71,791 research outputs found
Involvement of UDP-Glucuronosyltransferases and Sulfotransferases in the Excretion and Tissue Distribution of Resveratrol in Mice.
Resveratrol is a naturally occurring polyphenolic compound with various pharmacological activities. It is unknown whether the expression of metabolizing enzymes correlates with resveratrol levels in organs and tissues. Therefore, we investigated the metabolism and tissue distribution of resveratrol in mice and assessed its association with the expression of UDP-glucuronosyltransferase (Ugt) and sulfotransferase (Sult) genes. Plasma, urine, feces, and various organs were analyzed using high-performance liquid chromatography at up to 8 h after intragastric resveratrol administration. The metabolism of resveratrol was pronounced, leading to the formation of resveratrol glucuronides and sulfates. Concentrations of resveratrol and its metabolites were high in the gastrointestinal organs, urine, and feces, but low in the liver and kidneys. In lung, heart, thymus, and brain tissues, parent resveratrol levels exceeded the sulfate and glucuronide concentrations. The formation of resveratrol conjugates correlated with the expression of certain Ugt and Sult genes. Reverse transcription quantitative PCR (RT-qPCR) analysis revealed high mRNA expression of Ugt1a1 and Ugt1a6a in the liver, duodenum, jejunum, ileum, and colon, leading to high concentrations of resveratrol-3-O-glucuronide in these organs. Strong correlations of resveratrol-3-O-sulfate and resveratrol-3-O-4'-O-disulfate formation with Sult1a1 mRNA expression were also observed, particularly in the liver and colon. In summary, our data revealed organ-specific expression of Sults and Ugts in mice that strongly affects resveratrol concentrations; this may also be predictive in humans following oral uptake of dietary resveratrol
Resveratrol given intraperitoneally does not inhibit the growth of high-risk t(4;11) acute lymphoblastic leukemia cells in a NOD/SCID mouse model.
The efficacy of resveratrol as a preventive agent against the growth of t(4;11) acute lymphoblastic leukemia (ALL) was evaluated in NOD.CB17-Prkdcscid/J mice engrafted with the human t(4;11) ALL SEM cell line. SEM cells were injected into the tail vein and engraftment was monitored by flow cytometry. Once engraftment was observed, mice were injected intraperitoneally with resveratrol (10 mg/kg body weight) dissolved in dimethylsulfoxide (DMSO) or DMSO alone (control) every other day, or vincristine (0.5 mg/kg body weight) 3 times per week for 4 weeks (n=16 per group). Comparisons of the percent of human leukemia cells in blood and survival curves showed resveratrol did not inhibit progression of the disease. Liquid chromatography-tandem mass spectrometry analyses of mouse sera showed resveratrol was rapidly metabolized to glucuronidated and sulfated forms 1 h post-injection, with low to no resveratrol or metabolites observed in sera by 24-48 h. These data indicate that in contrast to findings in in vitro models, parenterally administered resveratrol does not have potential as a preventive agent against high risk t(4;11) ALL
Six Weeks of Resveratrol Improves Cardiovascular Health in Patients with COPD
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. One-third of people diagnosed with COPD die of cardiovascular (CV) complications as opposed to pulmonary. Despite these odds, there are no therapies that mitigate this important health issue. Resveratrol, a naturally occurring antioxidant, improves CV health in other populations. However, there is currently no literature on resveratrol in patients with COPD. The purpose of this pilot study was to test if six weeks of resveratrol supplementation could improve CV health in patients with COPD. METHODS: A randomized, double-blind, pilot trial was completed in 8 patients with COPD. Participants were given either resveratrol (n=5; 500 mg) or placebo (n=3) for six weeks. CV health was measured before and after treatment through arterial stiffness and 6-Minute Walk Test (6MWT). RESULTS: Six weeks of resveratrol improved arterial stiffness in patients with COPD through reductions in augmentation index and pulse pressure amplification. Improvements in total 6MWT distance were also observed after six weeks of resveratrol. No changes after placebo were observed in any of the measurements. CONCLUSIONS: Our results suggest that six weeks of resveratrol improves markers of CV health in patients with COPD. Future studies are warranted to expand this pilot study and understand the potential role of resveratrol in COPD CV health.https://scholarscompass.vcu.edu/gradposters/1110/thumbnail.jp
Effect of DNA repair deficiencies on the cytotoxicity of resveratrol
Numerous preclinical studies have shown that the
naturally-occurring polyphenol resveratrol may
produce health-beneficial effects in a variety of
disorders, including cancer, diabetes, Alzheimer, and
cardiovascular diseases. Resveratrol has entered
clinical trials for the prevention and treatment of
several of these disorders. This polyphenol is also
available in the market as a dietary supplement.
Experimental data have shown, however, that
resveratrol induces DNA damage in a variety of cells.
