New Insights into Dietary Pterostilbene: Sources, Metabolism, and Health Promotion Effects

Phytonutrients in the promotion of healthspan: a new perspective

Considering a growing, aging population, the need for interventions to improve the healthspan in aging are tantamount. Diet and nutrition are important determinants of the aging trajectory. Plant-based diets that provide bioactive phytonutrients may contribute to offsetting hallmarks of aging and reducing the risk of chronic disease. Researchers now advocate moving toward a positive model of aging which focuses on the preservation of functional abilities, rather than an emphasis on the absence of disease. This narrative review discusses the modulatory effect of nutrition on aging, with an emphasis on promising phytonutrients, and their potential to influence cellular, organ and functional parameters in aging. The literature is discussed against the backdrop of a recent conceptual framework which describes vitality, intrinsic capacity and expressed capacities in aging. This aims to better elucidate the role of phytonutrients on vitality and intrinsic capacity in aging adults. Such a review contributes to this new scientific perspective-namely-how nutrition might help to preserve functional abilities in aging, rather than purely offsetting the risk of chronic disease.

Synergistic Mechanisms of Selected Polyphenols in Overcoming Chemoresistance and Enhancing Chemosensitivity in Colorectal Cancer

Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. Despite significant advances in medical treatment, chemotherapy as monotherapy can lead to substantial side effects and chemoresistance. This underscores the need for therapeutic approaches that are not only pharmacologically safe but also modulate multiple potent signaling pathways and sensitize cancer cells to overcome resistance to standard drugs. In recent years, scientists have been searching for natural compounds that can be used as chemosensitizers in addition to conventional medications for the synergistic treatment of CRC. Polyphenols represent a diverse group of natural compounds that can target multiple signaling pathways in cancer cells to induce anti-cancer effects. Additionally, polyphenols have been shown to work synergistically with chemotherapeutics and other natural compounds in cancer cells. This review aims to provide a comprehensive insight into the synergistic mechanisms of selected polyphenols as chemosensitizers in CRC cells. Further research and clinical trials are warranted to fully harness the synergistic mechanisms of selected polyphenols combined with chemotherapy or natural compounds in improving cancer treatment outcomes.

Nanophytomedicine: A promising practical approach in phytotherapy

The long and rich history of herbal therapeutic nutrients is fascinating. It is incredible to think about how ancient civilizations used plants and herbs to treat various ailments and diseases. One group of bioactive phytochemicals that has gained significant attention recently is dietary polyphenols. These compounds are commonly found in a variety of fruits, vegetables, spices, nuts, drinks, legumes, and grains. Despite their incredible therapeutic properties, one challenge with polyphenols is their poor water solubility, stability, and bioavailability. This means that they are not easily absorbed by the body when consumed in essential diets. Because of structural complexity, polyphenols with high molecular weight cannot be absorbed in the small intestine and after arriving in the colon, they are metabolized by gut microbiota. However, researchers are constantly working on finding solutions to enhance the bioavailability and absorption of these compounds. This study aims to address this issue by applying nanotechnology approaches to overcome the challenges of the therapeutic application of dietary polyphenols. This combination of nanotechnology and phytochemicals could cause a completely new field called nanophytomedicine or herbal nanomedicine.

Pterostilbene Reverses Epigenetic Silencing of Nrf2 and Enhances Antioxidant Response in Endothelial Cells in Hyperglycemic Microenvironment

The epigenetic regulation of nuclear factor erythroid 2-related factor 2 (Nrf2), a pivotal redox transcription factor, plays a crucial role in maintaining cellular homeostasis. Recent research has underscored the significance of epigenetic modifications of Nrf2 in the pathogenesis of diabetic foot ulcers (DFUs). This study investigates the epigenetic reversal of Nrf2 by pterostilbene (PTS) in human endothelial cells in a hyperglycemic microenvironment (HGM). The activation potential of PTS on Nrf2 was evaluated through ARE-Luciferase reporter assays and nuclear translocation studies. Following 72 h of exposure to an HGM, mRNA expression and protein levels of Nrf2 and its downstream targets NAD(P)H quinone oxidoreductase 1 (NQO1), heme-oxygenase 1(HO-1), superoxide dismutase (SOD), and catalase (CAT) exhibited a decrease, which was mitigated in PTS-pretreated endothelial cells. Epigenetic markers, including histone deacetylases (HDACs class I-IV) and DNA methyltransferases (DNMTs 1/3A and 3B), were found to be downregulated under diabetic conditions. Specifically, Nrf2-associated HDACs, including HDAC1, HDAC2, HDAC3, and HDAC4, were upregulated in HGM-induced endothelial cells. This upregulation was reversed in PTS-pretreated cells, except for HDAC2, which exhibited elevated expression in endothelial cells treated with PTS in a hyperglycemic microenvironment. Additionally, PTS was observed to reverse the activity of the methyltransferase enzyme DNMT. Furthermore, CpG islands in the Nrf2 promoter were hypermethylated in cells exposed to an HGM, a phenomenon potentially counteracted by PTS pretreatment, as shown by methyl-sensitive restriction enzyme PCR (MSRE-qPCR) analysis. Collectively, our findings highlight the ability of PTS to epigenetically regulate Nrf2 expression under hyperglycemic conditions, suggesting its therapeutic potential in managing diabetic complications.

Effects of fruit and vegetable intake on memory and attention: a systematic review of randomized controlled trials

BACKGROUND

Memory and attention are important for daily functioning, and their function deteriorates due to aging. However, fruit and vegetable consumption are one of the protective factors against deterioration in memory and attention. This systematic review of randomized controlled trials (RCTs) aims to identify the effects of fruit and vegetable consumption on memory and attention.

