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In this study, we aimed to evaluate the antioxidant and anti-inflammatory properties of Opuntia ficus-indica cactus cladode extracts in microglia BV-2 cells. Inflammation associated with microglia activation in neuronal injury can be achieved by LPS exposure. Using four different structurally and biologically well-characterized LPS serotypes, we revealed a structure-related differential effect of LPS on fatty acid β-oxidation and antioxidant enzymes in peroxisomes: Escherichia coli -LPS decreased ACOX1 activity while Salmonella minnesota -LPS reduced only catalase activity. Different cactus cladode extracts showed an antioxidant effect through microglial catalase activity activation and an anti-inflammatory effect by reducing nitric oxide (NO) LPS-dependent production. These results suggest that cactus extracts may possess a neuroprotective activity through the induction of peroxisomal antioxidant activity and the inhibition of NO production by activated microglial cells.

State of the art. Osteoarthritis (OA) is a chronic articular disease characterized by cartilage degradation and osteophyte formation. OA physiopathology is multifactorial and involves mechanical and hereditary factors. So far, there is neither preventive medicine to delay cartilage breakdown nor curative treatment. Objectives. To investigate pro-inflammatory paracrine interactions between human primary chondrocytes and macrophages following interleukin-1-β (IL-1β) treatment; to evaluate the molecular mechanism responsible for the inhibitory effect of resveratrol. Results. The activation of NF-κB in chondrocytes by IL-1β induced IL-6 secretion. The latter will then activate STAT3 protein in macrophages. Moreover, STAT3 was able to positively regulate IL-6 secretion, as confirmed by the doubling level of IL-6 in the coculture compared to macrophage monoculture. These experiments confirm the usefulness of the coculture model in the inflammatory arthritis-linked process as a closer biological situation to the synovial joint than separated chondrocytes and macrophages. Il also demonstrated the presence of an inflammatory amplification loop induced by IL-1β. Resveratrol showed a strong inhibitory effect on the pro-inflammatory marker secretion. The decrease of IL-6 secretion is dependent on the NFκB inhibition in the chondrocytes. Such reduction of the IL-6 level can limit STAT3 activation in the macrophages, leading to the interruption of the inflammatory amplification loop. Conclusion. These results increase our understanding of the anti-inflammatory actions of resveratrol and open new potential approaches to prevent and treat osteoarthritis.

Resveratrol (3,4',5 trihydroxy-trans-stilbene) is one of the best known phytophenols with pleiotropic properties. It is a phytoalexin produced by vine and it leads to the stimulation of natural plant defenses but also exhibits many beneficial effects in animals and humans by acting on a wide range of organs and tissues. These include the prevention of cardiovascular diseases, anti-cancer potential, neuroprotective effects, homeostasia maintenance, aging delay and a decrease in inflammation. Age-related macular degeneration (AMD) is one of the main causes of deterioration of vision in adults in developed countries This review deals with resveratrol and ophthalmology by focusing on the antioxidant, anti-inflammatory, and anti-angiogenic effects of this molecule. The literature reports that resveratrol is able to act on various cell types of the eye by increasing the level of natural antioxidant enzymatic and molecular defenses. Resveratrol anti-inflammatory effects are due to its capacity to limit the expression of pro-inflammatory factors, such as interleukins and prostaglandins, and also to decrease the chemo-attraction and recruitment of immune cells to the inflammatory site. In addition to this, resveratrol was shown to possess anti-VEGF effects and to inhibit the proliferation and migration of vascular endothelial cells. Resveratrol has the potential to be used in a range of human ocular diseases and conditions, based on animal models and in vitro experiments.

In patients with sepsis, liver metabolism and its capacity to provide other organs with energetic substrates are impaired. This and many other pathophysiological changes seen in human patients are reproduced in mice injected with purified endotoxin (lipopolysaccharide, LPS). In the present study, down-regulation of genes involved in hepatic fatty acid oxidation (FAOx) and gluconeogenesis in mice exposed to LPS was challenged by nutritional intervention with Argan oil. Mice given a standard chow supplemented or not with either 6% (w/w) Argan oil (AO) or 6% (w/w) olive oil (OO) prior to exposure to LPS were explored for liver gene expressions assessed by mRNA transcript levels and/or enzyme activities. AO (or OO) food supplementation reveals that, in LPS-treated mice, hepatic expression of genes involved in FAOx and gluconeogenesis was preserved. This preventive protection might be related to the recovery of the gene expressions of nuclear receptors peroxisome proliferator-activated receptor α (PPARα) and estrogen related receptor α (ERRα) and their coactivator peroxisome proliferator-activated receptor gamma coactivator-1α, (PGC-1α). These preventive mechanisms conveyed by AO against LPS-induced metabolic dysregulation might add new therapeutic potentialities in the management of human sepsis.

This review presents recent evidence implicating microRNAs (miRNAs) in the beneficial effects of resveratrol (trihydroxystilbene), a nonflavonoid plant polyphenol, with emphasis on its anti-inflammatory effects. Many diseases and pathologies have been linked, directly or indirectly, to inflammation. These include infections, injuries, atherosclerosis, diabetes mellitus, obesity, cancer, osteoarthritis, age-related macular degeneration, demyelination, and neurodegenerative diseases. Resveratrol can both decrease the secretion of proinflammatory cytokines (e.g., IL-6, IL-8, and TNF-α) and increase the production of anti-inflammatory cytokines; it also decreases the expression of adhesion proteins (e.g., ICAM-1) and leukocyte chemoattractants (e.g., MCP-1). Resveratrol's primary targets appear to be the transcription factors AP-1 and NF-κB, as well as the gene COX2. Although no mechanistic link between any particular miRNA and resveratrol has been identified, resveratrol effects depend at least in part upon the modification of the expression of a variety of miRNAs that can be anti-inflammatory (e.g., miR-663), proinflammatory (e.g., miR-155), tumor suppressing (e.g., miR-663), or oncogenic (e.g., miR-21)., (© 2015 New York Academy of Sciences.)

Phytophenols are considered to have beneficial effects towards human physiology. They are food microcomponents with potent chemopreventive properties towards the most three frequent contemporary human diseases, e.g., cardiovascular alterations, cancer and neurodegenerative pathologies. Related to this, the plasmatic form and plasmatic level of plant polyphenols in the body circulation are crucial for their efficiency. Thus, determinations of the binding process of resveratrol and of common flavonoids produced by major edible plants, berries and fruits to plasma proteins are essential. The interactions between resveratrol and albumin, a major plasma protein, were compared with those already published, involving curcumin, genistein, quercetin and other well-known food-containing polyphenols. The approaches used are usually intrinsic fluorescence intensity changes, quenching of protein intrinsic fluorescence and infrared spectroscopy. It appears that: (1) all of the studied polyphenols interact with albumin; (2) while most of the studied polyphenols interact at one albumin binding site, there are two different types of resveratrol binding sites for bovine serum albumin, one with the highest affinity (apparent KD of 4 µM) with a stoichiometry of one per monomer and a second with a lower affinity (apparent KD of 20 µM) with also a stoichiometry of one per monomer; (3) at least one binding site is in the vicinity of one tryptophanyl residue of bovine serum albumin; and (4) resveratrol binding to bovine serum albumin produces a very small structural conformation change of the polypeptide chain. These results support a role played by polyphenols-albumin interactions in the plasma for the bio-activities of these food microcomponents in the body.

