Isorhapontigenin, a bioavailable dietary polyphenol, suppresses airway epithelial cell inflammation through a corticosteroid-independent mechanism

Transcriptome Analysis Reveals Anti-Cancer Effects of Isorhapontigenin (ISO) on Highly Invasive Human T24 Bladder Cancer Cells

Bladder cancer, the most common malignancy of the urinary tract, has a poor overall survival rate when the tumor becomes muscle invasive. The discovery and evaluation of new alternative medications targeting high-grade muscle invasive bladder cancer (MIBC) are of tremendous importance in reducing bladder cancer mortality. Isorhapontigenin (ISO), a stilbene derivative from the Chinese herb Gnetum cleistostachyum, exhibits a strong anti-cancer effect on MIBCs. Here, we report the whole transcriptome profiling of ISO-treated human bladder cancer T24 cells. A total of 1047 differentially expressed genes (DEGs) were identified, including 596 downregulated and 451 upregulated genes. Functional annotation and pathway analysis revealed that ISO treatment induced massive changes in gene expression associated with cell movement, migration, invasion, metabolism, proliferation, and angiogenesis. Additionally, ISO treatment-activated genes involved in the inflammatory response but repressed genes involved in hypoxia signaling, glycolysis, the actin cytoskeleton, and the tumor microenvironment. In summary, our whole transcriptome analysis demonstrated a shift in metabolism and altered actin cytoskeleton in ISO-treated T24 cells, which subsequently contribute to tumor microenvironment remodeling that suppresses tumor growth and progression.

Isorhapontigenin (ISO) inhibits malignant cell transformation, migration, and invasion through MEG3/NEDD9 signaling in Cr(VI)-transformed cells

Cr(VI) compounds are confirmed human carcinogens. Maternally expression 3 (MEG3) is the first long non-coding RNA to be identified as a tumor suppressor. MEG3 is frequently downregulated or lost in various primary human tumor tissues and cancer cell lines. Downregulation of MEG3 is associated with cancer initiation, progression, and metastasis. Our previous study has revealed that MEG3 was lost and NEDD9 was upregulated in Cr(VI)-transformed cells compared to those in passage-matched normal BEAS-2B cells. Overexpression of MEG3 reduced NEDD9. β-Catenin was activated in Cr(VI)-transformed cells, overexpression of MEG3 or knockdown of NEDD9 inhibited the activation of β-Catenin. The results from the present study showed that isorhapontigenin (ISO) treatment is able to suppress cell proliferation, migration, and invasion of Cr(VI)-transformed cells. Further study showed that ISO treatment in Cr(VI)-transformed cells decreases the levels of Ki67, a biomarker for cell proliferation, and of cyclin D1, a regulator for the cell cycle. ISO elevated the MEG3 expression level in Cr(VI)-transformed cells. The DNA methylation transferases DNMT3a, DNMT3b, and DNMT1 levels were reduced upon ISO treatment. ISO treatment decreased both mRNA and protein levels of NEDD9. In addition, ISO treatment reduced the activation of β-catenin. Slug was upregulated and E-Cadherin was downregulated in Cr(VI)-transformed cells, treatment with ISO decreased Slug and increased E-Cadherin. This study demonstrated that ISO is a potent therapeutical agent against lung cancer induced by Cr(VI).

Inhibition of TLR4 Signaling by Isorhapontigenin Targeting of the AHR Alleviates Cerebral Ischemia/Reperfusion Injury

Ischemic stroke is a major risk factor in human health, yet there are no drugs to cure cerebral ischemia/reperfusion injury (CIRI). Inflammation plays a fundamental role in the consequences of CIRI. Isorhapontigenin (ISOR) exhibits great anti-inflammatory activity; however, it is unclear whether ISOR can treat ischemic stroke through an anti-inflammation effect. Here, middle cerebral artery occlusion/reperfusion (MCAO/R) was used to investigate the effects of ISOR on CIRI. The in vitro activity was measured in BV-2 cells exposed to oxygen-glucose deprivation/reperfusion. As measured by neurological scores, brain water content, and infarction, neurological dysfunction was improved in the ISOR group. The neuronal death and microglial activation in the ipsilateral cortex were reduced by ISOR. TLR4 signaling was significantly inhibited by ISOR in vivo and in vitro. By reverse molecular docking, cellular thermal shift, and drug affinity-responsive target stability assays, an aryl hydrocarbon receptor (AHR) was found to be a target of ISOR. Furthermore, AHR knockdown blocked the effect of ISOR on TLR4 signaling, suggesting that ISOR may regulate TLR4-mediated inflammation through AHR, thereby protecting neurons from CIRI. This study demonstrated that ISOR is a promising drug candidate for the treatment of ischemic stroke and provided a theoretical basis for the development of the medicinal value of ISOR-derived foods, such as grapes.

Resveratrol and Other Natural Oligomeric Stilbenoid Compounds and Their Therapeutic Applications

The use of natural compounds as an alternative to synthetic molecules has become a significant subject of interest in recent decades. Stilbenoids are a group of phenolic compounds found in many plant species and they have recently gained the focus of a multitude of studies in medicine and chemistry, resveratrol being the most representative molecule. In this review, we focused on the research that illustrates the therapeutic potential of this class of natural molecules considering various diseases with higher incidence rates. PubChem database was searched for bioactivities of natural stilbenoids, while several keywords (i.e., "stilbenoids", "stilbenoid anticancer") were used to query PubMed database for relevant studies. The diversity and the simplicity of stilbenes' chemical structures together with the numerous biological sources are key elements that can simplify both the isolation of these compounds and the drug design of novel bioactive molecules. Resveratrol and other related compounds are heterogeneously distributed in plants and are mainly found in grapes and wine. Natural stilbenes were shown to possess a wide range of biological activities, such as antioxidant, anti-inflammatory, antihyperglycemic, cardioprotective, neuroprotective, and antineoplastic properties. While resveratrol is widely investigated for its benefits in various disorders, further studies are warranted to properly harness the therapeutic potential of less popular stilbenoid compounds.

Unripe Rubus occidentalis, Ellagic Acid, and Urolithin A Attenuate Inflammatory Responses in IL-1β-Stimulated A549 Cells and PMA-Stimulated Differentiated HL-60 Cells

Unripe Rubus occidentalis (uRO) contains various natural polyphenols with beneficial physiological activities and is particularly rich in ellagic acid (EA). EA has ameliorated type 2 inflammation and airway hyperresponsiveness in animal models of eosinophilic asthma. EA is metabolized by the gut microbiota to urolithin A (UA), which exhibits anti-inflammatory properties. However, it remains unclear whether uRO, EA, and UA reduce inflammatory responses and oxidative stress in respiratory epithelial cells and neutrophils. In this study, inflammation was induced in A549 (human lung epithelial cells) and dHL-60 cells (neutrophil-like cells differentiated from human promyelocytic leukemia HL-60 cells) and treated with various concentrations of water extract of uRO (uRO-w), EA, and UA. EA, uRO-w and UA suppressed the inflammatory cytokine and chemokine levels and reduced the expression of matrix metalloproteinase-9 in A549 cells stimulated with IL-1β. As a result of analyzing the mechanism by which these inflammatory molecules are expressed, it was found that EA, uRO-w, and UA regulated corticosteroid-sensitive mitogen activated protein kinase, nuclear factor κB, and corticosteroid-insensitive AKT. In addition, uRO-w, EA, and UA significantly reduced reactive oxygen species levels in phorbol 12-myristate 13-acetate-stimulated dHL-60 cells and inhibited neutrophil extracellular trap formation. Therefore, our results suggest that uRO-w, EA, and UA are potential therapeutic agents for preventing and treating inflammatory respiratory diseases.

