<em>Trans</em>-resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>) is one of the most promising stilbenes, a type of natural phenol that is produced naturally by some plant species in response to stress. Resveratrol exhibits multiple bioactivities and is used in the agriculture, medical, food, and cosmetic industries due to its antitumor, anti-inflammatory, cardioprotective, and antioxidant properties. Due to the increasing demand, an active area of investigation is the use of plant cell culture and metabolic engineering techniques to produce large quantities of active resveratrol. However, most recent studies have focused on the efficiency of synthesizing resveratrol in vitro, but have not investigated the contributions of the <em>trans</em>criptional activities of the genes encoding the related enzymes in the biosynthesis pathway. This article reviews recently developed methods for the biosynthesis of resveratrol and comprehensively reviews the current state of knowledge of the function of the key pathway enzymes in resveratrol synthesis. Approaches for enhancing resveratrol production, such as introducing non-pathway genes and co-localizing enzymes are described in detail.

Interactions between aromatic rings or other unsaturated systems, including pi-stacking and face-to-edge complexes, are the origin of many phenomena in both organic and biological chemistry. It is well known that these interactions play an important role in the stabilization of the stereo-structure of DNA and the tertiary structure of many proteins.Trans-resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>, <em>trans</em>-RSV) is a phytoalexin found in Vitis sp. and in many other plants and food products and has received much attention because of its possible positive health benefits. In this work, the pi-stacking interaction of <em>trans</em>-RSV was studied by nuclear magnetic resonance (NMR) and Fourier <em>trans</em>form infrared (FTIR) spectroscopy. In particular, the proton chemical shift dependence of the RSV concentration in the range 2 x 10(-2) - 1 x 10(-5) M and temperature were analysed. Moreover, the dynamics of the supramolecular aggregates were studied by nuclear spin relaxation data.

Leaves, shoots and flowers from two different economy-relevant grape cultivars, Merlot and Cabernet Sauvignon, were examined to assess the distribution of phytoalexins upon inoculation with Botrytis cinerea at pre-bloom, bloom, and post-bloom stages. Mass spectrometric analysis evidenced considerable levels of <em>trans</em>-resveratrol (<em>3,5,4</em>'-<em>trihydroxystilbene</em>), albeit higher in Cabernet Sauvignon, in leaves from both grape cultivars following fungal infection at all the examined stages of development. Although both these cultivars are reported to be sensitive against fungal infections, in Cabernet Sauvignon leaves and flowers, we were also able to measure relevant quantities of the resveratrol dehydrodimer delta-viniferin. While infection by B. cinerea occurs at bloom stage, high-sensitivity of the HPLC-mass spectrometric analytic method allowed detecting measurable levels of viniferins even in early pre-bloom stages in Cabernet Sauvignon flowers and to evidence even slight resveratrol differences between the cultivars. Concordingly, Cabernet Sauvignon better responded to fungal infection. This analysis allowed us to conclude that, even when analyzing fungal infection-sensitive cultivars, the HPLC-MS method holds the sensitivity to highlight the slightest differences in the concentrations of the two phytoalexins and correlate them to different anti-fungal response potential.

