stilbenes and Hemolysis

Fluorogens with aggregation-induced emission (AIE) characteristics (AIEgens) possess unique optical properties, design flexibility, and multi-functional capabilities and have established their niche as smart materials since their discovery in 2001. In recent years, AIEgens have found varied applications in sensing, imaging, and therapy in biomedical research. In this work, we systematically and comprehensively investigate the in vitro anticancer activity of AIEgens. We report the high cytotoxicity of AIEgens against cancer cells, especially against cancer stem cells (CSCs) which show high resistance to existing therapeutic drug regimens. Furthermore, we explore the role of AIEgens as novel image-guided chemotherapy agents that offer a new avenue for efficient cancer treatment.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Survival; Fluorescent Dyes; Hemolysis; Humans; Neoplasm Invasiveness; Neoplastic Stem Cells; Optical Imaging; Photochemotherapy; Photosensitizing Agents; Stilbenes; Theranostic Nanomedicine

The present investigation reports the development of PEG-modified liposomes for the delivery of naturally occurring resveratrol. PEG-modified liposomes were prepared by direct sonication of the phospholipid aqueous dispersion, in the presence of two PEG-surfactants. Small, spherical, unilamellar vesicles were produced, as demonstrated by light scattering, cryo-TEM, and SAXS. The aging of the vesicles was assessed by using the Turbiscan

Topics: Antioxidants; Drug Carriers; Drug Compounding; Drug Delivery Systems; Drug Stability; Dynamic Light Scattering; Erythrocytes; Free Radical Scavengers; Hemolysis; Humans; Liposomes; Oxidative Stress; Phospholipids; Polyethylene Glycols; Resveratrol; Stilbenes; Surface-Active Agents

This study was conducted to explore the potential benefits of using cinnamaldehyde (CIN), resveratrol (RES) separately or in combination on cyadox (CYA)-induced alterations in isolated rabbit erythrocytes. Erythrocytes suspensions were partitioned into 7 groups (5 replicates/group), 1st kept as control treated with phosphate buffered saline (PBS) with dimethyl sulphoxide (DMSO); 2nd group was subjected to CYA (40 μg/ml), 3rd group was incubated with CIN (40 μM), 4th group was subjected to RES (40 μM), 5th group was co-exposed to CYA (40 μg/ml) and CIN (40 μM), 6th group was co exposed to CYA (40 μg/ml) and RES (40 μM), and 7th group was exposed to CYA in combination with both CIN and RES at the same indicated concentrations. The reaction mixtures of different groups were incubated at 37 °C for 3 h with gentle shaking every 15 minutes. Our results revealed that exposure to CYA caused a significant decrease (linear and quadratic) in superoxide dismutase (SOD) and catalase (CAT) activities and the contents of reduced glutathione (GSH) and glutathione transferase (GST). Incubation of erythrocytes with CYA increased GSSG content, GSSG/GSH ratio, malonaldehyde (MDA) and protein carbonyl (PrC) concentrations while it decreased the total protein (TP). CYA also lead to hemolysis and energy depletion of erythrocytes beside activation of caspase cascades, suggesting the pro-oxidant effect CYA that could be implicated in eryptosis. CIN and RES were able to inverse these hazardous effects of CYA. However, CIN was more effective than RES, their combination showed a positive synergistic effect in protecting the cells against oxidative injury caused by CYA.

Topics: Acrolein; Animals; Antioxidants; Biomarkers; Biphenyl Compounds; Cytoprotection; Dose-Response Relationship, Drug; Drug Synergism; Energy Metabolism; Enzymes; Eryptosis; Erythrocytes; Glutathione; Hemoglobins; Hemolysis; Lipid Peroxidation; Male; Malondialdehyde; Oxidative Stress; Picrates; Protein Carbonylation; Quinoxalines; Rabbits; Resveratrol; Stilbenes

Resveratrol (RV) is a potent antioxidant, anticancer and anti-inflammatory agent. Its main target of action is the cell membrane; however, its effect on that of human erythrocytes has been scarcely investigated. With the aim to better understand the molecular mechanisms of the interaction of RV with cell membranes both human erythrocytes and molecular models of its membrane have been utilized. The latter consisted in bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of the erythrocyte membrane, respectively. Results by X-ray diffraction showed that RV produced a significant structural perturbation on DMPC bilayers, but no effects were observed in DMPE. Scanning electron (SEM) and defocusing microscopy (DM) observations showed that RV induced morphological alterations to the red cells from the normal discoid shape to echinocytes. These results imply that RV was located in the outer monolayer of the erythrocyte membrane. Results of its antioxidant properties showed that RV neutralized the oxidative capacity of HClO on DMPC and DMPE bilayers. On the other hand, SEM and DM observations as well as hemolysis assays demonstrated the protective effect of RV against the deleterious effects of HClO upon human erythrocytes.