Senotherapy for lung diseases

Increasing evidence suggests that there is acceleration of lung ageing in chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF), with the accumulation of senescent cells in the lung. Senescent cells fail to repair tissue damage and release an array of inflammatory proteins, known as the senescence-associated secretory phenotype, which drive further senescence and disease progression. This suggests that targeting cellular senescence with senotherapies may treat the underlying disease process in COPD and IPF and thus reduce disease progression and mortality. Several existing or future drugs may inhibit the development of cellular senescence which is driven by chronic oxidative stress (senostatics), including inhibitors of PI3K-mTOR signalling pathways, antagomirs of critical microRNAs and novel antioxidants. Other drugs (senolytics) selectively remove senescent cells by promoting apoptosis. Clinical studies with senotherapies are already underway in chronic lung diseases.

Isorhapontigenin Attenuates Cardiac Microvascular Injury in Diabetes via the Inhibition of Mitochondria-Associated Ferroptosis Through PRDX2-MFN2-ACSL4 Pathways

Ferroptosis is a newly identified form of regulated cell death that is driven by iron overload and uncontrolled lipid peroxidation, but the role of ferroptosis in cardiac microvascular dysfunction remains unclear. Isorhapontigenin (ISO) is an analog of resveratrol and possesses strong antioxidant capacity and cardiovascular-protective effects. Moreover, ISO has been shown to alleviate iron-induced oxidative damage and lipid peroxidation in mitochondria. Therefore, the current study aimed to explore the benefits of ISO treatment on cardiac microvascular dysfunction in diabetes and the possible mechanisms involved, with a focus on ferroptosis and mitochondria. Our data revealed that ISO treatment improved microvascular density and perfusion in db/db mice by mitigating vascular structural damage, normalizing nitric oxide (NO) production via endothelial NO synthase activation, and enhancing angiogenetic ability via vascular endothelial growth factor receptor 2 phosphorylation. PRDX2 was identified as a downstream target of ISO, and endothelial-specific overexpression of PRDX2 exerted effects on the cardiac microvascular function that were similar to those of ISO treatment. In addition, PRDX2 mediated the inhibitive effects of ISO treatment on ferroptosis by suppressing oxidative stress, iron overload, and lipid peroxidation. Further study suggested that mitochondrial dynamics and dysfunction contributed to ferroptosis, and ISO treatment or PRDX2 overexpression attenuated mitochondrial dysfunction via MFN2-dependent mitochondrial dynamics. Moreover, MFN2 overexpression suppressed the mitochondrial translocation of ACSL4, ultimately inhibiting mitochondria-associated ferroptosis. In contrast, enhancing mitochondria-associated ferroptosis via ACSL4 abolished the protective effects of ISO treatment on cardiac microcirculation. Taken together, the results of the present work demonstrated the beneficial effects of ISO treatment on cardiac microvascular protection in diabetes by suppressing mitochondria-associated ferroptosis through PRDX2-MFN2-ACSL4 pathways.

The Potential of Stilbene Compounds to Inhibit Mpro Protease as a Natural Treatment Strategy for Coronavirus Disease-2019

COVID-19 disease has had a global impact on human health with increased levels of morbidity and mortality. There is an unmet need to design and produce effective antivirals to treat COVID-19. This study aimed to explore the potential ability of natural stilbenes to inhibit the M^pro protease, an acute respiratory syndrome coronavirus-2 (SARS-CoV-2) enzyme involved in viral replication. The binding affinities of stilbene compounds against M^pro were scrutinized using molecular docking, prime molecular mechanics-generalized Born surface area (MM-GBSA) energy calculations, and molecular dynamic simulations. Seven stilbene molecules were docked with M^pro and compared with GC376 and N3, antivirals with demonstrated efficacy against M^pro. Ligand binding efficiencies and polar and non-polar interactions between stilbene compounds and M^pro were analyzed. The binding affinities of astringin, isorhapontin, and piceatannol were -9.319, -8.166, and -6.291 kcal/mol, respectively, and higher than either GC376 or N3 at -6.976 and -6.345 kcal/mol, respectively. Prime MM-GBSA revealed that these stilbene compounds exhibited useful ligand efficacy and binding affinity to M^pro. Molecular dynamic simulation studies of astringin, isorhapontin, and piceatannol showed their stability at 300 K throughout the simulation time. Collectively, these results suggest that stilbenes such as astringin, isorhapontin, and piceatannol could provide useful natural inhibitors of M^pro and thereby act as novel treatments to limit SARS-CoV-2 replication.

Induction of RAC1 protein translation and MKK7/JNK-dependent autophagy through dicer/miR-145/SOX2/miR-365a axis contributes to isorhapontigenin (ISO) inhibition of human bladder cancer invasion

Although our previous studies have identified that isorhapontigenin (ISO) is able to initiate autophagy in human bladder cancer (BC) cells by activating JNK/C-Jun/SESN2 axis and possesses an inhibitory effect on BC cell growth, association of autophagy directly with inhibition of BC invasion has never been explored. Also, upstream cascade responsible for ISO activating JNK remains unknown. Thus, we explored both important questions in the current study and discovered that ISO treatment initiated RAC1 protein translation, and its downstream kinase MKK7/JNK phosphorylation/activation, and in turn promoted autophagic responses in human BC cells. Inhibition of autophagy abolished ISO inhibition of BC invasion, revealing that autophagy inhibition was crucial for ISO inhibition of BC invasion. Consistently, knockout of RAC1 also attenuated induction of autophagy and inhibition of BC invasion by ISO treatment. Mechanistic studies showed that upregulation of RAC1 translation was due to ISO inhibition of miR-365a transcription, which reduced miR-365a binding to the 3'-UTR of RAC1 mRNA. Further study indicated that inhibition of miR-365a transcription was caused by downregulation of its transcription factor SOX2, while ISO-promoted Dicer protein translation increased miR-145 maturation, and consequently downregulating SOX2 expression. These findings not only provide a novel insight into the understanding association of autophagy induction with BC invasion inhibition by ISO, but also identify an upstream regulatory cascade, Dicer/miR145/SOX2/miR365a/RAC1, leading to MKK7/JNKs activation and autophagy induction.

Polyphenols, flavonoids and inflammasomes: the role of cigarette smoke in COPD

COPD is predicted to become the third leading cause of morbidity and mortality worldwide by 2030. Cigarette smoking (active or passive) is one of its chief causes, with about 20% of cigarette smokers developing COPD from cigarette smoke (CS)-induced irreversible damage and sustained inflammation of the airway epithelium. Inflammasome activation leads to the cleavage of pro-interleukin (IL)-1β and pro-IL-18, along with the release of pro-inflammatory cytokines via gasdermin D N-terminal fragment membrane pores, which further triggers acute phase pro-inflammatory responses and concurrent pyroptosis. There is currently intense interest in the role of nucleotide-binding oligomerisation domain-like receptor family, pyrin domain containing protein-3 inflammasomes in chronic inflammatory lung diseases such as COPD and their potential for therapeutic targeting. Phytochemicals including polyphenols and flavonoids have phyto-medicinal benefits in CS-COPD. Here, we review published articles from the last decade regarding the known associations between inflammasome-mediated responses and ameliorations in pre-clinical manifestations of CS-COPD via polyphenol and flavonoid treatment, with a focus on the underlying mechanistic insights. This article will potentially assist the development of drugs for the prevention and therapy of COPD, particularly in cigarette smokers.