Opuntia ficus-indica, commonly referred to as prickly pear or nopal cactus, is a dicotyledonous angiosperm plant. It belongs to the Cactaceae family and is characterized by its remarkable adaptation to arid and semi-arid climates in tropical and subtropical regions of the globe. In the last decade, compelling evidence for the nutritional and health benefit potential of this cactus has been provided by academic scientists and private companies. Notably, its rich composition in polyphenols, vitamins, polyunsaturated fatty acids and amino acids has been highlighted through the use of a large panel of extraction methods. The identified natural cactus compounds and derivatives were shown to be endowed with biologically relevant activities including anti-inflammatory, antioxidant, hypoglycemic, antimicrobial and neuroprotective properties. The present review is aimed at stressing the major classes of cactus components and their medical interest through emphasis on some of their biological effects, particularly those having the most promising expected health benefit and therapeutic impacts.

Further advances in understanding the mechanism of action of resveratrol and its application require new analogs to identify the structural determinants for the cell proliferation inhibition potency. Therefore, we synthesized new trans-resveratrol derivatives by using the Wittig and Heck methods, thus modifying the hydroxylation and methoxylation patterns of the parent molecule. Moreover, we also synthesized new ferrocenylstilbene analogs by using an original protective group in the Wittig procedure. By performing cell proliferation assays we observed that the resveratrol derivatives show inhibition on the human colorectal tumor SW480 cell line. On the other hand, cell viability/cytotoxicity assays showed a weaker effects on the human hepatoblastoma HepG2 cell line. Importantly, the lack of effect on non-tumor cells (IEC18 intestinal epithelium cells) demonstrates the selectivity of these molecules for cancer cells. Here, we show that the numbers and positions of hydroxy and methoxy groups are crucial for the inhibition efficacy. In addition, the presence of at least one phenolic group is essential for the antitumoral activity. Moreover, in the series of ferrocenylstilbene analogs, the presence of a hidden phenolic function allows for a better solubilization in the cellular environment and significantly increases the antitumoral activity.

Background: Inborn enzyme defects of mitochondrial fatty acid beta-oxidation (FAO) form a large group of genetic disorders associated to variable clinical presentations ranging from life-threatening pediatric manifestations up to milder late onset phenotypes, including myopathy. Very few candidate drugs have been identified in this group of disorders. Resveratrol (RSV) is a natural polyphenol with anti-oxidant and anti-inflammatory effects, recently shown to have beneficial metabolic properties in mice models. Our study explores its possible effects on FAO and mitochondrial energy metabolism in human cells, which are still very little documented., Methods: Using cells from controls and from patients with Carnitine Palmitoyl Transferase 2 (CPT2) or Very Long Chain AcylCoA Dehydrogenase (VLCAD) deficiency we characterized the metabolic effects of RSV, RSV metabolites, and other stilbenes. We also focused on analysis of RSV uptake, and on the effects of low RSV concentrations, considering the limited bioavailability of RSV in vivo., Results: Time course of RSV accumulation in fibroblasts over 48 h of treatment were consistent with the resulting stimulation or correction of FAO capacities. At 48 h, half maximal and maximal FAO stimulations were respectively achieved for 37,5 microM (EC50) and 75 microM RSV, but we found that serum content of culture medium negatively modulated RSV uptake and FAO induction. Indeed, decreasing serum from 12% to 3% led to shift EC50 from 37,5 to 13 microM, and a 2.6-3.6-fold FAO stimulation was reached with 20 microM RSV at 3% serum, that was absent at 12% serum. Two other stilbenes often found associated with RSV, i.e. cis- RSV and piceid, also triggered significant FAO up-regulation. Resveratrol glucuro- or sulfo- conjugates had modest or no effects. In contrast, dihydro-RSV, one of the most abundant circulating RSV metabolites in human significantly stimulated FAO (1.3-2.3-fold)., Conclusions: This study provides the first compared data on mitochondrial effects of resveratrol, its metabolites, and other natural compounds of the stilbene family in human cells. The results clearly indicate that several of these compounds can improve mitochondrial FAO capacities in human FAO-deficient cells.

The objective of this study was to evaluate the biological activities of the major phytosterols present in argan oil (AO) and in cactus seed oil (CSO) in BV2 microglial cells. Accordingly, we first determined the sterol composition of AO and CSO, showing the presence of Schottenol and Spinasterol as major sterols in AO. While in CSO, in addition to these two sterols, we found mainly another sterol, the Sitosterol. The chemical synthesis of Schottenol and Spinasterol was performed. Our results showed that these two phytosterols, as well as sterol extracts from AO or CSO, are not toxic to microglial BV2 cells. However, treatments by these phytosterols impact the mitochondrial membrane potential. Furthermore, both Schottenol and Spinasterol can modulate the gene expression of two nuclear receptors, liver X receptor (LXR)-α and LXRβ, their target genes ABCA1 and ABCG1. Nonetheless, only Schottenol exhibited a differential activation vis-à-vis the nuclear receptor LXRβ. Thus Schottenol and Spinasterol can be considered as new LXR agonists, which may play protective roles by the modulation of cholesterol metabolism., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Various epidemiological studies have shown that a regular and moderate consumption of red wine is correlated with a decreased relative risk of developing coronary heart disease and cancer. These health benefits are commonly attributed to high contents of polyphenols, particularly resveratrol, representing important sources of antioxidants. However, resveratrol does not seem to be the only bioactive compound present in the wine which contains numerous other polyphenols. The present study investigates the efficiency of red wine extracts (RWEs), containing different polyphenols, on colon cancer cell proliferation in vitro and on colonic aberrant crypt foci (ACF) in vivo. Proliferation, cell cycle analysis and incidence of ACF were monitored to examine the effects of RWEs. RWEs derived from a long vinification process exhibit superior anti-proliferative activity in colon cancer cells and prevent the appearance of ACF in mice. Interestingly, quercetin and resveratrol, representing two major bio-active polyphenols, exhibit synergistic anti-proliferative effects. These data suggest that the efficacy of RWEs on colon carcinogenesis may depend on the polyphenolic content, synergistic interaction of bio-active polyphenols and modulation of cellular uptake of polyphenols.

Since the first report by Rhodin in 1954, our knowledge on mammalian microbodies/peroxisomes has known several periods. An initial two decades period (1954-1973) has contributed to the biochemical individualisation of peroxisomes as a new class of subcellular organelles (de Duve, 1965). The corresponding research period failed to define a clear role of mammalian peroxisomes in vital functions and intermediary metabolism, explaining why feeling that peroxisomes might be in the human cell oddities has prevailed during several decades. The period standing from 1973 to nowadays has progressively removed this cell oddity view of peroxisomes by highlighting vital function and metabolic role of peroxisomes in health and disease along with genetic and metabolic regulation of peroxisomal protein content, organelle envelope formation and protein signal targeting mechanisms. Research on peroxisomes and their response to various drugs and metabolites, dietary and physiological conditions has also played a key role in the discovery of peroxisome proliferator activated receptors (PPARs) belonging to the nuclear hormone receptor superfamily and for which impact in science and medicine goes now by far beyond that of the peroxisomes., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