Topics: Antioxidants; Dimyristoylphosphatidylcholine; Dose-Response Relationship, Drug; Erythrocyte Membrane; Erythrocytes; Hemolysis; Humans; Hypochlorous Acid; Lipid Bilayers; Microscopy; Microscopy, Electron, Scanning; Molecular Structure; Oxidants; Oxidative Stress; Phosphatidylethanolamines; Protective Agents; Resveratrol; Stilbenes; X-Ray Diffraction

The emergence of antibiotic resistant Staphylococcus aureus presents a worldwide problem that requires non-antibiotic strategies. This study investigated the anti-biofilm and anti-hemolytic activities of four red wines and two white wines against three S. aureus strains. All red wines at 0.5-2% significantly inhibited S. aureus biofilm formation and hemolysis by S. aureus, whereas the two white wines had no effect. Furthermore, at these concentrations, red wines did not affect bacterial growth. Analyses of hemolysis and active component identification in red wines revealed that the anti-biofilm compounds and anti-hemolytic compounds largely responsible were tannic acid, trans-resveratrol, and several flavonoids. In addition, red wines attenuated S. aureus virulence in vivo in the nematode Caenorhabditis elegans, which is killed by S. aureus. These findings show that red wines and their compounds warrant further attention in antivirulence strategies against persistent S. aureus infection.

Topics: Animals; Anti-Bacterial Agents; Biofilms; Caenorhabditis elegans; Erythrocytes; Flavonoids; Hemolysis; Humans; Quercetin; Resveratrol; Staphylococcus aureus; Stilbenes; Tannins; Virulence; Wine

Stilbenoids have a broad range of beneficial health effects. On the other hand, the emergence of antibiotic-resistant Staphylococcus aureus presents a worldwide problem that requires new antibiotics or nonantibiotic strategies. S. aureus produces α-hemolysin (a pore-forming cytotoxin) that has been implicated in the pathogenesis of sepsis and pneumonia. Furthermore, the biofilms formed by S. aureus constitute a mechanism of antimicrobial resistance. In this study, we investigated the hemolytic and antibiofilm activities of 10 stilbene-related compounds against S. aureus. trans-Stilbene and resveratrol at 10 μg/mL were found to markedly inhibit human blood hemolysis by S. aureus, and trans-stilbene also inhibited S. aureus biofilm formation without affecting its bacterial growth. Furthermore, trans-stilbene and resveratrol attenuated S. aureus virulence in vivo in the nematode Caenorhabditis elegans, which is normally killed by S. aureus. Transcriptional analysis showed that trans-stilbene repressed the α-hemolysin hla gene and the intercellular adhesion locus (icaA and icaD) in S. aureus, and this finding was in line with observed reductions in virulence and biofilm formation. In addition, vitisin B, a stilbenoid tetramer, at 1 μg/mL was observed to significantly inhibit human blood hemolysis by S. aureus.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Bacterial Toxins; Biofilms; Caenorhabditis elegans; Hemolysin Proteins; Hemolysis; Humans; Staphylococcal Infections; Staphylococcus aureus; Stilbenes; Virulence

Resveratrol is a plant-derived polyphenol with chemotherapeutic properties in animal cancer models and many biochemical effects in vitro. Its bioavailability is low and raises the possibility that the metabolites of resveratrol have biological effects. Here we investigate the actions of resveratrol 3-O-D-glucuronide, resveratrol 4-O-D-glucuronide, and resveratrol 3-O-Dsulfate on the growth of colon cancer cells in vitro.. The growth of Caco-2, HCT-116, and CCL-228 cells was measured using the neutral red and MTT assays. Resveratrol and each metabolite inhibited cell growth with IC50 values of 9.8–31 μM. Resveratrol caused S phase arrest in all three cell lines. Resveratrol 3-O-D-glucuronide and resveratrol 4-O-D-glucuronide caused G1 arrest in CCL-228 and Caco-2 cells. Resveratrol 3-O-D-sulfate had no effect on cell cycle. Growth inhibition was reversed by an inhibitor of AMP-activated protein kinase (compound C) or an adenosine A3 receptor antagonist (MRS1191). The A3 receptor agonist 2Cl-IB-MECA inhibited growth and A3 receptors were detected in all cell lines. The resveratrol glucuronides also reduced cyclin D1 levels but at higher concentrations than in growth experiments and generally did not increase phosphorylated AMP-activated protein kinase.. Resveratrol glucuronides inhibit cell growth by G1 arrest and cyclin D1 depletion, and our results strongly suggest a role for A3 adenosine receptors in this inhibition.