Hormone replacement therapy (HRT) has been used to prevent osteoporosis in postmenopausal women. However, HRT is not for everyone, due to concerns of side effects as well as increased risk of breast and possibly uterine cancer. Therefore, Dietary alternatives are considered, which include <em>Trans</em>-<em>3,5,4</em>'-<em>Trihydroxystilbene</em> (<em>trans</em>-resveratrol), a phytoestrogen naturally found in grapes, peanuts and wine with beneficial effects in both cardioprotective and chemopreventive. The purpose of this study was to evaluate the effects of <em>trans</em>-resveratrol on the bone metabolism in ovariectomized rats. 48 Rats were assigned to the following groups: sham surgery + normal diet; ovariectomy (Ovx) + normal diet; Ovx + diethylstilbestrol 0.03 mg × kgbw(-1) × d(-1);Ovx +<em>Trans</em>-Resveratrol 5 mg × kgbw(-1) × d(-1); Ovx + <em>Trans</em>-Resveratrol 15 mg × kgbw(-1) × d(-1); <em>Trans</em>-Resveratrol 45 mg × kgbw(-1) × d(-1). The rats were fed for 90 days. In the 90th day, OVX + <em>Trans</em>-Resveratrol 45 mg/(kgbw(-1)·d) group had a greater bone mineral density (BMD) than other groups. In the OVX + <em>Trans</em>-Resveratrol 45 mg/(kgbw(-1)·d), indices of endocortical bone formation (ALP 37.90 ± 2.96U/100ml, BGP 1.27 ± 0.10 ng/ml) were greater than those of the other groups, while the index of endocortical bone absorption (TRAP 10.35 ± 1.72 U/L) were lower than those of the other groups. Histopathological examination showed that resveratrol had no endometrial hyperplasia adverse effect. All of these support that resveratroal may have positive effect on postmenopausal osteoporosis prevention.

OBJECTIVE

Moxifloxacin (MOX), a fourth generation fluoroquinolone (FQ), has a wide antibacterial spectrum, but may show cytotoxicity characterized by high productions of reactive oxygen species (ROS). This study investigated the protective role of a common antioxidant agent, resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>), against the cytotoxicity caused by MOX.

METHODS

Experiments were performed with a human corneal epithelial cell line (HCECs; ATCC-CRL-11515). Another commonly used FQ, levofloxacin (LEV), and the most commonly used preservatives, benzalkonium chloride (BAC), were also used for comparison with MOX. Cell viability and morphologic changes after treatment were evaluated with trypan blue exclusion assay, propidium iodine/annexin V-FITC staining, and flow cytometry. Chemiluminescence immunoassay was used for ROS quantification. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, wound healing assay, and intracellular detections of oxidative stress were performed to evaluate the effects of resveratrol.

RESULTS

The MOX group, similar to the BAC group, showed significant cell shrinkage and death compared with the LEV group. High ROS production in HCECs of MOX group was observed both by chemiluminescence immunoassay and intracellular images. Within the observations of MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay, live cell images, and wound healing process in vitro, the cytotoxic effects of the MOX and BAC groups were opposed by resveratrol. Human corneal epithelial cells pretreated with resveratrol demonstrated better cell viability and healing rate in the early stage.

CONCLUSIONS

The protective effects of antioxidant agents indicate that MOX, similar to BAC, causes oxidative stress-related cell damage. The results also inspired us to think about a "supplementary regimen" to increase safety and decrease the adverse effect in the treatment of corneal infections.

We present stilbenoid profiles of canes from 16 grapevines. Fifteen stilbenoids were obtained through isolation and structure identification using MS, NMR, and [α](D) or as commercial standards. An HPLC-UV method for the simultaneous quantification of nine of these stilbenoids was developed and applied to canes of Vitis amurensis, Vitis arizonica, Vitis berlandieri, Vitis betulifolia, Vitis cinerea, Vitis × champini, Vitis × doaniana, Vitis labrusca, Vitis candicans (syn. Vitis mustangensis), Vitis riparia, Vitis rupestris, Vitis vinifera, Muscadinia rotundifolia, and a V. vinifera × M. rotundifolia hybrid. In these species, E-ampelopsin E, E-amurensin B, E-piceid, E-piceatannol, E-resveratrol, E-resveratroloside, E-ε-viniferin, E-ω-viniferin, and E-vitisin B were quantified, when found in sufficient amounts. Total concentrations ranged from ~2.2 to 19.5 g/kg of dry weight. Additional stilbenoids, E-<em>3,5,4</em>'-<em>trihydroxystilbene</em> 2-C-glucoside, Z-ampelopsin E, Z-<em>trans</em>-miyabenol C, E-<em>trans</em>-miyabenol C, scirpusin A, and Z-vitisin B, were identified but not quantified. Our results indicate that canes, particularly those of non-vinifera species, have substantial quantities of valuable, health-promoting stilbenoids.

