Alkylated resveratrol prodrugs and metabolites as potential therapeutics for neurodegenerative diseases

Brain-Periphery Interactions in Huntington's Disease: Mediators and Lifestyle Interventions

Prominent pathological features of Huntington's disease (HD) are aggregations of mutated Huntingtin protein (mHtt) in the brain and neurodegeneration, which causes characteristic motor (such as chorea and dystonia) and non-motor symptoms. However, the numerous systemic and peripheral deficits in HD have gained increasing attention recently, since those factors likely modulate disease progression, including brain pathology. While whole-body metabolic abnormalities and organ-specific pathologies in HD have been relatively well described, the potential mediators of compromised inter-organ communication in HD have been insufficiently characterized. Therefore, we applied an exploratory literature search to identify such mediators. Unsurprisingly, dysregulation of inflammatory factors, circulating mHtt, and many other messenger molecules (hormones, lipids, RNAs) were found that suggest impaired inter-organ communication, including of the gut-brain and muscle-brain axis. Based on these findings, we aimed to assess the risks and potentials of lifestyle interventions that are thought to improve communication across these axes: dietary strategies and exercise. We conclude that appropriate lifestyle interventions have great potential to reduce symptoms and potentially modify disease progression (possibly via improving inter-organ signaling) in HD. However, impaired systemic metabolism and peripheral symptoms warrant particular care in the design of dietary and exercise programs for people with HD.

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.

Piceid Octanoate Protects Retinal Cells against Oxidative Damage by Regulating the Sirtuin 1/Poly-ADP-Ribose Polymerase 1 Axis In Vitro and in rd10 Mice

Retinitis pigmentosa is a common cause of inherited blindness in adults, which in many cases is associated with an increase in the formation of reactive oxygen species (ROS) that induces DNA damage, triggering Poly-ADP-Ribose Polymerase 1 (PARP1) activation and leading to parthanatos-mediated cell death. Previous studies have shown that resveratrol (RSV) is a promising molecule that can mitigate PARP1 overactivity, but its low bioavailability is a limitation for medical use. This study examined the impact of a synthesized new acylated RSV prodrug, piceid octanoate (PIC-OCT), in the 661W cell line against H2O2 oxidative stress and in rd10 mice. PIC-OCT possesses a better ADME profile than RSV. In response to H2O2, 661W cells pretreated with PIC-OCT preserved cell viability in more than 38% of cells by significantly promoting SIRT1 nuclear translocation, preserving NAD+/NADH ratio, and suppressing intracellular ROS formation. These effects result from expressing antioxidant genes, maintaining mitochondrial function, reducing PARP1 nuclear expression, and preventing AIF nuclear translocation. In rd10 mice, PIC-OCT inhibited PAR-polymer formation, increased SIRT1 expression, significantly reduced TUNEL-positive cells in the retinal outer nuclear layer, preserved ERGs, and enhanced light chamber activity (all p values < 0.05). Our findings corroborate that PIC-OCT protects photoreceptors by modulating the SIRT1/PARP1 axis in models of retinal degeneration.

Protective Effects of Alpha-lipoic Acid, Resveratrol, and Apigenin Against Oxidative Damages, Histopathological Changes, and Mortality Induced by Lung Irradiation in Rats

AIM

This study investigated the protective effects of three antioxidants on radiationinduced lung injury.

BACKGROUND

Oxidative stress is one of the key outcomes of radiotherapy in normal tissues. It can induce severe injuries in lung tissue, which may lead to pneumonitis and fibrosis. Recently, interest in natural chemicals as possible radioprotectors has increased due to their reduced toxicity, cheaper price, and other advantages.

OBJECTIVE

The present study was undertaken to evaluate the radioprotective effect of Alpha-lipoic Acid (LA), Resveratrol (RVT), and Apigenin (APG) against histopathological changes and oxidative damage and survival induced by ionizing radiation (IR) in the lung tissues of rats.

METHODS

First, the lung tissue of 50 mature male Wistar rats underwent an 18 Gy gamma irradiation. Next, the rats were sacrificed and transverse sections were obtained from the lung tissues and stained with hematoxylin and eosin (H and E) and Mason trichrome (MTC) for histopathological evaluation. Then, the activity of Glutathione peroxidase (GPx), Superoxide Dismutase (SOD), and Malondialdehyde (MDA) was measured by an ELISA reader at 340, 405, and 550 nm.

RESULTS

Based on the results of this study, IR led to a remarkable increase in morphological changes in the lung. However, APG, RVT, and LA could ameliorate the deleterious effects of IR in lung tissue. IR causes an increase in GPX level, and APG+IR administration causes a decrease in the level of GPX compared to the control group. Also, the results of this study showed that RVT has significant effects in reducing MDA levels in the short term. In addition, compared to the control group, IR and RVT+IR decrease the activity of SOD in the long term in the lung tissues of rats. Also, the analysis of results showed that weight changes in IR, LA+IR, APG+IR, and control groups were statistically significant.

CONCLUSION

APG and RVT could prevent tissue damage induced by radiation effects in rat lung tissues. Hence, APG, LA, and RVT could provide a novel preventive action with their potential antioxidant anti-inflammatory properties, as well as their great safety characteristic.

Synthesis and antimicrobial activity of aminoalkyl resveratrol derivatives inspired by cationic peptides

Antimicrobial resistance is a global concern, far from being resolved. The need of new drugs against new targets is imminent. In this work, we present a family of aminoalkyl resveratrol derivatives with antibacterial activity inspired by the properties of cationic amphipathic antimicrobial peptides. Surprisingly, the newly designed molecules display modest activity against aerobically growing bacteria but show surprisingly good antimicrobial activity against anaerobic bacteria (Gram-negative and Gram-positive) suggesting specificity towards this bacterial group. Preliminary studies into the action mechanism suggest that activity takes place at the membrane level, while no cross-resistance with traditional antibiotics is observed. Actually, some good synergistic relations with existing antibiotics were found against Gram-negative pathogens. However, some cytotoxicity was observed, despite their low haemolytic activity. Our results show the importance of the balance between positively charged moieties and hydrophobicity to improve antimicrobial activity, setting the stage for the design of new drugs based on these molecules.

