Stability and solubility of trans-resveratrol are strongly influenced by pH and temperature

Characteristics, Biological Properties and Analytical Methods of Trans-Resveratrol: A Review

Trans-resveratrol (TR) is the biological active isomer of resveratrol and the one responsible for therapeutic effects; both molecules are non-flavonoid phenolics of the stilbenes class found mainly in berries and red grapes. TR biological properties lie in modulation of various enzymatic classes. It is a promising candidate to novel drugs due its applications in pharmaceutical and cosmetic industries, such as anticarcinogenic, antidiabetic, antiacne, antioxidant, anti-inflammatory, neuroprotective, and photoprotector agent. It has effects on bone metabolism, gastrointestinal tract, eyes, kidneys, and in obesity treatment as well. Nevertheless, its low solubility in water and other polar solvents may be a hindrance to its therapeutic effects. Various strategies been developed to overcome these issues, such as the drug delivery systems. The present study performed a research about methods to identify TR and RESV in several samples (raw materials, wines, food supplements, drug delivery systems, and blood plasma). Most of the studies tend to analyze TR and RESV by high performance liquid chromatography (HPLC) coupled with different detectors, even so, there are reports of the use of capillary electrophoresis, electron spin resonance, gas chromatography, near-infrared luminescence, UV-Vis spectrophotometer, and vibrational spectrophotometry, for this purpose. Thus, the review evaluates the biological activity of TR and demonstrates the currently used analytical methods for its quantification in different matrices.

Strategies to Improve Resveratrol Systemic and Topical Bioavailability: An Update

In recent years, a great deal of attention has been paid to natural compounds due to their many biological effects. Polyphenols are a class of plant derivatives that have been widely investigated for preventing and treating many oxidative stress-related pathological conditions, such as neurodegenerative and cardiovascular diseases, cancer, diabetes mellitus and inflammation. Among these polyphenols, resveratrol (RSV) has attracted considerable interest owing to its high antioxidant and free radical scavenging activities. However, the poor water solubility and rapid metabolism of RSV lead to low bioavailability, thus limiting its clinical efficacy. After discussing the main biochemical mechanisms involved in RSV biological activities, this review will focus on the strategies attempted to improve RSV effectiveness, both for systemic and for topical administration. In particular, technological approaches involving RSV incorporation into different delivery systems such as liposomes, polymeric and lipid nanoparticles, microemulsions and cyclodextrins will be illustrated, highlighting their potential clinical applications. In addition, chemical modifications of this antioxidant aimed at improving its physicochemical properties will be described along with the results of in vitro and in vivo studies.

Encapsulation of Lipophilic Polyphenols into Nanoliposomes Using pH-Driven Method: Advantages and Disadvantages

The poor water solubility and oral bioavailability of many lipophilic polyphenols can be improved through the use of colloidal delivery systems. In this study, a pH-driven method was used to encapsulate curcumin, quercetin, and resveratrol within nanoliposomes. This method is based on the decrease in water-solubility of certain polyphenols when they move from alkaline to acid conditions. However, the chemical stability of some polyphenols is relatively poor under alkaline conditions. For this reason, the impact of pH on the chemical degradation of the three polyphenols was studied. The polyphenols were then encapsulated within nanoliposomes using the pH-driven method and the encapsulation efficiency (EE) and chemical stability were determined. The EE of curcumin, quercetin, and resveratrol in the nanoliposomes was 100, 54, and 93%, respectively. Differences in the EE were mainly attributed to differences in their stability under alkaline conditions. Our results show that the application of this method to other lipophilic polyphenols depends on the impact of pH on their solubility and chemical stability, which needs to be established on a case-by-case basis.