Polydatin (also named pieceid, (E)-piceid, (E)-polydatin, <em>trans</em>-polydatin, or <em>3,5,4</em>'-<em>trihydroxystilbene</em>-3-b-D-glucoside) is a monocrystalline compound isolated from the root and rhizome of <i>Polygonum cuspidatum</i> Sieb. et Zucc. (Polygonaceae). A previous study showed that polydatin has antioxidant and anti-inflammatory effects. However, the effect of polydatin in dry eye disease (DED) has not been elucidated. DED rat models were induced by exorbital lacrimal gland-excision. In vivo, the present study showed that the excision of lacrimal glands induced changes such as reduced tear fluid, severe corneal irregularity, damage, tear film break, and goblet cell loss as well as increased inflammation cytokine and NLRP3 expression in conjunctival tissue. However, these changes were restored by polydatin eye dropping. In vitro, polydatin inhibited hyperosmolar stress-induced inflammation through attenuation of the <em>trans</em>location of NF-κB to the nucleus and the mRNA expression of TNF-α, IL-6, IL-1β, and MMP9. In addition, the hyperosmolar stress-induced NLRP3 inflammasome pathway and ROS production were inhibited by polydatin. Our findings provided insight into the effect of polydatin as a candidate reagent for the treatment of DED.

High-fat diet (HFD)-induced obesity is often associated with immune dysfunction. Resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>), which has well-founded immunity-related beneficial properties, was used to elucidate the regulatory effect on glucose metabolism and T-lymphocyte subsets in the development of HFD-induced obesity. Resveratrol, being associated with decreases of plasma leptin and plasma lipids and the release of oxidative stress, significantly decreased the body weight and fat masses in HF mice after 26 weeks of feeding. Furthermore, resveratrol decreased the fasting blood glucose and fasting plasma insulin and increased the CD3(+)CD4(+)/CD3(+)CD8(+) subsets percentages and the regulatory T cells (Tregs) production after 13 and 26 weeks of feeding. The results indicate that resveratrol, as an effective supplement for HFD, maintained glucose homeostasis by activating the PI3K and SIRT1 signaling pathways. Moreover, resveratrol activated the Nrf2 signaling pathway-mediated antioxidant enzyme expression to alleviate inflammation by protecting against oxidative damage and T-lymphocyte subset-related chronic inflammatory response in the development of HFD-induced obesity.

Metabolites in safety testing have gained a lot of attention recently. Regulatory agencies have suggested that the kinetics of preformed and in vivo-formed metabolites are comparable. This subject has been a topic of debate. We have compared the kinetics of in vivo-formed with preformed metabolites. <em>trans</em>-<em>3,5,4</em>'-<em>Trihydroxystilbene</em> [<em>trans</em>-resveratrol (RES)] and its two major metabolites, resveratrol-3-sulfate (R3S) and resveratrol-3-glucuronide (R3G) were used as model substrates. The pharmacokinetics (PK) of R3S and R3G were characterized under two situations. First, the pharmacokinetics of R3S and R3G were characterized (in vivo-formed metabolite) after administration of RES. Then, synthetic R3S and R3G were administered (preformed metabolite) and their pharmacokinetics were characterized. PK models were developed to describe the data. A three-compartment model for RES, a two-compartment model for R3S (preformed), and an enterohepatic cycling model for R3G (preformed) was found to describe the data well. These three models were further combined to build a comprehensive PK model, which was used to perform simulations to predict in vivo-formed metabolite kinetics. Comparisons were made between in vivo-formed and preformed metabolite kinetics. Marked differences were observed in the kinetics of preformed and in vivo-formed metabolites.