This review compiles current investigations into the role of polyphenols/flavonoids in the alleviation of cigarette smoke-induced inflammasome; notably it provides a promising hit for rectifying the treatment of COPD.https://bit.ly/36OcUO9

Dried Blood Spots as Matrix for Evaluation of Valproate Levels and the Immediate and Delayed Metabolomic Changes Induced by Single Valproate Dose Treatment

The immediate and delayed metabolic changes in rats treated with valproate (VPA), a drug used for the treatment of epilepsy, were profiled. An established approach using dried blood spots (DBS) as sample matrices for gas chromatography/mass spectrometry-based metabolomics profiling was modified using double solvents in the extraction of analytes. With the modified method, some of the previously undetectable metabolites were recovered and subtle differences in the metabolic changes upon exposure to a single dose of VPA between males and female rats were identified. In male rats, changes in 2-hydroxybutyric acid, pipecolic acid, tetratriacontane and stearic acid were found between the control and treatment groups at various time points from 2.5 h up to 24 h. In contrast, such differences were not observed in female rats, which could be caused by the vast inter-individual variations in metabolite levels within the female group. Based on the measured DBS drug concentrations, clearance and apparent volume of distribution of VPA were estimated and the values were found to be comparable to those estimated previously from full blood drug concentrations. The current study indicated that DBS is a powerful tool to monitor drug levels and metabolic changes in response to drug treatment.

Isorhapontigenin Modulates SOX9/TOLLIP Expression to Attenuate Cell Apoptosis and Oxidative Stress in Paraquat-Induced Acute Kidney Injury

Paraquat (PQ) is a widely used herbicide but can be lethal to humans. The kidney is vital for PQ elimination; therefore, explorations for therapeutic approaches for PQ-induced acute kidney injury (AKI) are of great significance. Here, the effects of a natural bioactive polyphenol isorhapontigenin (ISO) on PQ-AKI were investigated. In vitro experiments carried out in PQ-intoxicated rat renal tubular epithelial cells (NRK-52E) showed that ISO treatment inhibited PQ-induced cell apoptosis and oxidative stress, which was evidenced by the decreased proapoptotic proteins [cleaved caspase 3/9 and poly (ADP-ribose) polymerase (PARP)], the reduced oxidative stress indicators [reactive oxygen species (ROS), malondialdehyde (MDA), and lactate dehydrogenase (LDH) leakage], and the increased antioxidants [superoxide dismutase (SOD), nuclear factor E2-related factor 2 (NRF2), and oxygenase-1 (HO-1)]. Furthermore, 50 mg/kg ISO pretreatment before PQ administration significantly attenuated PQ-AKI in rats, as manifested by the improved renal tubule damage, the reduced serum and urine markers of kidney injury, and the inhibited cell apoptosis and oxidative stress in the renal cortex. Furthermore, expression of sex-determining region Y box 9 (SOX9) and Toll-interacting protein (TOLLIP) in NRK-52E cells and the renal cortex was significantly upregulated after ISO treatment. Overexpression of SOX9 increased TOLLIP transcription and attenuated PQ-induced apoptosis and oxidative stress, whereas knockdown of SOX9 impaired the protective effects of ISO on NRK-52E cells against PQ toxicity. In conclusion, the present study demonstrated that ISO modulated SOX9/TOLLIP expression to attenuate cell apoptosis and oxidative stress in PQ-AKI, suggesting the potential of ISO in treating PQ-poisoned patients.

Induction of p27 contributes to inhibitory effect of isorhapontigenin (ISO) on malignant transformation of human urothelial cells

Bladder cancer (BC) is the most expensive cancer to manage on a per-patient basis, costing about $4 billion in total healthcare expenditure per annum in America alone. Therefore, identifying a natural compound for prevention of BC is of tremendous importance for managing this disease. Previous studies have identified isorhapontigenin (ISO) as having an 85% preventive effect against invasive BC formation induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). The results showed here that ISO treatment inhibited EGF-induced cell transformation of human urothelial cells through induction of tumor suppressor p27 transcription secondary to activation of an E2F1-dependentpathway.ISOtreatmentrenderedcellsresistanttoEGF-induced anchorage-independent growth concurrent with p27 protein induction in both UROtsa and SV-HUC-1 cells. ISO inhibition of EGF-induced cell transformation could be completely reversed by knockdown of p27, indicating that this protein was essential for the noted ISO inhibitory action. Mechanistic studies revealed that ISO treatment resulted in increased expression of E2F1, which in turn bound to its binding site in p27 promoter and initiated p27 transcription. The E2F1 induction was due to the elevation of its translation caused by ISO-induced miR-205 downregulation. Consistently, miR-205 was found to be overexpressed in human BCs, and ectopic expression of miR-205 mitigated ISO inhibitory effects against EGF-induced outcomes. Collectively, the results here demonstrate that ISO exhibits its preventive effect on EGF-induced human urothelial cell transformation by induction of p27 through a miR-205/E2F1 axis. This is distinct from what has been described for the therapeutic effects of ISO on human BC cells.

Isorhapontigenin (ISO) inhibits EMT through FOXO3A/METTL14/VIMENTIN pathway in bladder cancer cells

Epithelial mesenchymal transition (EMT) is highly correlated with metastasis during cancer development. Although previous studies have revealed that ISO is able to inhibit cancer cell invasion and stem-cell properties, little is known about the effects of ISO on EMT markers. The present study explores the potential regulation of ISO on EMT, leading to the inhibition of migration and invasion of bladder cancer cells. We found that ISO inhibited Vimentin, one of the EMT markers, in the invasive bladder cancer cell lines U5637 and T24T. ISO reduced Vimentin protein level by increasing the expression of METTL14. On the other hand, ISO upregulated the METTL14 mRNA by activating the transcription factor FOXO3a. The results demonstrate that ISO inhibits invasion by affecting the EMT marker and offer a novel insight into understanding the upregulation of METTL14 by ISO.

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.

Isorhapontigenin ameliorates cerebral ischemia/reperfusion injury via modulating Kinase Cε/Nrf2/HO-1 signaling pathway

BACKGROUND

Isorhapontigenin (ISO) has been shown to have antioxidant activity. This study aimed to investigate the antioxidant effects of ISO on cerebral ischemia/reperfusion (I/R) injury and its possible molecular mechanisms.

METHODS

Focal cerebral ischemia-reperfusion injury (MCAO/R) model and primary cortical neurons were established an oxygen-glucose deprivation (OGD / R) injury model. After 24 hr of reperfusion, the neurological deficits of the rats were analyzed and HE staining was performed, and the infarct volume was calculated by TTC staining. In addition, the reactive oxygen species (ROS) in rat brain tissue, the content of 4-Hydroxynonenal (4-HNE), and 8-hydroxy2deoxyguanosine (8-OHdG) were detected. Neuronal cell viability was determined by MTT assay. Western blot analysis was determined for protein expression.

RESULTS

ISO treatment significantly improved neurological scores, reduced infarct volume, necrotic neurons, ROS production, 4-HNE, and 8-OHdG levels. At the same time, ISO significantly increased the expression of Nrf2 and HO-1. The neuroprotective effects of ISO can be eliminated by knocking down Nrf2 and HO-1. In addition, knockdown of the PKCε blocked ISO-induced nuclear Nfr2, HO-1 expression.

CONCLUSION

ISO protected against oxidative damage induced by brain I/R, and its neuroprotective mechanism may be related to the PKCε/Nrf2/HO-1 pathway.