Brain targeting of resveratrol through intranasal lipid vesicles labelled with gold nanoparticles: in vivo evaluation and bioaccumulation investigation using computed tomography and histopathological examination

Resveratrol is a promising neuroprotective agent against neurodegenerative disorders such as Alzheimer's disease. Resveratrol-loaded transferosomes and nanoemulsions were developed and labelled with gold nanoparticles (GNPs). The water maze test was utilised to identify the effect on spatial memory recovery. The treated rats were examined for cellular uptake and bioaccumulation of drug in the brain using computed tomography (CT) and histopathological examination utilising GNPs as a biomarker. Compared with nanoemulsions, transferosomes displayed higher permeation of up to 81.29 ± 2.64% and higher fluorescence intensity with p < .05. Transferosomes significantly enhanced behavioural acquisition and spatial memory function in the amnesic rats compared with both the nanoemulsion formulation and the pure drug. CT effectively demonstrated the accumulation of GNPs in the brains of all treated rats, while superior accumulation of GNPs was observed in the rats that received the transferosome formulation. The histopathology also demonstrated GNP accumulation in the nuclei and cytoplasm in the brain tissues of both the transferosome- and nanoemulsion-treated groups. Therefore, the developed transferosomes may be considered as a well-designed brain targeting system that might further be applied for targeting many drugs to be used in the treatment of central nervous system diseases.

Development, Characterization, and In Vitro Evaluation of Resveratrol-Loaded Poly-(ε-caprolactone) Microcapsules Prepared by Ultrasonic Atomization for Intra-Articular Administration

: Intra-articular administration of drugs to the joint in the treatment of joint disease has the potential to minimize the systemic bioavailability and the usual side-effects associated with oral drug administration. In this work, a drug delivery system is proposed to achieve an anti-inflammatory local effect using resveratrol (RSV). This study aims to develop microcapsules made of poly-(ε-caprolactone) (PCL) by ultrasonic atomization to preserve the antioxidant activity of RSV, to prevent its degradation and to suppress the inflammatory response in activated RAW 264.7 macrophages. An experimental design was performed to build a mathematical model that could estimate the effect of nozzle power and polymer concentration on particle size and encapsulation efficiency. RSV-loaded microcapsules showed adequate morphology, particle size, and loading efficiency properties. RSV formulations exhibited negligible cytotoxicity and an efficient amelioration of inflammatory responses, in terms of Nitric Oxide (NO), ROS (Reactive Oxygen Species), and lipid peroxidation in macrophages. Thus, RSV-loaded microcapsules merit consideration as a drug delivery system suitable for intra-articular administration in inflammatory disorders affecting the joint.

Targeting Cancer Via Resveratrol-Loaded Nanoparticles Administration: Focusing on In Vivo Evidence

Resveratrol (RSV) is a polyphenol endowed with potential therapeutic effects in chronic diseases, particularly in cancer, the second leading cause of death worldwide in the twenty-first century. The advent of nanotechnology application in the field of drug delivery allows to overcome the constrains associated with the conventional anticancer treatments, in particular chemotherapy, reducing its adverse side effects, off target risks and surpassing cancer multidrug chemoresistance. Moreover, the use of nanotechnology-based carriers in the delivery of plant-derived anticancer agents, such as RSV, has already demonstrated to surpass the poor water solubility, instability and reduced bioavailability associated with phytochemicals, improving their therapeutic activity, thus prompting pharmaceutical developments. This review highlights the in vivo anticancer potential of RSV achieved by nanotherapeutic approaches. First, RSV physicochemical, stability and pharmacokinetic features are described. Thereupon, the chemotherapeutic and chemopreventive properties of RSV are underlined, emphasizing the RSV numerous cancer molecular targets. Lastly, a comprehensive analysis of the RSV-loaded nanoparticles (RSV-NPs) developed and administered in different in vivo cancer models to date is presented. Nanoparticles (NPs) have shown to improve RSV solubility, stability, pharmacokinetics and biodistribution in cancer tissues, enhancing markedly its in vivo anticancer activity. RSV-NPs are, thus, considered a potential nanomedicine-based strategy to fight cancer; however, further studies are still necessary to allow RSV-NP clinical translation.

Nanoencapsulation of functional food ingredients

Many functional food ingredients are poorly soluble in water, susceptible to chemical degradation, and incompatible with surrounding food matrix. Other issues are related to limited oral bioavailability, unpleasant sensory properties, and poor release profiles. Nanoencapsulation of functional food ingredients can help increase their water solubility/dispersibility in foods and beverages, improve their bioavailability by exhibiting good dose-dependent functionalities, mask undesired flavors/tastes to reduce the adverse effect on mouth-feel, enhance shelf-life and compatibility during production, storage, transportation and utilization of food products, and control release rate or specific delivery environment for better performance on their functionalities. This chapter provides an overview of different delivery systems for different functional food ingredients, the types of materials suitable for wall materials or building blocks of nanocapsules, the fabrication methods to assemble different delivery systems and release these active ingredients under different physiological conditions.