Resveratrol (RESV; <em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>), a phytoalexin that is produced by some plants, among other effects has well-known antioxidant, anti-inflammatory and immunomodulatory activities in mammals. In the present study, the effects of RESV on several functions of turbot, Psetta maxima (L.), kidney leucocytes (KLs) related to the innate and inflammatory responses were investigated. RESV exerted a dose-dependent inhibitory effect on the migratory response and on the production of reactive oxygen species in KL, after stimulation of the respiratory burst activity with phorbol myristate acetate (PMA). RESV also significantly inhibited the generation of the pro-inflammatory mediator prostaglandin E(2) (PGE(2)) in the supernatant of KL cultures stimulated with acidic sulphated polysaccharides (ASPs) from the seaweed Ulva rigida. The effects of the polyphenol on enzymatic activity and on myeloperoxidase (MPO) gene expression in neutrophils were also tested. It was found that RESV strongly inhibited intracellular and extracellular MPO activity, behaving as a noncompetitive and reversible inhibitor, and also induced a decrease in MPO mRNA levels in turbot neutrophils. These findings indicate that RESV exerts important modulatory effects on inflammatory responses in fish, and considering the importance of innate immunity in these vertebrates and the similarities with mammals, it may be possible to use fish for analysis of the effects of different substances on inflammatory responses.

Some recent studies have put forward the hypothesis that the presence of <em>trans</em>-resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>) in red wine may be related to some of its therapeutic properties. A fundamental step in view of this evaluation is the development of a method for the quick, accurate and precise analysis of this compound. Sample enrichment and purification can be obtained by solid-phase extraction using reverse-phase C18 cartridges. HPLC analysis carried out by means of a photodiode-array detector, with an internal standard method, allows the detection of up to 10 micrograms/L in wine, with a linear range between 0.6 and 300 ng injected and a precision of 3.3%. The results of the first analyses show that the concentrations of <em>trans</em>-resveratrol in wines might be much higher than so far reported in the literature.

Stem cell therapies are important treatment methodologies used in many areas of experimental or clinical medicine. In recent studies of cancer models, Mesenchymal stem cells (MSCs) suppressed the growth of cancer cells. However, also in some studies, stem cell treatments have been shown to induce cancer formation, increase tumor volume, induce the formation of new vessels, and lead to cancer invasion. The presence of MSC-secreted cytokines and their effects on cancer cells limits the reliability of MSC-based treatments. Resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>), an antioxidant found in red wine, has been shown to have therapeutic effects against several cancers. The aim of this study was to co-culture MSCs with A549 cancer cells to suppress the release of cancer-promoting cytokines from MSCs and to increase the applicability and reliability of stem cell therapies with resveratrol. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and neutral red cell viability assays were used to find safety dose of resveratrol. The MSCs secreted the cytokines IL-6 and VEGF, and the effect of resveratrol on these cytokines was analyzed by ELISA and western blot analysis of conditioned medium. One μM of resveratrol was found to be the safety dose for the A549 cancer cells and MSCs. We observed the highest release of IL-6 and VEGF from the co-cultured A549 cells and MSCs, and resveratrol was found to significantly decrease the release of these cytokines. Our study suggests that resveratrol exerts a positive effect on the release of cytokines. The safety dose of resveratrol can be administered together with stem cells during stem cell treatment.

Vasopressin-activated calcium-mobilizing (VACM-1) protein is a cul-5 gene product that forms complexes with a subclass of ubiquitin E3 ligases involved in proteasomal protein degradation. The expression of VACM-1 cDNA in the T47D breast cancer cell line inhibits growth and decreases phosphorylation of mitogen activated protein kinase. Factors that regulate expression or stability of VACM-1 protein have not been identified, however. In our search to identify drugs/substances that may control VACM-1 protein expression, we examined the effects of resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>), a natural component in the human diet which inhibits tumor initiation and promotion. CMV vector and VACM-1 cDNA stably <em>trans</em>fected T47D breast cancer-derived cells were treated with resveratrol and cell growth and VACM-1 protein concentrations were measured. Since the cellular mechanism of resveratrol-dependent inhibition of cell growth also involves the regulation of estrogen receptors, the effect of 17-β-estradiol and resveratrol on ERα levels and on cell growth was examined in control and in VACM-1 cDNA <em>trans</em>fected cells. Our results demonstrate that antiproliferative effect of resveratrol observed in the control T47D cancer cells was significantly enhanced in VACM-1 cDNA <em>trans</em>fected T47D cells. Western blot results indicated that resveratrol increased VACM-1 protein concentration. Finally, treatment with resveratrol for 24 and 48 h attenuated 17-β-estradiol induced increase in cell growth both in control and in VACM-1 cDNA <em>trans</em>fected cells. The effect was significantly higher in the VACM-1 cDNA <em>trans</em>fected cells when compared to controls. These results indicate that the antiproliferative effect of resveratrol may involve induction of VACM-1/cul5.