A Comprehensive Bioinformatics Approach to Identify Molecular Signatures and Key Pathways for the Huntington Disease

Huntington disease (HD) is a degenerative brain disease caused by the expansion of CAG (cytosine-adenine-guanine) repeats, which is inherited as a dominant trait and progressively worsens over time possessing threat. Although HD is monogenetic, the specific pathophysiology and biomarkers are yet unknown specifically, also, complex to diagnose at an early stage, and identification is restricted in accuracy and precision. This study combined bioinformatics analysis and network-based system biology approaches to discover the biomarker, pathways, and drug targets related to molecular mechanism of HD etiology. The gene expression profile data sets GSE64810 and GSE95343 were analyzed to predict the molecular markers in HD where 162 mutual differentially expressed genes (DEGs) were detected. Ten hub genes among them (DUSP1, NKX2-5, GLI1, KLF4, SCNN1B, NPHS1, SGK2, PITX2, S100A4, and MSX1) were identified from protein-protein interaction (PPI) network which were mostly expressed as down-regulated. Following that, transcription factors (TFs)-DEGs interactions (FOXC1, GATA2, etc), TF-microRNA (miRNA) interactions (hsa-miR-340, hsa-miR-34a, etc), protein-drug interactions, and disorders associated with DEGs were predicted. Furthermore, we used gene set enrichment analysis (GSEA) to emphasize relevant gene ontology terms (eg, TF activity, sequence-specific DNA binding) linked to DEGs in HD. Disease interactions revealed the diseases that are linked to HD, and the prospective small drug molecules like cytarabine and arsenite was predicted against HD. This study reveals molecular biomarkers at the RNA and protein levels that may be beneficial to improve the understanding of molecular mechanisms, early diagnosis, as well as prospective pharmacologic targets for designing beneficial HD treatment.

Metabolic profiling to evaluate the impact of amantadine and rimantadine on the secondary metabolism of a model organism

Metabolic profiling offers huge potential to highlight markers and mechanisms in support of toxicology and pathology investigations during drug development. The main objective was to modify therapy with adamantane derivatives: amantadine and rimantadine, to increase their bioavailability and evaluate the influence of such therapy on drug metabolism using Saccharomyces cerevisiae as the model organism. In this study, the profile of endogenous metabolites of a model organism was measured and interpreted to provide an opportunity to investigate changes induced by treatment with amantadine and rimantadine. It was found that resveratrol supplementation synergistically enhanced the effects of amantadine treatment and increased rimantadine metabolism, potentially reducing side effects. The fingerprinting strategy was used as an efficient technique for qualitatively evaluating and monitoring changes in the profiles of endogenous components and their contents in a model organism. Chemometric tools were employed to find marker compounds that can be defined as characteristic indicators of a pharmacological response to a therapeutic intervention. An improved understanding of the mechanisms involved in drug effect and an increased ability to predict individual variations in the drug response of organisms will improve the treatment process and the development of new therapies.

Generation of potent antibacterial compounds through enzymatic and chemical modifications of the trans-δ-viniferin scaffold

Stilbene dimers are well-known for their diverse biological activities. In particular, previous studies have demonstrated the high antibacterial potential of a series of trans-δ-viniferin-related compounds against gram-positive bacteria such as Staphylococcus aureus. The trans-δ-viniferin scaffold has multiple chemical functions and can therefore be modified in various ways to generate derivatives. Here we report the synthesis of 40 derivatives obtained by light isomerization, O-methylation, halogenation and dimerization of other stilbene monomers. The antibacterial activities of all generated trans-δ-viniferin derivatives were evaluated against S. aureus and information on their structure-activity relationships (SAR) was obtained using a linear regression model. Our results show how several parameters, such as the O-methylation pattern and the presence of halogen atoms at specific positions, can determine the antibacterial activity. Taken together, these results can serve as a starting point for further SAR investigations.

Conjugation, Prodrug, and Co-Administration Strategies in Support of Nanotechnologies to Improve the Therapeutic Efficacy of Phytochemicals in the Central Nervous System

Phytochemicals, produced as secondary plant metabolites, have shown interesting potential therapeutic activities against neurodegenerative diseases and cancer. Unfortunately, poor bioavailability and rapid metabolic processes compromise their therapeutic use, and several strategies are currently proposed for overcoming these issues. The present review summarises strategies for enhancing the central nervous system's phytochemical efficacy. Particular attention has been paid to the use of phytochemicals in combination with other drugs (co-administrations) or administration of phytochemicals as prodrugs or conjugates, particularly when these approaches are supported by nanotechnologies exploiting conjugation strategies with appropriate targeting molecules. These aspects are described for polyphenols and essential oil components, which can improve their loading as prodrugs in nanocarriers, or be part of nanocarriers designed for targeted co-delivery to achieve synergistic anti-glioma or anti-neurodegenerative effects. The use of in vitro models, able to simulate the blood-brain barrier, neurodegeneration or glioma, and useful for optimizing innovative formulations before their in vivo administration via intravenous, oral, or nasal routes, is also summarised. Among the described compounds, quercetin, curcumin, resveratrol, ferulic acid, geraniol, and cinnamaldehyde can be efficaciously formulated to attain brain-targeting characteristics, and may therefore be therapeutically useful against glioma or neurodegenerative diseases.

Resveratrol derivatives: Synthesis and their biological activities

Resveratrol, a natural compound known especially for its antioxidant properties and protective action, opens the door for both it and its structural derivatives to be considered not only as chemopreventive but also as cancer chemotherapeutic agents. Due to the pharmacokinetic problems of resveratrol that demonstrate its poor bioavailability, the study of new derivatives is of interest. Thus, in this work (E)-stilbenes derived directly from resveratrol and other cyclic analogues containing the benzofuran or indole nucleus have been synthesized. The synthesized compounds have been evaluated for their ability to affect tumor growth in vitro. Compounds 2, 3, 4 and 5 have shown cytotoxicity in human colon cancer (HT-29) and human pancreatic adenocarcinoma cells (MIA PaCa-2) higher than those of (E)-resveratrol. The indolic derivative 13, a cyclic analog of resveratrol, has shown in vitro cytotoxic activity 8 times higher than resveratrol against HT-29 cancer cells. The cyclic derivatives 8, 9 and 12 showed a high inhibition of cell growth in HCT-116 (KRas mutant) at 20 μM, while 13 shows moderate antiangiogenesis activity at 10 μM.

Future Prospective of Radiopharmaceuticals from Natural Compounds Using Iodine Radioisotopes as Theranostic Agents

Natural compounds provide precursors with various pharmacological activities and play an important role in discovering new chemical entities, including radiopharmaceuticals. In the development of new radiopharmaceuticals, iodine radioisotopes are widely used and interact with complex compounds including natural products. However, the development of radiopharmaceuticals from natural compounds with iodine radioisotopes has not been widely explored. This review summarizes the development of radiopharmaceuticals from natural compounds using iodine radioisotopes in the last 10 years, as well as discusses the challenges and strategies to improve future discovery of radiopharmaceuticals from natural resources. Literature research was conducted via PubMed, from which 32 research articles related to the development of natural compounds labeled with iodine radioisotopes were reported. From the literature, the challenges in developing radiopharmaceuticals from natural compounds were the purity and biodistribution. Despite the challenges, the development of radiopharmaceuticals from natural compounds is a golden opportunity for nuclear medicine advancement.