METHODS

We conducted a systematic search in EBSCOhost, ProQuest, PubMed, Embase, and Web of Science from inception up to 06/09/2022. The inclusion criteria were peer-reviewed articles, fruit and vegetable intake measured using randomized controlled trials, and the outcome measures that showed the results of memory and attention scores. Two researchers independently extracted articles that met the selection criteria and evaluated the quality of each study.

RESULTS

There were 70 articles identified from the databases, of which 13 articles met the inclusion criteria and were included in this systematic review. There were 493 participants in total. The results show that consumption of fruit and vegetable intake improved memory and attention in longitudinal studies (10 to 12 weeks). Children showed improvement in immediate recall after supplementation with blueberries. Older adults required a higher dose of fruit and vegetable intake consumption to achieve significant improvement compared with children and younger adults. Furthermore, the effect of fruits and vegetables on memory showed better immediate memory recall than delayed recall.

CONCLUSION

This systematic review showed that there is an improvement in memory and attention with fruit and vegetable intake consumption. Hence, awareness of fruit and vegetable intake consumption is important to maintain cognitive health.

Pterostilbene suppresses gastric cancer proliferation and metastasis by inhibiting oncogenic JAK2/STAT3 signaling: In vitro and in vivo therapeutic intervention

BACKGROUND

Gastric cancer (GC) represents a significant health burden with dire prognostic implications upon metastasis and recurrence. Pterostilbene (PTE) has been proven to have a strong ability to inhibit proliferation and metastasis in other cancers, while whether PTE exhibits anti-GC activity and its potential mechanism remain unclear.

PURPOSE

To explore the efficacy and potential mechanism of PTE in treating GC.

METHODS

We employed a comprehensive set of assays, including CCK-8, EdU staining, colony formation, flow cytometry, cell migration, and invasion assays, to detect the effect of PTE on the biological function of GC cells in vitro. The xenograft tumor model was established to evaluate the in vivo anti-GC activity of PTE. Network pharmacology was employed to predict PTE's potential targets and pathways within GC. Subsequently, Western blotting, immunofluorescence, and immunohistochemistry were utilized to analyze protein levels related to the cell cycle, EMT, and the JAK2/STAT3 pathway.

RESULTS

Our study demonstrated strong inhibitory effects of PTE on GC cells both in vitro and in vivo. In vitro, PTE significantly induced cell cycle arrest at G0/G1 and S phases and suppressed proliferation, migration, and invasion of GC cells. In vivo, PTE led to a dose-dependent reduction in tumor volume and weight. Importantly, PTE exhibited notable safety, leaving mouse weight, liver function, and kidney function unaffected. The involvement of the JAK2/STAT3 pathway in PTE's anti-GC effect was predicted utilizing network pharmacology. PTE suppressed JAK2 kinase activity by binding to the JH1 kinase structural domain and inhibited the downstream STAT3 signaling pathway. Western blotting confirmed PTE's inhibition of the JAK2/STAT3 pathway and EMT-associated protein levels. The anti-GC effect was partially reversed upon STAT3 activation, validating the pivotal role of the JAK2/STAT3 signaling pathway in PTE's activity.

CONCLUSION

Our investigation validates the potent inhibitory effects of PTE on the proliferation and metastasis of GC cells. Importantly, we present novel evidence implicating the JAK2/STAT3 pathway as the key mechanism through which PTE exerts its anti-GC activity. These findings not only establish the basis for considering PTE as a promising lead compound for GC therapeutics but also contribute significantly to our comprehension of the intricate molecular mechanisms underlying its exceptional anti-cancer properties.

Unveiling the neuroprotective properties of isoflavones: current evidence, molecular mechanisms and future perspectives

Neurodegenerative diseases encompass a wide range of debilitating and incurable brain disorders characterized by the progressive deterioration of the nervous system's structure and function. Isoflavones, which are naturally occurring polyphenolic phytochemicals, have been found to regulate various cellular signaling pathways associated with the nervous system. The main objective of this comprehensive review is to explore the neuroprotective effects of isoflavones, elucidate the underlying mechanisms, and assess their potential for treating neurodegenerative disorders. Relevant data regarding isoflavones and their impact on neurodegenerative diseases were gathered from multiple library databases and electronic sources, including PubMed, Google Scholar, Web of Science, and Science Direct. Numerous isoflavones, including genistein, daidzein, biochanin A, and formononetin, have exhibited potent neuroprotective properties against various neurodegenerative diseases. These compounds have been found to modulate neurotransmitters, which in turn contributes to their ability to protect against neurodegeneration. Both in vitro and in vivo experimental studies have provided evidence of their neuroprotection mechanisms, which involve interactions with estrogenic receptors, antioxidant effects, anti-inflammatory properties, anti-apoptotic activity, and modulation of neural plasticity. This review aims to provide current insights into the neuroprotective characteristics of isoflavones and shed light on their potential therapeutic applications in future clinical scenarios.

Comparative analyses of anti-inflammatory effects of Resveratrol, Pterostilbene and Curcumin: in-silico and in-vitro evidences

Inflammation is an adaptive response that involves activation, and recruitment of cells of innate and adaptive immune cells for restoring homeostasis. To safeguard the host from the threat of inflammatory agents, microbial invasion, or damage, the immune system activates the transcription factor NF-κB and produces cytokines such as TNF-α, IL- 6, IL-1β, and α. Sirtuin 1 (SIRT1) controls the increased amounts of proinflammatory cytokines, which in turn controls inflammation. Three phytoconstituents resveratrol (RES), pterostilbene (PTE), and curcumin (CUR) which are SIRT1- activators and that have marked anti-inflammatory effects (in-vivo), were chosen for the current study. These compounds were compared for their anti-inflammatory potential by in-silico docking studies for IL-6, TNF-α, NF-κB, and SIRT1 and in-vitro THP-1 cell line studies for IL-6, TNF-α. PTE was found to be more effective than RES and CUR in lowering the concentrations of IL-6 and TNF-α in THP-1 cell line studies, and it also showed a favorable docking profile with cytokines and SIRT1. Thus, PTE appears to be a better choice for further research and development as a drug or functional food supplement with the ability to reduce inflammation in metabolic disorders.