PI3K signalling in chronic obstructive pulmonary disease and opportunities for therapy

Chronic obstructive pulmonary disease (COPD) is a chronic lung disease characterised by airway inflammation and progressive obstruction of the lung airflow. Current pharmacological treatments include bronchodilators, alone or in combination with steroids, or other anti-inflammatory agents, which have only partially contributed to the inhibition of disease progression and mortality. Therefore, further research unravelling the underlying mechanisms is necessary to develop new anti-COPD drugs with both lower toxicity and higher efficacy. Extrinsic signalling pathways play crucial roles in COPD development and exacerbations. In particular, phosphoinositide 3-kinase (PI3K) signalling has recently been shown to be a major driver of the COPD phenotype. Therefore, several small-molecule inhibitors have been identified to block the hyperactivation of this signalling pathway in COPD patients, many of them showing promising outcomes in both preclinical animal models of COPD and human clinical trials. In this review, we discuss the critically important roles played by hyperactivated PI3K signalling in the pathogenesis of COPD. We also critically review current therapeutics based on PI3K inhibition, and provide suggestions focusing on PI3K signalling for the further improvement of the COPD phenotype. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Targeting P2 receptors in purinergic signaling: a new strategy of active ingredients in traditional Chinese herbals for diseases treatment

Adenosine triphosphate (ATP) and its metabolites adenosine diphosphate, adenosine monophosphate, and adenosine in purinergic signaling pathway play important roles in many diseases. Activation of P2 receptors (P2R) channels and subsequent membrane depolarization can induce accumulation of extracellular ATP, and furtherly cause kinds of diseases, such as pain- and immune-related diseases, cardiac dysfunction, and tumorigenesis. Active ingredients of traditional Chinese herbals which exhibit superior pharmacological activities on diversified P2R channels have been considered as an alternative strategy of disease treatment. Experimental evidence of potential ingredients in Chinese herbs targeting P2R and their pharmacological activities were outlined in the study.

Exploring the role of polyphenols in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, inflammatory and autoimmune disorder which is mainly characterized by inflammation in joints, bone erosions and cartilaginous destruction that leads to joint dysfunction, deformation, and/or permanent functional impairment. The prevalence of RA is increasing, incurring a considerable burden on healthcare systems globally. The exact etiology of RA is unknown, with various pathways implicated in its pathophysiology. Non-steroidal anti-inflammatory drugs (NSAIDs) including celecoxib, diclofenac and ibuprofen, disease-modifying anti-rheumatic drugs (DMARD) including azathioprine, methotrexate and cyclosporine, biological agents including anakinra, infliximab, and rituximab and immunosuppressants are used for symptomatic relief in patients with RA, but these medications have severe adverse effects such as gastric ulcers, hypertension, hepatotoxicity and renal abnormalities which restrict their use in the treatment of RA; new RA treatments with minimal side-effects are urgently required. There is accumulating evidence that dietary polyphenols may show therapeutic efficacy in RA through their antioxidant, anti-inflammatory, apoptotic, and immunosuppressant activities and modulation of the tumor necrosis factor-α (TNF-α), interleukin (IL)-6, mitogen-activated protein kinase (MAPK), IL-1β, c-Jun N-terminal kinase (JNK), and nuclear factor κ light-chain-enhancer of activated B cell (NF-κB) pathways. While resveratrol, genistein, carnosol, epigallocatechin gallate, curcumin, kaempferol, and hydroxytyrosol have also been studied for the treatment of RA, the majority of data are derived from animal models. Here, we review the various pathways involved in the development of RA and the preclinical and clinical data supporting polyphenols as potential therapeutic agents in RA patients. Our review highlights that high-quality clinical studies are required to decisively establish the anti-rheumatic efficacy of polyphenolic compounds.

Polyphenols Extracted from Shanxi-Aged Vinegar Inhibit Inflammation in LPS-Induced RAW264.7 Macrophages and ICR Mice via the Suppression of MAPK/NF-κB Pathway Activation

Shanxi-aged vinegar, a traditional Chinese grain-fermented food that is rich in polyphenols, has been shown to have therapeutic effects on a variety of diseases. However, there has been no comprehensive evaluation of the anti-inflammatory activity of polyphenols extracted from Shanxi-aged vinegar (SAVEP) to date. The anti-inflammatory activities of SAVEP, both in RAW 264.7 macrophages and mice, were extensively investigated for the potential application of SAVEP as a novel anti-inflammatory agent. In order to confirm the notion that polyphenols could improve inflammatory symptoms, SAVEP was firstly detected by gas chromatography mass spectrometry (GC-MS). In total, 19 polyphenols were detected, including 12 phenolic acids. The study further investigated the protective effect of SAVEP on lipopolysaccharide-induced inflammation in RAW264.7 macrophages and ICR mice. The results showed that compared with those of the model group, SAVEP could remarkably recover the inflammation of macrophage RAW264.7 and ICR mice. SAVEP can normalise the expression of related proteins via the suppression of MAPK/NF-κB pathway activation, inhibiting the expression of iNOS and COX-2 proteins, and consequently the production of inflammatory factors, thus alleviating inflammatory stress. These results suggest that SAVEP may have a potential function against inflammation.

Recent advances in chemistry and bioactivity of Sargentodoxa cuneata

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Sargentodoxa comprises only one species, Sargentodoxa cuneata (Oliv.) Rehd et al., widely distributed in the subtropical zone of China. The plant is extensively used in traditional medicine for treating arthritis, joint pains, amenorrhea, acute appendicitis and inflammatory intestinal obstruction. Pharmacological studies show anti-inflammatory, antioxidant, antitumor, antimicrobial, and anti-sepsis activities.

AIM OF THE REVIEW

This review aims to summarize the information about distribution, traditional uses, chemical constituents and pharmacological activities of S. cuneata, as an attempt to provide a scientific basis for its traditional uses and to support its application and development for new drug development.

METHODOLOGY

Scientific information of S. cuneata was retrieved from the online bibliographic databases, including Web of Science, Google Scholar, PubMed, Springer Link, the Wiley online library, SciFinder, Baidu Scholar, China national knowledge infrastructure (CNKI) and WANFANG DATA (up to March 2020). We also search doctoral dissertations, master dissertations conference papers and published books. The keywords were used: "Sargentodoxa", "Da Xue Teng", "Hong Teng", "Xue Teng", "secondary metabolites", "chemical components", "biological activity", "pharmacology", "traditional uses".

OBSERVATIONS AND RESULTS

S. cuneata is utilized as valuable herbal medicines to treat various diseases in China. Over 110 chemical constituents have been isolated and identified from the stem of S. cuneata, including phenolic acids, phenolic glycosides, lignans, flavones, triterpenoids and other compounds. The extract and compounds of S. cuneata have a wide spectrum of pharmacological activities, including antitumor, anti-inflammatory, antioxidant, antimicrobial, anti-sepsis and anti-arthritis effects, as well as protective activity against cerebrovascular diseases.

CONCLUSION

S. cuneata has a rich legacy for the treatment of many diseases, especially arthritis and sepsis, which is reinforced by current investigations. However, the present studies about bioactive chemical constituents and detail pharmacological mechanisms of S. cuneata were insufficient. Further studies should focus on these aspects in relation to its clinical applications. This review has systematically summarized the traditional uses, phytochemical constituents and pharmacological effects of S. cuneata, providing references for the therapeutic potential of new drug development.

Isorhapontigenin alleviates lipopolysaccharide-induced acute lung injury via modulating Nrf2 signaling

Nuclear factor erythroid-2 related factor 2 (Nrf2) is involved in mitigating various oxidative stress- and inflammation-induced diseases, including acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Isorhapontigenin (ISO), from the Chinese herb Gnetum cleistostachyum, exhibits antioxidant and anti-inflammatory properties. In this study, we explored the protective effects of ISO in ALI and its underlying molecular mechanisms. ISO significantly mitigated ALI by reducing the lung wet/dry weight ratio, protein concentration in the bronchoalveolar lavage fluid (BALF), and the levels of myeloperoxidase and malondialdehyde. ISO also improved the superoxide dismutase and glutathione activity in vivo. Moreover, ISO effectively ameliorated the changes in IL-1β, IL-6, and TNF-α concentrations in BALF, prevented IκB degradation, and inhibited the phosphorylation of NF-κB p65 subunit in lung tissues; furthermore, it enhanced the nuclear translocation of Nrf2 and inhibited IL-1β, IL-6, TNF-α, iNOS, COX-2, and ROS production in lipopolysaccharide-treated RAW264.7 cells. The protective effects of ISO in ALI were significantly reversed in ML385-treated RAW264.7 cells and the mouse model, indicating its role in Nrf2-activation. In conclusion, ISO effectively ameliorated lipopolysaccharide-induced ALI by reducing inflammation and oxidative stress, primarily through activation of Nrf2 signaling.