Topics: Adenosine A3 Receptor Antagonists; AMP-Activated Protein Kinases; Apoptosis; Caco-2 Cells; Cell Line, Tumor; Cell Proliferation; Cell Survival; Colonic Neoplasms; Cyclin D1; G1 Phase Cell Cycle Checkpoints; Glucuronides; Hemolysis; Humans; Receptor, Adenosine A3; Resveratrol; Stilbenes

Resveratrol (3,5,4'-trihydroxystilbene, RES), a star among dietary polyphenols, shows a wide range of biological activities, but it is rapidly and extensively metabolized into its glucuronide and sulfate conjugates as well as to the corresponding reduced products. This begs the question of whether the metabolites of RES contribute to its in vivo biological activity. To explore this possibility, we synthesized its glucuronidation (3-GR and 4'-GR) and reduction (DHR) metabolites, and evaluated the effect of these structure modifications on biological activities, including binding ability with human serum albumin (HSA), antioxidant activity in homogeneous solutions and heterogeneous media, anti-inflammatory activity, and cytotoxicity against various cancer cell lines. We found that 1) 4'-GR, DHR and RES show nearly equal binding to HSA, mainly through hydrogen bonding, whereas 3-GR adopts a quite different orientation mode upon binding, thereby resulting in reduced ability; 2) 3-GR shows comparable (even equal) ability to RES in FRAP- and AAPH-induced DNA strand breakage assays; DHR, 3-GR, and 4'-GR exhibit anti-hemolysis activity comparable to that of RES; additionally, 3-GR and DHR retain some degree activity of the parent molecule in DPPH.-scavenging and cupric ion-initiated oxidation of LDL assays, respectively; 3) compared to RES, 4'-GR displays equipotent ability in the inhibition of COX-2, and DHR presents comparable activity in inhibiting NO production and growth of SMMC-7721 cells. Relative to RES, its glucuronidation and reduction metabolites showed equal, comparable, or some degree of activity in the above assays, depending on the specific compound and test model, which probably supports their roles in contributing to the in vivo biological activities of the parent molecule.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Binding Sites; Cell Line, Tumor; Cell Survival; Drug Screening Assays, Antitumor; Glucuronides; Hemolysis; Humans; Kinetics; Mice; Molecular Docking Simulation; Oxidation-Reduction; Protein Binding; Protein Structure, Tertiary; Resveratrol; Serum Albumin; Stilbenes

Microparticles of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL) containing resveratrol were successfully prepared by simple emulsion/solvent evaporation. All formulations showed suitable encapsulation efficiency values higher than 80%. PHBV microparticles revealed spherical shape with rough surface and presence of pores. PCL microparticles were spherically shaped with smooth surface. Fourier-transformed infrared spectra demonstrated no chemical bond between resveratrol and polymers. X-ray powder diffraction patterns and differential scanning calorimetry analyses indicated that microencapsulation led to drug amorphization. These PHBV/PCL microparticles delayed the dissolution profile of resveratrol. Release profiles were better fitted to biexponential equation. The hypochlorous-acid-scavenging activity and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation discoloration assay confirmed that the antioxidant activity of PHBV/PCL microparticles was kept, but was dependent on the microparticle morphology and dissolution profile. Resveratrol-loaded PHBV/PCL microparticles showed no cytotoxic effect on red blood cells.