The role of resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>; RES) in lysophosphatidylcholine (LPC)‑induced injury and inflammation in endothelial cells (regarded as an early event in arteriosclerosis) is unclear. The present study investigated whether RES reduces lactate dehydrogenase (LDH) activity and secretion of inflammatory cytokines such asinterleukin‑6 and tumor necrosis factor‑α, via the Toll‑like receptor (TLR)‑4/myeloid differentiation primary response gene 88 (MyD88)/nuclear factor (NF)‑κB signal <em>trans</em>duction pathway in LPC‑induced damage and inflammation in human umbilical vein endothelial‑12 (HUVE‑12) cells. Using an ELISA and western blotting, the present study investigated the effects of RES on LDH activity and cytokine secretion. The effects of TLR‑4 short hairpin (sh)RNA and TLR‑4 cDNA <em>trans</em>fection on NF‑κB activation during LPC‑induced damage and inflammation was also investigated in HUVE‑12 cells. The results demonstrated that RES significantly inhibited the effect of LPC on enzyme activity, pro‑inflammatory cytokine secretion, and expression of TLR‑4, MyD88 and NF‑κBp65 expression. In addition, RES and TLR‑4 shRNA <em>trans</em>fection suppressed LPC‑induced injury and inflammation by blocking the TLR‑4/MyD88/NF‑κB signaling pathway Conversely, <em>trans</em>fection with TLR‑4 cDNA enhanced LPC‑induced injury and inflammation, which abrogated the protective effects of RES. These data suggested that RES significantly suppressed LPC‑induced damage and inflammation, via suppression of the TLR‑4/MyD88/NF‑κB signaling pathway, which may provide a new mechanistic evidence for the treatment of arteriosclerosis by RES.

Resveratrol (E-<em>3,5,4</em>'-<em>trihydroxystilbene</em>) is a polyphenol found in red wine that has been shown to have multiple anti-cancer properties. Although cis-(Z)- and <em>trans</em>-(E)-isomers of resveratrol occur in nature, the cis form is not biologically active. However, methylation at key positions of the cis form results in more potent anti-cancer properties. This study determined that synthetic cis-polymethoxystilbenes (methylated analogs of cis-resveratrol) inhibited cancer-related phenotypes of metastatic B16 F10 and non-metastatic B16 F1 mouse melanoma cells. In contrast with cis- or <em>trans</em>-resveratrol and <em>trans</em>-polymethoxystilbene which were ineffective at 10 μM, cis-polymethoxystilbenes inhibited motility and proliferation of melanoma cells with low micromolar specificity (IC50 < 10 μM). Inhibitory effects by cis-polymethoxystilbenes were significantly stronger with B16 F10 cells and were accompanied by decreased expression of β-tubulin and pleckstrin homology domain-interacting protein, a marker of metastatic B16 cells. Thus, cis-polymethoxystilbenes have potential as chemotherapeutic agents for metastatic melanoma.