Isorhapontigenin protects against doxorubicin-induced cardiotoxicity via increasing YAP1 expression

As an effective anticancer drug, the clinical limitation of doxorubicin (Dox) is the time- and dose-dependent cardiotoxicity. Yes-associated protein 1 (YAP1) interacts with transcription factor TEA domain 1 (TEAD1) and plays an important role in cell proliferation and survival. However, the role of YAP1 in Dox-induced cardiomyopathy has not been reported. In this study, the expression of YAP1 was reduced in clinical human failing hearts with dilated cardiomyopathy and Dox-induced in vivo and in vitro cardiotoxic model. Ectopic expression of Yap1 significantly blocked Dox-induced cardiomyocytes apoptosis in TEAD1 dependent manner. Isorhapontigenin (Isor) is a new derivative of stilbene and responsible for a wide range of biological processes. Here, we found that Isor effectively relieved Dox-induced cardiomyocytes apoptosis in a dose-dependent manner in vitro. Administration with Isor (30 mg/kg/day, intraperitoneally, 3 weeks) significantly protected against Dox-induced cardiotoxicity in mice. Interestingly, Isor increased Dox-caused repression in YAP1 and the expression of its target genes in vivo and in vitro. Knockout or inhibition of Yap1 blocked the protective effects of Isor on Dox-induced cardiotoxicity. In conclusion, YAP1 may be a novel target for Dox-induced cardiotoxicity and Isor might be a new compound to fight against Dox-induced cardiotoxicity by increasing YAP1 expression.

Resveratrol and other Stilbenes: Effects on Dysregulated Gene Expression in Cancers and Novel Delivery Systems

Trans-resveratrol (RESV), pterostilbene, trans-piceid and trans-viniferins are bioactive stilbenes present in grapes and other plants. Several groups applied biotechnology to introduce their synthesis in plant crops. Biochemical interaction with enzymes, regulation of non-coding RNAs, and activation of signaling pathways and transcription factors are among the main effects described in literature. However, solubility in ethanol, short half-life, metabolism by gut bacteria, make the concentration responsible for the effects observed in cultured cells difficult to achieve. Derivatives obtained by synthesis, trans-resveratrol analogs and methoxylated stilbenes show to be more stable and allow the synthesis of bioactive compounds with higher bioavailability. However, changes in chemical structure may require testing for toxicity. Thus, the delivery of RESV and its natural analogs incorporated into liposomes or nanoparticles, is the best choice to ensure stability during administration and appropriate absorption. The application of RESV and its derivatives with anti-inflammatory and anticancer activity is presented with description of novel clinical trials.

Resveratrol and Its Analogs as Functional Foods in Periodontal Disease Management

Periodontitis is a common chronic inflammatory disease driven by the interaction between a dysbiotic oral microbiome and the dysregulated host immune-inflammatory response. Naturally derived nutraceuticals, such as resveratrol and its analogs, are potential adjunctive therapies in periodontal treatment due to their antimicrobial and anti-inflammatory properties. Furthermore, different analogs of resveratrol and the choice of solvents used may lead to varying effects on therapeutic properties. This review presents the current findings and gaps in our understanding on the potential utility of resveratrol and its analogs in periodontal treatment.

Piceatannol Is Superior to Resveratrol at Suppressing Adipogenesis in Human Visceral Adipose-Derived Stem Cells

Resveratrol (3,4′,5-trans-trihydroxystilbene) and piceatannol (3,3′,4′,5-trans-tetraphydroxystilbene) are major stilbene compounds that are predominantly present in various natural foods, such as berries and fruits. Both phytochemical compounds are consumed as dietary supplements to prevent various metabolic diseases and for their anti-aging properties. Adipose-derived stem cells from human visceral adipose tissue (vASCs) are a useful in vitro model for evaluating their adipogenic effect. Treatment with resveratrol and piceatannol significantly inhibited lipid accumulation in vASCs. Their effective concentrations were 5, 10, and 20 μM for inhibiting adipogenesis of vASCs. Interestingly, despite the similar chemical structures of the two compounds, piceatannol showed a higher anti-adipogenic effect at 20 μM than resveratrol in vASCs. Moreover, the inhibitory capacity of lipid droplet generation was higher for piceatannol at 20 μM than that of resveratrol. Piceatannol significantly attenuated the expression level of adipogenic markers (e.g., CCAAT/enhanced binding protein α (C/EBPα), peroxisome proliferator-activated receptor γ (PPARγ), and adipocyte fatty acid binding protein (aP2)) compared to resveratrol at the mRNA and protein levels. These results suggest that piceatannol is a superior anti-adipogenic compound compared to resveratrol in the vASC model of visceral obesity.

Artemether-Loaded Zein Nanoparticles: An Innovative Intravenous Dosage Form for the Management of Severe Malaria

Artemether, an artemisinin derivative, is used in the management of life-threatening severe malaria. This study aimed to develop an intravenous dosage form of artemether using nanotechnology. Artemether-loaded zein nanoparticles were prepared by modified antisolvent precipitation using sodium caseinate as a stabilizer. Subsequently, the physicochemical properties of the nanoparticles were characterized; the in vitro hemolytic property was examined with red blood cells, while the pharmacokinetic profile was evaluated in Sprague–Dawley rats after intravenous administration. The artemether-loaded zein nanoparticles were found to display good encapsulation efficiency, excellent physical stability and offer an in vitro extended-release property. Interestingly, encapsulation of artemether into zein nanoparticles substantially suppressed hemolysis, a common clinical phenomenon occurring after artemisinin-based antimalarial therapy. Upon intravenous administration, artemether-loaded zein nanoparticles extended the mean residence time of artemether by ~80% in comparison to the free artemether formulation (82.9 ± 15.2 versus 45.6 ± 16.4 min, p < 0.01), suggesting that the nanoparticles may prolong the therapeutic duration and reduce the dosing frequency in a clinical setting. In conclusion, intravenous delivery of artemether by artemether-loaded zein nanoparticles appears to be a promising therapeutic option for severe malaria.

Targeting cellular senescence as a new approach to chronic obstructive pulmonary disease therapy

Increasing evidence suggests that there is acceleration of normal lung ageing in chronic obstructive pulmonary disease (COPD), with the accumulation of senescent cells in the lung, which release an array of inflammatory proteins, which drive further senescence and disease progression. This suggests that drugs that target cellular senescence (senotherapies) may treat the underlying disease process in COPD and reduce disease progression and mortality. Several existing or future drugs may inhibit the development of cellular senescence, which is driven by chronic oxidative stress (senostatics), whereas other drugs selectively remove senescent cells (senolytics). Clinical studies of senotherapies have commenced in several age-related diseases, and these approaches appear to be safe and feasible, although no clinical studies in COPD patients have yet been reported.

Plant-Derived Natural Products in Cancer Research: Extraction, Mechanism of Action, and Drug Formulation

Cancer is one of the main causes of death globally and considered as a major challenge for the public health system. The high toxicity and the lack of selectivity of conventional anticancer therapies make the search for alternative treatments a priority. In this review, we describe the main plant-derived natural products used as anticancer agents. Natural sources, extraction methods, anticancer mechanisms, clinical studies, and pharmaceutical formulation are discussed in this review. Studies covered by this review should provide a solid foundation for researchers and physicians to enhance basic and clinical research on developing alternative anticancer therapies.