Topics: Antioxidants; Calorimetry, Differential Scanning; Drug Carriers; Erythrocytes; Hemolysis; Humans; Microscopy, Electron, Scanning; Particle Size; Polyesters; Resveratrol; Stilbenes; Thermogravimetry

The reactions of resveratrol with proinflammatory oxidants including hypochlorous and hypobromous acids in phosphate-buffered saline/methanol solution were carried out and eight halogenated resveratrol derivatives differing in the number and position of halogen atoms, and the configuration of double bond were obtained. Halogenation of resveratrol took place only at the aromatic A ring, and interestingly, the halogenation increased antioxidant activity of this parent molecule in the 2,2'-azobis(2-amidinopropane) hydrochloride-induced RBC haemolysis model. Additionally, antimicrobial activity of the derivatives against Gram-positive bacteria, Gram-negative bacteria and fungi were tested, and toward Candida albicans, 2-chloro-resveratrol and 2-bromo-resveratrol were more active than the unmodified form and the reference compound fluconazole.

Topics: Anti-Infective Agents; Antioxidants; Bacteria; Bromates; Cell Line; Fungi; Halogenation; Hemolysis; Humans; Hypochlorous Acid; Molecular Structure; Resveratrol; Stilbenes; Structure-Activity Relationship

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a naturally occurring polyphenol widely distributed in food and dietary plants. This phytochemical has been intensively studied as an efficient antioxidant and anticancer agent, and a variety of substituted stilbenes have been developed in order to improve the potency of resveratrol. In this work, we described the synthesis of 3,4,4 -trihydroxy-trans-stilbene (3,4,4'-THS), an analogue of resveratrol, and studied its antioxidant and cytotoxic activity in vitro. 3,4,4 -THS was much more efficient than resveratrol in protecting against free radical-induced lipid peroxidation, photo-sensitized DNA oxidative damage, and free radical-induced hemolysis of human red blood cells. More potent growth inhibition in cultured human leukemia cells (HL-60) was also observed for 3,4,4 -THS. The relationship between the antioxidant efficiency and cytotoxic activity was discussed, with the emphasis on inhibition of the free radical enzyme ribonucleotide reductase by antioxidants. The result that this subtle structure modification of resveratrol drastically improves its bioactivity provides important strategy to develop novel resveratrol-based molecules.

Topics: Anisoles; Antineoplastic Agents; Antioxidants; Cell Proliferation; DNA Damage; Free Radicals; Hemolysis; HL-60 Cells; Humans; Kinetics; Linoleic Acid; Lipid Peroxidation; Molecular Structure; Oxidative Stress; Resveratrol; Stilbenes; Structure-Activity Relationship

There is evidence that a diet rich in fruit and vegetables may reduce the risk of cancer and other degenerative diseases. However, potential health impact of bioactive phytochemicals is limited by their low amount and relatively poor bioavailability. It has been suggested that the health benefits associated with fruit and red wine consumption could be due to the whole antioxidant pool of the diet microcomponents. In this study, the antioxidant activities of trans-resveratrol, pterostilbene and quercetin, and the effect of their combination were investigated in human erythrocytes in vitro. H(2)O(2)-induced lipid peroxidation was assessed by measuring the amount of thiobarbituric acid reactive species. Quercetin and pterostilbene protected erythrocyte membranes against lipid peroxidation (IC(50) values = 64 +/- 8.7 microM and 44.5 +/- 7.8 microM, respectively). Resveratrol was significantly less effective. However, the three compounds protected the erythocytes against hemolysis and GSH (reduced glutathione) depletion to the same extent. Combinations consisting of two compounds (molar ratio 1:1) influenced lipid peroxidation in a concentration-dependent manner. At lower concentrations, resveratrol with quercetin or pterostilbene inhibited synergistically the oxidative injury of membrane lipids At higher concentrations, an additive effect was observed. These protective effects may partially explain the health benefit of these bioactive microcomponents when together in the diet.

Topics: Antioxidants; Cell Membrane; Dose-Response Relationship, Drug; Drug Combinations; Drug Synergism; Erythrocytes; Glutathione; Hemolysis; Humans; Hydrogen Peroxide; Lipid Metabolism; Lipid Peroxidation; Plant Extracts; Quercetin; Resveratrol; Stilbenes

This work deals with the preparation of stilbene-based resveratrol analogs by employing the Perkin reaction, aiming at synthesizing potential antitumor lead compounds and evaluating their pharmacological activities. The proliferation inhibitor test against tumor cell lines identified analogs 9 and 11 as the most active among all synthesized derivatives, presenting IC(50) in micromolar range for certain cell lines. For study on the embryonic development, compounds 8 and 9 at the lowest tested concentration (41.7 microM) that inhibited sea urchin egg development, but only after third cleavage were used. Both the compounds inhibited 100% of normal development since first cleavage. These data partially corroborated the results obtained with MTT assay using tumor cell lines. None of the tested compounds revealed hemolytic action in assay with mouse erythrocytes.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Screening Assays, Antitumor; Embryonic Development; Erythrocytes; Hemolysis; Humans; Inhibitory Concentration 50; Mice; Ovum; Resveratrol; Sea Urchins; Stilbenes

