Polydatin inhibits mitochondrial damage and mitochondrial ROS by promoting PINK1-Parkin-mediated mitophagy in allergic rhinitis.

Polydatin (PD), a natural product derived from Polygonum cuspidatum, has anti-inflammatory and antioxidant effects and has significant benefits in treating allergic diseases. However, its role and mechanism in allergic rhinitis (AR) have not been fully elucidated. Herein, we investigated the effect and mechanism of PD in AR. AR model was established in mice with OVA. Human nasal epithelial cells (HNEpCs) were stimulated with IL-13. HNEpCs were also treated with an inhibitor of mitochondrial division or transfected with siRNA. The levels of IgE and cellular inflammatory factors were examined by enzyme linked immunosorbent assay and flow cytometry. The expressions of PINK1, Parkin, P62, LC3B, NLRP3 inflammasome proteins, and apoptosis proteins in nasal tissues and HNEpCs were measured by Western blot. We found that PD suppressed OVA-induced epithelial thickening and eosinophil accumulation in the nasal mucosa, reduced IL-4 production in NALF, and regulated Th1/Th2 balance. In addition, mitophagy was induced in AR mice after OVA challenge and in HNEpCs after IL-13 stimulation. Meanwhile, PD enhanced PINK1-Parkin-mediated mitophagy but decreased mitochondrial reactive oxygen species (mtROS) production, NLRP3 inflammasome activation, and apoptosis. However, PD-induced mitophagy was abrogated after PINK1 knockdown or Mdivi-1 treatment, indicating a key role of the PINK1-Parkin in PD-induced mitophagy. Moreover, mitochondrial damage, mtROS production, NLRP3 inflammasome activation, and HNEpCs apoptosis under IL-13 exposure were more severe after PINK1 knockdown or Mdivi-1 treatment. Conclusively, PD may exert protective effects on AR by promoting PINK1-Parkin-mediated mitophagy, which further suppresses apoptosis and tissue damage in AR through decreasing mtROS production and NLRP3 inflammasome activation.

The Synergistic Combination of Curcumin and Polydatin Improves Temozolomide Efficacy on Glioblastoma Cells.

Glioblastoma (GBL) is one of the more malignant primary brain tumors; it is currently treated by a multimodality strategy including surgery, and radio- and chemotherapy, mainly consisting of temozolomide (TMZ)-based chemotherapy. Tumor relapse often occurs due to the establishment of TMZ resistance, with a patient median survival time of <2 years. The identification of natural molecules with strong anti-tumor activity led to the combination of these compounds with conventional chemotherapeutic agents, developing protocols for integrated anticancer therapies. Curcumin (CUR), resveratrol (RES), and its glucoside polydatin (PLD) are widely employed in the pharmaceutical and nutraceutical fields, and several studies have demonstrated that the combination of these natural products was more cytotoxic than the individual compounds alone against different cancers. Some of us recently demonstrated the synergistic efficacy of the sublingual administration of a new nutraceutical formulation of CUR+PLD in reducing tumor size and improving GBL patient survival. To provide some experimental evidence to reinforce these clinical results, we investigated if pretreatment with a combination of CUR+PLD can improve TMZ cytotoxicity on GBL cells by analyzing the effects on cell cycle, viability, morphology, expression of proteins related to cell proliferation, differentiation, apoptosis or autophagy, and the actin network. Cell viability was assessed using the MTT assay or a CytoSmart cell counter. CalcuSyn software was used to study the CUR+PLD synergism. The morphology was evaluated by optical and scanning electron microscopy, and protein expression was analyzed by Western blot. Flow cytometry was used for the cell cycle, autophagic flux, and apoptosis analyses. The results provide evidence that CUR and PLD, acting in synergy with each other, strongly improve the efficacy of alkylating anti-tumor agents such as TMZ on drug-resistant GBL cells through their ability to affect survival, differentiation, and tumor invasiveness.

Hyaluronic acid/lactoferrin-coated polydatin/PLGA nanoparticles for active targeting of CD44 receptors in lung cancer.