Demystifying phytoconstituent-derived nanomedicines in their immunoregulatory and therapeutic roles in inflammatory diseases

In the past decades, phytoconstituents have appeared as critical mediators for immune regulations among various diseases, both in eukaryotes and prokaryotes. These bioactive molecules, showing a broad range of biological functions, would hold tremendous promise for developing new therapeutics. The discovery of phytoconstituents' capability of functionally regulating immune cells and associating cytokines, suppressing systemic inflammation, and remodeling immunity have rapidly promoted the idea of their employment as anti-inflammatory agents. In this review, we discuss various roles of phyto-derived medicines in the field of inflammatory diseases, including chronic inflammation, autoimmune diseases, and acute inflammatory disease such as COVID-19. Nevertheless, traditional phyto-derived medicines often concurred with their clinical administration limitations, such as their lack of cell specificity, inefficient cytoplasmic delivery, and rapid clearance by the immune system. As alternatives, phyto-derived nano-approaches may provide significant benefits. Both unmodified and engineered nanocarriers present the potential to serve as phytoconstituent delivery systems to improve therapeutic physio-chemical properties and pharmacokinetic profiles. Thus, the development of phytoconstituents' nano-delivery designs, their new and perspective approaches for therapeutical applications are elaborated herein.

Chemically Tuning Resveratrol for the Effective Killing of Gram-Positive Pathogens

In the era of antimicrobial resistance, the identification of new compounds with strong antimicrobial activity and the development of alternative therapies to fight drug-resistant bacteria are urgently needed. Here, we have used resveratrol, a safe and well-known plant-derived stilbene with poor antimicrobial properties, as a scaffold to design several new families of antimicrobials by adding different chemical entities at specific positions. We have characterized the mode of action of the most active compounds prepared and have examined their synergistic antibacterial activity in combination with traditional antibiotics. Some alkyl- and silyl-resveratrol derivatives show bactericidal activity against Gram-positive bacteria in the same low micromolar range of traditional antibiotics, with an original mechanism of action that combines membrane permeability activity with ionophore-related activities. No cross-resistance or antagonistic effect was observed with traditional antibiotics. Synergism was observed for some specific general-use antibiotics, such as aminoglycosides and cationic antimicrobial peptide antibiotics. No hemolytic activity was observed at the active concentrations or above, although some low toxicity against an MRC-5 cell line was noted.

Heterologous biosynthesis of prenylated resveratrol and evaluation of antioxidant activity

Prenylated stilbenoids are good candidates of nutraceuticals presented in food resources. The levels of natural prenylated stilbenoids are usually low. Biotransformation is a promising synthesis strategy to produce novel bioactive compounds. However, information regarding biosynthesis of prenylated stilbenoids is rare. In this work, prenyltransferase and geranyl diphosphate biosynthesispathway were overexpressed in E. coli. Multiple prenyltransferase genes were tested and Ambp1 was found to be effective on resveratrol geranylation. The products were identified by mass spectrometry and nuclear magnetic resonance spectroscopy as 4-C-geranyl resveratrol (1) and 3-O-geranyl resveratrol (2, novel chemical). By optimization of culture conditions, a yield of 36.9% was achieved for the conversion to geranylated resveratrol from resveratrol. These two compounds demonstrated good antioxidant activities with IC₅₀ values of 28.09 μM for 4-C-geranyl resveratrol and 403.88 μM for 3-O-geranyl resveratrol. The results were helpful for developing novel technique to produce prenylated phenolics.

Resveratrol and neuroprotection: an insight into prospective therapeutic approaches against Alzheimer's disease from bench to bedside

Alzheimer's disease (AD) is the most common cause of dementia and cognitive impairment; yet, there is currently no treatment. A buildup of Aβ, tau protein phosphorylation, oxidative stress, and inflammation in AD is pathogenic. The accumulation of amyloid-beta (Aβ) peptides in these neurocognitive areas is a significant characteristic of the disease. Therefore, inhibiting Aβ peptide aggregation has been proposed as the critical therapeutic approach for AD treatment. Resveratrol has been demonstrated in multiple studies to have a neuroprotective, anti-inflammatory, and antioxidant characteristic and the ability to minimize Aβ peptides aggregation and toxicity in the hippocampus of Alzheimer's patients, stimulating neurogenesis and inhibiting hippocampal degeneration. Furthermore, resveratrol's antioxidant effect promotes neuronal development by activating the silent information regulator-1 (SIRT1), which can protect against the detrimental effects of oxidative stress. Resveratrol-induced SIRT1 activation is becoming more crucial in developing novel therapeutic options for AD and other diseases that have neurodegenerative characteristics. This review highlighted a better knowledge of resveratrol's mechanism of action and its promising therapeutic efficacy in treating AD. We also highlighted the therapeutic potential of resveratrol as an AD therapeutic agent, which is effective against neurodegenerative disorders.

Structural derivatization strategies of natural phenols by semi-synthesis and total-synthesis

Structural derivatization of natural products has been a continuing and irreplaceable source of novel drug leads. Natural phenols are a broad category of natural products with wide pharmacological activity and have offered plenty of clinical drugs. However, the structural complexity and wide variety of natural phenols leads to the difficulty of structural derivatization. Skeleton analysis indicated most types of natural phenols can be structured by the combination and extension of three common fragments containing phenol, phenylpropanoid and benzoyl. Based on these fragments, the derivatization strategies of natural phenols were unified and comprehensively analyzed in this review. In addition to classical methods, advanced strategies with high selectivity, efficiency and practicality were emphasized. Total synthesis strategies of typical fragments such as stilbenes, chalcones and flavonoids were also covered and analyzed as the supplementary for supporting the diversity-oriented derivatization of natural phenols.

Assessment of resveratrol on diabetes of zebrafish (Danio rerio)

Purpose

Zebrafish (Danio rerio) is an established model for studying various metabolic diseases. The aim of this study was to evaluate the effect of resveratrol as a natural polyphenol on reducing inflammation caused by hyperglycemia (diabetes) and its effect on digestive tissue as well as TNF-α, IFN-γ, and INL1β genes in zebrafish.

Methods

Within a 20-day period, the research was performed on 120 adult zebrafish, which were randomly classified into eight groups: two experimental treatments (induced glucose = +G) and (without glucose = -G), where each main group was as follows: CTRL = control and RSV resveratrol with doses 10, 20, and 30 μmol/L. At the end of the period, the blood glucose level was measured using glucose test strip, staining of intestinal tissue was done by hematoxylin and eosin (H&E), and expression of INF-γ, IL1-β, and TNF-α genes extracted from the intestinal was measured via internal method RT-PCR. Data analysis in this study was performed using SPSS software version 21. One-way ANOVA and mean comparison of treatments by Duncan test were used for data analysis. All statistical analyses were performed at a significant level (P < 0.5) where the mean data were presented with standard deviation.