Plants have been genetically enhanced to produce a number of products for agricultural, industrial and pharmaceutical purposes. This technology could potentially be applied to providing chemoprevention strategies to the general population. Resveratrol (<em>3,5,4</em>'-<em>trihydroxystilbene</em>) is a compound that has been shown to have protective activity against a number of cancers and could be an ideal candidate for such an application. Alfalfa that was genetically modified to express resveratrol-synthase was used as a model in applying biotechnological approaches to cancer prevention. The <em>trans</em>genic alfalfa, which accumulates resveratrol as a glucoside (piceid = <em>trans</em>-resveratrol-3-O-Beta-D-glucopyranoside) (152 +/- 17.5 microg piceid/g dry weight), was incorporated into a standard mouse diet at 20% of the diet by weight and fed for 5 wk to 6-wk-old, female CF-1 mice (N = 17-30) that were injected with a single dose of azoxymethane (5 mg/kg body weight). While the addition of resveratrol-aglycone (20 mg/kg diet) to the basal diet reduced the number of aberrant crypt foci/mouse, the <em>trans</em>genic alfalfa did not inhibit the number, size, or multiplicity of aberrant crypt foci in the colon of the CF-1 mice relative to control alfalfa which does not accumulate resveratrol-glucoside. However, diets containing <em>trans</em>genic alfalfa with an exogenous Beta-glucosidase (860 U/kg diet) did significantly inhibit the number of aberrant crypt foci in the distal 2 cm of the colon of the mice relative to mice fed diets containing the <em>trans</em>genic alfalfa without the enzyme (P < 0.05; Fisher's Combination of p-values). The Beta-glucosidase alone appeared to have no effect on the inhibition of aberrant crypt foci. These results suggest that piceid in <em>trans</em>genic piceid-accumulating alfalfa was not bioavailable.

This work presents a novel method for the accurate determining <em>trans</em>- and cis-resveratrol (<em>3,5,4</em>'-<em>trihydroxystilbene</em>) by nonaqueous capillary electrophoresis/fluorescence spectroscopy at 77 K. The proposed method permits not only the separation of resveratrol isomers, but also ensures that on-line spectra are readily distinguishable and unambiguously assigned. The experimental results also indicate that the effect of nonaqueous capillary electrophoresis buffer and low-temperature technique increase the detection limit by more than 150-fold.

There has been considerable public interest and a growing number of scientific studies linking certain phenolic compounds in grapes and wines, particularly <em>trans</em>-resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>, TRA), to human health benefits. Typical TRA concentrations in wine are very low. It is a polar compound with very low volatility, which makes it difficult to extract and to separate on a gas chromatography (GC) column without derivatization. In this study, a new method for trace analysis of TRA was developed using solid-phase microextraction (SPME) with on-fiber silylation derivatization. Multidimensional GC equipped with a heartcut valve and cryogenic focusing was coupled with a mass-selective detector and used for improved separations and analysis. The effects of SPME fiber selection, extraction time, temperature, and desorption time were investigated. The derivatization conditions, time/temperature and the volume of derivatization reagent were also optimized. The calibration curve was linear over the concentration range from 10 ng L(-1) to 5 mg L(-1), with a correlation coefficient of 0.9996. The average recovery of TRA in red wine was 83.6+/-5.6%. The method detection limit (MDL) for TRA in ethanol:water (12.5:87.5, v/v) solution in this study was 7.08 ng L(-1) whereas the MDL for TRA in pure water was 2.85 ng L(-1). The new method was used to test the TRA content in six selected Iowa red wine samples. Measured concentrations varied from 12.72 to 851.9 microg L(-1).

