Novel trans-Resveratrol Derivatives: Design, Synthesis, Antibacterial Activity, and Mechanisms.

Rice bacterial leaf blight and rice bacterial leaf streak have induced tremendous damage to production of rice worldwide. To discover an effective novel antibacterial agent, a series of novel trans-resveratrol (RSV) derivatives containing 1,3,4-oxadiazole and amide moieties were designed and synthesized for the first time. Most of them showed excellent antibacterial activities against Xanthomonas oryzae pv oryzicola and Xanthomonas oryzae pv oryzae. Especially, compound J12 had the best inhibitory with the half-maximal effective concentration values of 4.2 and 5.0 mg/L, respectively, which were better than that of RSV (63.7 and 75.4 mg/L), bismerthiazol (79.5 and 89.6 mg/L), and thiodiazole copper (105.4 and 112.8 mg/L). Furthermore, compound J12 had an excellent control effect against rice bacterial leaf streak and rice bacterial leaf blight, with protective activities of 46.2 and 42.1% and curative activities of 44.5 and 41.7%, respectively. Preliminary mechanisms indicated that compound J12 could not only remarkably decrease biofilm formation, extracellular polysaccharide production, and the synthesis of extracellular enzymes but also destroy bacterial cell surface morphology, thereby reducing the pathogenicity of bacteria. In addition, compound J12 could increase the activity of defense-related enzymes and affect the expression of multiple pathogenic-related genes including plant-pathogen interaction, the MAPK signaling pathway, and phenylpropanoid biosynthesis, and this could improve the defense of rice against rice bacterial leaf streak infection. The present work indicates that the RSV derivatives can be used as promising candidates for the development of antibacterial agents.

Trans-resveratrol reduced hepatic oxidative stress in an animal model without inducing an upregulation of nuclear factor erythroid 2-related factor 2.

Trans-resveratrol, a widely used supplement for humans, aims to enhance the body's antioxidant defense. Studies suggest that it exerts anti-inflammatory and antioxidant effects by activating the nuclear factor erythroid 2-related factor 2 (Nrf2). In order to evaluate this hypothesis, LDLr(-/-) mice were fed a Western diet to induce liver inflammation and oxidative stress. One group was fed a diet containing 0.60 mg/day of trans-resveratrol (RESV), while another group received no dietary supplementation (CONT). Oxidative stress biomarkers and inflammatory cytokines were assessed in liver homogenates. It was observed that trans-resveratrol decreased hepatic oxidative stress by increasing the GSH/GSSG ratio and reducing malondialdehyde (MDA) concentration. However, the RESV group exhibited a reduction in Nrf2 relative expression compared to CONT. Additionally, trans-resveratrol supplementation reduced nuclear factor-κB (NF-κB) expression but led to an increase in IL-6, with no significant changes observed in tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) concentrations. Overall, these findings indicate that the in vivo antioxidant impact induced by trans-resveratrol supplementation in hepatic tissue did not correlate with increase of inflammatory cytokines and Nrf2 relative expression. Further exploration of alternative mechanisms, such as direct radical scavenger activity, is warranted to elucidate the antioxidant effect.

Intestinal Targeted Nanogel with Broad-Spectrum Autonomous ROS Scavenging Performance for Enhancing the Bioactivity of trans-Resveratrol.

Introduction: To improve the bioavailability of trans-resveratrol (trans-Res), it is commonly co-delivered with antioxidant bioactives using a complex synthetic intestinal targeted carrier, however, which makes practical application challenging. Methods: A nanogel (Ngel), as broad-spectrum autonomous ROS scavenger, was prepared using selenized thiolated sodium alginate (TSA-Se) and crosslinked with calcium lactate (CL) for loading trans-Res to obtain Ngel@Res, which maintained spherical morphology in the upper digestive tract but broke down in the lower digestive tract, resulting in trans-Res release. Results: Under protection of Ngel, trans-Res showed enhanced stability and broad-spectrum ROS scavenging activity. The synergistic mucoadhesion of Ngel prolonged the retention time of trans-Res in the intestine. Ngel and Ngel@Res increased the lifespan of Caenorhabditis elegans to 26.00 ± 2.17 and 26.00 ± 4.27 days by enhancing the activity of antioxidases, upregulating the expression of daf-16, sod-5 and skn-1, while downregulating the expression of daf-2 and age-1. Conclusion: This readily available, intestinal targeted selenized alginate-based nanogel effectively improves the bioactivity of trans-Res.