More Than Resveratrol: New Insights into Stilbene-Based Compounds

The concept of a scaffold concerns many aspects at different steps on the drug development path. In medicinal chemistry, the choice of relevant "drug-likeness" scaffold is a starting point for the design of the structure dedicated to specific molecular targets. For many years, the chemical uniqueness of the stilbene structure has inspired scientists from different fields such as chemistry, biology, pharmacy, and medicine. In this review, we present the outstanding potential of the stilbene-based derivatives. Naturally occurring stilbenes, together with powerful synthetic chemistry possibilities, may offer an excellent approach for discovering new structures and identifying their therapeutic targets. With the development of scientific tools, sophisticated equipment, and a better understanding of the disease pathogenesis at the molecular level, the stilbene scaffold has moved innovation in science. This paper mainly focuses on the stilbene-based compounds beyond resveratrol, which are particularly attractive due to their biological activity. Given the "fresh outlook" about different stilbene-based compounds starting from stilbenoids with particular regard to isorhapontigenin and methoxy- and hydroxyl- analogues, the update about the combretastatins, and the very often overlooked and underestimated benzanilide analogues, we present a new story about this remarkable structure.

More Than Resveratrol: New Insights into Stilbene-Based Compounds

The concept of a scaffold concerns many aspects at different steps on the drug development path. In medicinal chemistry, the choice of relevant "drug-likeness" scaffold is a starting point for the design of the structure dedicated to specific molecular targets. For many years, the chemical uniqueness of the stilbene structure has inspired scientists from different fields such as chemistry, biology, pharmacy, and medicine. In this review, we present the outstanding potential of the stilbene-based derivatives. Naturally occurring stilbenes, together with powerful synthetic chemistry possibilities, may offer an excellent approach for discovering new structures and identifying their therapeutic targets. With the development of scientific tools, sophisticated equipment, and a better understanding of the disease pathogenesis at the molecular level, the stilbene scaffold has moved innovation in science. This paper mainly focuses on the stilbene-based compounds beyond resveratrol, which are particularly attractive due to their biological activity. Given the "fresh outlook" about different stilbene-based compounds starting from stilbenoids with particular regard to isorhapontigenin and methoxy- and hydroxyl- analogues, the update about the combretastatins, and the very often overlooked and underestimated benzanilide analogues, we present a new story about this remarkable structure.

Isorhapontigenin Improves Diabetes in Mice via Regulating the Activity and Stability of PPARγ in Adipocytes

Isorhapontigenin is a natural bioactive stilbene isolated from various plants and fruits. It has been reported to exhibit several physiological activities including anticancer and anti-inflammation activity in vitro and in experimental animal models. This study aimed to investigate whether isorhapontigenin exerts antidiabetic effects in vivo. To this end, diabetic db/db mice were treated with either 25 mg kg^-1 of isorhapontigenin or vehicle intraperitoneally for a period of 5 weeks. The results show that isorhapontigenin treatment significantly reduced postprandial levels of glucose, insulin, as well as free fatty acid, three markers of diabetes. Further studies show that isorhapontigenin treatment markedly improves insulin sensitivity and glucose tolerance of db/db mice as shown by ITT and GTT. Together, these physiological results show that isorhapontigenin possesses antidiabetic properties in vivo. Mechanistically, the isorhapontigenin-mediated antidiabetic effect is caused by favorable changes in adipose tissue, including reductions in adipocyte diameter and improved adipose insulin sensitivity. Further studies with 3T3-L1 cells show that isorhapontigenin treatment promotes preadipocyte differentiation by upregulation of the activity of the master adipogenic regulator PPARγ and deceleration of its proteasomal degradation. Together, our results establish for the first time an important role of isorhapontigenin as a potential nutraceutical agent for diabetes treatment.

Synthesis of antiplatelet ortho-carbonyl hydroquinones with differential action on platelet aggregation stimulated by collagen or TRAP-6

Cardiovascular diseases are the leading cause of death in the world. Platelets have a major role in cardiovascular events as they bind to the damaged endothelium activating and forming thrombi. Although some hydroquinone scaffold-containing compounds have known antiplatelet activities, currently there is a lack of evidence on the antiplatelet activity of hydroquinones carrying electron attractor groups. In this work, we evaluate the antiplatelet effect of a series of ortho-carbonyl hydroquinone derivatives on cytotoxicity and function of human platelets, using collagen and thrombin receptor activator peptide 6 (TRAP-6) as agonists. Our structure-activity relationship study shows that gem-diethyl/methyl substitutions and the addition/modifications of the third ring of ortho-carbonyl hydroquinone scaffold influence on the selective index (IC₅₀ TRAP-6/IC₅₀ Collagen) and the inhibitory capacity of platelet aggregation. Compounds 3 and 8 inhibit agonist-induced platelet aggregation in a non-competitive manner with IC₅₀ values of 1.77 ± 2.09 μM (collagen) and 11.88 ± 4.59 μM (TRAP-6), respectively and show no cytotoxicity. Both compounds do not affect intracellular calcium levels and mitochondrial bioenergetics. Consistently, they reduce the expression of P-selectin, activation of glycoprotein IIb/IIIa, and release of adenosine triphosphate and CD63 from platelet. Our findings may be used for further development of new drugs in platelet-related thrombosis diseases.

Targeting defective pulmonary innate immunity - A new therapeutic option?

Chronic pulmonary conditions now account for 1 in 15 deaths in the US and mortality is increasing. Chronic obstructive pulmonary disease (COPD) is due to become the 3rd largest cause of mortality by 2030 and mortality from other respiratory conditions such as asthma, idiopathic pulmonary fibrosis and cystic fibrosis are not reducing. There is an urgent need for novel therapies to address this problem as many of the current strategies targeting inflammation are not sufficient. The innate immune system of the lung is an important defence against invading pathogens, but in many chronic pulmonary diseases, this system mounts an inappropriate response. In COPD, macrophages are increased in number, but fail to clear pathogens correctly and become highly activated. This leads to increased damage and remodelling of the airways. In idiopathic fibrosis, there is a switch of macrophage phenotype to a cell that promotes abnormal repair. Neutrophils also display dysfunction in COPD where aberrant migratory profiles may lead to increased damage to lung tissue and emphysema; while in cystic fibrosis the proteolytic lung environment damages neutrophil receptors leading to ineffective phagocytosis and migration. Targeting the innate immune system to restore 'normal function' could have enormous benefits. Improving phagocytosis of pathogens could reduce exacerbations and hence the associated decline in lung function, and novel therapeutics such as sulforaphane appear to do this in vitro. Other natural products such as resveratrol and derivatives also have anti-inflammatory properties. Statins have traditionally been used to manage cholesterol levels in hypercholesterolaemia, however these molecules also have beneficial effects on the innate immune cells. Statins have been shown to be anti-inflammatory and restore aberrant neutrophil chemotaxis in aged cells. Other possible agents that may be efficacious are senolytics. These compounds include natural products such as quercetin which have anti-inflammatory properties but can also suppress viral replication. As viruses have been shown to suppress phagocytosis of macrophages, it is possible that these compounds could have benefit during viral exacerbations to protect this innate response. These compounds demonstrate that it is possible to address defective innate responses in the lung but a better understanding of the mechanisms driving defective innate immunity in pulmonary disease may lead to improved therapeutics.

Biotransformation of Piceatannol, a Dietary Resveratrol Derivative: Promises to Human Health

SCOPE

To evaluate the health-promoting potentials of piceatannol (PIC), a dietary resveratrol derivative, its biotransformation is examined.