Graphical abstract

Schematic representation of in-silico and in-vitro analysis of Resveratrol, Pterostilbene, and Curcumin.

Co-assembled whey protein and proanthocyanidins as a promising biocarrier for hydrophobic pterostilbene: Fabrication, characterization, and cellular antioxidant potential

The usage of food-derived polyphenols with different polarities has been limited by their instability and incompatibility. Therefore, a biocarrier was developed by co-assembly of whey protein isolate (WPI) and hydrophilic proanthocyanidin (PC) for loading hydrophobic pterostilbene (PTE). Such biocarrier has superior affinity for PTE than WPI alone, as determined by encapsulation efficiency and loading capacity assay, fluorescence quenching analysis, and molecular docking, whereas the assembly process was characterized by particle size and zeta potential, 3-dimensional fluorescence, and scanning electron microscopy. Circular dichroism and Fourier transform infrared spectroscopy spectra confirmed the α-helix to β-sheet and random coil transition of proteins during the formation of nanocomplexes. Whey protein isolate acted as a mediator through altering the binding mode of PC and PTE, allowing them to perform significant synergistic effects in enhancing 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging and reducing H2O2-induced cell damage. This research may serve to develop new protein/polyphenol co-loading systems and offer a reliable nutritional fortification.

Danggui Buxue Tang improves therapeutic efficacy of doxorubicin in triple negative breast cancer via ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Danggui Buxue Tang (DBT) has been used for over 800 years to enhance Qi and nourish Blood, and it is particularly beneficial for cancer patients. Recent research has shown that combining DBT with chemotherapy agents leads to superior anti-cancer effects, thereby enhancing therapeutic efficacy.

AIM OF THE STUDY

The aim of this study was to evaluate the effectiveness of a combination therapy involving doxorubicin (DOX) and Danggui Buxue Tang (DBT) in the treatment of triple-negative breast cancer (TNBC) and to elucidate the underlying mechanisms of action.

MATERIALS AND METHODS

In vitro experiments were performed using MDA-MB-231 and 4T1 cells, while in vivo experiments were carried out using MDA-MB-231 xenograft mice. The therapeutic effects of the combination therapy were evaluated using various techniques, including MTT assay, colony formation assay, flow cytometry, transwell assay, immunofluorescence, transmission electron microscopy (TEM), histological analysis, western blotting, and bioluminescence assay.

RESULTS

DBT was found to enhance DOX's anti-TNBC activity in vitro by promoting ferroptosis, as evidenced by the observed mitochondrial morphological changes using TEM. The combination therapy was also found to reduce the expression of Nrf2, HO-1, and GPX4, which are all targets for ferroptosis induction, while simultaneously increasing ROS production. Additionally, the combination therapy reduced nuclear accumulation and constitutive activation of Nrf2, which is a significant cause of chemotherapy resistance and promotes cancer growth. In vivo experiments using an MDA-MB-231 xenograft animal model revealed that the combination therapy significantly reduced tumor cell proliferation and accelerated TNBC deaths by modulating the Nrf2/HO-1/GPX4 axis, with no evidence of tissue abnormalities. Moreover, the combination therapy exhibited a liver protective effect, and administration of Fer-1 was able to reduce the ROS formation produced by the DBT + DOX combination therapy.

CONCLUSION

This study provides evidence that the combination therapy of DOX and DBT has the potential to treat TNBC by promoting ferroptosis through the Nrf2/HO-1/GPX4 axis.

Therapeutic effect and mechanism of action of pterostilbene nano drugs in dry eye models

Dry eye disease is a multifactorial dysfunction of the tear film and ocular surface, with etiology involving inflammation and oxidative stress on the ocular surface. Pterostilbene (PS) is a secondary metabolite extracted from plants, which possesses remarkable anti-inflammatory and antioxidant effects. However, its application is limited by light instability and very poor water solubility. We modified fat-soluble PS into a biparental pterostilbene-glutaric anhydride-arginine-glycine-aspartic acid (PS-GA-RGD) nanomedicine by prodrug ligation of functional peptides. The aim of this study was to explore the protective effect and potential mechanism of PS-GA-RGD on dry eye disease in vitro and in vivo. We demonstrated good long-term biocompatibility of PS-GA-RGD through rabbit eye stimulation test. Lipopolysaccharide (LPS) was used to induce murine macrophages RAW 264.7 to establish an inflammation and oxidative stress model. In this model, PS-GA-RGD effectively reduced the production of ROS and 8-OHdG, enhancing the expression of antioxidant factor Nrf2 and antioxidant enzyme heme oxygenase-1. In addition, the expression of NF-κB inflammatory pathway significantly increased in LPS-induced RAW 264.7 cells, while PS-GA-RGD could significantly reduce this pathway. Hypertonic saline was utilized to establish a hypertonic model of human corneal epithelial cells. PS-GA-RGD was found to significantly reduce the production of ROS and NLRP3 inflammasomes in this model, exhibiting superior efficacy compared to PS. Experimental dry eye animal models were co-induced with subcutaneous injection of scopolamine and an intelligently controlled environmental system. We demonstrated that PS-GA-RGD nano drugs can prevent and reduce corneal epithelial cell defects and apoptosis, protect conjunctival goblet cells, and have an excellent anti-inflammatory effect. Finally, we demonstrated that RGD sequence in PS-GA-RGD can enhance cellular uptake, corneal retention, and penetration, thereby increasing their bioavailability and efficacy by a cell uptake assay and rabbit corneal drug retention experiment. Overall, this study highlights the potential of PS-GA-RGD nanomedicines in the treatment of dry eyes.