Engineering resveratrol-loaded chitosan nanoparticles for potential use against Helicobacter pylori infection.

Helicobacter pylori (H. pylori) is a microorganism directly linked to severe clinical conditions affecting the stomach. The virulence factors and its ability to form biofilms increase resistance to conventional antibiotics, growing the need for new substances and strategies for the treatment of H. pylori infection. The trans-resveratrol (RESV), a bioactive polyphenol from natural sources, has a potential activity against this gastric pathogen. Here, Chitosan nanoparticles (NP) containing RESV (RESV-NP) were developed for H. pylori management. The RESV-NP were prepared using the ionic gelation method and characterized by Dynamic Light Scattering (DLS), Nanoparticle Tracking Analysis (NTA) and, Cryogenic Transmission Electron Microscopy (Cryo - TEM). The encapsulation efficiency (EE) and in vitro release rate of RESV were quantified using high-performance liquid chromatography (HPLC). RESV-NP performance against H. pylori was evaluated by the quantification of the minimum inhibitory/bactericidal concentrations (MIC/MBC), time to kill, alterations in H. pylori morphology in its planktonic form, effects against H. pylori biofilm and in an in vitro infection model. RESV-NP cytotoxicity was evaluated against AGS and MKN-74 cell lines and by hemolysis assay. Acute toxicity was tested using Galleria mellonella model assays. RESV-NP showed a spherical shape, size of 145.3 ± 24.7 nm, polydispersity index (PDI) of 0.28 ± 0.008, and zeta potential (ZP) of + 16.9 ± 1.81 mV in DLS, while particle concentration was 3.12 x 1011 NP/mL (NTA). RESV-NP EE was 72 %, with full release within the first 5 min. In microbiological assays, RESV-NP presented a MIC/MBC of 3.9 µg/mL, a time to kill of 24 h for complete eradication of H. pylori. At a concentration of 2xMIC (7.8 µg/mL), RESV-NP completely eradicated the H. pylori biofilm, and in an in vitro infection model, RESV-NP (4xMIC - 15.6 µg/mL) showed a significant decrease in bacterial load (1 Log10CFU/mL) when compared to the H. pylori J99 control. In addition, they did not demonstrate a toxic character at MIC concentration for both cell lines. The use of the RESV-NP with mucoadhesion profile is an interesting strategy for oral administration of substances targeting gastric disorders, linked to H. pylori infections.

Therapeutic potential of stilbenes in neuropsychiatric and neurological disorders: A comprehensive review of preclinical and clinical evidence.

Neuropsychiatric disorders are anticipated to be a leading health concern in the near future, emphasizing an outstanding need for the development of new effective therapeutics to treat them. Stilbenes, with resveratrol attracting the most attention, are an example of multi-target compounds with promising therapeutic potential for a broad array of neuropsychiatric and neurological conditions. This review is a comprehensive summary of the current state of research on stilbenes in several neuropsychiatric and neurological disorders such as depression, anxiety, schizophrenia, autism spectrum disorders, epilepsy, traumatic brain injury, and neurodegenerative disorders. We describe and discuss the results of both in vitro and in vivo studies. The majority of studies concentrate on resveratrol, with limited findings exploring other stilbenes such as pterostilbene, piceatannol, polydatin, tetrahydroxystilbene glucoside, or synthetic resveratrol derivatives. Overall, although extensive preclinical studies show the potential benefits of stilbenes in various central nervous system disorders, clinical evidence on their therapeutic efficacy is largely missing.

Resveratrol and Resveratrol-Loaded Galactosylated Liposomes: Anti-Adherence and Cell Wall Damage Effects on Staphylococcus aureus and MRSA.

Antibiotic resistance due to bacterial biofilm formation is a major global health concern that makes the search for new therapeutic approaches an urgent need. In this context,, trans-resveratrol (RSV), a polyphenolic natural substance, seems to be a good candidate for preventing and eradicating biofilm-associated infections but its mechanism of action is poorly understood. In addition, RSV suffers from low bioavailability and chemical instability in the biological media that make its encapsulation in delivery systems necessary. In this work, the anti-biofilm activity of free RSV was investigated on Staphylococcus aureus and, to highlight the possible mechanism of action, we studied the anti-adherence activity and also the cell wall damage on a MRSA strain. Free RSV activity was compared to that of RSV loaded in liposomes, specifically neutral liposomes (L = DOPC/Cholesterol) and cationic liposomes (LG = DOPC/Chol/GLT1) characterized by a galactosylated amphiphile (GLT1) that promotes the interaction with bacteria. The results indicate that RSV loaded in LG has anti-adherence and anti-biofilm activity higher than free RSV. On the other side, free RSV has a higher bacterial-growth-inhibiting effect than encapsulated RSV and it can damage cell walls by creating pores; however, this effect can not prevent bacteria from growing again. This RSV ability may underlie its bacteriostatic activity.

