean populations. The efficacy and feasibility of the Mediterranean dietary pattern for the management of chronic diseases has not been extensively evaluated in non-Mediterranean settings. This paper aims to describe the development of a MD model that complies with principles of the traditional MD applied in a multiethnic context. Optimal macronutrient and food-based composition was defined, and a two-week menu was devised incorporating traditional ingredients with evidence based on improvements in chronic disease management. Strategies were developed for the implementation of the diet model in a multiethnic population. Consistent with the principles of a traditional MD, the MD model was plant-based and high in dietary fat, predominantly monounsaturated fatty acids from extra virgin olive oil. Fruits, vegetables and wholegrains were a mainstay, and moderate amounts of nuts and seeds, fish, dairy and red wine were recommended. The diet encompassed key features of the MD including cuisine, biodiversity and sustainability. The MD model preserved traditional dietary components likely to elicit health benefits for individuals with chronic diseases, even with the adaptation to an Australian multiethnic population.

Protective Effects of Isorhamnetin on Cardiomyocytes Against Anoxia/Reoxygenation-induced Injury Is Mediated by SIRT1

It has been reported that apoptosis plays a very important role on anoxia/reoxygenation (A/R)-induced injury, and human silent information regulator type 1 (SIRT1) can inhibit the apoptosis of cardiomyocytes. It has been proved that isorhamnetin (IsoRN), 3'-O-methyl-quecetin, can protect the cardiomyocytes, but the mechanism is still not clear. The aim of the study was to explore whether the protective effects of IsoRN on the cardiomyocytes against the A/R-induced injury are mediated by SIRT1. The effects of IsoRN on cardioprotection against A/R injury in neonatal rat cardiomyocytes were monitored by cell viability, the levels of mitochondrial membrane potential (Δψm), apoptosis, and intracellular reactive oxygen species (ROS), the levels of lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and mitochondrial permeability transition pores (mPTP). The effects on protein expression were measured by western blot assay. The results showed that IsoRN can reduce A/R-induced injury by decreasing the level of lactate dehydrogenase and creatine phosphokinase release from the cardiomyocytes, increasing cell viability and expression of SIRT1, reducing the generation of reactive oxygen species, inhibiting opening of mitochondrial permeability transition pores and loss of Δψm and activation of caspase-3, and decreasing the release of cytochrome c, and reducing apoptosis. In addition, sirtinol, a SIRT1 inhibitor, drastically reduced the protective effects of IsoRN on cardioprotective effects in cardiomocytes. In conclusion, we firstly demonstrated that SIRT1 may be involved in the protective effects of IsoRN on cardiomocytes against the A/R-induced injury.

Chemical characterization, antioxidant and cytotoxic activities of the methanolic extract of Hymenocrater longiflorus grown in Iraq

Hymenocrater longiflorus was collected from northern Iraq, and the chemical composition and antioxidant and cytotoxic activities of this plant were investigated. Ten compounds detected by HPLC-ESI/MS were identified as flavonoids and phenolic acids. The free radical scavenging activity of the 70% methanol extract was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The antioxidant activities of the extract may be attributed to its polyphenolic composition. The cytotoxicity of the plant extract against the osteosarcoma (U2OS) cell line was assessed with the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The extract significantly reduced the viability of cells in a concentration- and time-dependent manner. Cells were arrested during the S-phase of the cell cycle, and DNA damage was revealed by antibodies against histone H2AX. The apoptotic features of cell shrinkage and decrease in cell size were also observed. Western blot analysis revealed cleavage of poly (ADP-ribose)-polymerase 1 (PARP-1), in addition to increases in the proteins p53, p21, and γ-H2AX. Collectively, our findings demonstrate that the H. longiflorus extract is highly cytotoxic to U2OS cells, most likely due to its polyphenolic composition.

Regulation of heme oxygenase-1 expression and MAPK pathways in response to kaempferol and rhamnocitrin in PC12 cells

Oxidative stress has been considered as a major cause of cellular injuries in a variety of clinical abnormalities, especially neural diseases. Our aim of research is to investigate the protective effects and mechanisms of kaempferol and rhamnocitrin (kaempferol-7-methyl ether) on oxidative damage in rat pheochromocytoma PC12 cells induced by a limited supply of serum and hydrogen peroxide (H2O2). The current result demonstrated that kaempferol protected PC12 cells from serum deprivation-induced apoptosis. Pretreatment of cells with kaempferol also diminished intracellular generation of reactive oxygen species (ROS) in response to H2O2 and strongly elevated cell viability. RT-Q-PCR and Western blotting revealed that kaempferol and rhamnocitrin significantly induced heme oxygenase (HO)-1 gene expression. Addition of zinc protoporphyrin (Znpp), a HO-1 competitive inhibitor, significantly attenuated their protective effects in H2O2-treated cells, indicating the vital role of HO-1 in cell resistance to oxidative injury. While investigating the signaling pathways responsible for HO-1 induction, we observed that kaempferol induced sustained extracellular signal-regulated protein kinase 1/2 (ERK1/2) in PC12 cells grown in low serum medium; while rhamnocitrin only stimulated transient ERK cascade. Addition of U0126, a highly selective inhibitor of MEK1/2, which is upstream of ERK1/2, had no effect on kaempferol- or rhamnocitrin-induced HO-1 mRNA expression, indicating no direct cross-talk between these two pathways. Furthermore, both kaempferol and rhamnocitrin were able to persistently attenuate p38 phosphorylation. Taking together, the above findings suggest that kaempferol and rhamnocitrin can augment cellular antioxidant defense capacity, at least in part, through regulation of HO-1 expression and MAPK signal transduction.