Analysing the Anticancer Properties of Pterostilbene Through Absorption, Distribution, Metabolism, and Excretion (ADME) and Molecular Docking Studies

Aim The aim of this study is to examine the possible therapeutic effect of pterostilbene (PTS), a chemical present in grapes and blueberries, in the treatment of liver cancer by analysing its interactions with important proteins linked to the wingless/integrated (Wnt) signaling system. Objective Using computational techniques like molecular docking and absorption, distribution, metabolism, and excretion (ADME) studies, this research focuses on examining the pharmacokinetics and molecular interactions of PTS with proteins such as vimentin (Vim), glycogen synthase kinase 3 beta (GSK3-β), epithelial cadherin (E-cadherin), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), c-Jun N-terminal kinase (JNK), and Wnt, all of which are connected to the Wnt signaling pathway in liver cancer. Methods The study includes the synthesis of proteins and ligands, ADME investigations for PTS, and AutoDock Vina molecular docking simulations to evaluate binding affinities and interactions. PTS is obtained from PubChem, while protein structures are obtained from the Protein Data Bank. Results Strong binding affinities between PTS and essential proteins in the Wnt signaling cascade are shown by molecular docking, which also highlights noteworthy hydrogen bonds, hydrophobic interactions, and electrostatic contacts. According to an ADME study, PTS has advantageous pharmacokinetic properties, such as moderate solubility, membrane permeability, and a minimal chance of drug interactions. Conclusion The extensive study highlights PTS's potential as a viable treatment option for liver cancer. The study promotes its investigation in cutting-edge liver cancer therapy approaches and urges more investigation into the molecular mechanisms, underpinning its anticancer properties. This paper sheds important light on the role of natural chemicals in cancer therapy and emphasizes the need for computational methods in drug discovery.

Pterostilbene: a potential therapeutic agent for fibrotic diseases

Fibrosis is a prevailing pathology in chronic diseases and accounts for 45% of deaths in developed countries. This condition is primarily identified by the transformation of fibroblasts into myofibroblasts and the overproduction of extracellular matrix (ECM) by myofibroblasts. Pterostilbene (PTS) is a natural analogue of resveratrol and is most commonly found in blueberries. Research has shown that PTS exerts a wide range of pharmacological effects, such as antioxidant, anti-inflammatory, and anticancer effects. As a result, PTS has the potential to prevent and cure numerous diseases. Emerging evidence has indicated that PTS can alleviate myocardial fibrosis, renal fibrosis, pulmonary fibrosis, hepatic fibrosis, and colon fibrosis via the inhibition of inflammation, oxidative stress, and fibrogenesis effects in vivo and in vitro, and the potential mechanisms are linked to various pathways, including transforming growth factor-β1 (TGF-β1)/small mother against decapentaplegic proteins (Smads) signalling, the reactive oxygen species (ROS)-driven Pitx2c/mir-15b pathway, nuclear factor kappa B (NF-κB) signalling, Kelch-like epichlorohydrin-associated protein-1 (Keap-1)/NF-E2-related factor-2 (Nrf2) cascade, the NLR family pyridine structure domain 3 (NLRP3) pathway, the Janus kinase-2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway, and the Src/STAT3 pathway. In this review, we comprehensively summarize the antifibrotic effects of PTS both in vivo and in vitro and the pharmacological mechanisms, pharmacokinetics, and toxicology of PTS and provide insights into and strategies for exploring promising agents for the treatment of fibrosis.

Involvement of Ferroptosis Induction and Oxidative Phosphorylation Inhibition in the Anticancer-Drug-Induced Myocardial Injury: Ameliorative Role of Pterostilbene

Patients with cancer die from cardiac dysfunction second only to the disease itself. Cardiotoxicity caused by anticancer drugs has been emphasized as a possible cause; however, the details remain unclear. To investigate this mechanism, we treated rat cardiomyoblast H9c2 cells with sunitinib, lapatinib, 5-fluorouracil, and cisplatin to examine their effects. All anticancer drugs increased ROS, lipid peroxide, and iron (II) levels in the mitochondria and decreased glutathione peroxidase-4 levels and the GSH/GSSG ratio. Against this background, mitochondrial iron (II) accumulates through the unregulated expression of haem oxygenase-1 and ferrochelatase. Anticancer-drug-induced cell death was suppressed by N-acetylcysteine, deferoxamine, and ferrostatin, indicating ferroptosis. Anticancer drug treatment impairs mitochondrial DNA and inhibits oxidative phosphorylation in H9c2 cells. Similar results were observed in the hearts of cancer-free rats treated with anticancer drugs in vitro. In contrast, treatment with pterostilbene inhibited the induction of ferroptosis and rescued the energy restriction induced by anticancer drugs both in vitro and in vivo. These findings suggest that induction of ferroptosis and inhibition of oxidative phosphorylation are mechanisms by which anticancer drugs cause myocardial damage. As pterostilbene ameliorates these mechanisms, it is expected to have significant clinical applications.

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.

Ononin ameliorates depression-like behaviors by regulating BDNF-TrkB-CREB signaling in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Ononin is a flavonoid compound found in several medicinal plants, including Astragalus membranaceus, Sophora flavescens, and Ononis spinosa. These plants have been traditionally used in various parts of the world for their medicinal properties, including anti-inflammatory, antioxidant, and antitumor effects. Major depression is a common, long-lasting, and recurrent psychiatric disorder with a high suicide rate. Naturally occurring flavonoids treat depression via poorly understood mechanisms.

AIM OF THE STUDY

The present study aimed to determine whether ononin conferred an antidepressant-like effect in PC12 cell models and chronic mild stress (CMS)-induced depressive rat models and to explore its possible mechanisms.