Preparation and Evaluation of Novel Transfersomes Combined with the Natural Antioxidant Resveratrol

Resveratrol (tran-3,5,4′-trihydroxystibene, RSV) is a kind of polyphenol which has anti-inflammatory, antioxidant, anti-allergy, and anti-cancer properties, as well as being a scavenger of free radicals and preventing cardiovascular diseases. However, it is quite unstable in light, heat, and other conditions, and decays easily due to environmental factors. For these reasons, this study used a new type of carrier, transfersome, to encapsulate RSV. Transfersome consists of phosphatidyl choline (PC) from a liposomal system and non-ionic edge activators (EA). EA are an important ingredient in the formulation of transfersome; they can enhance the flexibility of the lipid bimolecular membrane of transfersome. Due to its ultradeformability, it also allows drugs to penetrate the skin, even through the stratum corneum. We hope that this new encapsulation technique will improve the stability and enhance the permeability of RSV. Concluding all the tested parameters, the best production condition was 5% PC/EA (3:1) and 5% ethanol in distilled water, with an ultrasonic bath and stirring at 500 rpm, followed by high pressure homogenization. The optimal particle size was 40.13 ± 0.51 nm and the entrapment efficiency (EE) was 59.93 ± 0.99%. The results of antioxidant activity analysis showed that transfersomes were comparable to the RSV group (unencapsulated). During in vitro transdermal delivery analysis, after 6 h, D1-20(W) increased 27.59% by accumulation. Cell viability assay showed that the cytotoxicity of D3-80(W) was reduced by 34.45% compared with the same concentration of RSV. Therefore, we successfully prepared RSV transfersomes and also improved the stability, solubility, and safety of RSV.

Can we conserve trans-resveratrol content and antioxidant activity during industrial production of chocolate?

BACKGROUND

Cocoa exhibits high content of phenolic compounds, among which trans-resveratrol stands out, associated with several bioactive activities such as antioxidant properties. Chocolate contains reduced amounts of these bioactive compounds due to losses during the production process. Therefore, this study aimed to assess changes in total phenolic content, and specifically trans-resveratrol, as well as changes in the antioxidant activity of cocoa and its products during industrial production of chocolate.

RESULTS

A total of ten different cocoa products were analyzed. The processes of fermentation and roasting caused significant loss of total phenolic compounds and antioxidant activity. The high temperature of roasting had a major influence on this loss (71% for total phenolic compounds and 53-77% for antioxidant activity), except for trans-resveratrol. The trans-resveratrol content formed after fermentation (9.8 μg kg^-1 ) showed little variation during the processes, and it was detected in higher concentrations both in natural (11.4 μg kg^-1 ) and in alkalized cocoa powder (13.5 μg kg^-1 ). Alkalization of cocoa products led to loss of capacity of deactivating superoxide radical.

CONCLUSION

These findings contribute to the optimization of the production process of chocolate and other food products containing cocoa and its derivatives, aiming to better preserve their bioactive compounds. © 2018 Society of Chemical Industry.

Evidence of the effectiveness of Resveratrol in the prevention of guanine one-electron oxidation: possible benefits in cancer prevention

Evidence of the antioxidant properties of Resveratrol in the one-electron oxidation of guanine nucleotide, a component of DNA molecules.

First-time oral administration of resveratrol-loaded layer-by-layer nanoparticles to rats – a pharmacokinetics study

trans-Resveratrol (RSV) is a plant-derived polyphenol endowed with a broad spectrum of promising therapeutic activities.