Molecular pathogenesis of Alzheimer's disease: reductionist versus expansionist approaches

Alzheimer's disease (AD) is characterized clinically by dementia and pathologically by two hallmark lesions, senile plaques and neurofibrillary tangles. About a quarter century ago these hallmark lesions were purified and their protein constituents identified, precipitating an avalanche of molecular studies as well as substantial optimism about successful therapeutic intervention. In 2009, we now have copious knowledge on the biochemical cascades that produce these proteins, the different modifications and forms in which these proteins exist, and the ability to selectively target these proteins for therapeutic intervention on an experimental basis. At the same time, there has been no discernible alteration in the natural course of AD in humans. While it may be that the complexity of AD will exceed our capacity to make significant treatment progress for decades or more, a paradigm shift from the reductionism that defines amyloid-beta and tau hypotheses, to one that more accurately reflects the meaning of neuropathological changes, may be warranted. We and others have demonstrated that AD pathology is a manifestation of cellular adaptation, specifically as a defense against oxidative injury. As such, AD pathology is therefore a host response rather than a manifestation of cytotoxic protein injury, and is unlikely to be a fruitful target for therapeutic intervention. An "expansionist" view of the disease, we believe, with oxidative stress as a pleiotropic and upstream process, more aptly describes the relationship between various and numerous molecular alterations and clinical disease.

Bioactivity and structure of biophenols as mediators of chronic diseases

Biophenols and their associated activity have generated intense interest. Current topics of debate are their bioavailability and bioactivity. It is generally assumed that their plasma concentrations are insufficient to produce the health benefits previously attributed to their consumption. However, data on localized in vivo concentrations are not available and many questions remain unanswered. Potential mechanisms by which they may exert significant bioactivity are discussed together with structure activity relationships. Biophenols are highly reactive species and they can react with a range of other compounds. Products of their reaction when functioning as antioxidants are examined.

Importance of functional foods in the Mediterranean diet

Objective

Analyse the importance of components of Mediterranean diet in functional feeding.

Design

We have based the study in a bibliographic review.

Results

Many of the characteristic components of the traditional Mediterranean diet (MD) are known to have positive effects on health, capacity and well-being, and can be used to design functional foods. Vegetables, fruits and nuts are all rich in phenols, flavonoids, isoflavonoids, phytosterols and phytic acid—essential bioactive compounds providing health benefits. The polyunsaturated fatty acids found in fish effectively regulate haemostatic factors, protect against cardiac arrhythmias, cancer and hypertension, and play a vital role in the maintenance of neural functions and the prevention of certain psychiatric disorders. Accumulating evidence suggests that olive oil, an integral component of the MD, may have health benefits, including the reduction of the risk of coronary heart disease, the prevention of several types of cancer and the modification of the immune and inflammatory responses. Olive oil is known for its high levels of monounsaturated fatty acids and is a good source of phytochemicals, such as polyphenolic compounds, squalene and α-tocopherol.

In the context of the MD, the benefits associated with the consumption of several functional components may be intensified by certain forms of food preparation. In addition, the practice of more physical activity (once common among Mediterranean populations) and the following of other healthy lifestyle habits may have additive effects.

Conclusions

The identification of the active constituents of the MD is crucial in the formulation of appropriate dietary guidelines. Research into the pharmacological properties of the minor components of this diet (vitamins, sterols, polyphenols, etc.) is very active and could lead to the formulation of functional foods and nutraceuticals.

Involvement of oxidative stress in Alzheimer disease

Genetic and lifestyle-related risk factors for Alzheimer disease (AD) are associated with an increase in oxidative stress, suggesting that oxidative stress is involved at an early stage of the pathologic cascade. Moreover, oxidative stress is mechanistically and chronologically associated with other key features of AD, namely, metabolic, mitochondrial, metal, and cell-cycle abnormalities. Contrary to the commonly held notion that pathologic hallmarks of AD signify etiology, several lines of evidence now indicate that aggregation of amyloid-beta and tau is a compensatory response to underlying oxidative stress. Therefore, removal of proteinaceous accumulations may treat the epiphenomenon rather than the disease and may actually enhance oxidative damage. Although some antioxidants have been shown to reduce the incidence of AD, the magnitude of the effect may be modified by individual factors such as genetic predisposition (e.g. apolipoprotein E genotype) and habitual behaviors. Because caloric restriction, exercise, and intellectual activity have been experimentally shown to promote neuronal survival through enhancement of endogenous antioxidant defenses, a combination of dietary regimen of low total calorie and rich antioxidant nutrients and maintaining physical and intellectual activities may ultimately prove to be one of the most efficacious strategies for AD prevention.