Traditional chemotherapeutic drugs lack optimal efficacy and invoke severe adverse effects in cancer patients. Polydatin (PD), a phytomedicine, has gradually gained attention due to its antitumor activity. However, its low solubility and poor bioavailability are still cornerstone issues. The present study aimed to fabricate and develop hyaluronic acid/lactoferrin-double coated PD/PLGA nanoparticles via a layer-by-layer self-assembly technique for active targeting of CD44 receptors in lung cancer. Different molecular weights (M.wt.) of HA (32 and 110 kDa) were exploited to study the relationship between the HA M.wt. and the NPs targeting efficacy. The optimized formulations were fully characterized. Their cytotoxicity and cellular uptake were investigated against A549 cell line by CCK-8 kit and fluorescence imaging, respectively. Finally, HA110/Lf-coated PD/PLGA NPs (F9) were subjected to a competitive inhibition study to prove internalization through CD44 overexpressed receptors. The results verified the fabrication of F9 with a particle size of 174.87 ± 3.97 nm and a zeta potential of -24.37 ± 1.19 mV as well as spherical NPs architecture. Importantly, it provoked enhanced cytotoxicity (IC50 = 0.57 ± 0.02 µg/mL) and superior cellular uptake efficacy. To conclude, the current investigation lays the foundation for the prospective therapeutic avenue of F9 for active targeting of CD44 receptors in lung cancer.

PD protects Müller cells through the SIRT1/NLRP3 inflammasome pathway.

PURPOSE: Polydatin (PD) has widely pharmacological activities. However, the effects of PD on high glucose (HG)-induced Müller cells in diabetic retinopathy (DR) are rarely studied. METHODS: The protective effects of PD were evaluated in HG-induced human retinal Müller cells. The levels of pro-angiogenic factors and pro-inflammatory factors were detected using the ELISA kits. The expressions of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing-3 (NLRP3) and sirtuin-1 (SIRT1) were determined by western blot. RESULTS: PD inhibited proliferation and activation of HG-induced MIO-M1 cells. PD treatment reduced the levels of pro-angiogenic factors, pro-inflammatory factors, and oxidative stress, while these effects were attenuated by NLRP3 agonist ATP in HG-induced MIO-M1 cells. Furthermore, PD inhibited the activation of NLRP3 inflammasome by regulating the SIRT1 expression after HG stimulation, and knockdown of SIRT1 reversed the inhibition effects of PD on NLRP3 inflammasome, pro-angiogenic factors, pro-inflammatory factors, and oxidative stress in HG-induced MIO-M1 cells. CONCLUSION: PD may inhibit HG-induced Müller cells proliferation and activation and suppress pro-angiogenic factors, pro-inflammatory factors, and oxidative stress through the SIRT1/NLRP3 inflammasome pathway. In summary, PD treatment may be an effective therapeutic strategy for DR.

Polydatin alleviates bleomycin-induced pulmonary fibrosis and alters the gut microbiota in a mouse model.

To investigate the effect and mechanism of polydatin on bleomycin (BLM)-induced pulmonary fibrosis in a mouse model. The lung fibrosis model was induced by BLM. The contents of TNF-α, LPS, IL-6 and IL-1ß in lung tissue, intestine and serum were detected by ELISA. Gut microbiota diversity was detected by 16S rDNA sequencing; R language was used to analyse species composition, α-diversity, ß-diversity, species differences and marker species. Mice were fed drinking water mixed with four antibiotics (ampicillin, neomycin, metronidazole, vancomycin; antibiotics, ABx) to build a mouse model of ABx-induced bacterial depletion; and faecal microbiota from different groups were transplanted into BLM-treated or untreated ABx mice. The histopathological changes and collagen I and α-SMA expression were determined. Polydatin effectively reduced the degree of fibrosis in a BLM-induced pulmonary fibrosis mouse model; BLM and/or polydatin affected the abundance of the dominant gut microbiota in mice. Moreover, faecal microbiota transplantation (FMT) from polydatin-treated BLM mice effectively alleviated lung fibrosis in BLM-treated ABx mice compared with FMT from BLM mice. Polydatin can reduce fibrosis and inflammation in a BLM-induced mouse pulmonary fibrosis model. The alteration of gut microbiota by polydatin may be involved in the therapeutic effect.