Grapevine Shoot Extract Rich in Trans-Resveratrol and Trans-ε-Viniferin: Evaluation of Their Potential Use for Cardiac Health.

A grapevine shoot extract (GSE) was obtained using ultrasound-assisted extraction and characterized. The main phenolic constituents were identified as stilbenoids. Among them, trans-resveratrol and trans-ε-viniferin stood out. The GSE was administered to an isoproterenol-induced myocardial injury animal model. The extract alleviated the associated symptoms of the administration of the drug, i.e., the plasma lipid profile was improved, while the disturbed plasma ion concentration, the cardiac dysfunction markers, the DNA laddering, and the necrosis of myocardial tissue were diminished. This effect could be related to the anti-oxidative potential of GSE associated with its antioxidant properties, the increased levels of endogenous antioxidants (glutathione and enzymatic antioxidants), and the diminished lipid peroxidative markers in the heart. The results also revealed angiotensin-converting enzyme (ACE)-inhibitory activity, which indicated the potential of GSE to deal with cardiovascular disease events. This work suggests that not only trans-resveratrol has a protective role in heart function but also GSE containing this biomolecule and derivatives. Therefore, GSE has the potential to be utilized in the creation of innovative functional ingredients.

Identification of Escherichia coli β-glucuronidase inhibitors from Polygonum cuspidatum Siebold & Zucc

Abstract Gut bacterial β-glucuronidase (GUS) can reactivate xenobiotics that exert enterohepatic circulation- triggered gastrointestinal tract toxicity. GUS inhibitors can alleviate drug-induced enteropathy and improve treatment outcomes. We evaluated the inhibitory effect of Polygonum cuspidatum Siebold & Zucc. and its major constituents against Escherichia coli GUS (EcGUS), and characterized the inhibitory mechanism of each of the components. Trans-resveratrol 4'-O-β-D-glucopyranoside (HZ-1) and (-)-epicatechin gallate (HZ-2) isolated from P. cuspidatum were identified as the key components and potent inhibitors. These two components displayed strong to moderate inhibitory effects on EcGUS, with Ki values of 9.95 and 1.95 μM, respectively. Results from molecular docking indicated that HZ-1 and HZ-2 could interact with the key residues Asp163, Ser360, Ile 363, Glu413, Glu504, and Lys 568 of EcGUS via hydrogen bonding. Our findings demonstrate the inhibitory effect of P. cuspidatum and its two components on EcGUS, which supported the further evaluation and development of P. cuspidatum and its two active components as novel candidates for alleviating drug-induced damage in the mammalian gut.

Effect of trans-resveratrol on oxidative stress biomarkers associated with atherosclerosis / Efeito do trans-resveratrol em biomarcadores de estresse oxidativo associados à aterosclerose

Growing evidence indicates that oxidative stress plays an important role in the pathophysiology of many cardiovascular diseases, including atherosclerosis. In this context, the use of bioactive compounds with antioxidant action can bring health benefits, especially in the prevention and control of pathophysiological events. Studies suggest that the polyphenol trans-resveratrol can reduce oxidative stress by acting on the nuclear factor erythroid-2-related factor 2 (Nrf2) and this effect would be associated with dosage. Thus, the present study aimed to investigate the effect of different doses of trans-resveratrol on biomarkers related to atherosclerosis and oxidative stress. In the first step, 27 randomized clinical trials, which evaluated the effect of trans-resveratrol on atherosclerosis-related biomarkers, were classified according to their protocol characteristics and profile of each outcome. Biochemical data from 12 biomarkers were selected to calculate the net change (%). Using multivariate analysis, the trials were distributed into 3 clusters. The studies that composed Clusters II and III were more effective in improving blood pressure and reducing dyslipidemia, respectively. These studies were characterized by a longer intervention time (> 2 months) with doses of around 200-500 mg/day. These results showed that the effects of transresveratrol are mainly related to dosage and intervention time. Based on these results, two doses were selected to apply in an experimental protocol to investigate the effect of trans-resveratrol on hepatic oxidative stress biomarkers mediated by Nrf2 pathway. LDLr(-/-) mice were fed for 8 weeks on a standard diet, followed by over 24 weeks on a Western diet, both containing trans-resveratrol at doses of 250 mg/kg diet/day (low dose resveratrol, LRD) or 400 mg/kg diet/day (high dose resveratrol, HRD). A control group (CONT) was maintained without supplementation. In general, both doses of trans-resveratrol did not affect the body weight and lipid profile of the animals. Only the LRD group showed reduced levels of two important biomarkers of oxidative stress in the liver (GSH/GSSG ratio and malonaldehyde), besides to reduced expression of factor nuclear kappa B (NF-kB). However, contrary to our hypothesis, both doses reduced Nrf2 expression in the liver compared to the CONT group. Regarding inflammatory cytokines, no changes were observed in the levels of TNF-α and IL-10. Furthermore, both doses increased the level of the pro-inflammatory cytokine IL-6. Taken together, our results suggest that trans-resveratrol supplementation at doses lower than 500 mg/day may contribute to the reduction of biomarkers related to atherosclerosis and oxidative stress