Results

According to the results, the lowest blood sugar level at the end of the experiment belonged to the group (G-RSV20) where no significant difference was observed between treatments (P > 0.05). The highest expression of IL1-β gene belonged to the (G + CTRL) group (P < 0.05), while the (G + RSV20) group showed the lowest expression of the INF-γ gene and had a significant difference with other groups (P < 0.05). In (G + RSV10) treatment, the lowest expression of TNF-α gene was observed and there was no significant difference with other treatments (P > 0.05). Resveratrol would improve the absorption of nutrients in the intestinal tissue by increasing the number of goblet cells as well as the width and height of the villi.

Conclusion

Collectively, this study indicated that treatment with resveratrol could improve metabolic-mediated performances by reducing blood glucose, increasing food absorption in the intestine tissue, and reducing the expression of inflammatory genes in type 2 diabetic zebrafish model.

Mechanisms Involved in Microglial-Interceded Alzheimer's Disease and Nanocarrier-Based Treatment Approaches

Alzheimer's disease (AD) is a common neurodegenerative disorder accountable for dementia and cognitive dysfunction. The etiology of AD is complex and multifactorial in origin. The formation and deposition of amyloid-beta (Aβ), hyperphosphorylated tau protein, neuroinflammation, persistent oxidative stress, and alteration in signaling pathways have been extensively explored among the various etiological hallmarks. However, more recently, the immunogenic regulation of AD has been identified, and macroglial activation is considered a limiting factor in its etiological cascade. Macroglial activation causes neuroinflammation via modulation of the NLRP3/NF-kB/p38 MAPKs pathway and is also involved in tau pathology via modulation of the GSK-3β/p38 MAPK pathways. Additionally, microglial activation contributes to the discrete release of neurotransmitters and an altered neuronal synaptic plasticity. Therefore, activated microglial cells appear to be an emerging target for managing and treating AD. This review article discussed the pathology of microglial activation in AD and the role of various nanocarrier-based anti-Alzeihmenr's therapeutic approaches that can either reverse or inhibit this activation. Thus, as a targeted drug delivery system, nanocarrier approaches could emerge as a novel means to overcome existing AD therapy limitations.

Resveratrol (RV): A pharmacological review and call for further research

Resveratrol (RV) is a well-known polyphenolic compound in various plants, including grape, peanut, and berry fruits, which is quite famous for its association with several health benefits such as anti-obesity, cardioprotective neuroprotective, antitumor, antidiabetic, antioxidants, anti-age effects, and glucose metabolism. Significantly, promising therapeutic properties have been reported in various cancer, neurodegeneration, and atherosclerosis and are regulated by several synergistic pathways that control oxidative stress, cell death, and inflammation. Similarly, RV possesses a strong anti-adipogenic effect by inhibiting fat accumulation processes and activating oxidative and lipolytic pathways, exhibiting their cardioprotective effects by inhibiting platelet aggregation. The RV also shows significant antibacterial effects against various food-borne pathogens (Listeria, Campylobacter, Staphylococcus aureus, and E. coli) by inhibiting an electron transport chain (ETC) and F0F1-ATPase, which decreases the production of cellular energy that leads to the spread of pathogens. After collecting and analyzing scientific literature, it may be concluded that RV is well tolerated and favorably affects cardiovascular, neurological, and diabetic disorders. As such, it is possible that RV can be considered the best nutritional additive and a complementary drug, especially a therapeutic candidate. Therefore, this review would increase knowledge about the blend of RV as well as inspire researchers around the world to consider RV as a pharmaceutical drug to combat future health crises against various inhumane diseases. In the future, this article will be aware of discoveries about the potential of this promising natural compound as the best nutraceuticals and therapeutic drugs in medicine.

Tailored Functionalization of Natural Phenols to Improve Biological Activity

Phenols are widespread in nature, being the major components of several plants and essential oils. Natural phenols' anti-microbial, anti-bacterial, anti-oxidant, pharmacological and nutritional properties are, nowadays, well established. Hence, given their peculiar biological role, numerous studies are currently ongoing to overcome their limitations, as well as to enhance their activity. In this review, the functionalization of selected natural phenols is critically examined, mainly highlighting their improved bioactivity after the proper chemical transformations. In particular, functionalization of the most abundant naturally occurring monophenols, diphenols, lipidic phenols, phenolic acids, polyphenols and curcumin derivatives is explored.

Overview of Beneficial Effects of (Poly)phenol Metabolites in the Context of Neurodegenerative Diseases on Model Organisms

The rise of neurodegenerative diseases in an aging population is an increasing problem of health, social and economic consequences. Epidemiological and intervention studies have demonstrated that diets rich in (poly)phenols can have potent health benefits on cognitive decline and neurodegenerative diseases. Meanwhile, the role of gut microbiota is ever more evident in modulating the catabolism of (poly)phenols to dozens of low molecular weight (poly)phenol metabolites that have been identified in plasma and urine. These metabolites can reach circulation in higher concentrations than parent (poly)phenols and persist for longer periods of time. However, studies addressing their potential brain effects are still lacking. In this review, we will discuss different model organisms that have been used to study how low molecular weight (poly)phenol metabolites affect neuronal related mechanisms gathering critical insight on their potential to tackle the major hallmarks of neurodegeneration.

A Brief Updated Review of Advances to Enhance Resveratrol's Bioavailability

Resveratrol (RES) has a low bioavailability. This limitation was addressed in an earlier review and several recommendations were offered. A literature search was conducted in order to determine the extent of the research that was conducted in line with these recommendations, along with new developments in this field. Most of the identified studies were pre-clinical and confirmed the heightened activity of RES analogues compared to their parent compound. Although this has provided additional scientific kudos for these compounds and has strengthened their potential to be developed into phytopharmaceutical products, clinical trials designed to confirm this increased activity remain lacking and are warranted.