Polydatin alleviates mycoplasma pneumoniae-induced injury via inhibition of Caspase-1/GSDMD-dependent pyroptosis.

Mycoplasma pneumoniae (MP) is one of the main pathogens causing community acquired pneumonia (CAP) in children and adults. Previous pharmacological and clinical studies have shown that Polydatin (PD) exerts anti-inflammatory action by conferring protective benefit in MP pneumonia. However, the mechanism underlying the of PD on MP infection remains unclear. It was found that PD alleviated MP-induced injury by inhibiting caspase-1/gasdermin D (GSDMD)-mediated epithelial pyroptosis. The results demonstrated that PD inhibited the transformation of GSDMD to N-terminal gasdermin-N (GSDMD-N) by decreasing caspase-1 activation, as well as suppressed the formation and secretion of interleukin-1ß (IL-1ß) and interleukin-18 (IL-18), reversed Na, K-ATPase reduction, and suppressed LDH release both in vitro and vivo. Taken together, epithelial pyroptosis in BEAS-2B cells and lung injury in mice were prevented by PD. In conclusion, PD suppressed pulmonary injury triggered by MP infection, by inhibiting the caspase-1/GSDMD-mediated epithelial pyroptosis signaling pathway. Thus, PD may be regarded as a potential therapy for MP-induced inflammation.

Protein acetylation and related potential therapeutic strategies in kidney disease.

Kidney disease can be caused by various internal and external factors that have led to a continual increase in global deaths. Current treatment methods can alleviate but do not markedly prevent disease development. Further research on kidney disease has revealed the crucial function of epigenetics, especially acetylation, in the pathology and physiology of the kidney. Histone acetyltransferases (HATs), histone deacetylases (HDACs), and acetyllysine readers jointly regulate acetylation, thus affecting kidney physiological homoeostasis. Recent studies have shown that acetylation improves mechanisms and pathways involved in various types of nephropathy. The discovery and application of novel inhibitors and activators have further confirmed the important role of acetylation. In this review, we provide insights into the physiological process of acetylation and summarise its specific mechanisms and potential therapeutic effects on renal pathology.

Glucose metabolic reprogramming and modulation in glycerol biosynthesis regulates drug resistance in clinical isolates of Candida.

AIMS: The study is aimed at understanding the novel molecular mechanisms governing drug resistance in the opportunistic fungi belonging to the genus Candida. METHODS AND RESULTS: This is a multipronged study wherein different assays like drug susceptibility and whole cell proteome analysis, stress tolerance assay, measurement of total internal glycerol content, western blot analysis, reactive oxygen species (ROS) measurement, glucose uptake, lactate production, ATP generation, and NADPH measurements were made.The study reveals an incidence of different species of Candida in the northern most part of India (Kashmir valley). Resistant isolates, mostly resistant to azoles were reported across all the species. The study revealed a difference in resistance mechanisms between Candida albicans and C. glabrata clinical isolates. Further, such resistance mechanism (in the case of C. albicans) was mostly mediated by Hexokinase 2 (Hxk2) and Glucose-6-phosphate dehydrogenase (G6pd). Increased expression of Hxk2 was associated with increased glucose uptake, more lactate production, and more ATP generation in drug-resistant C. albicans. At the same time, increased G6pd expression was responsible for the increased production of NADPH, which imparts a better ROS scavenging potential. While in C. glabrata the resistance was linked with glycerol metabolism, where the drug-resistant isolate tends to accumulate more glycerol as an osmolyte in response to external stresses. This glycerol accumulation was found to be triggered by the HOG1-MAPK pathway. CONCLUSION: The study concludes that, like various human malignant tumors, there is a strong correlation between drug resistance and aberrant cellular metabolism in the opportunistic fungi belonging to the genus Candida.

Mechanisms of polydatin against spinal cord ischemia-reperfusion injury based on network pharmacology, molecular docking and molecular dynamics simulation.