Bile acids are a special group of biological surfactants which can express different physiological and pharmacological effects. Micellar solutions of bile acids can solubilizate poorly soluble organic substances and improve their resorbtion. Above their critical micellar concentration (CMC) values, bile acids can cause interruption of membrane's integrity. Resveratrol (trans-3,5,4'-trihydroxystilbene) is a stilbene phytoalexine and studies reported that it can prevent or reduce diseases such as cancer and coronary heart disease. In this study, we examined affinity of different bile acids (CA, 12-MDCA, 12-MCA, 7-MCA, 7,12-DCA, 3,7,12-TCA) micellar solutions for resveratrol solubilization. CMC values for bile acids were determined by conductivity measurements. Concentration of micellar solutions were 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0 CMC value, for each acid respectively. At the same time, we investigated membranolytical potential of each acid. Solubilizated resveratrol was quantified using HPLC system with UV detection. Membranolytical potential was determined from citrate rabbit blood. Structures of mixed micelles of each bile acid and resveratrol were explained, and multiple linear regression equations for solubilization of resveratrol on different concentrations of bile acids were obtained. Micellar solution of 3,7,12-TCA had the biggest affinity for resveratrol solubilization and then, in decreasing order 7-MCA>7, 12-DCA>12-MCA>12-MDCA>CA. Also, 3,7,12-TCA had the lowest membranolytical potential.

Topics: Animals; Bile Acids and Salts; Buffers; Cluster Analysis; Conductometry; Hemolysis; Micelles; Rabbits; Regression Analysis; Resveratrol; Solubility; Solutions; Stilbenes

An emulsion system composed of vitamin E, coconut oil, soybean phosphatidylcholine, non-ionic surfactants, and polyethylene glycol (PEG) derivatives (referred to as the tocol emulsion) was characterized in terms of its physicochemical properties, drug release, in vivo efficacy, toxicity, and stability. Systems without vitamin E (referred to as the lipid emulsion) and without any oils (referred to as the aqueous micelle system) were prepared for comparison. A lipophilic antioxidant, resveratrol, was used as the model drug for emulsion loading. The incorporation of Brij 35 and PEG derivatives reduced the vesicle diameter to <100nm. The inclusion of resveratrol into the emulsions and aqueous micelles retarded the drug release. The in vitro release rate showed a decrease in the order of aqueous micelle system>tocol emulsion>lipid emulsion. Treatment of resveratrol dramatically reduced the intimal hyperplasia of the injured vascular wall in rats. There was no significant difference in this reduction when resveratrol was delivered by either emulsion or the aqueous micelle system. The percentages of erythrocyte hemolysis by the emulsions and aqueous micelle system were approximately 0 and approximately 10%, respectively. Vitamin E prevented the aggregation of emulsion vesicles. The mean vesicle size of the tocol emulsion remained unchanged during 30 days at 37 degrees C. The lipid emulsion and aqueous micelle system, respectively, showed 11- and 16-fold increases in vesicle size after 30 days of storage.

Topics: Animals; Antioxidants; Biphenyl Compounds; Carotid Stenosis; Chemistry, Pharmaceutical; Coconut Oil; Disease Models, Animal; Drug Carriers; Drug Compounding; Emulsions; Hemolysis; Male; Micelles; Oils; Particle Size; Phosphatidylcholines; Picrates; Plant Oils; Polyethylene Glycols; Rats; Rats, Sprague-Dawley; Resveratrol; Solubility; Stilbenes; Surface-Active Agents; Technology, Pharmaceutical; Time Factors; Vitamin E

Acoustically active lipospheres (AALs) were prepared using perfluorocarbons and coconut oil as the cores of inner phase. These AALs were stabilized using coconut oil and phospholipid coatings. A lipophilic antioxidant, resveratrol, was the model drug loaded into the AALs. AALs with various percentages of perfluorocarbons and oil were prepared to examine their physicochemical and drug release properties. Co-emulsifiers such as Brij 98 and Pluronic F68 (PF68) were also incorporated into AALs for evaluation. AALs with high resveratrol encapsulation rates ( approximately 90%) were prepared, with a mean droplet size of 250-350nm. The AALs produced with perfluorohexane as the core material had larger particle sizes than those with perfluoropentane. Resveratrol in these systems exhibited retarded drug release in both the presence and absence of plasma in vitro; the formulations with high oil and perfluorocarbon percentages showed the lowest drug release rates. The addition of PF68 slightly but significantly reduced resveratrol delivery from the AALs. Ultrasound treatment of 1MHz produced an increase in the drug release from the systems, illustrating the drug-targeting effect of the combination of AALs and ultrasound.