Evidências crescentes indicam que o estresse oxidativo desempenha um papel importante na fisiopatologia de muitas doenças cardiovasculares, incluindo a aterosclerose. Nesse contexto, o uso de compostos bioativos com ação antioxidante pode trazer benefícios à saúde, principalmente na prevenção e controle de eventos fisiopatológicos. Estudos sugerem que o polifenol trans-resveratrol pode reduzir o estresse oxidativo atuando na via do fator nuclear eritroide 2 relacionado ao fator 2 (Nrf2) e que esse efeito estaria associado a dosagem. Assim, o presente estudo teve como objetivo investigar o efeito de diferentes doses de trans-resveratrol sobre biomarcadores relacionados à aterosclerose e estresse oxidativo. Na primeira etapa, 27 ensaios clínicos randomizados, que avaliaram o efeito do trans-resveratrol em biomarcadores relacionados à aterosclerose, foram classificados de acordo com suas características de protocolo e perfil de cada resultado. Dados bioquímicos de 12 biomarcadores foram selecionados para calcular a variação líquida (%). Usando análise multivariada, os ensaios foram distribuídos em 3 Clusters. Os estudos que compuseram os Clusters II e III foram mais eficazes na melhora da pressão arterial e na redução da dislipidemia, respectivamente. Esses estudos foram caracterizados por um tempo de intervenção mais longo (> 2 meses) com doses de cerca de 200-500 mg/dia. Esses resultados mostraram que os efeitos do transresveratrol estão relacionados principalmente à dosagem e ao tempo de intervenção. Com base nesses resultados, duas doses foram selecionadas para aplicar em um protocolo experimental para investigar o efeito do trans-resveratrol em biomarcadores de estresse oxidativo hepático mediados pela via do Nrf2. Camundongos LDLr(-/-) foram alimentados por 8 semanas com dieta padrão, seguidos por mais de 24 semanas com Western diet, ambos contendo trans-resveratrol nas doses de 250 mg/kg de dieta/dia (baixa dose de resveratrol, LRD) ou 400 mg/kg de dieta/dia (alta dose de resveratrol, HRD). Um grupo controle (CONT) foi mantido sem suplementação. Em geral, ambas as doses de trans-resveratrol não afetaram o peso corporal e o perfil lipídico dos animais. Apenas o grupo LRD apresentou níveis reduzidos de dois importantes biomarcadores de estresse oxidativo no fígado (razão GSH/GSSG e malonaldeído), além da redução da expressão de fator nuclear kappa B (NF-kB). No entanto, ao contrário da nossa hipótese, ambas as doses reduziram a expressão de Nrf2 no fígado em comparação com o grupo CONT. Em relação às citocinas inflamatórias, não foram observadas alterações nos níveis de TNF-α e IL-10. Além disso, ambas as doses aumentaram o nível da citocina pró-inflamatória IL-6. Em conjunto, nossos resultados sugerem que a suplementação de trans-resveratrol em doses menores de 500 mg/dia podem contribuir para a redução de biomarcadores relacionados à aterosclerose e ao estresse oxidativo

Tempeh & soybean seed coat: the alternative sources of trans-resveratrol as neuroprotective agents / Tempeh y cubierta de semillas de soja: fuentes alternativas de trans-resveratrol como agentes neuroprotectores