Silyl resveratrol derivatives as potential therapeutic agents for neurodegenerative and neurological diseases

Natural phenolic compounds found in food have demonstrated interesting preventive and therapeutic effects on a large variety of pathologies. Indeed, some of them, such as resveratrol (RES), have been examined in clinical trials. Nevertheless, their success has been scarce mainly due to their low bioavailability. In this study, we found serendipitously that O-silyl RES derivatives exerted a better neuroprotective activity than resveratrol itself and decided to explore them as potential drugs for neurodegenerative and neurological diseases. We have also designed and prepared a series of O-silyl RES prodrugs to improve their bioavailability. We found that di-triethylsilyl and di-triisopropylsilyl RES derivatives were better in vitro neuroprotective and anti-inflammatory agents than RES. Among these derivatives and their corresponding acyl-, glycosyl- and carbamoyl-prodrugs, 3,5-triethylsilyl-4'-(6″-octanoylglucopyranosyl) resveratrol 26 showed the best profile on toxicity and neuroprotective activity in zebra fish embryo. Compound 26 was also capable of reducing the loss of motor coordination in a 3-nitropropionic acid mice model of Huntington's disease, in a similar way to RES. However, 26 diminished pro-inflammatory cytokine IL-6 to a higher extent than RES and improved the latency to fall in the rotarod test by 10% with respect to RES. Finally, we investigated 26 and RES as potential treatments on an experimental autoimmune encephalomyelitis (EAE) multiple sclerosis mice model. We observed that, in a therapeutic regimen, 26 significantly diminished the progression of EAE severity and reduced the percentage of animals with moderate to severe clinical score, whereas RES showed no improvement.

Role of Polyphenols on Gut Microbiota and the Ubiquitin-Proteasome System in Neurodegenerative Diseases

Today, neurodegenerative diseases have become a remarkable public health challenge due to their direct relation with aging. Accordingly, understanding the molecular and cellular mechanisms occurring in the pathogenesis of them is essential. Both protein aggregations as a result of the ubiquitin-proteasome system (UPS) inefficiency and gut microbiota alternation are the main pathogenic hallmarks. Polyphenols upregulating this system may decrease the developing rate of neurodegenerative diseases. Most of the dietary intake of polyphenols is converted into other microbial metabolites, which have completely different biological properties from the original polyphenols and should be thoroughly investigated. Herein, several prevalent neurodegenerative diseases are pinpointed to explain the role of gut microbiota alternations and the role of molecular changes, especially UPS down-regulation in their pathogenesis. Some of the most important polyphenols found in our diet are explained along with their microbial metabolites in the body.

Transcriptome Analysis of Juvenile Tilapia (Oreochromis niloticus) Blood, Fed With Different Concentrations of Resveratrol

Oreochromis niloticus (genetically improved farmed tilapia, GIFT) often bites the root of Polygonum cuspidatum when it is used as a floating bed, and resveratrol (RES) is mainly accumulated in the root of P. cuspidatum. Blood acts as a pipeline for the fish immune system. Generating blood transcriptomic resources is crucial for understanding molecular mechanisms underlying blood immune responses. In this study, we determined the effects of RES administration on blood transcriptomic response in GIFT. With increasing RES concentration, 133 (0.025 vs. 0.05 g/kg RES), 155 (0.025 vs. 0.1 g/kg RES), and 123 (0.05 vs. 0.1 g/kg RES) genes were detected as significant differentially expressed genes (DEGs). Three and ninety-five shared significant DEGs were found to be enriched among the three (except 0.1 g/kg RES) and four groups (0, 0.025, 0.05, and 0.1 g/kg RES), respectively. To determine the relationship between mitochondrial regulation and RES supplementation, the results of RNA-Seq were analyzed and nine mitochondria-related genes (ATP synthase or mitochondrial-function-related genes) were verified. The results revealed the same expression pattern: cytochrome c isoform X2 (cox2), katanin p60 ATPase-containing subunit A1 isoform X1 (katna1), plasma membrane calcium-transporting ATPase 1-like (atp2b1) and GTP-binding protein A-like (gtpbpal) showed the highest expression in the 0.1 g/kg RES group, while NADH dehydrogenase [ubiquinone] iron-sulfur protein 2 mitochondrial (nad7), ATP synthase subunit beta, mitochondrial (atpb), ATP synthase subunit alpha, mitochondrial-like (atpal), ATP synthase subunit alpha, mitochondrial (atpa) and ATP-dependent Clp protease proteolytic subunit, mitochondrial (clpp) revealed a dose-dependent expression following RES supplementation. Blood Ca²⁺-ATPase activity, and malondialdehyde, glutathione, and ATP content were significantly increased in the 0.05 (except Ca²⁺-ATPase activity), 0.1 g/kg RES group when compared with the controls. Eighty-nine shared DGEs were mainly enriched in antigen processing and presentation, cell adhesion molecules and phagosome pathways, based on the comparison between previous reported hepatic and the present blood transcriptome. Our study demonstrated that RES supplementation might improve the resistance to metabolism dysfunction via mitochondrial energy synthesis and/or the respiratory chain (e.g., ATPase).

Activity of Pterostilbene Metabolites against Liver Steatosis in Cultured Hepatocytes

Pterostilbene is a dimethyl ether derivative of resveratrol, less metabolized than its analogue, due to the substitution of two hydroxyl groups with methoxyl groups. Nevertheless, the amounts of pterostilbene phase II metabolites found in plasma and tissues are higher than those of the parent compound. The first aim of this study was to assess whether pterostilbene-4′-O-glucuronide (PT-G) and pterostilbene-4′-O-sulfate (PT-S) were able to prevent triglyceride accumulation in AML12 (alpha mouse liver 12) hepatocytes. This being the case, we aimed to analyze the mechanisms involved in their effects. For this purpose, an in vitro model mimicking the hepatocyte situation in fatty liver was developed by incubating mouse AML12 hepatocytes with palmitic acid (PA). For cell treatments, hepatocytes were incubated with 1, 10 or 25 µM of pterostilbene, pterostilbene-4′-O-glucuronide or pterostilbene-4′-O-sulfate for 18 h. Triglycerides and cell viability were assessed by a commercial kit and crystal violet assay, respectively. Protein expression of enzymes and transporters involved in triglyceride metabolism was analyzed by immunoblot. The results showed for the first time the anti-steatotic effect of pterostilbene metabolites and thus, that they contribute to the preventive effect induced by pterostilbene on steatosis in in vivo models. This anti-steatotic effect is mainly due to the inhibition of de novo lipogenesis.

Resveratrol Metabolites Are Able to Reduce Steatosis in Cultured Hepatocytes

Steatosis is characterized primarily by excessive lipid accumulation in the form of triglycerides in the liver. Although resveratrol shows a low bioavailability, it has significant positive effects on steatosis. The aim of this study was to analyze whether some phase II and microbial resveratrol metabolites (trans-resveratrol-4'-O-glucuronide (R-4G); trans-resveratrol-3-O-glucuronide (R-3G); trans-resveratrol-3-O-sulfate (R-S) and dihydro-resveratrol (DH-R) were effective in reducing hepatocyte fat accumulation. An in vitro model mimicking the hepatocyte situation in fatty liver was developed by incubating mouse AML12 hepatocytes with palmitic acid (PA). For cell treatments, hepatocytes were incubated with 1, 10, or 25 µM resveratrol or its metabolites. Triglycerides and cell viability were assessed using commercial kits. Protein expression of enzymes and transporters involved in triglyceride metabolism were analyzed by western blot. We show for the first time that resveratrol and all the tested metabolites, at 1 µM, partially prevented lipid accumulation induced by the saturated fatty acid PA in AML12 hepatocytes. This effect was mainly due to the inhibition of de novo lipogenesis. This demonstrates that the low bioavailability of resveratrol is not as big a problem as it was thought to be, because resveratrol metabolites contribute to the delipidating effects of the parent compound.