Resveratrol Delivery from Porous Poly(lactide- co-glycolide) Scaffolds Promotes an Anti-Inflammatory Environment within Visceral Adipose Tissue

As biomaterial therapies emerge to address adipose tissue dysfunction that underlies metabolic disease, the immune response to these systems must be established. As a potential therapy, we are investigating resveratrol delivery from porous poly(lactide- co-glycolide) scaffolds designed to integrate with adipose tissue. Resveratrol was selected for its ability to protect mice and primates from high fat diet and broad anti-inflammatory properties. Herein, we report fabrication of scaffolds with high resveratrol loading that are stable and active for up to one year. In vitro release profiles indicate that drug release is biphasic with a burst release over 3 days followed by a plateau. Surprisingly, we find that PLG scaffolds implanted into adipose tissue of mice promote an anti-inflammatory environment characterized by high arginase-1 and low TNF-α and IL-6 compared to naïve unmanipulated fat. Resveratrol delivery from the scaffold augments this anti-inflammatory environment by decreasing monocyte and lymphocyte numbers at the implant site and increasing expression of IL-10 and IL-13, cytokines that promote healthy adipose tissue. In terms of therapeutic applications, implant of scaffolds designed to release resveratrol into the visceral fat decreases MCP-1 expression in mice fed a high fat diet, a molecule that drives both local and systemic inflammation during obesity. Taken together, resveratrol delivery to adipose tissue using poly(lactide- co-glycolide) scaffolds is a promising therapeutic strategy for the treatment of adipose tissue inflammation that drives metabolic disease.

Resveratrol-loaded PLGA nanoparticles: enhanced stability, solubility and bioactivity of resveratrol for non-alcoholic fatty liver disease therapy

Resveratrol (3, 4', 5-trihydroxy-trans-stilbene, RSV), a nutraceutical, has recently attracted lots of attention because of its outstanding pharmacological potential. The effects of RSV on non-alcoholic fatty liver disease (NAFLD) remain inconclusive, although a wealth of research has been done. The major obstacle presented was RSV's poor bioavailability due to its poor aqueous solubility, chemical instability and intestinal metabolism. In this study, nanotechnology was used to encapsulate RSV to enhance its stability, water solubility and bioactivity, which can be used to treat NAFLD by HepG2 hepatocytes-induced in vitro. RSV-loaded poly (d, l-lactide-co-glycolide acid) (PLGA) nanoparticles (RSV-PLGA-NPs) were prepared according to an oil/water (O/W) emulsion technique. The RSV-PLGA-NPs were of spherical morphology with an average size of 176.1 nm and a negative charge of -22.6 mV. These nanoparticles exhibited remarkable encapsulation efficiency (EE%) (97.25%) and drug loading (14.9%) for RSV. A sustained RSV release from RSV-PLGA-NPs could be achieved especially in acidic conditions when simulating transporting through the gastrointestinal tract. In addition, these nanoparticles were stable enough to store at 4°C for a least six months with unchanged EE%. Moreover, RSV-PLGA-NPs were more efficient in alleviating lipogenesis, promoting lipolysis and reducing hepatocellular proliferation than free RSV due to its improved stability, water solubility and bioactivity. These findings indicated that the RSV-PLGA-NPs provided superb and stable drug delivery with small particle size, high capsulation efficiency, well-controlled drug release, which greatly enhanced the stability, water solubility and bioactivity. Besides, the discovery that the inhibitory effect of RSV-PLGA-NPs on hepatocellular proliferation and lipid accumulation in steatotic HepG2 cells may provide a new way to study the mechanism of NAFLD. Therefore, RSV-PLGA-NPs have a promising potential for NAFLD therapy.

Novel Approach with Controlled Nucleation and Growth for Green Synthesis of Size-Controlled Cyclodextrin-Based Metal-Organic Frameworks Based on Short-Chain Starch Nanoparticles

In this study, the nano- and microsized cyclodextrin-based metal-organic frameworks (CD-MOFs) were successfully conducted using short-chain starch nanoparticles as seeds through the seed-mediated method. The morphology, size, crystal structure, thermal, and N₂ adsorption properties of CD-MOFs prepared at different time intervals were investigated. The scanning electron microscopy results showed that the size variation from nanometer to millimeter could be controlled by crystal growth time. The CD-MOFs based on short-chain starch nanoparticle had higher crystallinity and N₂ uptake, thus indicating that the method of seed-mediated was more facile and efficient than the previous approach. Resveratrol (Res) is a natural polyphenol compound that has anticancer and antimicrobial activities against several pathogens. However, this compound suffers from poor stability. trans-Res rapidly isomerizes when exposed under ultraviolet or visible light. The results showed that the stability of Res was substantially enhanced by its encapsulation in CD-MOF crystals.