Topics: Chemistry, Pharmaceutical; Chromatography, High Pressure Liquid; Coconut Oil; Drug Carriers; Drug Compounding; Drug Delivery Systems; Emulsions; Erythrocytes; Excipients; Fluorocarbons; Hemolysis; Humans; In Vitro Techniques; Liposomes; Particle Size; Plant Oils; Poloxamer; Polyethylene Glycols; Resveratrol; Stilbenes; Ultrasonics

There is increasing interest in the study of the antioxidant actions of plant phenolic compounds as evidence shows that consumption of plant products rich in these compounds contributes to protection from a number of ailments including cardiovascular diseases. In the present study, the antioxidant effects of selected phenolic compounds from dietary sources, namely barbaloin, 6-gingerol and rhapontin, were investigated.. Low-density lipoprotein (LDL), erythrocytes and erythrocyte membranes were subjected to several in vitro oxidative systems. The antioxidant effects of the phenolic compounds were assessed by their abilities in inhibiting hemolysis and lipid peroxidation of LDL and erythrocyte membranes, and in protecting ATPase activities and protein sulfhydryl groups of erythrocyte membranes.. 6-Gingerol and rhapontin were found to exhibit strong inhibition against lipid peroxidation in LDL induced by 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH) and hemin while barbaloin possessed weaker effects. A similar order of antioxidant potencies among the three compounds was observed on the lipid peroxidation of erythrocyte membranes in a tert-butylhydroperoxide (tBHP)/hemin oxidation system. On the other hand, barbaloin and rhapontin were comparatively stronger antioxidants than 6-gingerol in preventing AAPH-induced hemolysis of erythrocytes. Among the three compounds, only barbaloin protected Ca2+-ATPase and protein sulfhydryl groups on erythrocyte membranes against oxidative attack by tBHP/hemin. Interestingly, rhapontin demonstrated protective actions on Na+/K+-ATPase in a sulfhydryl group-independent manner under the same experimental conditions.. In view of their protective effects on LDL and erythrocytes against oxidative damage, these phenolic compounds might have potential applications in prooxidant state-related cardiovascular disorders.

Topics: Amidines; Animals; Anthracenes; Antioxidants; Cardiovascular Diseases; Catechols; Cells, Cultured; DNA Damage; Dose-Response Relationship, Drug; Erythrocyte Membrane; Fatty Alcohols; Hemolysis; Humans; Lipid Peroxidation; Lipoproteins, LDL; Male; Oxidation-Reduction; Phenols; Rats; Rats, Sprague-Dawley; Stilbenes

Resveratrol, a phenolic antioxidant found in grapes, has been known to mediate various biological activities on the human body. In the present study, we tested the antifungal activity of resveratrol against human pathogenic fungi before carrying out further studies to elucidate the antifungal mechanism(s) of resveratrol. Resveratrol displayed potent antifungal activity against human pathogenic fungi at concentration levels of 10-20 microg/mL. Furthermore, time-kill curve exhibited fungicidal effect of resveratrol on C. albicans, but the compound had no hemolytic activity against human erythrocytes. The destruction of C. albicans cells by resveratrol was confirmed by scanning electron microscopy. These results suggest that resveratrol could be employed as a therapeutic agent to treat fungal infections of humans.

Topics: Antifungal Agents; Candida albicans; Hemolysis; Humans; Microbial Sensitivity Tests; Resveratrol; Stilbenes

Resveratrol and its analogs, six other polyhydroxystilbenes, were synthesized and their antioxidative activities were evaluated in vitro by determination of the levels of malondialdehyde and hydrogen peroxide. Results clearly exhibited that resveratrol and its analogs had various potencies in inhibiting lipid peroxidation in rat brain, kidney, and liver homogenates and rat erythrocyte hemolysis. Several polyhydroxystilbenes were found to be more active than resveratrol in these models, and structure-activity relationship studies on polyhydroxystilbenes are described in this paper.