<em>trans</em>-Resveratrol (RVT) (<em>3,5,4</em>'-<em>trihydroxystilbene</em>), a polyphenolic constituent of red wine, is thought to be beneficial in reducing the incidence of cardiovascular diseases, partly via its antioxidant properties. However, the mechanism of action by which <em>trans</em>-resveratrol displays its antioxidant effect has not been totally unravelled. This study aimed at establishing a comprehensive scheme of the reaction mechanisms of the direct scavenging of HO(*) and O(2)(*-) radicals generated by water gamma radiolysis. Aerated aqueous solutions of <em>trans</em>-RVT (from 10 to 100μmolL(-1)) were irradiated with increasing radiation doses (from 25 to 400Gy) and further analyzed by UV-visible absorption spectrophotometry for detection of <em>trans</em>-RVT oxidation products. Separation and quantification of RVT and its four oxidation products previously identified by mass spectrometry, i.e., piceatannol (PCT), 3,5-dihydroxybenzoic acid (3,5-DHBA), 3,5-dihydroxybenzaldehyde (3,5-DHB) and para-hydroxybenzaldehyde (PHB), were performed by HPLC/UV-visible spectrophotometry. Determination of the radiolytic yields of <em>trans</em>-RVT consumption and oxidation product formation has allowed us to establish balance between <em>trans</em>-RVT disappearance and the sum of oxidation products formation. Under our conditions, O(2)(-) radicals seemed to poorly initiate oxidation of <em>trans</em>-RVT, whereas the latter, whatever its initial concentration, quantitatively reacted with HO() radicals, via a dismutation mechanism. Two reaction pathways involving HO()-induced <em>trans</em>-RVT primary radicals have been proposed to explain the formation of the oxidation end-products of <em>trans</em>-RVT.

In peanuts, a mechanism of resistance to fungal infection is reportedly due to the synthesis of stilbene phytoalexins, which are antibiotic, low molecular weight metabolites. The phytoalexin-associated response of different peanut genotypes to exogenous invasion in the field has not been investigated and may be useful for breeding resistant peanut cultivars. Five peanut genotypes, Georgia Green, Tifton 8, C-99R, GK-7 High Oleic, and MARC I, which differ in resistance to major peanut diseases, were investigated for their ability to produce phytoalexins under field conditions in South Georgia in 2001 and 2002. Five known peanut phytoalexins, <em>trans</em>-resveratrol, <em>trans</em>-arachidin-1, <em>trans</em>-arachidin-2, <em>trans</em>-arachidin-3, and <em>trans</em>-3'-isopentadienyl-<em>3,5,4</em>'-<em>trihydroxystilbene</em>, were quantitated. The phytoalexins were measured in peanuts of different pod maturity (yellow, orange, brown, and black) with or without insect pod damage (externally scarified or penetrated). Kernels from insect-damaged pods of C-99R and Tifton 8 genotypes had significantly higher concentrations of phytoalexins than other genotypes. The same genotypes were the most resistant to tomato spotted wilt virus and late leaf spot, while MARC I, which is highly susceptible to these diseases, produced very low concentrations of phytoalexins. However, there was no significant difference in phytoalexin production by undamaged peanut pods of all tested genotypes. <em>trans</em>-Arachidin-3 and <em>trans</em>-resveratrol were the major phytoalexins produced by insect-damaged peanuts. In damaged seeds, the concentrations of <em>trans</em>-3'-isopentadienyl-<em>3,5,4</em>'-<em>trihydroxystilbene</em> were significantly higher in Tifton 8 as compared to other genotypes. There was an association between total phytoalexin production and published genotype resistance to major peanut diseases. Stilbene phytoalexins may be considered potential chemical markers in breeding programs for disease-resistant peanuts.

OBJECTIVE

The present study aimed to investigate the possible beneficial activities of resveratrol (<em>3,5,4</em>'-<em>trans</em>-<em>trihydroxystilbene</em>), a natural phytoalexin, on contractility and oxidant damage after ischemia/reperfusion (I/R) of the rat urinary bladder.

METHODS

The abdominal aorta of Sprague-Dawley rats was occluded for 60 min to induce ischemia and then allowed 60 min of reperfusion. Resveratrol (10 mg/kg) or saline was administered intraperitoneally 15 min before ischemia and immediately before reperfusion. In the sham-operated group, the abdominal aorta was left intact and the animals were treated with resveratrol or saline. The bladder samples were either used for functional studies or stored for biochemical assays.