Determination of flavonoids and phenolics and their distribution in almonds

Limited information is available concerning the qualitative and quantitative composition of polyphenolic compounds, especially flavonoids, in almonds. We determined total phenols, flavonoids, and phenolic acids in California almond (Prunus dulcis) skins and kernels among the principal almond varieties (Butte, Carmel, Fritz, Mission, Monterey, Nonpareil, Padre, and Price) with high-performance liquid chromatography (HPLC)/electrochemical detection and UV detection. Liquid chromatography/tandem mass spectrometry under identical HPLC conditions was utilized to verify identities of the predominant flavonoids and phenolic acids. Total phenols ranged from 127 (Fritz) to 241 (Padre) mg gallic acid equivalents/100 g of fresh weight. The analyses were compiled to produce a data set of 18 flavonoids and three phenolic acids. The predominant flavonoids were isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-glucoside (in combination), catechin, kaempferol-3-O-rutinoside, epicatechin, quercetin-3-O-galactoside, and isorhamnetin-3-O-galactoside at 16.81, 1.93, 1.17, 0.85, 0.83, and 0.50 mg/100 g of fresh weight almonds, respectively. Using the existing approach of calculating only the aglycone form of flavonoids for use in the U.S. Department of Agriculture nutrient database, whole almonds would provide the most prevalent aglycones of isorhamnetin at 11.70 (3.32), kaempferol at 0.60 (0.17), catechin at 1.93 (0.55), quercetin at 0.72 (0.20), and epicatechin at 0.85 (0.24) mg/100 g of fresh weight (mg/oz serving), respectively. These data can lead to a better understanding of the mechanisms of action underlying the relationship between almond consumption and health-related outcomes and provide values for whole and blanched almonds suitable for inclusion in nutrient databases.

Antioxidative stress activity of oligophosphopeptides derived from hen egg yolk phosvitin in Caco-2 cells

The protective effects of hen egg yolk phosvitin phosphopeptides (PPPs) against hydrogen peroxide (H2O2)-induced oxidative stress were evaluated in an in vitro assay using human intestinal epithelial cells. Caco-2 cells were stimulated with 1 mM H2O2 for 6 h, and the secretion of IL-8, a proinflammatory mediator, was determined by ELISA as a biomarker of oxidative stress. The inhibition of H2O2-induced IL-8 secretion from Caco-2 cells was observed by pretreatment for 2 h with PPPs, but not with phosvitin. PPPs also suppressed the formation of malondialdehyde in H2O2-treated Caco-2 cells. Furthermore, intracellular glutathione levels and glutathione reductase activity were elevated by the addition of PPPs. The protective effects of PPPs against H2O2-induced oxidative stress were almost the same as that of glutathione, and PPPs with a high content of phosphorus exhibited higher protective activity than PPPs without phosphorus; however, phosphoserine itself did not show any significant antioxidative stress activity. These findings suggest that oligophosphopeptides from hen egg yolk phosvitin possess novel antioxidative activity against oxidative stress in intestinal epithelial cells and that phosphorus and peptide structure seem to have a key role in the activity.

Elevated levels of DNA repair enzymes and antioxidative enzymes by (+)-catechin in murine microglia cells after oxidative stress

(+)-Catechin possesses a broad range of pharmacological properties, including antioxidative effect. However, little is reported on the mechanism by which (+)-catechin protects microglia cells from DNA damage by oxidative stress. In this study, TUNEL assay and DNA electrophorysis indicated that (+)-catechin markedly blocked DNA fragmentation and apoptosis of microglia cells by tBHP exposure. A potent antioxidative effect of (+)-catechin was confirmed by comparison with a putative antioxidant agent, N-acetylcysteine at the lower doses. Furthermore, the increased intracellular ROS by tBHP exposure were scavenged by elevated activities of catalase (CAT) and superoxide dismutase (SOD) after (+)-catechin treatment. (+)-Catechin partially inhibited the activation of caspase-3, thereby both cleavage of poly (ADP-ribose) polymerase (PARP) and degradation of inhibitor of caspase-activated DNase (ICAD) were effectively abolished. In addition, the expression of PARP for repair of impaired DNA was significantly increased by (+)-catechin treatment. Taken together, these data suggest that protective effects of (+)-catechin against oxidative DNA damage of microglia cells is exerted by the increased expression of DNA repair enzyme PARP and antioxidant enzyme activities.