Resveratrol Can Be Stable in a Medium Containing Fetal Bovine Serum with Pyruvate but Shortens the Lifespan of Human Fibroblastic Hs68 Cells

This study is aimed at developing a method that can inhibit resveratrol (Res) degradation in Dulbecco's modified Eagle medium (DMEM) and at evaluating the effects of Res on the replicative lifespan of Hs68 cells. We hypothesized that Res can extend the lifespan of Hs68 cells if we can inhibit the oxidative degradation of Res in the medium. We found that the addition of ≥5 U/mL SOD to the medium could completely inhibit Res degradation in DMEM. Fetal bovine serum (FBS) contained 29.3 ± 1.1 U/mL of SOD activity. FBS could prevent Res degradation in the medium through SOD activity and Res–FBS interaction, but the regular FBS concentration (i.e., 10% FBS) exhibited an insufficient ability to completely inhibit Res degradation. We found that pyruvate (1 mM) could potentiate SOD to scavenge superoxide at approximately 2.2-fold. Thus, 10% FBS combined with pyruvate (1 mM) could completely inhibit Res degradation. When Res was not degraded, it still shortened the lifespan of Hs68 cells. Overall, the proposed method involving 10% FBS combined with pyruvate (1 mM) could completely prevent Res degradation. However, in contrast to our hypothesis, Res could induce the shortening of the lifespan of Hs68 cells. The stability of Res analogs (i.e., oxy-Res and acetyl-Res) in the medium and their effects on the lifespan of Hs68 cells were also investigated.

Resveratrol inhibits the proliferation and induces the apoptosis in ovarian cancer cells via inhibiting glycolysis and targeting AMPK/mTOR signaling pathway

Aerobic glycolysis is an important metabolic rewiring in cancer cells to promote glucose uptake and lactate production, and targeting aerobic glycolysis becomes a promising therapeutic approach for cancer. Here we reported that a small polyphenol resveratrol exhibited profound anti-tumor efficacy on human ovarian cancer. Resveratrol markedly inhibited the proliferation, migration, and invasion of A2780 and SKOV3 ovarian cancer cells, while impaired glycolysis, and induced apoptosis in these cells. Exposure to resveratrol increased the expression and activation of AMPK and Caspase 3, and decreased the expression and activation of AMPK downstream kinase mTOR. Moreover, AMPK inhibitor Compound C significantly abolished the effects of resveratrol on the activation of AMPK and Caspase 3 and the inhibition of mTOR. In addition, in vivo data indicated that resveratrol suppressed ovarian cancer growth and liver metastasis in xenograft mouse model. In conclusion, our findings provide new insight into the mechanism underlying anticancer efficacy of resveratrol and help the utilization of resveratrol as a novel agent for the treatment of ovarian cancer.

Antioxidant activity and photostability assessment of trans-resveratrol acrylate microspheres

Trans-resveratrol (RSV) was microencapsulated in Eudragit^® RS100 and RL100 resin blends. Lyophilized microspheres were characterized in the solid state for their micromeritic properties and drug loading. FT-IR, PXRD, and DSC analyzes suggested that RSV formed an intimate microcrystalline dispersion within the polymer network, also confirmed by SEM analysis. This produced a reduced degradation of RSV after storage at 40 °C, compared to the neat drug, and a protection of the drug from UV light-induced trans-cis isomerization (60% intact drug was found after 60 s irradiation at 350 nm, compared to 37% for the pure drug). Solubility and in vitro dissolution studies indicated that microencapsulation did not improve the dissolution pattern of RSV in simulated gastric and intestinal aqueous fluids. Evaluation of the in vitro antioxidant activity showed that, compared to the neat drug in aqueous solution, RSV loaded in the microspheres retained for a longer time, up to 22 days of incubation, the initial ORAC capacity. The present study thus demonstrated that Eudragit^® Retard resins can be used to easily produce micro-sized solid dispersions with RSV, for potential oral administration, contributing to ameliorate the physico-chemical stability and antioxidant activity of this compound.