METHODS AND RESULTS

The biotransformation is tested in human/rat hepatic microsomes and cytosols; its pharmacokinetic profiles are assessed in rats. Although limited phase I metabolism exists in microsomes, PIC is rapidly converted to two pharmacologically active metabolites, namely rhapontigenin (RHA) and isorhapontigenin (ISO) in cytosols. Such biotransformation is completely blocked by entacapone, a well-known catechol-O-methyltransferase (COMT) inhibitor, demonstrating that the O-methylation is mediated by COMT. Moreover, PIC is identified as a substrate inhibitor of COMT, suggesting its potential benefits in Alzheimer's disease. Due to extensive phase II metabolism including glucuronidation, sulfation, and O-methylation, PIC displays rapid clearance and at least 4.02% ± 0.61% and 17.70% ± 0.91% of PIC is converted to RHA and ISO, respectively, in rats after intravenous administration. Similarly, PIC serves as an effective precursor of ISO upon oral administration.

CONCLUSION

Since PIC and its metabolites possess pleiotropic health-promoting activities, it has emerged as a promising nutraceutical candidate for further development. This study also reinforces the importance of in vivo testing in nutritional researches as the active metabolite(s) may be absent from the in vitro system.

A Stilbenoid Isorhapontigenin as a Potential Anti-Cancer Agent against Breast Cancer through Inhibiting Sphingosine Kinases/Tubulin Stabilization

Isorhapontigenin (ISO), a tetrahydroxylated stilbenoid, is an analog of resveratrol (Rsv). The various biological activities of Rsv and its derivatives have been previously reported in the context of both cancer and inflammation. However, the anti-cancer effect of ISO against breast cancer has not been well established, despite being an orally bioavailable dietary polyphenol. In this study, we determine the anti-cancer effects of ISO against breast cancer using MCF7, T47D, and MDA-MB-231 cell lines. We observed that ISO induces breast cancer cell death, cell cycle arrest, oxidative stress, and the inhibition of cell proliferation. Additionally, sphingosine kinase inhibition by ISO controlled tubulin polymerization and cancer cell growth by regulating MAPK/PI3K-mediated cell cycle arrest in MCF7 cells. Interestingly, SPHK1/2 gene silencing increased oxidative stress, cell death, and tubulin destabilization in MCF7 cells. This suggests that the anti-cancer effect of ISO can be regulated by SPHK/tubulin destabilization pathways. Overall, ISO successfully induced breast cancer cell death and cell growth arrest, suggesting this phytochemical is a better alternative for breast cancer treatment. Further studies in animal models could confirm the potency and usability of ISO over Rsv for targeting breast cancer, potentially posing an alternative candidate for improved therapy in the near future.

Isorhapontigenin, a resveratrol analogue selectively inhibits ADP-stimulated platelet activation

Isorhapontigenin is a polyphenolic compound found in Chinese herbs and grapes. It is a methoxylated analogue of a stilbenoid, resveratrol, which is well-known for its various beneficial effects including anti-platelet activity. Isorhapontigenin possesses greater oral bioavailability than resveratrol and has also been identified to possess anti-cancer and anti-inflammatory properties. However, its effects on platelet function have not been reported previously. In this study, we report the effects of isorhapontigenin on the modulation of platelet function. Isorhapontigenin was found to selectively inhibit ADP-induced platelet aggregation with an IC₅₀ of 1.85 μM although it displayed marginal inhibition on platelet aggregation induced by other platelet agonists at 100 μM. However, resveratrol exhibited weaker inhibition on ADP-induced platelet aggregation (IC₅₀ > 100 μM) but inhibited collagen induced platelet aggregation at 50 μM and 100 μM. Isorhapontigenin also inhibited integrin αIIbβ3 mediated inside-out and outside-in signalling and dense granule secretion in ADP-induced platelet activation but interestingly, no effect was observed on α-granule secretion. Isorhapontigenin did not exert any cytotoxicity on platelets at the concentrations of up to 100 μM. Furthermore, it did not affect haemostasis in mice at the IC₅₀ concentration (1.85 μM). In addition, the mechanistic studies demonstrated that isorhapontigenin increased cAMP levels and VASP phosphorylation at Ser157 and decreased Akt phosphorylation. This suggests that isorhapontigenin may interfere with cAMP and PI3K signalling pathways that are associated with the P2Y₁₂ receptor. Molecular docking studies emphasised that isorhapontigenin has greater binding affinity to P2Y₁₂ receptor than resveratrol. Our results demonstrate that isorhapontigenin has selective inhibitory effects on ADP-stimulated platelet activation possibly via P2Y₁₂ receptor.

Polyphenols in the treatment of autoimmune diseases

In addition to protecting body from infections and diseases, the immune system produces auto-antibodies that can cause complex autoimmune disorders, such as Type I diabetes, primary biliary cirrhosis, rheumatoid arthritis, and multiple sclerosis, to name a few. In such cases, the immune system fails to recognize between foreign agents and its own body cells. Different factors, such as genetic factors (CD25, STAT4), epigenetic factors (DNA methylation, histone modifications) and environmental factors (xenobiotics, drugs, hormones) trigger autoimmunity. Glucocorticoids, non-steroidal anti-inflammatory drugs (NSAIDs), immunosuppressive and biological agents are currently used to manage autoimmune diseases of different origins. However, complete cure remains elusive. Many dietary and natural products including polyphenols have been widely studied as possible alternative treatment strategies for the management of autoimmune disorders. Polyphenols possess a wide-range of pharmacological and therapeutic properties, including antioxidant and anti-inflammatory activities. As immunomodulatory agents, polyphenols are emerging pharmaceutical tools for management of various autoimmune disorders including vitiligo, ulcerative colitis and multiple sclerosis (MS). Polyphenols activate intracellular pathways such as arachidonic acid dependent pathway, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway, mitogen-activated protein kinases (MAPKs) pathway, phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway and epigenetic modulation, which regulate the host's immune response. This timely review discusses putative points of action of polyphenols in autoimmune diseases, characterizing their efficacy and safety as therapeutic agents in managing autoimmune disorders.

Pulmonary Diseases and Ageing

Chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis are regarded as a diseases of accelerated lung ageing and show all of the hallmarks of ageing, including telomere shortening, cellular senescence, activation of PI3 kinase-mTOR signaling, impaired autophagy, mitochondrial dysfunction, stem cell exhaustion, epigenetic changes, abnormal microRNA profiles, immunosenescence and a low grade chronic inflammation due to senescence-associated secretory phenotype (SASP). Many of these ageing mechanisms are driven by exogenous and endogenous oxidative stress. There is also a reduction in anti-ageing molecules, such as sirtuins and Klotho, which further accelerate the ageing process. Understanding these molecular mechanisms has identified several novel therapeutic targets and several drugs and dietary interventions are now in development to treat chronic lung disease.

Pre-clinical Pharmacokinetic and Metabolomic Analyses of Isorhapontigenin, a Dietary Resveratrol Derivative

Background: Isorhapontigenin (trans-3,5,4'-trihydroxy-3'-methoxystilbene, ISO), a dietary resveratrol (trans-3,5,4'-trihydroxystilbene) derivative, possesses various health-promoting activities. To further evaluate its medicinal potentials, the pharmacokinetic and metabolomic profiles of ISO were examined in Sprague-Dawley rats. Methods: The plasma pharmacokinetics and metabolomics were monitored by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively. Results: Upon intravenous injection (90 μmol/kg), ISO exhibited a fairly rapid clearance (CL) and short mean residence time (MRT). After a single oral administration (100 μmol/kg), ISO was rapidly absorbed and showed a long residence in the systemic circulation. Dose escalation to 200 μmol/kg resulted in higher dose-normalized maximal plasma concentrations (C_max/Dose), dose-normalized plasma exposures (AUC/Dose), and oral bioavailability (F). One-week repeated daily dosing of ISO did not alter its major oral pharmacokinetic parameters. Pharmacokinetic comparisons clearly indicated that ISO displayed pharmacokinetic profiles superior to resveratrol as its C_max/Dose, AUC/Dose, and F were approximately two to three folds greater than resveratrol. Metabolomic investigation revealed that 1-week ISO administration significantly reduced plasma concentrations of arachidonic acid, cholesterol, fructose, allantoin, and cadaverine but increased tryptamine levels, indicating its impact on metabolic pathways related to health-promoting effects. Conclusion: ISO displayed favorable pharmacokinetic profiles and may be a promising nutraceutical in view of its health-promoting properties.