The peroxisomal 3-ketoacyl-CoA thiolase B (ThB) catalyzes the thiolytic cleavage of straight chain 3-ketoacyl-CoAs. Up to now, the ability of ThB to interfere with lipid metabolism was studied in mice fed a laboratory chow enriched or not with the synthetic agonist Wy14,643, a pharmacological activator of the nuclear hormone receptor PPARα. The aim of the present study was therefore to determine whether ThB could play a role in obesity and lipid metabolism when mice are chronically fed a synthetic High Fat Diet (HFD) or a Low Fat Diet (LFD) as a control diet. To investigate this possibility, wild-type (WT) mice and mice deficient for Thb (Thb(-/-)) were subjected to either a synthetic LFD or a HFD for 25 weeks, and their responses were compared. First, when fed a normal regulatory laboratory chow, Thb(-/-) mice displayed growth retardation as well as a severe reduction in the plasma level of Growth Hormone (GH) and Insulin Growth Factor-I (IGF-I), suggesting alterations in the GH/IGF-1 pathway. When fed the synthetic diets, the corrected energy intake to body mass was significantly higher in Thb(-/-) mice, yet those mice were protected from HFD-induced adiposity. Importantly, Thb(-/-) mice also suffered from hypoglycemia, exhibited reduction in liver glycogen stores and circulating insulin levels under the LFD and the HFD. Thb deficiency was also associated with higher levels of plasma HDL (High Density Lipoproteins) cholesterol and increased liver content of cholesterol under both the LFD and the HFD. As shown by the plasma lathosterol to cholesterol ratio, a surrogate marker for cholesterol biosynthesis, whole body cholesterol de novo synthesis was increased in Thb(-/-) mice. By comparing liver RNA from WT mice and Thb(-/-) mice using oligonucleotide microarray and RT-qPCR, a coordinated decrease in the expression of critical cholesterol synthesizing genes and an increased expression of genes involved in bile acid synthesis (Cyp7a1, Cyp17a1, Akr1d1) were observed in Thb(-/-) mice. In parallel, the elevation of the lathosterol to cholesterol ratio as well as the increased expression of cholesterol synthesizing genes were observed in the kidney of Thb(-/-) mice fed the LFD and the HFD. Overall, the data indicate that ThB is not fully interchangeable with the thiolase A isoform. The present study also reveals that modulating the expression of the peroxisomal ThB enzyme can largely reverberate not only throughout fatty acid metabolism but also cholesterol, bile acid and glucose metabolism., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Besides synthesizing nutritive substances (proteins, fats and carbohydrates) for energy and growth, plants produce numerous non-energetic so-called secondary metabolites (mainly polyphenols) that allow them to protect themselves against infections and other types of hostile environments. Interestingly, these polyphenols often provide cells with valuable bioactive properties for the maintenance of their functions and homeostasis (signaling, gene regulation, protection against acquired or infectious diseases, etc.) both in humans and animals. Namely, from a nutritional point of view, and based on epidemiological data, it is now well accepted that the regular consumption of green vegetables, fruits and fibers has protective effects against the onset of cancer as well as of inflammatory, neurodegenerative, metabolic and cardiovascular diseases, and consequently increases the overall longevity. In particular, grapevine plants produce large amounts of a wide variety of polyphenols. The most prominent of those-resveratrol-has been shown to impair or delay cardiovascular alterations, cancer, inflammation, aging, etc. Until recently, the molecular bases of the pleiotropic effects of resveratrol remained largely unclear despite numerous studies on a variety of signaling pathways and the transcriptional networks that they control. However, it has been recently proposed that the protective properties of resveratrol may arise from its modulation of small non-coding regulatory RNAs, namely microRNAs. The aim of this review is to present up-to-date data on the control of microRNA expression by dietary phytophenols in different types of human cells, and their impact on cell differentiation, cancer development and the regulation of the inflammatory response., (© 2013 Society of Chemical Industry.)

Scope: Resveratrol (RSV) has been proposed to prevent tumor growth; nevertheless, these preventive effects are controversial since RSV pharmacokinetics studies show a low bioavailability. Recent clinical trials show that patients with colorectal cancer and receiving oral RSV have high levels of RSV conjugates in the colorectum, mainly RSV-3-O-sulfate (R3S), RSV-3-O-glucuronide, and RSV-4'-O-glucuronide. However, their potential biological activity has not yet been established. This study thus investigated in human colorectal cancer cell lines whether RSV main metabolites retain anticarcinogenic properties as their parental molecule., Methods and Results: Proliferation, apoptosis assays and cell cycle analysis were performed to study the effect of RSV, R3S, RSV-3-O-glucuronide, or RSV-4'-O-glucuronide alone or of a mixture of the three metabolites. R3S inhibits colon cancer cells proliferation and an accumulation of cells in S phase. Interestingly, the mixture induced a synergistic effect. This process was associated with an induction of DNA damages and apoptotic process, which allowed sensitization of colon cancer cells to the anticancer drugs., Conclusion: Altogether, our data provide significant new insight into the molecular mechanism of RSV and support the notion that despite low bioavailability in vivo, RSV biological effects could be mediated by its metabolites., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Resveratrol (RSV), a plant-derived stilbene, induces cell death in Hodgkin lymphoma (HL)-derived L-428 cells in a dose-dependent manner (IC50 = 27 μM, trypan blue exclusion assay). At a lower range (25 μM), RSV treatment for 48 hr causes arrest in the S-phase of the cell cycle, while at a higher concentration range (50 μM), apoptosis can be detected, with activation of caspase-3. The histone/protein deacetylase SIRT1 has been described as a putative target of RSV action in other model systems, even though its role in cancer cells is still controversial. Here we show that RSV, at both concentration ranges, leads to a marked increase in p53, while a decrease of SIRT1 expression level, as well as enzyme activity, only occurred at the higher concentration range. Concomitantly, however, treatments at both concentration ranges resulted in a marked increase in K373-acetylated p53 and lysine-acetylated FOXO3a. Immunohistochemical stainings of human lymph nodes show a preferential distribution of SIRT1 in the germinal center of the follicles while the mantle zone shows nearly no staining to few positive cells. The classical HL-affected lymph nodes show a strong positivity of the diagnostic Hodgkin Reed-Sternberg cells. Notably, both the HL-derived cell lines and the Hodgkin Reed-Sternberg cells of the affected lymph nodes derive from germinal center-derived B cells. The study of SIRT1 distribution and expression on a larger number of biopsies might disclose a novel role for this histone/protein deacetylase as therapeutic target., (Copyright © 2012 UICC.)

Grape polyphenols are abundant. They play essential roles in the plant's life, particularly in defence mechanisms. Moreover, the grape, fresh or dried, is a widely consumed fruit by humans, as are its by-products, grape juice and wine. They also contain vast and highly varied quantities of polyphenols. Like other phytophenols, grape and wine resveratrol is considered a protective micronutrient. Resveratrol is a well known antioxidant, for example, a protector of low-density lipoproteins against oxidation. Its applications are therefore highly varied. Research supports the idea that wine consumed regularly, without excess, is a natural biological product possesses preventive properties, and not only well-known properties against vascular diseases (illustrated by the so-called French paradox). At least in experimental models so far, resveratrol prevents infections, inflammation, neurodegenerative diseases, and cancer. This review addresses whether the pro-longevity properties of resveratrol are preserved in the human species. If such is the case, it will be possible to imagine new ways of eating based on natural foods, with or without supplements, based on resveratrol. On the other hand, studies such as ours are investigating the synergies between resveratrol and some of the many polyphenols found in wine. These studies should fill in the gaps between the study of a molecule tested in isolation or in a binary system (e.g., with alcohol) and this same molecule in its biological context.