MATERIALS AND METHODS

Depression-related behaviors were measured using sucrose preference, tail suspension and open-field tests. Furthermore, to explore these mechanisms, we employed in vitro and in vivo assay methods, including neurite outgrowth, western blotting, quantitative RT-PCR, and staining methods.

RESULTS

Treatment with ononin or BDNF significantly increased PC12 cells' neuronal growth and differentiation. Furthermore, ononin promotes the activation of TrkB and growth factors and upregulates the PI3K/Akt and BDNF/TrkB/CREB signaling pathways. The in vitro results were consistent with CMS-induced depressive rat models, in which ononin treatment significantly decreased depression-like behaviors and activated TrkB, growth factors, and BDNF/TrkB/CREB signaling pathways in the frontal cortex and hippocampus. Depression-induced microscopic alterations in the frontal cortex and hippocampus of rats with CMS-induced depression were also mitigated following ononin treatment.

CONCLUSION

Based on these findings, we suggest that ononin is a promising antidepressant candidate for treating depression.

E-Stilbenes: General Chemical and Biological Aspects, Potential Pharmacological Activity Based on the Nrf2 Pathway

Stilbenes are phytoalexins, and their biosynthesis can occur through a natural route (shikimate precursor) or an alternative route (in microorganism cultures). The latter is a metabolic engineering strategy to enhance production due to stilbenes recognized pharmacological and medicinal potential. It is believed that in the human body, these potential activities can be modulated by the regulation of the nuclear factor erythroid derived 2 (Nrf2), which increases the expression of antioxidant enzymes. Given this, our review aims to critically analyze evidence regarding E-stilbenes in human metabolism and the Nrf2 activation pathway, with an emphasis on inflammatory and oxidative stress aspects related to the pathophysiology of chronic and metabolic diseases. In this comprehensive literature review, it can be observed that despite the broad number of stilbenes, those most frequently explored in clinical trials and preclinical studies (in vitro and in vivo) were resveratrol, piceatannol, pterostilbene, polydatin, stilbestrol, and pinosylvin. In some cases, depending on the dose/concentration and chemical nature of the stilbene, it was possible to identify activation of the Nrf2 pathway. Furthermore, the use of some experimental models presented a challenge in comparing results. In view of the above, it can be suggested that E-stilbenes have a relationship with the Nrf2 pathway, whether directly or indirectly, through different biological pathways, and in different diseases or conditions that are mainly related to inflammation and oxidative stress.

Resveratrol-based biorefinery models for favoring its inclusion along the market value-added chains: A critical review

Resveratrol, a natural organic polyhydroxyphenolic compound, has gained significant attention in the last years given its potential health benefits, including antioxidant, anti-cancer, and anti-inflammatory properties. It can be directly extracted from plants, vegetables, and related products and waste resources, but also chemically/enzymatically/microbially synthesized. However, certain process strategies have some limitations, such as high costs, reduced yield or high energy demand, thus implying significant environmental loads. In this context, the search for more sustainable and circular process schemes is key to the integration of resveratrol into the market value chain of the food, cosmetic and pharmaceutical sectors. The extraction of resveratrol has traditionally been based on conventional methods such as solvent extraction, but advanced green extraction techniques offer more efficient and environmentally friendly alternatives. This review analyses both conventional and green alternative extraction technologies, as well as its bioproduction through microbial fermentation, in terms of production capacity, yield, purity and sustainability. It also presents alternative biorefinery models based on resveratrol bioproduction using by-products and waste streams as resources, specifically considering wine residues, peanut shells and wood bark as input resources, and also following a circular approach. This critical review provides some insight into the opportunities that resveratrol offers for promoting sustainable development and circularity in the related market value chains, and thus provides some criteria for decision making for biorefinery models in which resveratrol is one of the targeted high value-added products. It also identifies the future challenges to promote the inclusion of resveratrol in value chains, with the scale-up of green technologies and its demonstrated economic feasibility being the most prominent.

Alzheimer, Parkinson, dementia, and phytochemicals: insight review

Alzheimer's, Parkinson's, and dementia are the leading neurodegenerative diseases that threaten the world with the aging population. Although the pathophysiology of each disease is unique, the steps to be taken to prevent diseases are similar. One of the changes that a person can make alone is to gain the habit of an antioxidant-rich diet. Phytochemicals known for their antioxidant properties have been reported to prevent neurodegenerative diseases in various studies. Phytochemicals with similar chemical structures are grouped. Accordingly, there are two main groups of phytochemicals, flavonoid and non-flavonoid. Various in vitro and in vivo studies on phytochemicals have proven neuroprotective effects by increasing cognitive function with their anti-inflammatory and antioxidant mechanisms. The purpose of this review is to summarize the in vitro and in vivo studies on phytochemicals with neuroprotective effects and to provide insight.

Pterostilbene in the treatment of inflammatory and oncological diseases

Pterostilbene (PTS), a naturally occurring analog of resveratrol (RSV), has garnered significant attention due to its potential therapeutic effects in treating inflammatory and oncological diseases. This comprehensive review elucidates the pharmacological properties, mechanisms of action, and therapeutic potential of PTS. Various studies indicate that PTS exhibits anti-inflammatory, antioxidant, and antitumour properties, potentially making it a promising candidate for clinical applications. Its influence on regulatory pathways like NF-κB and PI3K/Akt underscores its diverse strategies in addressing diseases. Additionally, PTS showcases a favorable pharmacokinetic profile with better oral bioavailability compared to other stilbenoids, thus enhancing its therapeutic potential. Given these findings, there is an increased interest in incorporating PTS into treatment regimens for inflammatory and cancer-related conditions. However, more extensive clinical trials are imperative to establish its safety and efficacy in diverse patient populations.