Enhanced pH and thermal stability, solubility and antioxidant activity of resveratrol by nanocomplexation with α-lactalbumin

The health-promoting benefits of resveratrol (RES) have attracted significant attention.

Stability, biocompatibility and antioxidant activity of PEG-modified liposomes containing resveratrol

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^® technology, and their physical stability was evaluated in vitro in simulated body fluids, results showing that the key features of the liposomes were preserved. The biocompatibility of the formulations was demonstrated in an ex vivo model of hemolysis in human erythrocytes. Further, the incorporation of resveratrol in PEG-modified liposomes did not affect its intrinsic antioxidant activity, as DPPH radical was almost completely inhibited, and the vesicles were also able to ensure an optimal protection against oxidative stress in an ex vivo human erythrocytes-based model. Therefore, the proposed PEG-modified liposomes, which were prepared by a simple and reliable method, represent an interesting approach to safely deliver resveratrol, ensuring the preservation of the carrier structural integrity in the biological fluids, and the antioxidant efficacy of the polyphenol to be exploited against oxidative stress associated with cancer.

Resveratrol as a potential therapeutic drug for respiratory system diseases

Respiratory system diseases are common and major ailments that seriously endanger human health. Resveratrol, a polyphenolic phytoalexin, is considered an anti-inflammatory, antioxidant, and anticancer agent. Thanks to its wide range of biological activities, resveratrol has become a hotspot in many fields, including respiratory system diseases. Indeed, research has demonstrated that resveratrol is helpful to relieve pulmonary function in the general population. Meanwhile, growing evidence indicates that resveratrol plays a protective role in respiratory system diseases. This review aimed to summarize the main protective effects of resveratrol in respiratory system diseases, including its anti-inflammatory, antiapoptotic, antioxidant, antifibrotic, antihypertensive, and anticancer activities. We found that resveratrol plays a protective role in the respiratory system through a variety of mechanisms, and so it may become a new drug for the treatment of respiratory system diseases.

Preparation, characterization, and cellular uptake of resveratrol-loaded trimethyl chitosan nanoparticles

The aim of the study was to encapsulate resveratrol (RV) in trimethyl chitosan (TMC) nanoparticles cross-linked with tripolyphosphate (TPP) and/or alginate to achieve controlled release and improved cellular uptake. TMC (degree of quaternization of 78%) was prepared by reacting purified chitosan with iodomethane. Three types of RV-loaded TMC nanoparticles were prepared: TMC-TPP (TP-NPs), TMC-alginate (TA-NPs), and TMC-alginate-TPP (TAP-NPs). TA-NPs and TAP-NPs showed lower particle size and encapsulation efficiency (EE), better distribution, and more sustained release than TP-NPs due to the high molecular weight and viscous property of alginate. Caco-2 cellular uptake of RV was improved by TMC nanoencapsulation, and TP-NPs showed the highest uptake due to its significantly higher EE. Compared with TAP-NPs, TA-NPs with higher positive surface charge showed higher cellular uptake. Moreover, Caco-2 cell growth-inhibiting activity of RV was significantly increased by TMC nanoencapsulation and TP-NPs showed the significantly highest activity with a good agreement with the permeability results.

In Vitro Dissolution, Cellular Membrane Permeability, and Anti-Inflammatory Response of Resveratrol-Encapsulated Mesoporous Silica Nanoparticles

Sizing drugs down to the submicron and nanometer scale using nanoparticles has been extensively used in pharmaceutical industries to overcome the poor aqueous solubility of potential therapeutic agents. Here, we report the encapsulation and release of resveratrol, a promising anti-inflammatory and anticancer nutraceutical, from the mesopores of MCM-48-type silica nanospheres of various particle sizes, i.e., 90, 150, and 300 nm. Furthermore, the influence of the carrier pore size on drug solubility was also evaluated (3.5 vs 7 nm). From our results, it is observed that the saturated solubility could depend not only on the pore size but also on the particle size of the nanocarriers. Moreover, with our resveratrol-mesoporous silica nanoparticles formulation, we have observed that the permeability of resveratrol encapsulated in MCM-48 nanoparticles (90 nm) can be enhanced compared to a resveratrol suspension when tested through the human colon carcinoma cell monolayer (Caco-2). Using an in vitro NF-κB assay, we showed that resveratrol encapsulation did not alter its bioactivity and, at lower concentration, i.e., 5 μg mL^-1, resveratrol encapsulation provided higher anti-inflammatory activity compared to both resveratrol suspension and solution. All combined, the reported results clearly highlight the potential of small size mesoporous silica nanoparticles as next generation nanocarriers for hydrophobic drugs and nutraceuticals.