In mammals, the liver is the major organ of fatty acid catabolism. This pathway is involved in both mitochondria and peroxisome. While mitochondria breaks down fatty acids with short, medium and long carbon chains, peroxisomes are involved in the catabolism of very long and branched chain fatty acids, which are degraded by three enzymes: acyl-CoA oxidase, multifunctional enzyme and thiolase enzyme. The active pathway results mainly from a tight transcriptional control of these gene-encoding enzymes. Two major nuclear receptors that are highly expressed in this organ are involved in this control, e.g. PPARα (peroxisome proliferator-activated receptor, α isoform) and HNF4α (hepatic nuclear factor 4, α isotype). Both are key regulators of liver lipid metabolism. While numerous papers have reported on the role of PPARα in liver lipid homeostasis, less is known on the implication of HNF4α in this metabolism. Moreover, very few studies have taken an interest in the important question of the implication of these two receptors and most particularly their crosstalk. This review therefore presents the current knowledge on the PPARα/HNF4α interplay in diversified DNA responsive elements and its relevance in the regulation fatty acid catabolism. It presents a review of the properties of the nuclear receptors PPARα and HNF4α, then the genes regulated by HNF4α and PPARα, particularly the peroxisomal enzyme target genes. To conclude, the consequences of the regulation of these genes in the liver by PPARα and HNF4α will be analyzed. The current data indicate the requirement of PPARα and HNF4α for regulation in the liver of peroxisomal and mitochondrial fatty acid β-oxidation, cholesterol and bile acid metabolism, lipoprotein metabolism and consequently the prevention of liver steatosis. However, several questions remain unsolved. To show the interplay of PPARα and HNF4α in the regulation of liver fatty acid metabolism, different strategies are proposed.

This review is aimed at illustrating that mitochondrial dysfunction and altered lipid homeostasis may concur in a variety of pathogenesis states, being either contributive or consecutive to primary disease events. Underlying mechanisms for this concurrence are far from being the exhaustive elements taking place in disease development. They may however complicate, contribute or cause the disease. In the first part of the review, physiological roles of mitochondria in coordinating lipid metabolism and in controlling reactive oxygen species (ROS), ATP and calcium levels are briefly presented. In a second part, clues for how mitochondria-driven alterations in lipid metabolism may induce toxicity are discussed. In the third part, it is illustrated how mitochondrial dysfunction and lipid homeostasis disruption may be associated (i) to complicate type 1 diabetes (pancreatic β-cell mitochondrial dysfunction in ATP yield induces reduced insulin secretion and hence disruption of glucose and lipid metabolism), (ii) to contribute to type 2 diabetes and other insulin resistant states (mitochondrial impairment may induce adipocyte dysfunction with subsequent increase in circulating free fatty acids and their abnormal deposit in non adipose tissues (pancreatic β-cells, skeletal muscle and liver) which results in lipotoxicity and mitochondrial dysfunction), (iii) to offer new clues in our understanding of how the brain controls feeding supply and energy expenditure, (iv) to promote cancer development notably via fatty acid oxidation/synthesis imbalance (in favor of synthesis) further strengthened in some cancers by a lipogenetic benefit induced by a HER2/fatty acid synthase cross-talk, and (v) to favor cardiovascular disorders by impacting heart function and arterial wall integrity.

Resveratrol is one of the most widely studied bio-active plant polyphenols. While its effect on endothelial blood vessel cells, cancer cells, inflammatory processes and neurodegenerative events is well documented, little is known about the implication of this phytophenol in differentiating processes, particularly in skeletal muscle cells. Here, we report the effects of resveratrol on mouse skeletal muscle-derived cells (C2C12) in either a nondifferentiated (myoblasts) or differentiated state (myotubes) by evaluating resveratrol uptake, cell proliferation, changes in cell shape, and the expression of genes encoding muscle-specific transcription factors or contractile proteins. Resveratrol: (1) rapidly accumulates within cells through passive and facilitated processes; (2) does not strongly affect cell viability, cell cycle and apoptosis; (3) behaves as a pro-differentiating agent as shown by the lengthening of cells, leading to a myotube phenotype; (4) upregulates muscular pro-differentiation markers and transcription factors (myogenin, Scrp3) starting after 12h of exposure and strongly increases heavy chain myosin content after 18h of exposure to resveratrol; (5) increases the Srf transcription factor's transcript level, a target mRNA of the miRNA-133b, which is itself downregulated by this polyphenol. These results put forward new pro-differentiating regulatory properties of resveratrol on skeletal muscles at least partly via modulation of specific miRNAs., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Grapes produce large amounts of polyphenols. Many of them accumulate in the skin, pulp, and seeds and are consequently found in wine. The health benefits of a moderate consumption of wine have been attributed at least in part to grape's polyphenols. Among them, resveratrol (3,5,4'-trihydroxystilbene) is a phytoalexin that stimulates plant cell defenses against infections and also plays protective roles in humans, where it delays cardiovascular alterations and exerts anticancer and anti-inflammatory effects. Despite numerous studies, the molecular mechanisms of resveratrol action are only partially understood. Given its pleiotropic effects, it was previously suggested that resveratrol protective properties may arise from its modulation of the expression of microRNAs. Therefore, this review will focus on the effects of resveratrol on microRNA populations in humans and human cell lines, especially emphasizing the microRNAs that have been implicated in resveratrol effects on inflammation, cancer, metabolism, and muscle differentiation.

While the cardioprotective effect of moderate and regular wine consumption in primary prevention has been well documented, the goal of the present investigation was to explore the effect of wine intake on blood parameters (lipid, anti-oxidant capacity, and erythrocyte membrane potential and fluidity) in post myocardial infarct patients to evaluate perspectives in secondary prevention. A clinical intervention trial has been undertaken on a group of selected post myocardial infarct patients who gave written informed consent for participation in this study prior to enrolment. This two-week study has been conducted on hospitalized patients during a cardiac readaptation period. During this period, patients were submitted to a "Western prudent" diet (inspired by the Mediterranean diet) and two groups have been compared on a drawn basis: patients receiving red wine (250 mL daily) to patients receiving water. Physical, clinical, and blood parameters were evaluated on Days 1 and 14. The data show a positive effect of low wine consumption on blood parameters (decrease in total cholesterol and LDL; increase in erythrocyte membrane fluidity and antioxidant status). The results show that a moderate consumption of red wine even for a short period associated with a "Western prudent" diet improves various blood parameters in lipid and anti-oxidative status in patients with previous coronary ischemic accidents., (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

trans-Resveratrol has been proposed to prevent tumor growth and to sensitize cancer cells to anticancer agents. Polyphenol entry into the cells has remained poorly understood. Here, we show that [(3)H]-resveratrol enters colon cancer cells (SW480, SW620, HT29) and leukemia U937 cells through a monensin (5-20 μmol/L) -sensitive process that suggests clathrin-independent endocytosis. Uptake of the molecule can be prevented by methyl-β-cyclodextrin (2-12 mg/mL), nystatin (12 ng/mL), and filipin (1 μg/mL), which all disrupt plasma membrane lipid rafts. Accordingly, radiolabeled resveratrol accumulates in sphingomyelin- and cholesterol-enriched cell fractions. Interestingly, extracellular signal-regulated kinases (ERK), c-Jun NH(2)-terminal kinases (JNK), and Akt also accumulate in lipid rafts on resveratrol exposure (IC(50) at 48 h ≈ 30 μmol/L in SW480 and U937 cells). In these rafts also, resveratrol promotes the recruitment, by the integrin α(V)β(3) (revealed by coimmunoprecipitation with an anti-integrin α(V)β(3) antibody), of signaling molecules that include the FAK (focal adhesion kinase), Fyn, Grb2, Ras, and SOS proteins. Resveratrol-induced activation of downstream signaling pathways and caspase-dependent apoptosis is prevented by endocytosis inhibitors, lipid raft-disrupting molecules, and the integrin antagonist peptide arginine-glycine-aspartate (500 nmol/L). Altogether, these data show the role played by lipid rafts in resveratrol endocytosis and activation of downstream pathways leading to cell death.