Skin delivery of synthetic benzoyl pterostilbenes suppresses atopic dermatitis-like inflammation through the inhibition of keratinocyte and macrophage activation

Atopic dermatitis (AD) is one of the most common skin autoimmune diseases needing continuous anti-inflammatory management. Pterostilbene is reported to exhibit anti-inflammatory activity with higher bioavailability and stability than its parent compound, resveratrol. In this study, a series of synthetic pterostilbene analogs were designed by the hybridization of pterostilbene with chalcones or benzoyl chloride. Seventeen analogs derived from pterostilbene were synthesized with differences in the positions of hydroxyl, methoxyl, or fluoro moieties. These compounds were screened by the inhibitory effect on the overexpressed Th2-associated cytokines/chemokines in the activated human keratinocytes (HaCaT). The anti-IL-5 and anti-CCL5 activity of these compounds led to the identification of three effective compounds: 3a ((E)- 4-(3,5-dimethoxystyryl)phenyl benzoate), 3d ((E)- 4-(3,5-dimethoxystyryl)phenyl 2-methoxybenzoate), and 3g ((E)- 4-(3,5-dimethoxystyryl)phenyl 2-fluorobenzoate). These benzoyl pterostilbenes also significantly decreased Th1/Th17-associated proinflammatory mediators in the activated macrophages (differentiated THP-1). The result showed that the conditioned medium of benzoyl pterostilbene-treated macrophages reduced the phosphorylated STAT3 in the keratinocytes, indicating the blockade of crosstalk between resident and immune cells. Compounds 3d and 3g generally showed greater skin absorption than 3a. The flux of 3g across barrier-defective skins mimicking the AD skin was 3-fold higher than that of across intact skin. The dinitrochlorobenzene (DNCB)-induced AD mouse model manifested that topical delivery with 3g improved the pathological signs through inhibiting cytokines/chemokines (IL-5, TNF-α, CCL17, and CCL22) and macrophage recruitment. The epidermal thickness was reduced from 76 to 55 µm after topical 3g delivery. The therapeutic activity of 3g was comparable to that of tacrolimus (TAC) used as a positive control. The benzoyl pterostilbenes attenuated the inflammation via the MAPK and c-Jun signaling. Furthermore, this study provided experimental evidence of benzoyl pterostilbene analogs for therapeutic potential on AD.

3'-Hydroxypterostilbene Potently Suppresses Tumor Growth via Inhibiting the Activation of the JAK2/STAT3 Pathway in Ovarian Clear Cell Carcinoma

SCOPE

Ovarian clear cell carcinoma (OCCC) is a subtype of epithelial ovarian cancer (EOC) that is associated with higher interleukin-6 (IL-6) levels, and suppression of the Janus kinase 2/Signal transducer and activator of transription 3 (JAK2/STAT3) pathway may contribute to the suppression of this cancer. This study aims to compare the anti-cancer effect of pterostilbene (PSB) and 2'- and 3'-hydroxypterostilbene (2HPSB and 3HPSB, respectively) on the JAK2/STAT3 pathway.

METHODS AND RESULTS

In vitro experiments with the OCCC cell line TOV21G and a xenograft nude mouse model are used to achieve the study aims. The results showed that 3HPSB has the greatest anti-proliferative and pro-apoptotic effects of the three compounds studied. Activation of the JAK2/STAT3 pathway and the nuclear translocation of STAT3 are effectively inhibited by 3HPSB and PSB. Both 3HPSB and PSB can effectively suppress tumor growth, which is mediated by the inhibition of JAK2/STAT3 phosphorylation.

CONCLUSION

This is the first study to compare the efficacy of PSB, 3HPSB, and the newly identified compound 2HPSB regarding ovarian cancer. Moreover, targeting JAK2/STAT3 is shown to be a potentially effective strategy for OCCC treatment. This study is expected to provide new insights into the potential of the abovementioned phytochemicals for development as adjuvants for cancer treatment in the future.

Protective potential of pterostilbene against cyclophosphamide-induced nephrotoxicity and cystitis in rats

PURPOSE

Cyclophosphamide (CYP) is an antitumor drug. However, in addition to its antitumor affect, CYP can also lead to nephrotoxicity and hemorrhagic cystitis. The purpose of this study was to investigate the potential protective effects of Pterostilbene (Pte), a natural antioxidant as a resveratrol analog against CYP-induced nephrotoxicity and cystitis in rats.

METHODS

Twenty-one male Sprague Dawley rats were divided into 3 equal groups. The control group and the CYP group (CYPG) received 1 ml/kg sunflower oil per day, and the CYP + Pte group (CYP + PteG) 40 mg/kg per day Pte dissolved in sunflower oil once a day via the oral route for 14 days. In addition, on day 9 of the experiment, CYPG and CYP + PteG received a single dose of 200 mg/kg CYP dissolved in saline solution, while the control group received a single dose of 10 ml/kg saline solution, via the intraperitoneal route. Bladder and kidney tissues were collected for histological and biochemical evaluations.

RESULTS

Pte was observed to reduce CYP-derived increases in malondialdehyde level, total oxidant status (TOS), the oxidative stress index (OSI), and apoptosis in kidney tissues and to cause an increase in superoxide dismutase levels. It also reduced CYP-derived increases in TOS, OSI, and apoptosis in bladder tissue. Moreover, Pte also ameliorated histopathological findings associated with CYP-induced tissue damage in both the kidney and bladder.

CONCLUSION

Our study findings show that Pte may exhibit a protective effect against CYP-induced nephrotoxicity and cystitis.