The novel resveratrol derivative 3,5-diethoxy-3',4'-dihydroxy-trans-stilbene induces mitochondrial ROS-mediated ER stress and cell death in human hepatoma cells in vitro

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a well-known polyphenol that is present in grapes, peanuts, pine seeds, and several other plants. Resveratrol exerts deleterious effects on various types of human cancer cells. Here, we analyzed the cell death-inducing mechanisms of resveratrol-006 (Res-006), a novel resveratrol derivative in human liver cancer cells in vitro. Res-006 was more effectively suppressed the viability of HepG2 human hepatoma cells than resveratrol (the IC₅₀ values were 67.2 and 354.8 μmol/L, respectively). Co-treatment with the ER stress regulator 4-phenylbutyrate (0.5 mmol/L) or the ROS inhibitor N-acetyl-L-cysteine (NAC, 1 mmol/L) significantly attenuated Res-006-induced HepG2 cell death, suggesting that pro-apoptotic ER stress and/or ROS may govern the Res-006-induced HepG2 cell death. We further revealed that treatment of HepG2 cells with Res-006 (65 μmol/L) immediately elicited the dysregulation of mitochondrial dynamics and the accumulation of mitochondrial ROS. It also collapsed the mitochondrial membrane potential and further induced ER stress and cell death. These events, except for the change in mitochondrial morphology, were prevented by the exposure of the HepG2 cells to the mitochondrial ROS scavenger, Mito-TEMPO (300-1000 μmol/L). The results suggest that Res-006 may kill HepG2 cells through cell death pathways, including the ER stress initiated by mitochondrial ROS accumulation. The cell death induced by this novel resveratrol derivative involves crosstalk between the mitochondria and ER stress mechanisms.

Ultrasound processed nanoemulsion: A comparative approach between resveratrol and resveratrol cyclodextrin inclusion complex to study its binding interactions, antioxidant activity and UV light stability

Resveratrol is a naturally occurring therapeutic molecule used for treatment of diseases caused by oxidative stress. This investigation elucidates the advantages of fabrication of size controlled resveratrol inclusion complex. This has been done by encapsulating resveratrol-cyclodextrin inclusion complex in a phospholipid stabilized nanoemulsion formulated by ultrasonication emulsification method. The prepared nanoemulsion has been compared with resveratrol encapsulated nanoemulsion system. The morphology of the resveratrol nanoemulsion and inclusion complex nanoemulsion have been observed using transmission electron microscopy with average size 20.41±3.41 and 24.48±5.70nm respectively. The nanoemulsion showed good loading and release efficiency. The radical diminishing potential of resveratrol and its inclusion complex has been compared in nanoemulsion. The effect of UV irradiation (365nm) on resveratrol in different solvent systems (ethanol, water and nanoemulsion) indicated that nanoemulsion prevents degradation of resveratrol. Efforts have also been made to explore the interactions between bovine serum albumin and resveratrol in nanoemulsion.

Antimicrobial, Optical and Mechanical Properties of Chitosan-Starch Films with Natural Extracts

Natural extracts possess several kinds of antioxidants (anthocyanins, betalains, thymol, carvacrol, and resveratrol) that have also demonstrated antimicrobial properties. In order to study these properties, extracts from cranberry, blueberry, beetroot, pomegranate, oregano, pitaya, and resveratrol (from grapes) were obtained. Growth inhibition tests of mesophilic aerobes, coliforms, and fungi were conducted in films prepared from the extracts in accordance with Mexican Official Norms (NOM). Optical properties such as transparency and opacity, mechanical properties, and pH were also analyzed in these materials. The films with beetroot, cranberry, and blueberry extracts demonstrated the best antimicrobial activity against various bacteria and fungi in comparison with unmodified chitosan–starch film. This study shows that the addition of antioxidants improved the antimicrobial performance of these films. It was also found that antimicrobial properties are inherent to the films. These polymers combined with the extracts effectively inhibit or reduce microorganism growth from human and environmental contact; therefore, previous sterilization could be unnecessary in comparison with traditional plastics. The presence of extracts decreased transmittance percentages at 280 and 400 nm, as well as the transparency values, while increasing their opacity values, providing better UV–VIS light barrier properties. Despite diminished glass transition temperatures (Tg), the values obtained are still adequate for food packaging applications.