Topics: Animals; Antioxidants; Ascorbic Acid; Brain Chemistry; Erythrocytes; Hemolysis; Hydrogen Peroxide; Indicators and Reagents; Kidney; Liver; Male; Malondialdehyde; Rats; Rats, Wistar; Resveratrol; Stilbenes; Structure-Activity Relationship

Resveratrol is a phytoalexin with several biological and pharmacological activities including the "French paradox". We investigated the effect of resveratrol on cytolytic activity by oxygen reactive species and on soluble and particulate tyrosine kinases from human placenta and human prostatic adenoma. These effects were compared with those of piceatannol, quercetin, catechin and epicatechin. Fifty percent of erythrocyte lysis due to H2O2-lactoperoxidase-KI incubation, in which I3-, OI- and oxygen singlet are produced, was obtained after 22 +/- 7 (SD) min in the absence of the tested compounds. The 50% lysis was obtained after 66 +/- 15, 129 +/- 35, 196 +/- 21, 240 +/- 63 and 420 +/- 80 min with 40 microM piceatannol, quercetin, resveratrol, epicatechin and catechin respectively. Protection was concentration dependent. The assay of tyrosine kinase activity was performed using two different substrates as follows: substrate A corresponded to the sequence 1-17 of gastrin, and substrate B to sequence 6-20 of cell division kinase p34cdc2. In all experiments, initial velocity was measured. When assayed with both substrates, tyrosine kinase activities from particulate and cytosolic fractions of placenta were more inhibited by piceatannol and quercetin. Resveratrol significantly inhibited the particulate fraction and the cytosolic fraction respectively when substrates A and B were employed: Catechin acted as an inhibitor with substrate A and particulate fraction while in the other experimental conditions it acted as an activator. Resveratrol inhibited the tyrosine kinase of particulate and cytosolic fractions of prostatic adenoma assayed with substrate A and B.

Topics: Anti-Infective Agents; Dose-Response Relationship, Drug; Enzyme Inhibitors; Erythrocytes; Hemolysis; Humans; In Vitro Techniques; Male; Phytoalexins; Placenta; Plant Extracts; Prostatic Hyperplasia; Protein-Tyrosine Kinases; Reactive Oxygen Species; Resveratrol; Sesquiterpenes; Stilbenes; Terpenes; Time Factors; Wine

It has been suggested that Lys-430 of band 3, with which eosin-5-maleimide (EM) reacts, is located in the external channel through which anions gain access to the external transport site, and that EM inhibits anion exchange by blocking this channel. To test this, we have used 35Cl nuclear magnetic resonance (NMR) to measure Cl- binding to the external transport site in control and EM-treated human red blood cells. Intact cells were used rather than ghosts, because in this case all line broadening (LB) results from binding to external sites. In an NMR spectrometer with a 9.4-T magnetic field, red blood cells at 50% concentration (v/v) in 150 mM Cl- medium at 3 degrees C caused 19.0 +/- 1.2 Hz LB. Of this, 7.9 +/- 0.7 Hz was due to Cl- binding to the high affinity band 3 transport sites, because it was prevented by an apparently competitive inhibitor of anion exchange, 4,4'-dinitrostilbene-2,2'-disulfonate (DNDS). The LB was not due to hemoglobin released from the cells, as little LB remained in the supernatant after cells were removed by centrifugation. Saturable Cl- binding remained in EM-treated cells, although the binding was no longer DNDS-sensitive, because EM prevents binding of DNDS. The lower limit for the rate at which Cl- goes from the binding site to the external medium is 2.15 x 10(5) s-1 for control cells and 1.10 x 10(5) s-1 for EM-treated cells, far higher than the Cl- translocation rate at 3 degrees C (about 400 s-1). Thus, EM does not inhibit Cl- exchange by blocking the external access channel. EM may therefore be useful for fixing band 3 in one conformation for studies of Cl- binding to the external transport site.