Resveratrol is a stilbenoid, a type of natural phenol, and a phytoalexin produced by several plants in response to injury or attack by fungi. The underutilization of soybean seed coat (Glycine max (L.) Merrill.) and tempeh, cheap Indonesia fermented food thus opens up a new opportunity for developing a Resveratrol-based medicine for Plants-Derived Neuroprotective Agents purposes. In this study, it was isolated from tempeh, ordinarily well-known as Indonesian soybean fermented food, and soybean seed coat. The finding of this compound was confirmed by TLC and HPLC analysis applying fluorescence detection. From this, the Rf-value for transresveratrol is 0.64. As eluent, a mixture of chloroform, ethyl acetate, and formic acid (2.5+1+0.1, v/v) was selected. In addition, retention time for tempeh was 14.467 and for soybean seed coat was 11.977. The extraction yield of resveratrol was 65.15 % in tempeh and 55.35 % in soybean seed coat. Resveratrol isolated from Tempeh and Soybean seed coat gave prevents some reaction by modulating intracellular signaling pathways: protein kinase C (PKC), a family of 12 serine/ threonine kinases and providing a new lead molecule for neuroprotective affects in addition to has prevented cell death by apoptosis.

El resveratrol es un estilbenoide, un tipo de fenol natural, y fitoalexina producida por varias plantas en respuesta a una lesión o ataque de hongos. La subutilización de la cubierta de la semilla de soja (Glycine max (L.) Merrill.) y el tempeh, alimento fermentado barato de Indonesia, abren una nueva oportunidad para obtener un medicamento a base de resveratrol para propósitos de desarrollo de agentes neuroprotectores derivados de plantas. En este estudio, se aisló el resveratrol del tempeh, generalmente conocido como alimento fermentado de soja de Indonesia y de la cubierta de la semilla de soja. El hallazgo de este compuesto se confirmó mediante análisis de TLC y HPLC aplicando detección de fluorescencia. A partir de esto, el valor de Rf para trans-resveratrol es 0,64. Como eluyente, se seleccionó una mezcla de cloroformo, acetato de etilo y ácido fórmico (2,5 + 1 + 0,1, v / v). Además, el tiempo de retención para el tempeh fue de 14,467 y para el revestimiento de semilla de soja fue de 11,977. El rendimiento de extracción del resveratrol fue del 65,15 % en tempeh y del 55,35 % en la cubierta de la semilla de soja. El resveratrol aislado de tempeh y de la cubierta de la semilla de soja previno reacciones mediante la modulación de ciertas vías de señalización intracelular: proteína quinasa C (PKC), una familia de 12 serina/treonin quinasas, proporcionando una nueva molécula de plomo con efectos neuroprotectores, además de prevenir la muerte celular por apoptosis.

Stimulation of trans-resveratrol biosynthesis in Vitis vinifera cv. Kyoho cell suspension cultures by 2, 3-dihydroxypropyl jasmonate elicitation

Background: Plant cell suspension culture of Vitis vinifera is a promising technology for investigating different factors that are able to induce and/or modify stilbenes biosynthesis. Jasmonates have been reported to play an important role in a signal transduction pathway that regulates defence responses as well as the production of secondary metabolites. In this study, 2, 3-dihydroxypropyl jasmonate (DHPJA) was used to investigate its effect on stimulating trans-resveratrol (t-R) accumulation and the plant defence responses in Vitis vinifera cv. Kyoho cell suspension cultures for the first time. Results: It demonstrated that DHPJA had superior effects on stilbenoids accumulation over methyl jasmonate (MeJA). The optimal condition was 150 uM DHPJA added on day 15 of cultivation period, with the highest level of t-R accumulation which was increased 1.8-fold and 1.3-fold compared with the control and 150 uM MeJA respectively. DHPJA induced stronger plant defence responses, including oxidative burst and activation of L-phenylalanine ammonia lyase (PAL) than MeJA. H2O2 generation induced by DHPJA played a significant role in enhancing t-R accumulation. Adding a specific inhibitor of H2O2 signalling pathway inhibited DHPJA-induced t-R accumulation, but had no effects on DHPJA-induced other metabolites accumulation, which resulted in regulations of product diversity. Conclusions: This study demonstrated that DHPJA was an efficient elicitor to enhance t-R accumulation by activating stronger oxidative burst, and H2O2 signalling pathway could regulate product diversity in DHPJA-induced V. vinifera cv. Kyoho cell suspension cultures.