Structure and dynamics of cetyltrimethylammonium chloride-sodium dodecylsulfate (CTAC-SDS) catanionic vesicles: High-value nano-vehicles from low-cost surfactants

HYPOTHESIS

Catanionic vesicles based on large-scale produced surfactants represent a promising platform for the design of innovative, effective and relatively inexpensive nano-vehicles for a variety of actives. Structural, dynamic and functional behavior of these aggregates is finely tuned by the molecular features of their components and can be opportunely tailored for their applications as drug carriers.

EXPERIMENTS

Here we investigate the aggregates formed by CTAC and SDS, two of the most diffused surfactants, by means of Dynamic Light Scattering, Small Angle Neutron Scattering and Electron Paramagnetic Resonance spectroscopy (EPR). The exploitation of these aggregates as nano-vehicles is explored using the poorly water-soluble antioxidant trans-resveratrol (t-RESV), testing t-RESV solubility and antioxidant activity by means of UV, fluorescence spectroscopy and EPR.

FINDINGS

The presence of a large stability region of catanionic vesicles on the CTAC-rich side of the phase diagram is highlighted and interpreted in terms of the mismatch between the lengths of the surfactant tails and of first reported effects of the chloride counterions. CTAC-SDS vesicles massively solubilize t-RESV, which in catanionic vesicles exerts a potent antioxidant and radical-scavenging activity. This behavior arises from the positioning of the active at the surface of the vesicular aggregates thus being sufficiently exposed to the external medium.

Formation of a Multiligand Complex of Bovine Serum Albumin with Retinol, Resveratrol, and (-)-Epigallocatechin-3-gallate for the Protection of Bioactive Components

Clarification of the interaction mechanisms between proteins and bioactive components is important to develop effective carriers for encapsulation and protection of bioactive components. Bovine serum albumin (BSA), a globular protein in serum and milk, contains multiple sites to bind a variety of low-molecular-weight molecules, forming protein-monoligand complexes. In this study, the interactions of BSA with retinol, resveratrol, and/or (-)-epigallocatechin-3-gallate (EGCG) were investigated by using fluorescence, circular dichroism, and molecular docking techniques. BSA-triligand complexes were successfully formed when added in the sequence of retinol, resveratrol, and EGCG. The stability of these bioactive components was improved in the complexes relative to free ones. The complexes provided a better protective effect on retinol and resveratrol than did BSA-monoligand complexes, in which the presence of EGCG played an important role.

Characterization of an extracellular β-glucosidase from Dekkera bruxellensis for resveratrol production

Polygonum cuspidatum is a widely grown crop with a rich source of polydatin (also called piceid) for resveratrol production. Resveratrol is produced from piceid via enzymatic cleavage of the sugar moiety of piceid. In this study, Dekkera bruxellensis mutants were selected based on their high p-nitrophenyl-β-d-glucopyranoside and piceid conversion activities. The enzyme responsible for piceid conversion was a heterodimeric protein complex that was predominantly secreted to the extracellular medium and consisted of two subunits at an equal ratio with molecular masses of 30.5 kDa and 48.3 kDa. The two subunits were identified as SCW4p and glucan-β-glucosidase precursor in D. bruxellensis. Both proteins were individually expressed in Saccharomyces cerevisiae exg1Δ mutants, which lack extracellular β-glucosidase activity, to confirm each protein’s enzymatic activities. Only the glucan-β-glucosidase precursor was shown to be a secretory protein with piceid deglycosylation activity. Our pilot experiments of piceid bioconversion demonstrate the possible industrial applications for this glucan-β-glucosidase precursor in the future.