Topics: Anion Exchange Protein 1, Erythrocyte; Binding Sites; Binding, Competitive; Biophysical Phenomena; Biophysics; Chlorides; Eosine Yellowish-(YS); Fluorescent Dyes; Hematocrit; Hemolysis; Humans; In Vitro Techniques; Iodides; Ion Channels; Ion Exchange; Magnetic Resonance Spectroscopy; Models, Chemical; Stilbenes

The effect of DIDS on osmotic properties of bovine erythrocytes was studied. The isoosmotic volume, the amount of intracellular solutes, and the osmotically non-active volume were not influenced by DIDS. An increase of osmotic fragility of erythrocytes upon DIDS treatment was evident and identical both in NaCl and in NaCl + KCl hypotonic solutions. These results suggest that the critical cell volume decreases. The link between the effect of DIDS on the membrane skeleton extractability and on the osmotic fragility was postulated.

Topics: 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; Animals; Anions; Bicarbonates; Cattle; Chlorides; Erythrocytes; Hemolysis; In Vitro Techniques; Kinetics; Osmolar Concentration; Osmotic Fragility; Stilbenes

Human erythrocytes suspended at 37 degrees C in hypertonic solution of either electrolytes or nonelectrolytes undergo hemolysis when the temperature is lowered toward 0 degrees C (Green, F.A., Jung, C.Y. 1977 J. Membrane Biol. 33:249). In the present studies this hypertonic cryohemolysis was profoundly affected by the pH of incubation, and was completely abolished at ph 5. In hypertonic NaCl, there was an apparent pH optimum at 6--6.5. In hypertonic sucrose, on the other hand, hemolysis increased progressively with increasing pH between 6 and 9. Amphotericin B inhibited hypertonic cryohemolysis in NaCl or KCl solution. No inhibiting effect of amphotericin B was observed when hypertonicity was due to sodium sulfate or sucrose. Valinomycin also inhibited hypertonic cryohemolysis in KCl, but did not affect the process in NaCl or sucrose solution. SITS (4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonate) and phloretin interfered with this valinomycin effect, whereas phlorizin did not. These results indicate that dissipation of an osmotic gradient across membranes may be responsible for the inhibition of the hemolysis by these inophores. Iso-osmotic cell shrinkage induced by valinomycin in 150 mM NaCl solution did not result in cryohemolysis.

Topics: Amphotericin B; Cold Temperature; Cytochalasins; Glutaral; Hemolysis; Humans; Hydrogen-Ion Concentration; Hypertonic Solutions; Ionophores; Phloretin; Phlorhizin; Stilbenes; Valinomycin

Mono-, di-, and trisulfonic acids, including 4,4'-diacetamido stilbene-2,2'-disulfonic acid (DAS) and 2-(4'-amino phenyl)-6-methylbenzene thiazol-3',7-disulfonic acid (APMB) produce a reversible inhibition of sulfate equilibrium exchange in human red cells. A study of the sidedness of the action of a number of these sulfonic acids in red cell ghosts revealed that some, like DAS, inhibit only at the outer membrane surface while others, like APMB, inhibit at either surface. This finding suggests that at least two different types of membrane sites are involved in the control of anion permeability. The nature of the anion permeability controlling sites in the outer cell surface was investigated by studying the effects of DAS on the inhibition by dinitrofluorobenzene (DNFB) of anion equilibrium exchange and on the binding of DNFB to the proteins of the red blood cell membrane. After exposure to DNFB in the presence of DAS for a certain period of time, there was a reduction of both the inhibitory effect of DNFB on sulfate exchange and the binding of DNFB to the protein in band 3 of SDS polyacrylamide gel electropherograms (nomenclature of Steck, J. Cell. Biol., 62: 1, '74). Since binding to other membrane proteins was not affected, this observation supports the assumption that the protein in band 3 plays some role in anion transport. In accordance with the absence of an inhibitory effect at the inner membrane surface, internal DAS does not affect DNFB binding to the protein in band 3. DAS protected the anion exchange system not only against inhibition by DNFB but also by m-isothiocyanato benzene sulfonic acid. In contrast to DAS, the equally inhibitory phlorizin does not reduce the rate of dinitrophenylation of the protein in band 3. This suggests that either not all inhibitors of anion exchange exert their action by a combination with sites on the protein in band 3 or that in spite of the described evidence this protein is not involved in the control of anion movements.

Topics: Anthraquinones; Binding Sites; Blood Proteins; Cell Membrane; Cell Membrane Permeability; Coloring Agents; Dinitrofluorobenzene; Erythrocytes; Hemolysis; Humans; Naphthalenesulfonates; Phlorhizin; Stilbenes; Structure-Activity Relationship; Sulfates; Sulfonic Acids; Thiazoles