Unlocking the therapeutic potential of natural stilbene: Exploring pterostilbene as a powerful ally against aging and cognitive decline

The therapeutic potential of natural stilbenes, with a particular focus on pterostilbene (PTE), has emerged as a promising avenue of research targeting age-associated conditions encompassing cardiovascular diseases (CVD), diabetes mellitus (DM), and cognitive decline. This comprehensive investigation delves into the intricate mechanisms through which PTE, a polyphenolic compound abundant in grapes and blueberries, exerts its advantageous effects as an anti-aging agent. Central to its action is the modulation of hallmark aging processes, including oxidative damage, inflammatory responses, telomere attrition, and cellular senescence. PTE's ability to effectively penetrate the blood-brain barrier amplifies its potential for safeguarding neural health, thereby facilitating the regulation of neuronal signalling cascades, synaptic plasticity, and mitochondrial functionality. Through engagement with sirtuin proteins, it orchestrates cellular resilience, longevity, and metabolic equilibrium. Encouraging findings from preclinical studies portray PTE as a robust candidate for counteracting age-linked cognitive decline, augmenting memory consolidation, and potentially ameliorating neurodegenerative maladies such as Alzheimer's disease (AD). The synthesis of current scientific insights accentuates the promising translational prospects of PTE as a potent, naturally derived therapeutic agent against cognitive impairments associated with aging. Consequently, these collective findings lay a solid groundwork for forthcoming clinical inquiries and innovative therapeutic interventions in this realm.

Pterostilbene as a Therapeutic Alternative for Central Nervous System Disorders: A Review of the Current Status and Perspectives

Neurological disorders are diverse, have complex causes, and often result in disability; yet, effective treatments remain scarce. The resveratrol derivative pterostilbene possesses numerous physiological activities that hold promise as a novel therapy for the central nervous system (CNS) disorders. This review aimed to summarize the protective mechanisms of pterostilbene in in vitro and in vivo models of CNS disorders and the pharmacokinetics and safety to assess its possible effects on CNS disorders. Available evidence supports the protective effects of pterostilbene in CNS disorders involving mechanisms such as antioxidant and anti-inflammatory activity, regulation of lipid metabolism and vascular smooth muscle cell proliferation, improvement of synaptic function and neurogenesis, induction of glioma cell cycle arrest, and inhibition of glioma cell migration and invasion. Studies have identified possible molecular targets and pathways for the protective actions of pterostilbene in CNS disorders including the AMPK/STAT3, Akt, NF-κB, MAPK, and ERK signaling pathways. The possible pharmacological effects and molecular pathways of pterostilbene in CNS disorders are critically discussed in this review. Future studies should aim to increase our understanding of pterostilbene in animal models and humans to further evaluate its role in CNS disorders and the detailed mechanisms.

MicroRNA-27b Impairs Nrf2-Mediated Angiogenesis in the Progression of Diabetic Foot Ulcer

Nuclear factor erythroid-2-related factor 2 (Nrf2) is a stress-activated transcription factor regulating antioxidant genes, and a deficiency thereof, slowing lymphangiogenesis, has been reported in diabetic foot ulcer (DFU). The mode of Nrf2 regulation in DFU has been less explored. Emerging studies on miRNA-mediated target regulation show miRNA to be the leading player in the pathogenesis of the disease. In the present study, we demonstrated the role of miR-27b in regulating Nrf2-mediated angiogenesis in DFU. A lower expression of mRNA targets, such as Nrf2, HO-1, SDF-1α, and VEGF, was observed in tissue biopsied from chronic DFU subjects, which was in line with miR-27b, signifying a positive correlation with Nrf2. Similarly, we found significantly reduced expression of miR-27b and target mRNAs Nrf2, HO-1, SDF-1α, and VEGF in endothelial cells under a hyperglycemic microenvironment (HGM). To confirm the association of miR-27b on regulating Nrf2-mediated angiogenesis, we inhibited its expression through RNA interference-mediated knockdown and observed disturbances in angiogenic signaling with reduced endothelial cell migration. In addition, to explore the role of miR-27b and angiogenesis in the activation of Nrf2, we pretreated the endothelial cells with two well-known pharmacological compounds-pterostilbene and resveratrol. We observed that activation of Nrf2 through these compounds ameliorates impaired angiogenesis on HGM-induced endothelial cells. This study suggests a positive role of miR-27b in regulating Nrf2, which seems to be decreased in DFU and improves on treatment with pterostilbene and resveratrol.

Potential Chemopreventive Role of Pterostilbene in Its Modulation of the Apoptosis Pathway

Cancer incidence keeps increasing every year around the world and is one of the leading causes of death worldwide. Cancer has imposed a major burden on the human population, including the deterioration of physical and mental health as well as economic or financial loss among cancer patients. Conventional cancer treatments including chemotherapy, surgery, and radiotherapy have improved the mortality rate. However, conventional treatments have many challenges; for example, drug resistance, side effects, and cancer recurrence. Chemoprevention is one of the promising interventions to reduce the burden of cancer together with cancer treatments and early detection. Pterostilbene is a natural chemopreventive compound with various pharmacological properties such as anti-oxidant, anti-proliferative, and anti-inflammatory properties. Moreover, pterostilbene, due to its potential chemopreventive effect on inducing apoptosis in eliminating the mutated cells or preventing the progression of premalignant cells to cancerous cells, should be explored as a chemopreventive agent. Hence, in the review, we discuss the role of pterostilbene as a chemopreventive agent against various types of cancer via its modulation of the apoptosis pathway at the molecular levels.

Therapeutic application of natural products: NAD+ metabolism as potential target

BACKGROUND

Nicotinamide adenine dinucleotide (NAD⁺) metabolism is involved in the entire physiopathological process and is critical to human health. Long-term imbalance in NAD⁺ homeostasis is associated with various diseases, including non-alcoholic fatty liver disease, diabetes mellitus, cardiovascular diseases, neurodegenerative disorders, aging, and cancer, making it a potential target for effective therapeutic strategies. Currently, several natural products that target NAD⁺ metabolism have been widely reported to have significant therapeutic effects, but systematic summaries are lacking.