Microglia-targeting nanotherapeutics for neurodegenerative diseases

Advances in nanotechnology have enabled the design of nanotherapeutic platforms that could address the challenges of targeted delivery of active therapeutic agents to the central nervous system (CNS). While the majority of previous research studies on CNS nanotherapeutics have focused on neurons and endothelial cells, the predominant resident immune cells of the CNS, microglia, are also emerging as a promising cellular target for neurodegeneration considering their prominent role in neuroinflammation. Under normal physiological conditions, microglia protect neurons by removing pathological agents. However, long-term exposure of microglia to stimulants will cause sustained activation and lead to neuronal damage due to the release of pro-inflammatory agents, resulting in neuroinflammation and neurodegeneration. This Perspective highlights criteria to be considered when designing microglia-targeting nanotherapeutics for the treatment of neurodegenerative disorders. These criteria include conjugating specific microglial receptor-targeting ligands or peptides to the nanoparticle surface to achieve targeted delivery, leveraging microglial phagocytic properties, and utilizing biocompatible and biodegradable nanomaterials with low immune reactivity and neurotoxicity. In addition, certain therapeutic agents for the controlled inhibition of toxic protein aggregation and for modulation of microglial activation pathways can also be incorporated within the nanoparticle structure without compromising stability. Overall, considering the multifaceted disease mechanisms of neurodegeneration, microglia-targeted nanodrugs and nanotherapeutic particles may have the potential to resolve multiple pathological determinants of the disease and to guide a shift in the microglial phenotype spectrum toward a more neuroprotective state.

Resveratrol, a SIRT1 Activator, Ameliorates MK-801-Induced Cognitive and Motor Impairments in a Neonatal Rat Model of Schizophrenia

BACKGROUND

In neonatal rats, MK-801 treatment generates schizophrenia-like symptoms. Resveratrol (RSV) is a phenolic compound and a potent neuroprotective agent. This research aimed to illustrate the effect of RSV on the amelioration of MK-801-induced cognitive and motor impairments in a neonatal rat schizophrenia model and the related potential molecular changes.

METHODS

Rats were administrated with MK-801, MK-801 + RSV (40 mg/kg), or MK-801 + RSV (80 mg/kg). Motor learning, coordination, locomotor and exploratory activity, and spatial memory were measured by rotarod test, pen field test, and Morris water maze test. Relative protein levels were analyzed by Western blot and ELISA. mRNA levels were shown by qRT-PCR.

RESULTS

In the hippocampus of MK-801-induced schizophrenia rat model, RSV enhanced silent information regulator 1 (SIRT1) and brain derived neurotrophic factor (BDNF) expression and alleviated oxidative stress. Motor perturbations and learning impairments by MK-801 treatment were ameliorated by the administration of RSV.

CONCLUSION

In conclusion, RSV showed neuroprotective effect on MK-801-induced schizophrenia rat model through regulating SIRT1 and downstream BDNF expression in the hippocampus.

Synthesis of furocoumarin-stilbene hybrids as potential multifunctional drugs against multiple biochemical targets associated with Alzheimer's disease

A series of furocoumarin-stilbene hybrids has been synthesized and evaluated in vitro for inhibitory effect against acetylcholinesterase (AChE), butyrylcholinestarase (BChE), β-secretase, cyclooxygenase-2 (COX-2), and lipoxygenase-5 (LOX-5) activities including free radical-scavenging properties. Among these hybrids, 8-(3,5-dimethoxyphenyl)-4-(3,5-dimethoxystyryl)furochromen-2-one 4h exhibited significant anticholinesterase activity and inhibitory effect against β-secretase, COX-2 and LOX-5 activities. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and an in vitro cell-based antioxidant activity assay involving lipopolysaccharide induced reactive oxygen species production revealed that 4h has capability of scavenging free radicals. Molecular docking into AChE, BChE, β-secretase, COX-2 and LOX-5 active sites has also been performed.

Natural Product-Based Nanomedicine in Treatment of Inflammatory Bowel Disease

: Many synthetic drugs and monoclonal antibodies are currently in use to treat Inflammatory Bowel Disease (IBD). However, they all are implicated in causing severe side effects and long-term use results in many complications. Numerous in vitro and in vivo experiments demonstrate that phytochemicals and natural macromolecules from plants and animals reduce IBD-related complications with encouraging results. Additionally, many of them modify enzymatic activity, alleviate oxidative stress, and downregulate pro-inflammatory transcriptional factors and cytokine secretion. Translational significance of natural nanomedicine and strategies to investigate future natural product-based nanomedicine is discussed. Our focus in this review is to summarize the use of phytochemicals and macromolecules encapsulated in nanoparticles for the treatment of IBD and IBD-associated colorectal cancer.

Resveratrol: Multi-Targets Mechanism on Neurodegenerative Diseases Based on Network Pharmacology

Resveratrol is a natural polyphenol in lots of foods and traditional Chinese medicines, which has shown promising treatment for neurodegenerative diseases (NDs). However, the molecular mechanisms of its action have not been systematically studied yet. In order to elucidate the network pharmacological prospective effects of resveratrol on NDs, we assessed of pharmacokinetics (PK) properties of resveratrol, studied target prediction and network analysis, and discussed interacting pathways using a network pharmacology method. Main PK properties of resveratrol were acquired. A total of 13,612 genes related to NDs, and 138 overlapping genes were determined through matching the 175 potential targets of resveratrol with disease-associated genes. Gene Ontology (GO) function analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed to obtain more in-depth understanding of resveratrol on NDs. Accordingly, nodes with high degrees were obtained according using a PPI network, and AKT1, TP53, IL6, CASP3, VEGFA, TNF, MYC, MAPK3, MAPK8, and ALB were identified as hub target genes, which showed better affinity with resveratrol in silico studies. In addition, our experimental results demonstrated that resveratrol markedly enhanced the decreased levels of Bcl-2 and significantly reduced the increased expression of Bax and Caspase-3 in hippocampal neurons induced by glutamate exposure. Western blot results confirmed that resveratrol inhibited glutamate-induced apoptosis of hippocampal neurons partly by regulating the PI3K/AKT/mTOR pathway. In conclusion, we found that resveratrol could target multiple pathways forming a systematic network with pharmacological effects.