RESULTS

In the I/R group, the isometric contractile responses of the bladder strips to carbachol (CCh; 10(-8)-10(-4) mol/l) were lower than those of the control group and were reversed by treatment with resveratrol. Histological evaluation revealed loss of urothelial cells, detachment and loss of urothelial cells and local ulcerated areas and severe inflammatory cell infiltration in the untreated I/R group, and regeneration of luminal mucosa and a significant decrease in the density of the inflammatory cell population in the resveratrol-treated I/R group. Lipid peroxidation and the myeloperoxidase activity of the bladder tissues in the I/R group were higher than in the sham-operated group. Resveratrol treatment in the I/R group decreased these parameters compared with I/R alone. Similarly, the significant decrease in tissue glutathione level in the I/R group compared with controls was also prevented by resveratrol.

CONCLUSIONS

Treatment with resveratrol almost completely reversed the low contractile responses of the rat urinary bladder to CCh and prevented oxidative tissue damage following I/R.

Hopeanolin (1), an unusual resveratral trimer with an ortho-quinone nucleus, was isolated and characterized from the stem bark of Hopea exalata. Also obtained were six known stibenoids, shoreaphenol (2), vaticanol G (3), alpha-viniferin (4), pauciflorol A (5), vaticanol A (6), and <em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em> 2-C-glucoside (7). The structure of 1 was determined by spectroscopic data interpretation. Compounds 1-7 were tested for antifungal activity and inhibitory effects against jack bean urease. Hopeanolin (1) demonstrated antifungal activity in the MIC value range 0.1-22.5 microg/mL.

Resveratrol (<em>trans</em>-<em>3,5,4</em>'-<em>trihydroxystilbene</em>) is a phytoalexin produced by grapevines in response to fungal infection, particularly to Botrytis cinerea. It has been shown that it possess various biological effects such as prevention of cardiovascular diseases and anti-inflammatory and anticancerogenic properties. Red wines are a primary source of resveratrol. Although a number of investigations have focused on the determination of resveratrol in wines of different countries, there is no similar study about the wines produced in Serbia. As authors are aware, the only study concerning resveratrol content in wine in the Balkan region was conducted in Greece. In this study, the <em>trans</em>- and cis-resveratrol content in samples obtained from 18 commercial Serbian wines (10 red, 7 white, and 1 rose) were analyzed. Analyses were performed after solid-phase extraction by high-performance liquid chromatography with a diode array detection system using an RP-C(18) column with gradient elution [solvent A: acetonitrile-acetic acid-water (20:2:78 v/v), solvent B: acetonitrile-acetic acid-water (90:2:8 v/v)]. Detection of <em>trans</em>- and cis-resveratrol was performed on 306 and 286 nm, respectively. It was clearly established that there was a presence of <em>trans</em>-resveratrol isomers in all analyzed wines (0.11-1.69 mg/L) except in one white wine. Cis-resveratrol was present in 12 from 18 samples in different amounts (0.12-1.49 mg/L).

UNASSIGNED

The aim of this study was to investigate the effects of pterostilbene (PTS) (<em>trans</em>-3,5-dimethoxy-4'-hydroxystilbene) and resveratrol (RSV) (<em>trans</em>-<em>3,5,4</em>' <em>trihydroxystilbene</em>) applied at different doses for the treatment of streptozotocin- (STZ-) induced diabetic rats.

UNASSIGNED

At the end of the 5-week experimental period, the right gastrocnemius muscles of the rats were examined biomechanically, while the left ones were examined histologically. In addition, blood glucose, serum insulin, and malondialdehyde (MDA) levels were analyzed in blood samples taken from the rats.

UNASSIGNED

The skeletal muscle isometric contraction forces, which showed a decrease with diabetes, were observed to increase with antioxidant applications. Blood glucose, serum insulin, and MDA levels in diabetic rats approached normal levels after applying PTS. When the electron microscopic images of the rat skeletal muscle were examined, those in the combination treatment group were observed to show a better enhancement in the skeletal muscle morphological structure compared to the other diabetic and treatment groups.

UNASSIGNED

According to the findings, we suggest that these antioxidant treatments might have good therapeutic nutraceutical potential for some muscle diseases that coexist with diabetes. These treatments should be comprehensively investigated in the future.