Resveratrol is a natural dietary polyphenol found in grape skin, red wine, and various other food products. Resveratrol has proved to be an effective chemopreventive agent for different malignant tumors. It has also been shown to prevent vascular alterations such as atherosclerosis and inflammatory-associated events. In view of these observations, we investigated the anti-proliferative and pro-apoptotic activities of resveratrol on a tumoral cardiac cell line (HL-1 NB) derived from mouse tumoral atrial cardiac myocytes. These effects were compared with those found on normal neonatal mouse cardiomyocytes. HL-1 NB cells and neonatal cardiomyocytes were treated with resveratrol (5, 30, and/or 100 μM) for different times of culture (24, 48, and/or 72 h). Resveratrol effects were determined by various microscopical and flow cytometric methods. After resveratrol treatment, a strong inhibition of tumoral cardiac HL1-NB cell growth associated with a loss of cell adhesion was observed. This cell proliferation arrest was associated with an apoptotic process revealed by an increased percentage of cells with fragmented and/or condensed nuclei (characteristic of apoptotic cells) identified after staining with Hoechst 33342 and by the presence of cells in subG1. At the opposite, on normal cardiomyocytes, no cytotoxic effects of resveratrol were observed, and a protective effect of resveratrol against norepinephrine-induced apoptosis was found on normal cardiomyocytes. Altogether, the present data demonstrate that resveratrol (1) induces apoptosis of tumoral cardiac HL1-NB cells, (2) does not induce cell death on normal cardiomyocytes, and (3) prevents norepinephrine-induced apoptosis on normal cardiomyocytes.

Peroxisomal 3-ketoacyl-CoA thiolase B (Thb) catalyzes the final step in the peroxisomal β-oxidation of straight-chain acyl-CoAs and is under the transcription control of the nuclear hormone receptor PPARα. PPARα binds to and is activated by the synthetic compound Wy14,643 (Wy). Here, we show that the magnitude of Wy-mediated induction of peroxisomal β-oxidation of radiolabeled (1-(14)C) palmitate was significantly reduced in mice deficient for Thb. In contrast, mitochondrial β-oxidation was unaltered in Thb(-/-) mice. Given that Wy-treatment induced Acox1 and MFP-1/-2 activity at a similar level in both genotypes, we concluded that the thiolase step alone was responsible for the reduced peroxisomal β-oxidation of fatty acids. Electron microscopic analysis and cytochemical localization of catalase indicated that peroxisome proliferation in the liver after Wy-treatment was normal in Thb(-/-) mice. Intriguingly, micro-array analysis revealed that mRNA levels of genes encoding cholesterol biosynthesis enzymes were upregulated by Wy in Wild-Type (WT) mice but not in Thb(-/-) mice, which was confirmed at the protein level for the selected genes. The non-induction of genes encoding cholesterol biosynthesis enzymes by Wy in Thb(-/-) mice appeared to be unrelated to defective SREBP-2 or PPARα signaling. No difference was observed in the plasma lathosterol/cholesterol ratio (a marker for de novo cholesterol biosynthesis) between Wy-treated WT and Thb(-/-) mice, suggesting functional compensation. Overall, we conclude that ThA and SCPx/SCP2 thiolases cannot fully compensate for the absence of ThB. In addition, our data indicate that ThB is involved in the regulation of genes encoding cholesterol biosynthesis enzymes in the liver, suggesting that the peroxisome could be a promising candidate for the correction of cholesterol imbalance in dyslipidemia., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

The biological properties and possible pharmacological applications of benzo[kl]xanthene lignans, rare among natural products and synthetic compounds, are almost unexplored. In the present contribution, the possible interaction of six synthetic benzo[kl]xanthene lignans and the natural metabolite rufescidride with DNA has been investigated through a combined STD-NMR and molecular docking approach, paralleled by in vitro biological assays on their antiproliferative activity towards two different cancer cell lines: SW 480 and HepG2. Our data suggest that the benzo[kl]xanthene lignans are suitable lead compounds for the design of DNA selective ligands with potential antitumour properties.

Numerous studies have reported interesting properties of trans-resveratrol, a phytoalexin, as a preventive agent of several important pathologies: vascular diseases, cancers, viral infections, and neurodegenerative processes. These beneficial effects of resveratrol have been supported by observations at the cellular and molecular levels in both cellular and in vivo models, but the cellular fate of resveratrol remains unclear. We suggest here that resveratrol uptake, metabolism, and stability of the parent molecule could influence the biological effects of resveratrol. It appears that resveratrol stability involves redox reactions and biotransformation that influence its antioxidant properties. Resveratrol's pharmacokinetics and metabolism represent other important issues, notably, the putative effects of its metabolites on pathology models. For example, some metabolites, mainly sulfate-conjugated resveratrol, show biological effects in cellular models. The modifications of resveratrol stability, chemical structure, and metabolism could change its cellular and molecular targets and could be crucial for improving or decreasing its chemopreventive properties., (© 2011 New York Academy of Sciences.)

Resveratrol (trans-3,4',5-trihydroxystilbene) is a natural antioxidant with cardiovascular and cancer preventive properties that is currently at the stage of pre-clinical studies for human cancer prevention. Beside its known effects on protein coding genes, one possible mechanism for resveratrol protective activities is by modulating the levels of non-coding RNAs. Here, we analyzed the effects of resveratrol on microRNA populations in human SW480 colon cancer cells. We establish that resveratrol treatment decreases the levels of several oncogenic microRNAs targeting genes encoding Dicer1, a cytoplasmic RNase III producing mature microRNAs from their immediate precursors, tumor-suppressor factors such as PDCD4 or PTEN, as well as key effectors of the TGFβ signaling pathway, while increasing the levels of miR-663, a tumor-suppressor microRNA targeting TGFβ1 transcripts. We also show that, while upregulating several components of the TGFβ signaling pathway such as TGFβ receptors type I (TGFβR1) and type II (TGFβR2), resveratrol decreases the transcriptional activity of SMADs, the main effectors of the canonical TGFβ pathway. Our results establish that protective properties of resveratrol may arise at least in part from its capability to modify the composition of microRNA populations in cells, and suggest that the manipulation of the levels of key microRNAs, such as miR-663, may help to potentiate the anti-cancer and anti-metastatic effects of resveratrol., (Copyright © 2010 Elsevier Inc. All rights reserved.)

An inflammatory component is present in the microenvironment of most neoplastic tissues, including those not causally related to an obvious inflammatory process. Several microRNAs, and especially miR-155, play an essential role in both the innate and adaptative immune response. Resveratrol (trans-3,4',5-trihydroxystilbene) is a natural antioxidant with anti-inflammatory properties that is currently at the stage of preclinical studies for human cancer prevention. Here, we establish that, in human THP-1 monocytic cells as well as in human blood monocytes, resveratrol upregulates miR-663, a microRNA potentially targeting multiple genes implicated in the immune response. In THP-1 cells, miR-663 decreases endogenous activator protein-1 (AP-1) activity and impairs its upregulation by lipopolysaccharides (LPS), at least in part by directly targeting JunB and JunD transcripts. We further establish that the downregulation of AP-1 activity by resveratrol is miR-663 dependent and that the effects of resveratrol on both AP-1 activity and JunB levels are dose dependent. Finally, we show that resveratrol impairs the upregulation of miR-155 by LPS in a miR-663-dependent manner. Given the role of miR-155 in the innate immune response and the fact that it is upregulated in many cancers, our results suggest that manipulating miR-663 levels may help to optimize the use of resveratrol as both an anti-inflammatory and anticancer agent against malignancies associated with high levels of miR-155.