Combination of urea-crosslinked hyaluronic acid and sodium ascorbyl phosphate for the treatment of inflammatory lung diseases: An in vitro study

This in vitro study evaluated, for the first time, the safety and the biological activity of a novel urea-crosslinked hyaluronic acid component and sodium ascorbyl phosphate (HA-CL - SAP), singularly and/or in combination, intended for the treatment of inflammatory lung diseases. The aim was to understand if the combination HA-CL - SAP had an enhanced activity with respect to the combination native hyaluronic acid (HA) - SAP and the single SAP, HA and HA-CL components. Sample solutions displayed pH, osmolality and viscosity values suitable for lung delivery and showed to be not toxic on epithelial Calu-3 cells at the concentrations used in this study. The HA-CL - SAP displayed the most significant reduction in interleukin-6 (IL-6) and reactive oxygen species (ROS) levels, due to the combined action of HA-CL and SAP. Moreover, this combination showed improved cellular healing (wound closure) with respect to HA - SAP, SAP and HA, although at a lower rate than HA-CL alone. These preliminary results showed that the combination HA-CL - SAP could be suitable to reduce inflammation and oxidative stress in lung disorders like acute respiratory distress syndrome, asthma, emphysema and chronic obstructive pulmonary disease, where inflammation is prominent.

Quantification of desoxyrhapontigenin (4-methoxyresveratrol) in rat plasma by LC-MS/MS: Application to pre-clinical pharmacokinetic study

Desoxyrhapontigenin (DRG, 4-methoxyresveratrol or trans-3,5-dihydroxy-4'-methoxystilbene) is a naturally occurring resveratrol (RES) derivative with a variety of biological activities. To facilitate its further medicinal exploration, a reliable LC-MS/MS method was developed and validated for the quantification of DRG in rat plasma using heavy isotope labelled RES as an internal standard. The ESI was operated in its negative ion mode while DRG and RES were determined by multiple reaction monitoring (MRM) using precursor-to-product ion transitions of m/z 241.1 → 180.8 and m/z 233.0 → 191.0, respectively. This LC-MS/MS method displayed excellent selectivity, sensitivity (LLOQ = 2.5 ng/ml), accuracy (both intra- and interday mean analytical recovery within 100 ± 15%) and precision (both intra- and interday CV < 15%). The mean matrix factors were all within 1.000 ± 0.150 with CV < 15%. The pharmacokinetic profiles of DRG were subsequently examined in Sprague-Dawley rats. Upon intravenous administration (4 or 10 mg/kg), DRG displayed very rapid clearance (Cl = 338 ± 66 or 275 ± 30 ml/min/kg) and short mean residence time (MRT = 12.9 ± 4.7 or 10.4 ± 0.5 min). After oral administration of DRG fully solubilized by 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), the plasma profiles of DRG were highly erratic with a low absolute bioavailability (F < 9.83 ± 5.31%). When DRG was given at a higher dose (50 mg/kg) in suspension form, the F was increased to 24.1 ± 5.6%. The pharmacokinetic comparison among DRG, RES and some of its hydroxyl analogues stilbenes was performed. The information obtained from this study will facilitate further exploration on DRG as well as other RES derivatives.

Oral delivery system enhanced the bioavailability of stilbenes: Resveratrol and pterostilbene

Stilbenes are a large group of compounds with the C₆ C₂ C₆ skeleton, in which two aromatic rings are connected by an ethylene bridge. Resveratrol and its structural analog, pterostilbene, are by far the two most widely researched stilbenes in terms of their beneficial bioactivities. However, the bioefficacy of these compounds is greatly reduced when consumed orally due to their poor aqueous solubility, which leads to poor bioavailability. To overcome the limitation, strategies improving their solubility, absorption, and systemic concentration were applied when designing a suitable edible delivery system. This review will summarize the findings from the studies evaluating the oral bioavailability of stilbenes with emphasize on the resveratrol and pterostilbene. It will also include the edible delivery systems currently available and their effect on the oral bioavailability. © 2018 BioFactors, 44(1):5-15, 2018.

Resveratrol in management of bone and spinal cancers

Bone cancer is a malignant primary tumour of the bone with different typing, such as, osteosarcoma, chondrosarcoma, Ewing's sarcoma and fibrosarcoma. Despite the clinical efficacy of conventional therapies of bone cancer, most patients eventually relapse and the disease remains incurable. Therefore, new therapeutic strategies are needed to improve patient outcome. In this review article, we have discussed the role of resveratrol in preventing bone and spinal cancers and therapeutics. Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural polyphenol, which has been widely reported as an anticancer molecule. Resveratrol exhibits multiple tumour-suppressing activities in bone cancer by affecting a series of critical events. It has the protective effects against oxidative injury, possesses antiproliferative activity and induces apoptosis in cancer cells. Resveratrol might be a good option for the treatment of different types of bone and spinal cancers.

Isorhapontigenin, a bioavailable dietary polyphenol, suppresses airway epithelial cell inflammation through a corticosteroid-independent mechanism

BACKGROUND AND PURPOSE

Chronic obstructive pulmonary disease (COPD) is a corticosteroid-resistant airway inflammatory condition. Resveratrol exhibits anti-inflammatory activities in COPD but has weak potency and poor pharmacokinetics. This study aimed to evaluate the potential of isorhapontigenin, another dietary polyphenol, as a novel anti-inflammatory agent for COPD by examining its effects in vitro and pharmacokinetics in vivo.

EXPERIMENTAL APPROACH

Primary human airway epithelial cells derived from healthy and COPD subjects, and A549 epithelial cells were incubated with isorhapontigenin or resveratrol and stimulated with IL-1β in the presence or absence of cigarette smoke extract. Effects of isorhapontigenin and resveratrol on the release of IL-6 and chemokine (C-X-C motif) ligand 8 (CXCL8), and the activation of NF-κB, activator protein-1 (AP-1), MAPKs and PI3K/Akt/FoxO3A pathways were determined and compared with those of dexamethasone. The pharmacokinetic profiles of isorhapontigenin, after i.v. or oral administration, were assessed in Sprague-Dawley rats.

KEY RESULTS

Isorhapontigenin concentration-dependently inhibited IL-6 and CXCL8 release, with IC₅₀ values at least twofold lower than those of resveratrol. These were associated with reduced activation of NF-κB and AP-1 and, notably, the PI3K/Akt/FoxO3A pathway, that was relatively insensitive to dexamethasone. In vivo, isorhapontigenin was rapidly absorbed with abundant plasma levels after oral dosing. Its oral bioavailability was approximately 50% higher than resveratrol.

CONCLUSIONS AND IMPLICATIONS

Isorhapontigenin, an orally bioavailable dietary polyphenol, displayed superior anti-inflammatory effects compared with resveratrol. Furthermore, it suppressed the PI3K/Akt pathway that is insensitive to corticosteroids. These favourable efficacy and pharmacokinetic properties support its further development as a novel anti-inflammatory agent for COPD.