Here we review such evidence and evaluate the
cytotoxicity of resveratrol (MTT assay) in cells deficient
in several major DNA repair pathways (i.e.,
homologous recombination, non-homologous end
joining, base excision repair, nucleotide excision repair,
mismatch repair, and Fanconi anemia repair). Cells
deficient in base excision repair (EM9), nucleotide
excision repair (UV4 and UV5) and Fanconi Anemia
(KO40) were slightly hypersensitive to
resveratrol-induced cytotoxicity with respect to their
parental cells (AA8). Our results suggest that these
pathways may participate in the repair of the DNA
damage induced by resveratrol and that deficiencies in
these pathways may confer hypersensitivity to the
genotoxic activity of this dietary constituen
ISOLATION AND IDENTIFICATION STRUCTURE OF RESVERATROL AND THEIR ACTIVITY TEST AS ANTIOXIDANT AND UV-B PROTECTION FROM STEM BARK OF MELINJO (GNETUM GNEMON)
Resveratrol (1) had been isolated from the stem bark of melinjo (Gnetum gnemon). The structure of this compound were elucidated based on physical and spectroscopic data (UV, IR, 1H and 13C NMR). The compound showed as radical hidroxyl scavenger (IC50 45,17 g/ml) and has maximum protection at 50 g/ml with SPF 8,03. These results suggest that resveratrol from stem bark of melinjo may be useful as potential sources of natural antioxidants and UV-B protection. Key word: resveratrol, gnetum gnemon, antioxidant, UV-B protection FMIPA, 2006 (PEND. KIMIA
Effects of Polyphenols on Oxidative Stress-Mediated Injury in Cardiomyocytes
Cardiovascular diseases are the main cause of mortality and morbidity in the world. Hypertension, ischemia/reperfusion, diabetes and anti-cancer drugs contribute to heart failure through oxidative and nitrosative stresses which cause cardiomyocytes nuclear and mitochondrial DNA damage, denaturation of intracellular proteins, lipid peroxidation and inflammation. Oxidative or nitrosative stress-mediated injury lead to cardiomyocytes apoptosis or necrosis. The reactive oxygen (ROS) and nitrogen species (RNS) concentration is dependent on their production and on the expression and activity of anti-oxidant enzymes. Polyphenols are a large group of natural compounds ubiquitously expressed in plants, and epidemiological studies have shown associations between a diet rich in polyphenols and the prevention of various ROS-mediated human diseases. Polyphenols reduce cardiomyocytes damage, necrosis, apoptosis, infarct size and improve cardiac function by decreasing oxidative stress-induced production of ROS or RNS. These effects are achieved by the ability of polyphenols to modulate the expression and activity of anti-oxidant enzymes and several signaling pathways involved in cells survival. This report reviews current knowledge on the potential anti-oxidative effects of polyphenols to control the cardiotoxicity induced by ROS and RNS stress
In Vitro Toxicity Assessment of Stilbene Extract for Its Potential Use as Antioxidant in the Wine Industry
The reduction of sulfur dioxide in wine is a consumer’s demand, considering the allergic effects that may occur in people who are sensitive to it. Stilbenes are candidates of great interest for this purpose because of their antioxidant/antimicrobial activities and health properties, and also because they are naturally found in the grapevine. In the present study, the in vitro toxicity of an extract from grapevine shoots (with a stilbene richness of 45.4%) was assessed in two human cell lines. Significant damage was observed from 30 μg/mL after 24 h, and 40 µg/mL after 48 h of exposure. Similarly, the ultrastructural study revealed a significant impairment of cell growing. The extract was able to protect cells against an induced oxidative stress at all concentrations studied. In view of the promising results, a more exhaustive toxicological assessment of the extract is needed to confirm the safety of its further use as additive in wine.España,Ministerio de Economía, Industria y Competitividad and INIA for the financial support for this project (RTA2015-00005-C02-02
Suppression of 12-O-tetradecanoylphorbol-13-acetate-induced ornithine decarboxylase activity by resveratrol derivatives
As demonstrated previously, resveratrol (3,4',5-trihydroxy-trans-stilbene) inhibits 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ornithine decarboxylase (ODC), the key rate limiting enzyme in mammalian polyamine synthesis. Using human bladder epithelial carcinoma HTB-24 cells in culture where resveratrol inhibits induction with an IC50 of 8.8 µM, we now report potential metabolites demonstrate greater activity [tetrabutylammonium (E)-4-(3,5-dihydroxystyryl)phenyl sulfate (IC50 1.2 µM), resveratrol tripotassium 3,5,4'-trisulfate (IC50 1.8 µM), resveratrol tripotassium 3,4'-disulfate (IC50 1.8 µM), and resveratrol tripotassium 3,5-disulfate (IC50 2.3 µM)]. Based on RT-PCR studies, ODC inhibition occurs at the transcriptional level, but this was not due to direct inhibition of protein kinase C (e.g., resveratrol IC50, 79 µM; resveratrol tripotassium 3,5-disulfate IC50, 49 µM). Additional work is underway to more fully investigate this potentially important observation. [This work was supported by program project P01 CA48112 awarded by the National Cancer Institute. SL acknowledges Indo-US Science and Technology Forum (IUSSTF), New Delhi for a Research Fellowship]
Nanostructured Chitosan-Based Biomaterials for Sustained and Colon-Specific Resveratrol Release
In the present work, we demonstrate the preparation of chitosan-based composites as vehicles of the natural occurring multi-drug resveratrol (RES). Such systems are endowed with potential therapeutic effects on inflammatory bowel diseases (IBD), such as Crohn’s disease (CD) and ulcerative colitis, through the sustained colonic release of RES from long-lasting mucoadhesive drug depots. The loading of RES into nanoparticles (NPs) was optimized regarding two independent variables: RES/polymer ratio, and temperature. Twenty experiments were carried out and a Box–Behnken experimental design was used to evaluate the significance of these independent variables related to encapsulation efficiency (EE). The enhanced RES EE values were achieved in 24 h at 39 °C and at RES/polymer ratio of 0.75:1 w/w. Sizes and polydispersities of the optimized NPs were studied by dynamic light scattering (DLS). Chitosan (CTS) dispersions containing the RES-loaded NPs were ionically gelled with tricarballylic acid to yield CTS-NPs composites. Macro- and microscopic features (morphology and porosity studied by SEM and spreadability), thermal stability (studied by TGA), and release kinetics of the RES-loaded CTS-NPs were investigated. Release patterns in simulated colon conditions for 48 h displayed significant differences between the NPs (final cumulative drug release: 79–81%), and the CTS-NPs composites (29–34%)
- …