To put forward BDH from Pseudomonas aeruginosa's enzymatic properties, we report a two-step purification of BDH and its gene sequencing allowing the investigation of its structural properties. Purification of BDH was achieved, using ammonium sulfate fractionation and Blue Sepharose CL-6B affinity chromatography. SDS-PAGE analysis reveals a MM of 29 kDa, whereas the native enzyme showed a MM of 120 kDa suggesting a homotetrameric structure. BDH encoding gene sequence shows a nucleotide open reading frame sequence of 771 bp encoding a 265 amino acid residues polypeptide chain. The modeling analysis of the three dimensional structure fits with the importance of amino acids in the catalysis reaction especially a strictly conserved tetrad. Amino-acid residues in interaction with the coenzyme NAD(+) were also identified.

Resveratrol is the subject of intense research because of the abundance of this compound in the human diet and as one of the most valuable natural chemopreventive agents. Further advances require new resveratrol analogs be used to identify the structural determinants of resveratrol for the inhibition potency of cell proliferation by comparing experimental and docking studies. Therefore, we synthesized new trans/(E)- and cis/(Z)-resveratrol - analogs not reported to date - by modifying the hydroxylation pattern of resveratrol and a double bond geometry. We included them in a larger panel of 14 molecules, including (Z)-3,5,4'-trimethoxystilbene, the most powerful molecule that is used as reference. Using a docking model complementary to experimental studies on the proliferation inhibition of the human colorectal tumor SW480 cell line, we show that methylation is the determinant substitution in inhibition efficacy, but only in molecules bearing a Z configuration. Most of the synthetic methylated derivatives (E or Z) stop mitosis at the M phase and lead to polyploid cells, while (E)-resveratrol inhibits cells at the S phase. Docking studies show that almost all of the docked structures of (Z)-polymethoxy isomers, but not most of the (E)-polymethoxy isomers substantially overlap the docked structure of combretastatin A-4, taken as reference ligand at the colchicine-tubulin binding site., (Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.)

The peroxisomal 3-ketoacyl-CoA thiolase B (Thb) gene was previously identified as a direct target gene of PPARalpha, a nuclear hormone receptor activated by hypolipidemic fibrate drugs. To better understand the role of ThB in hepatic lipid metabolism in mice, Sv129 wild-type and Thb null mice were fed or not the selective PPARalpha agonist Wy14,643 (Wy). Here, it is shown that in contrast to some other mouse models deficient for peroxisomal enzymes, the hepatic PPARalpha signaling cascade in Thb null mice was normal under regular conditions. It is of interest that the hypotriglyceridemic action of Wy was reduced in Thb null mice underlining the conclusion that neither thiolase A nor SCPx/SCP2 thiolase can fully substitute for ThB in vivo. Moreover, a significant increased in the expression of lipogenic genes such as Stearoyl CoA Desaturase-1 (SCD1) was observed in Thb null mice fed Wy. Elevation of Scd1 mRNA and protein levels led to higher SCD1 activity, through a molecular mechanism that is probably SREBP1 independent. In agreement with higher SCD1, enrichment of liver mono-unsaturated fatty acids of the n-7 and n-9 series was found in Thb null mice fed Wy. Overall, we show that the reduced peroxisomal beta-oxidation of fat observed in Thb null mice fed Wy is associated with enhanced hepatic lipogenesis, through the combined elevation of microsomal SCD1 protein and activity. Ultimately, not only the amount but also the quality of the hepatic fatty acid pool is modulated upon the deletion of Thb.

Ciprofibrate is a well-known drug used to normalize lipid parameters and fibrinogen in atherosclerosis patients. In laboratory rodents such as rats or mice, ciprofibrate exhibits peroxisome proliferator activity. However, to date, no clear alterations or side effects caused by ciprofibrate have been noted in humans. In order to further investigate such possible relationships, we studied the effects of sustained ciprofibrate treatment in jerboas (Jaculus orientalis). In these rodents, ciprofibrate does not induce hepatomegaly or promote liver cell DNA replication, confirming that this species more closely resembles humans than do rats or mice. The jerboas were treated daily with ciprofibrate at 3 mg/kg body weight for 4 weeks. Subcellular markers, clinical enzymes and enzymatic antioxidant defenses were then assessed. The results showed a strong decrease in peroxisomal catalase activity and an increase in the level of malondialdehyde (a stress biomarker). Moreover, ciprofibrate in vivo and in vitro inhibited D-3-hydroxybutyrate dehydrogenase, a mitochondrial enzyme of the ketone body interconversion that is important in redox balance (NAD+/NADH+H+ ratio). In conclusion, under these conditions, ciprofibrate induced alterations in the liver oxidative metabolism.

Epidemiological studies suggested that trans-resveratrol, a wine grape component, could prevent malignant tumor development. This compound also demonstrated cytostatic and cytotoxic effects on tumor cells in vitro. To obtain trans-resveratrol derivatives with a better cellular uptake and enhanced antiproliferative effects, we synthesized a triacetate derivative as well as an oligomer, epsilon-viniferin and its acetylated form, epsilon-viniferin penta-acetate. We also obtained vineatrol, a wine grape shoot extract that associates several polyphenols that may act synergistically, including trans-resveratrol and epsilon-viniferin. We show here that resveratrol triacetate and vineatrol are as efficient as trans-resveratrol in inducing the accumulation of human colon cancer cells in early S phase of the cell cycle. This effect is associated with a nuclear redistribution of cyclin A and the formation of a cyclin A/cyclin-dependent kinase 2 complex whose kinase activity is increased. In contrast, epsilon-viniferin and its acetylated form do not demonstrate any significant activity on these cells when tested alone. Interestingly, resveratrol triacetate and vineatrol dramatically enhance 5-Fluoro-Uracil-mediated inhibition of colon cancer cell proliferation. Thus, acetylated derivatives of resveratrol have retained the cytostatic and cytotoxic activities of the parental molecule and thus deserve to be tested as chemosensitizers in animal models., (Copyright 2008 UICC.)

Seasonal obesity and fasting-associated hibernation are the two major metabolic events governing hepatic lipid metabolism in hibernating mammals. In this process, however, the role of the nuclear receptor known as peroxisome proliferator-activated receptor (PPAR)-alpha has not been elucidated yet. Here we show, as in human, that jerboa (Jaculus orientalis) liver expresses both active wild-type PPARalpha (PPARalpha1wt) and truncated PPARalpha forms and that the PPARalpha1wt to truncated PPARalpha2 ratio, which indicates the availability of active PPARalpha1wt, is differentially regulated during fasting-associated hibernation. Functional activation of hepatic jerboa PPARalpha, during prehibernating and hibernating states, was demonstrated by the induction of its target genes, which encode peroxisomal proteins such as acyl-CoA oxidase 1, peroxisomal membrane protein 70, and catalase, accompanied by a concomitant induction of PPARalpha thermogenic coactivator PPARgamma coactivator-1alpha. Interestingly, sustained activation of PPARalpha by its hypolipidemic ligand, ciprofibrate, abrogates the adaptive fasting response of PPARalpha during prehibernation and overinduces its target genes, disrupting the prehibernation fattening process. In striking contrast, during fasting-associated hibernation, jerboas exhibit preferential up-regulation of hepatic peroxisomal fatty acid oxidation instead of the mitochondrial pathway, which is down-regulated. Taken together, our results strongly suggest that PPARalpha is subject to a hibernation-dependent splicing regulation in response to feeding-fasting conditions, which defines the activity of PPARalpha and the activation of its target genes during hibernation bouts of jerboas.