PURPOSE

To summarize the latest findings on the prevention and treatment of various diseases through the regulation of NAD⁺ metabolism by various natural products in vivo and in vitro models, and evaluate the toxicities of the natural products.

METHODS

PubMed, Web of Science, and ScienceDirect were searched using the keywords "natural products sources," "toxicology," "NAD⁺ clinical trials," and "NAD⁺," and/or paired with "natural products" and "diseases" for studies published within the last decade until January 2023.

RESULTS

We found that the natural products mainly include phenols (curcumin, cyclocurcumin, 4-hydroxybenzyl alcohol, salvianolic acid B, pterostilbene, EGCG), flavonoids (pinostrobin, apigenin, acacetin, tilianin, kaempferol, quercetin, isoliquiritigenin, luteolin, silybin, hydroxysafflor yellow A, scutellarin), glycosides (salidroside), quinones (emodin, embelin, β-LAPachone, shikonin), terpenoids (notoginsenoside R1, ginsenoside F2, ginsenoside Rd, ginsenoside Rb1, ginsenoside Rg3, thymoquinone, genipin), pyrazines (tetramethylpyrazine), alkaloids (evodiamine, berberine), and phenylpropanoids (ferulic acid). These natural products have antioxidant, energy-producing, anti-inflammatory, anti-apoptotic and anti-aging effects, which mainly influence the NAMPT/NAD⁺/SIRT, AMPK/SIRT1/PGC-1α, Nrf2/HO-1, PKCs/PARPs/NF-κB, and AMPK/Nrf2/mTOR signaling pathways, thereby regulating NAD⁺ metabolism to prevent and treat various diseases. These natural products have been shown to be safe, tolerable and have fewer adverse effects in various in vivo and in vitro studies and clinical trials.

CONCLUSION

We evaluated the toxic effects of natural products and summarized the available clinical trials on NAD⁺ metabolism, as well as the recent advances in the therapeutic application of natural products targeting NAD⁺ metabolism, with the aim to provide new insights into the treatment of multiple disorders.

The Research Progress of Extraction, Purification and Analysis Methods of Phenolic Compounds from Blueberry: A Comprehensive Review

Blueberry is the source of a variety of bioactive substances, including phenolic compounds, such as anthocyanins, pterostilbene, phenolic acids, etc. Several studies have revealed that polyphenols in blueberry have important bioactivities in maintaining health, such as antioxidant and anti-tumor activities, immune regulation, the prevention of chronic diseases, etc. Therefore, these phenolic compounds in blueberries have been widely used in the field of healthcare, and the extraction, isolation, and purification of phenolic compounds are the prerequisites for their utilization. It is imperative to systematically review the research progress and prospects of phenolic compounds present in blueberries. Herein, the latest progress in the extraction, purification, and analysis of phenolic compounds from blueberries is reviewed, which can in turn provide a foundation for further research and usage of blueberries.

Determination of Pterostilbene in Pharmaceutical Products Using a New HPLC Method and Its Application to Solubility and Stability Samples

The quantification of a natural bioactive compound, pterostilbene (PTT), in commercial capsule dosage form, solubility, and stability samples was carried out using a rapid and sensitive high-performance liquid chromatography (HPLC) approach. PTT was quantified on a Nucleodur (150 mm × 4.6 mm) RP C18 column with a particle size of 5 µm. Acetonitrile and water (90:10 v/v) made up the mobile phase, which was pumped at a flow speed of 1.0 mL/min. At a wavelength of 254 nm, PTT was detected. The developed HPLC approach was linear in 1–75 µg/g range, with a determination coefficient of 0.9995. The developed HPLC approach for PTT estimation was also rapid (Rt = 2.54 min), accurate (%recoveries = 98.10–101.93), precise (%CV = 0.59–1.25), and sensitive (LOD = 2.65 ng/g and LOQ = 7.95 ng/g). The applicability of developed HPLC approach was revealed by determining PTT in commercial capsule dosage form, solubility, and stability samples. The % assay of PTT in marketed capsules was determined to be 99.31%. The solubility of PTT in five different green solvents, including water, propylene glycol, ethanol, polyethylene glycol-400, and Carbitol was found to be 0.0180 mg/g, 1127 mg/g, 710.0 mg/g, 340.0 mg/g, and 571.0 mg/g, respectively. In addition, the precision and accuracy of stability samples were within the acceptable limit, hence PTT was found to be stable in solution. These results suggested that PTT in commercial products, solubility, and stability samples may be routinely determined using the established HPLC method.

Phase I Metabolism of Pterostilbene, a Dietary Resveratrol Derivative: Metabolite Identification, Species Differences, Isozyme Contribution, and Further Bioactivation

Pterostilbene (PTE), a dietary derivative of resveratrol, displayed pleiotropic health-promoting activities. This study aimed to explore the metabolic profiles and species differences of the phase I metabolism of PTE and to investigate subsequent detoxification after PTE bioactivation. PTE was found to be biotransformed to two pharmacologically active metabolites, pinostilbene and 3'-hydroxypterostilbene, in vivo and in vitro with substantial species differences. Human CYP1A2 was proved to be mainly responsible for the demethylation and 3'-hydroxylation of PTE, with its contribution to a demethylation of 94.5% and to a 3'-hydroxylation of 97.9%. An in vitro glutathione trapping experiment revealed the presence of an ortho-quinone intermediate formed by further oxidation of 3'-hydroxypterostilbene. Human glutathione S-transferase isoforms A2, T1, and A1 inactivated the ortho-quinone intermediate by catalyzing glutathione conjugation, implicating a potential protective pathway against PTE bioactivation-derived toxicity. Overall, this study provided a comprehensive view of PTE phase I metabolism and facilitated its further development as a promising nutraceutical.