The Potential for Reducing Lynch Syndrome Cancer Risk with Nutritional Nrf2 Activators

Lynch syndrome (LS), is an autosomal dominant disorder predisposing patients to multiple cancers, predominantly colorectal (CRC) and endometrial, and is implicated in 2-4% of all CRC cases. LS is characterized by mutations of four mismatch repair (MMR) genes which code for proteins responsible for recognizing and repairing DNA lesions occurring through multiple mechanisms including oxidative stress (OS). Increased OS can cause DNA mutations and is considered carcinogenic. Due to reduced MMR activity, LS patients have an increased risk of cancer as a result of a decreased ability to recognize and repair DNA lesions caused by OS. Due to its carcinogenic properties, reducing the level of OS may reduce the risk of cancer. Nutritional Nrf2 activators have been shown to reduce the risk of carcinogenesis in the general population through activation of the endogenous antioxidant system. Common nutritional Nrf2 activators include sulforaphane, curcumin, DATS, quercetin, resveratrol, and EGCG. Since LS patients are more susceptible to carcinogenesis caused by OS, it is hypothesized that nutritional Nrf2 activators may have the potential to reduce the risk of cancer in those with LS by modulating OS and inflammation. The purpose of this paper is to review the available evidence in support of this statement.

Preventive Role of Resveratrol Against Inflammatory Cytokines and Related Diseases

BACKGROUND

Immunity is the ultimate barrier between foreign stimuli and a host cell. Unwanted immune responses can threaten the host cells and may eventually damage a vital organ. Overproduction of inflammatory cytokines may also lead to autoimmune diseases. Inflammatory cells and pro-inflammatory cytokines can eventually progress to renal, cardiac, brain, hepatic, pancreatic and ocular inflammation that can result in severe damage in the long run. Evidence also suggests that inflammation may lead to atherosclerosis, Alzheimer's, hypertension, stroke, cysts and cancers.

METHODS

This study was designed to correlate the possible molecular mechanisms for inflammatory diseases and prevent biochemical changes owing to inflammatory cytokines by using Resveratrol. Therefore, we searched and accumulated very recent literature on inflammatory disorders and Resveratrol. We scoured PubMed, Scopus, Science Direct, PLoS One and Google Scholar to gather papers and related information.

RESULTS

Reports show that inflammatory diseases are very complex, as multiple cascade systems are involved; therefore, they are quite difficult to cure. However, our literature search also correlates some possible molecular interactions by which inflammation can be prevented. We noticed that Resveratrol is a potent lead component and has multiple activities against harmful inflammatory cytokines and related microRNA. Our study also suggests that the anti-inflammatory properties of Resveratrol have been highly studied on animal models, cell lines and human subjects and proven to be very effective in reducing inflammatory cell production and pro-inflammatory cytokine accumulation. Our tables and figures also demonstrate recent findings and possible preventive activities to minimize inflammatory diseases.

CONCLUSION

This study would outline the role of harmful inflammatory cytokines as well as how they accelerate pathophysiology and progress to an inflammatory disorder. Therefore, this study might show a potential therapeutic value of using Resveratrol by health professionals in preventing inflammatory disorders.

Resveratrol Mitigates Sevoflurane-Induced Neurotoxicity by the SIRT1-Dependent Regulation of BDNF Expression in Developing Mice

Various lines of evidence suggest that neonatal exposure to general anesthetics, especially repeatedly, results in neuropathological brain changes and long-term cognitive impairment. Although progress has been made in experimental models, the exact mechanism of GA-induced neurotoxicity in the developing brain remains to be clarified. Sirtuin 1 (SIRT1) plays an important role in synaptic plasticity and cognitive performance, and its abnormal reduction is associated with cognitive dysfunction in neurodegenerative diseases. However, the role of SIRT1 in GA-induced neurotoxicity is unclear to date. In this study, we found that the protein level of SIRT1 was inhibited in the hippocampi of developing mice exposed to sevoflurane. Furthermore, the SIRT1 inhibition in hippocampi was associated with brain-derived neurotrophic factor (BDNF) downregulation modulated by methyl-cytosine-phosphate-guanine–binding protein 2 (MeCP2) and cAMP response element-binding protein (CREB). Pretreatment of neonatal mice with resveratrol nearly reversed the reduction in hippocampal SIRT1 expression, which increased the expression of BDNF in developing mice exposed to sevoflurane. Moreover, changes in the levels of CREB and MeCP2, which were considered to interact with BDNF promoter IV, were also rescued by resveratrol. Furthermore, resveratrol improved the cognitive performance in the Morris water maze test of the adult mice with exposure to sevoflurane in the neonatal stage, without changing motor function in the open field test. Taken together, our findings suggested that SIRT1 deficiency regulated BDNF signaling via regulation of the epigenetic activity of MeCP2 and CREB, and resveratrol might be a promising agent for mitigating sevoflurane-induced neurotoxicity in developing mice.

Neuroprotective and Anti-inflammatory Effects of Pterostilbene Metabolites in Human Neuroblastoma SH-SY5Y and RAW 264.7 Macrophage Cells

Oxidative stress is known to be a key factor in many neurodegenerative diseases. Inflammation also plays a relevant role in a myriad of pathologies such as diabetes and atherosclerosis. Polyphenols coming from dietary sources, such as pterostilbene, may be beneficial in this type of diseases. However, most of them are rapidly metabolized and excreted, yielding very low phenolic bioavailability what makes it difficult to find out which are the mechanisms responsible for the observed bioactivity. Herein, we evaluate the effects of pterostilbene and its metabolites against H₂O₂-induced cell damage in human neuroblastoma SH-SY5Y cells and against lipopolysaccharide (LPS)-challenged RAW 264.7 macrophages. Among the metabolites tested, 3-methyl-4'-glucuronate-resveratrol (also called 4'-glucuronate pinostilbene, PIN-GlcAc, 11) prevented neuronal death via attenuation of reactive oxygen species (ROS) levels and increased REDOX activity in neurons. This compound is also able to ameliorate LPS-mediated inflammation on macrophages via inhibition of IL-6 and NO production. Thus, polyphenol from dietary sources could be part of potential functional foods designed to ameliorate the onset and progression of certain neurodegenerative diseases via oxidative stress reduction.