Resveratrol is a well known polyphenol largely produced in grapevine. It is a strong antioxidant and a free radical scavenger. It exhibits several beneficial effects for health including cancer. Resveratrol antioxidant activity is essential in the prevention of chemical-induced cancer by inhibiting initiation step of carcinogenesis process but it is also considered to inhibit cancer promotion and progression steps. While the effects of resveratrol on cancer cells are widely described, the data available on the antiproliferative potential of resveratrol derivatives remain weak. Nevertheless, resveratrol analogs could exhibit stronger potentials than the parent molecule. So, we compared the cellular effects of trans-resveratrol, trans-epsilon-viniferin and their respective acetate derivatives, as well as a polyphenol mixture extracted from grapevine shoots, called vineatrol. We studied their abilities to interfere with cell proliferation, their uptake and their effects on parameters of cellular state in human hepatoma cells (HepG2). Cell growth experiments show that resveratrol triacetate presents a slightly better antiproliferative potential than resveratrol. The dimer epsilon-viniferin,as well as its pentaacetate analog, is less powerful than resveratrol, although a similar uptake kinetics in cells. Interestingly, among the tested polyphenols, vineatrol is the most potent solution, indicating a possible synergistic effect of both resveratrol and epsilon-viniferin. We took advantage of the fluorescence properties of these compounds to evidence cellular uptake by using flow cytometry. In addition, by competition assay, we demonstrate that resveratrol triacetate enters in hepatic HepG2 cells by the same way as resveratrol. By autofluorescence in situ measurement we observed that resveratrol and related compounds induce deep changes in cells activity. These changes occur mainly by increasing NADPH cell content and the number of green fluorescent cytoplasmic granular structures which may be related to an induction of detoxifying enzyme mechanisms.

In order to provide a global analysis of the effects of endocrine disruptors on the hormone cellular bioavailability, we combined 17beta-estradiol (E2) cellular flow studies with real-time PCR and Western blot expression measurements of genes involved in the hormone metabolism and excretion. Three endocrine disruptors commonly found in food were chosen for this study, which was conducted in the estrogen receptor (ER) negative hepatoblastoma HepG2 cell line: bisphenol A (BPA), genistein (GEN) and resveratrol (RES). We showed that 24 h after a single dose treatment with genistein, resveratrol or bisphenol A, the expression of ATP-binding cassette transporters (the multidrug resistance or MDR, and the multidrug resistance associated proteins or MRP) uridine diphosphate-glucuronosyltransferases (UGT) and/or sulfotransferases (ST) involved in 17beta-estradiol elimination process were significantly modulated and that 17beta-estradiol cellular flow was modified. Resveratrol induced MDR1 and MRP3 expressions, bisphenol A induced MRP2 and MRP3 expressions, and both enhanced 17beta-estradiol efflux. Genistein, on the other hand, inhibited ST1E1 and UGT1A1 expressions, and led to 17beta-estradiol cellular retention. Thus, we demonstrate that bisphenol A, genistein and resveratrol modulate 17beta-estradiol cellular bioavailability in HepG2 and that these modulations most probably involve regulations of 17beta-estradiol phase II and III metabolism proteins. Up to now, the estrogenicity of environmental estrogenic pollutants has been based on the property of these compounds to bind to ERs. Our results obtained with ER negative cells provide strong evidence for the existence of ER-independent pathways leading to endocrine disruption.

Background: The interconversion of two important energy metabolites, 3-hydroxybutyrate and acetoacetate (the major ketone bodies), is catalyzed by D-3-hydroxybutyrate dehydrogenase (BDH1: EC 1.1.1.30), a NAD+-dependent enzyme. The eukaryotic enzyme is bound to the mitochondrial inner membrane and harbors a unique lecithin-dependent activity. Here, we report an advanced purification method of the mammalian BDH applied to the liver enzyme from jerboa (Jaculus orientalis), a hibernating rodent adapted to extreme diet and environmental conditions., Results: Purifying BDH from jerboa liver overcomes its low specific activity in mitochondria for further biochemical characterization of the enzyme. This new procedure is based on the use of polyclonal antibodies raised against BDH from bacterial Pseudomonas aeruginosa. This study improves the procedure for purification of both soluble microbial and mammalian membrane-bound BDH. Even though the Jaculus orientalis genome has not yet been sequenced, for the first time a D-3-hydroxybutyrate dehydrogenase cDNA from jerboa was cloned and sequenced., Conclusion: This study applies immunoaffinity chromatography to purify BDH, the membrane-bound and lipid-dependent enzyme, as a 31 kDa single polypeptide chain. In addition, bacterial BDH isolation was achieved in a two-step purification procedure, improving the knowledge of an enzyme involved in the lipid metabolism of a unique hibernating mammal. Sequence alignment revealed conserved putative amino acids for possible NAD+ interaction.

Resveratrol may function as a cancer chemopreventive agent. However, few data are available on the antitumoral activities of its dimer, epsilon-viniferin, also present in human diet. So, the effects of resveratrol, epsilon-viniferin, of their acetylated forms (resveratrol triacetate, epsilon-viniferin pentaacetate) and of vineatrol (a wine grape extract) were compared on human adenocarcinoma colon cells. Resveratrol and resveratrol triacetate inhibit cell proliferation and arrest cell cycle. epsilon-Viniferin and epsilon-viniferin pentaacetate slightly reduce cell proliferation. Vineatrol inhibits cell proliferation and favors an accumulation in the S phase of the cell cycle. Consequently, resveratrol triacetate and vineatrol could constitute new putative anticancer agents on colon carcinoma.

The D-3-hydroxybutyrate dehydrogenase (BDH) (EC 1.1.1.30) from liver jerboa (Jaculus orientalis), a ketone body converting enzyme in mitochondria, in two populations of mitochondria (heavy and light) has been studied in different jerboa states (euthermic, prehibernating and hibernating). The results reveal: (1) important variations between states in terms of ketones bodies, glucose and lipid levels; (2) significant differences between the BDH of the two mitochondrial populations in term of protein expression and kinetic properties. These results suggest that BDH leads an important conformational change depending on the physiological state of jerboa. This BDH structural change could be the consequence of the lipid composition modifications in inner mitochondrial membrane leading to changes in BDH catalytic properties.

trans-Resveratrol is a polyphenol present in several plant species. Its chemopreventive properties against several diseases have been largely documented. To validate a model for the study of the factors influencing its biological fate at the hepatic level, the metabolism and the efflux of resveratrol were studied in the human hepatoblastoma cell line, HepG2. Comparative high-performance liquid chromatography analysis of cell culture media before and after deconjugation showed that resveratrol was rapidly conjugated; at the concentration of 10 microM, it was entirely metabolized at 8 h of incubation. Two main resveratrol metabolites, monosulfate and disulfate, were identified by atmospheric pressure chemical ionization-mass spectrometry, thanks to their quasi-molecular ion and their characteristic fragmentation. To correlate with the auto-induction of resveratrol metabolism evidenced in HepG2 cells after a pretreatment for 48 h with 10 microM resveratrol, the inducibility of phase II enzymes by resveratrol was studied by real-time quantitative reverse transcriptase-polymerase chain reaction and flow cytometry. Observed, in particular, were an increase in mRNA expression levels of three metabolizing enzymes, two isoforms of UDP-glucuronosyltransferases, UGT1A1 and UGT2B7 (5-fold increased), and a sulfotransferase, ST1E1, in cells pretreated for 24 h with 10 microM resveratrol. These results were correlated with an increase in protein expression, especially after 48 h of treatment. On the other hand, the intracellular resveratrol retention in cells treated with MK571 (3-[[3-[2-(7-chloroquinolin-2-yl)vinyl]phenyl]-(2-dimethylcarbamoylethylsulfanyl)methylsulfanyl] propionic acid), a multidrug resistance-associated protein inhibitor, strongly suggests the involvement of this ABC transporter family in the efflux of resveratrol conjugates from human liver.

Resveratrol (3,4',5 tri-hydroxystilbene) is a phytoalexin produced in hudge amount in grapevine skin in response to infection by Bothrytis cinerea. This production of resveratrol blocks the proliferation of the pathogen, thereby acting as a natural antibiotic. Numerous studies have reported interesting properties of trans-resveratrol as a preventive agent against important pathologies i.e. vascular diseases, cancers, viral infection or neurodegenerative processes. Moreover, several epidemiological studies have revealed that resveratrol is probably one of the main microcomponents of wine responsible for its health benefits such as prevention of vaso-coronary diseases and cancer. Resveratrol acts on the process of carcinogenesis by affecting the three phases: tumor initiation, promotion and progression phases and suppresses the final steps of carcinogenesis, i.e. angiogenesis and metastasis. It is also able to activate apoptosis, to arrest the cell cycle or to inhibit kinase pathways. Interestingly, resveratrol does not present any cytotoxicity in animal models. Moreover, concentrations of resveratrol in blood seem to be sufficient for anti-invasive activity. The enterohepatic recirculation may contribute to a delayed elimination of the drug from the body and bring about a prolonged effect. By its binding to plasmatic proteins, resveratrol also exhibits a prolonged effect. Interestingly, low doses of resveratrol can sensitize to low doses of cytotoxic drugs and so provide an innovative strategy to enhance the efficacy of anticancer therapy in various human cancers. By these properties, resveratrol appears to be a good candidate in chemopreventive or chemotherapeutic strategies and is believed to be a novel weapon for new therapeutic strategies.

Mitochondrial membrane-bound and phospholipid-dependent D-beta-hydroxybutyrate dehydrogenase (BDH) (EC 1.1.1.30), a ketone body converting enzyme in mitochondria, has been studied in two populations of mitochondria (heavy and light) of jerboa (Jaculus orientalis) liver. The results reveal significant differences between the BDH of the two mitochondrial populations in terms of protein expression, kinetic parameters and physico-chemical properties. These results suggest that the beta-hydroxybutyrate dehydrogenases from heavy and light mitochondria are isoform variants. These differences in BDH distribution could be the consequence of cell changes in the lipid composition of the inner mitochondrial membrane of heavy and light mitochondria. These changes could modify both BDH insertion and BDH lipid-dependent catalytic properties.

The measurement of the thickness of DNA films on microarray as a function of the medium (liquid, air) is gaining importance for understanding the signal response of biosensors. Thiol group has been used to attach DNA strands to gold micropads deposited on silicon surface. Atomic force microscopy (AFM) was employed in its height mode to measure the change in the pad thickness and in its force mode to measure the indentation depth of the nanofilm. A good coherence between the height and force modes is observed for the film thickness in air. The adhesion force was found to be an alternative way to measure the surface coverage of the biolayer at nanoscopic scale. However the force analysis (compression, steric and electrostatic) provides baseline information necessary to interpret the AFM height image in liquid. Analysis of the film thickness distribution shows that the height of the DNA strands depends on both the DNA strand length (15-35 base pairs) and the environment (air, liquid). In air, longer strands lay down onto gold surface whereas the charge reversal of gold in liquid causes a repulsion of longer strands, which stand up.

Humans appear to be refractory to some effects of peroxisome proliferators including alterations in cell proliferation, whereas rodents are susceptible. In this study, differences between the human and rat response to peroxisome proliferators were evaluated using rat and human tumour liver cell lines. Rat 7777 cells were more responsive than human HepG2 cells to ciprofibrate as they exhibited a higher decrease in cell number than HepG2, and underwent apoptosis. Results from these studies reveal a surprising response in tumour cell lines as the typical in vivo response of increased cell proliferation and reduced apoptosis was not observed in rat tumour cell lines at concentrations greater than those used to elicit the former response.

Cardiovascular diseases are the leading cause of death in developed countries where the common pathological substrate underlying this process is atherosclerosis. Several new concepts have emerged in relation to mechanisms that contribute to the regulation of the vascular diseases and associated inflammatory effects. Recently, potential antioxidants (vitamin E, polyphenols) have received much attention as potential anti-atherosclerotic agents. Among the polyphenols with health benefic properties, resveratrol, a phytoalexin of grape, seem to be a good candidate protecting the vascular walls from oxidation, inflammation, platelet aggregation, and thrombus formation. In this review, we focus on the mechanism of resveratrol cardiovascular benefic effects. We analyze, in relation with the different steps of atherosclerotic process, the resveratrol properties at multiple levels, such as cellular signaling, enzymatic pathways, apoptosis, and gene expression. We show and discuss the relationship with reactive oxygen species, regulation of pro-inflammatory genes including cycloxygenases and cytokines in molecular inflammatory and aging processes, and how the regulation of these activites by resveratrol can lead to a prevention of vascular diseases.

The natural phytoalexin resveratrol (3, 5, 4'-trihydroxystilbene) exhibits both chemopreventive and antitumor activities through a variety of mechanisms. We have shown previously that resveratrol-induced apoptosis of a human colon cancer cell line involved the redistribution of CD95 (Fas/Apo-1) into lipid rafts. Here, we show that, in colon cancer cells that resist to resveratrol-induced apoptosis, the polyphenol also induces a redistribution of death receptors into lipid rafts. This effect sensitizes these tumor cells to death receptor-mediated apoptosis. In resveratrol-treated cells, tumor necrosis factor (TNF), anti-CD95 antibodies and TNF-related apoptosis-inducing ligand (TRAIL) activate a caspase-dependent death pathway that escapes Bcl-2-mediated inhibition. Resveratrol does not enhance the number of death receptors at the surface of tumor cells but induces their redistribution into lipid rafts and facilitates the caspase cascade activation in response to death receptor stimulation. The cholesterol sequestering agent nystatin prevents resveratrol-induced death receptor redistribution and cell sensitization to death receptor stimulation. Thus, whatever its ability to induce apoptosis in a tumor cell, resveratrol induces redistribution of death receptors into lipid rafts. This redistribution sensitizes the cells to death receptor stimulation. Such a sensitizing effect may be of therapeutic interest if TRAIL agonists are introduced in clinics.

The peroxisomal beta-oxidation system consists of four steps catalysed by three enzymes: acyl-CoA oxidase, 3-hydroxyacyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase (multifunctional enzyme) and thiolase. In humans, thiolase activity is encoded by one gene, whereas in rodents, three enzymes encoded by three distinct genes (i.e. thiolase A, thiolase B and SCP2/thiolase) catalyse the thiolase activity. So far, acyl-CoA oxidase- and multifunctional enzyme-deficient patients have been identified and knock-out mice for these genes have been produced. Conversely, no isolated thiolase-deficient patient has been found, and no thiolase (A or B)-deficient mice have been generated. Hence, to better understand the cause of isolated human thiolase deficiency, we disrupted the catalytic site of the mouse thiolase B by homologous recombination in order to analyse the phenotype of these thiolase B-deficient mice. Mice, made homozygous for the mutation, lack expression of thiolase B mRNA and are viable, fertile and healthy at birth. They exhibit no detectable phenotype defects and no compensation, rather a slight decrease in other peroxisomal thiolase (thiolase A and SCPx) mRNAs, was found.