Protective Effects of Resveratrol Supplementation on Contusion Induced Muscle Injury

Muscle injuries frequently occur in contact sports events. The current treatment options for soft tissue injuries remain suboptimal and often result in delayed or incomplete recovery of damaged muscles. Resveratrol (RES) is a phenolic phytochemical, well-known for its antioxidant and anti-inflammatory properties. The purpose of this study is to evaluate the potential beneficial effects of RES supplementation on inflammation and regeneration in skeletal muscle after a contusion injury, in comparison to a conventional treatment of nonsteroidal anti-inflammatory drugs (NSAID). After one week of acclimation, forty eight -week-old male ICR mice were randomly divided into the five groups (n=8 per group): 1) normal control (NC), 2) mass-drop injury without any treatment (mass-drop injury, MDI), 3) post-injury NSAID treatment (MDI+ 10mg/kg NSAID), 4) post-injury RES supplementation (MDI+ 25mg/kg/day RES) and 5) post-injury treatment with RES and NSAID (MDI + resveratrol+ NSAID). After muscle contusion injury of the left gastrocnemius muscle, RES or NSAID were orally administered post-injury once a day for 7 days. Results showed that the MDI group had significantly higher serum uric acid (UA), CREA (creatinine), LDH (lactic dehydrogenase) and creatine kinase (CK) than the normal control group. Treatment with resveratrol reduced muscle damage as evidenced by the significantly decreased serum levels of UA, CREA, LDH and CK after contusion-induced muscle injuries in mice. In addition, RES and RES + NSAID groups promoted muscle satellite cell regeneration with increase in desmin protein after injury. Our results suggest that resveratrol combined with NSAID potentially improve muscle recovery and may be a potential candidate for further development as an effective clinical treatment for muscle repair.

The low levels of nerve growth factor and its upstream regulatory kinases in prion infection is reversed by resveratrol

Resveratrol shows ability to eliminate prion replication, but the exact mechanism for prion eradication was not clear yet. Our previous studies demonstrate a downregulation of brain-derived nerve growth factor (BDNF) during prion infection, meanwhile recovery of cerebral nerve growth factor (NGF) level by resveratrol treatment has been reported in other neurodegenerative models. To obtain the possible changes of brain NGF and its upstream regulatory cascade during prion infection and after removal of prion propagation, the levels of NGF and its upstream regulatory factors in various prion-infected and prion-eradicated SMB cell lines and mice brains inoculated with various SMB cellular lysates were assessed with various methodologies. The levels of NGF were significantly decreased during prion replication, while recovered after removal of PrP^Sc by resveratrol in vitro. Morphological assays revealed that the NGF signals mainly colocalized within neurons, but not in the proliferative astrocytes and microglia. The upstream positive regulatory kinases, such as p-CREB, p-CaMKIV, CaMKK2 were decreased in the prion infected cells and mice brains, whereas the negative regulatory one, p-CaMKK2, was increased. The aberrant situations of those kinases in prion infected cell lines or mice brains could be also partially reversed by removal of prion agent. Moreover, we demonstrated that the signals of CaMKK2 and p-CaMKK2 were also distributed predominately in neurons in the brain tissues. The data illustrate a direct linkage of abnormally repressive NGF and its upstream regulatory kinases with prion infection. Resveratrol has not only the ability to inhibit prion replication, but also to improve the expression of NGF via CaMKK2/CaMKIV cascade, which might benefit the microenvironment in brains.

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.

Strategies to target bioactive molecules to subcellular compartments. Focus on natural compounds

Many potential pharmacological targets are present in multiple subcellular compartments and have different pathophysiological roles depending on location. In these cases, selective targeting of a drug to the relevant subcellular domain(s) may help to sharpen its impact by providing topological specificity, thus limiting side effects, and to concentrate the compound where needed, thus increasing its effectiveness. We review here the state of the art in precision subcellular delivery. The major approaches confer "homing" properties to the active principle via permanent or reversible (in pro-drug fashion) modifications, or through the use of special-design nanoparticles or liposomes to ferry a drug(s) cargo to its desired destination. An assortment of peptides, substituents with delocalized positive charges, custom-blended lipid mixtures, pH- or enzyme-sensitive groups provide the main tools of the trade. Mitochondria, lysosomes and the cell membrane may be mentioned as the fronts on which the most significant advances have been made. Most of the examples presented here have to do with targeting natural compounds - in particular polyphenols, known as pleiotropic agents - to one or the other subcellular compartment.

Nanostructured Chitosan-Based Biomaterials for Sustained and Colon-Specific Resveratrol Release

In the present work, we demonstrate the preparation of chitosan-based composites as vehicles of the natural occurring multi-drug resveratrol (RES). Such systems are endowed with potential therapeutic effects on inflammatory bowel diseases (IBD), such as Crohn's disease (CD) and ulcerative colitis, through the sustained colonic release of RES from long-lasting mucoadhesive drug depots. The loading of RES into nanoparticles (NPs) was optimized regarding two independent variables: RES/polymer ratio, and temperature. Twenty experiments were carried out and a Box⁻Behnken experimental design was used to evaluate the significance of these independent variables related to encapsulation efficiency (EE). The enhanced RES EE values were achieved in 24 h at 39 °C and at RES/polymer ratio of 0.75:1 w/w. Sizes and polydispersities of the optimized NPs were studied by dynamic light scattering (DLS). Chitosan (CTS) dispersions containing the RES-loaded NPs were ionically gelled with tricarballylic acid to yield CTS-NPs composites. Macro- and microscopic features (morphology and porosity studied by SEM and spreadability), thermal stability (studied by TGA), and release kinetics of the RES-loaded CTS-NPs were investigated. Release patterns in simulated colon conditions for 48 h displayed significant differences between the NPs (final cumulative drug release: 79⁻81%), and the CTS-NPs composites (29⁻34%).

The Synergistic Effects of Resveratrol combined with Resistant Training on Exercise Performance and Physiological Adaption

The comprehensive studies done on resveratrol (RES) support that this polyphenol has multiple bioactivities and is widely accepted for dietary supplementation. Furthermore, regular exercise is known to have benefits on health and is considered as a form of preventive medicine. Although the vast majority of prior studies emphasize the efficacy of aerobic exercise in promoting physiological adaptions, other types of exercise, such as resistance exercise and high-intensity interval training (HIIT), may achieve similar or different physiological outcomes. Few studies have looked into the effectiveness of a combinational, synergistic approach to exercise using a weight-loading ladder climbing animal platform. In this study, ICR mice were allocated randomly to the RES and training groups using a two-way ANOVA (RES × Training) design. Exercise capacities, including grip strength, aerobic performance, and anaerobic performance, were assessed and the physiological adaptions were evaluated using fatigue-associated indexes that were implemented immediately after the exercise intervention. In addition, glycogen levels, muscular characteristics, and safety issues, including body composition, histopathology, and biochemistry, were further elucidated. Synergistic effects were observed on grip strength, anaerobic capacities, and exercise lactate, with significant interaction effects. Moreover, the training or RES may have contributed significantly to elevating aerobic capacity, tissue glycogen, and muscle hypertrophy. Toxic and other deleterious effects were also considered to evaluate the safety of the intervention. Resistance exercise in combination with resveratrol supplementation may be applied in the general population to achieve better physiological benefits, promote overall health, and promote participation in regular physical activities.