BACKGROUND: Polydatin has shown considerable pharmacological activities in ischemia-reperfusion injuries of various organs. However, its effects and mechanisms in spinal cord ischemia-reperfusion injury have not been fully established. In this study, the mechanisms of polydatin against spinal cord ischemia-reperfusion injury were investigated via network pharmacology, molecular docking and molecular dynamics simulation. METHODS: Spinal cord ischemia-reperfusion injury-related targets were obtained from the GeneCards database, while polydatin-related action targets were obtained from the CTD and SwissTarget databases. A protein-protein interaction network of potential targets was constructed using the String platform. After selecting the potential key targets, GO functional enrichment and KEGG pathway enrichment analyses were performed via the Metascape database, and a network map of "drug-target-pathway-disease" constructed. The relationships between polydatin and various key targets were assessed via molecular docking. Molecular dynamics simulation was conducted for optimal core protein-compound complexes obtained by molecular docking. RESULTS: Topological analysis of the PPI network revealed 14 core targets. GO functional enrichment analysis revealed that 435 biological processes, 12 cell components and 29 molecular functions were enriched while KEGG pathway enrichment analysis revealed 91 enriched signaling pathways. Molecular docking showed that polydatin had the highest binding affinity for MAPK3, suggesting that MAPK3 is a key target of polydatin against spinal cord ischemia-reperfusion injury. Molecular dynamics simulations revealed good binding abilities between polydatin and MAPK3. CONCLUSIONS: Polydatin exerts its effects on spinal cord ischemia-reperfusion injury through multiple targets and pathways. MAPK3 may be a key target of polydatin in spinal cord ischemia-reperfusion injury.

Protective effects of polydatin against bone and joint disorders: the in vitro and in vivo evidence so far.

Polydatin is an active polyphenol displaying multifaceted benefits. Recently, growing studies have noticed its potential therapeutic effects on bone and joint disorders (BJDs). Therefore, this article reviews recent in vivo and in vitro progress on the protective role of polydatin against BJDs. An insight into the underlying mechanisms is also presented. It was found that polydatin could promote osteogenesis in vitro, and symptom improvements have been disclosed with animal models of osteoporosis, osteosarcoma, osteoarthritis and rheumatic arthritis. These beneficial effects obtained in laboratory could be mainly attributed to the bone metabolism-regulating, anti-inflammatory, antioxidative, apoptosis-regulating and autophagy-regulating functions of polydatin. However, studies on human subjects with BJDs that can lead to early identification of the clinical efficacy and adverse effects of polydatin have not been reported yet. Accordingly, this review serves as a starting point for pursuing clinical trials. Additionally, future emphasis should also be devoted to the low bioavailability and prompt metabolism nature of polydatin. In summary, well-designed clinical trials of polydatin in patients with BJD are in demand, and its pharmacokinetic nature must be taken into account.

Natural Compounds, Optimal Combination of Brusatol and Polydatin Promote Anti-Tumor Effect in Breast Cancer by Targeting Nrf2 Signaling Pathway.

Triple-negative breast cancer (TNBC) has been clearly recognized as a heterogeneous tumor with the worst prognosis among the subtypes of breast cancer (BC). The advent and application of current small-molecule drugs for treating TNBC, as well as other novel inhibitors, among others, have made treatment options for TNBC more selective. However, there are still problems, such as poor patient tolerance, large administration doses, high dosing frequency, and toxic side effects, necessitating the development of more efficient and less toxic treatment strategies. High expression of Nrf2, a vital antioxidant transcription factor, often promotes tumor progression, and it is also one of the most effective targets in BC therapy. We found that in MDA-MB-231 cells and SUM159 cells, brusatol (BRU) combined with polydatin (PD) could significantly inhibit cell proliferation in vitro, significantly downregulate the expression of Nrf2 protein as well as the expression of downstream related target genes Heme Oxygenase-1 (HO-1) and NAD(P)H dehydrogenase, quinone 1 (NQO1), and promote reactive oxygen species (ROS) levels to further strengthen the anti-tumor effect. Furthermore, we discovered in our in vivo experiments that by reducing the drug dosage three times, we could significantly reduce tumor cell growth while avoiding toxic side effects, providing a treatment method with greater clinical application value for TNBC treatment.

Xuanfei Baidu Decoction reduces acute lung injury by regulating infiltration of neutrophils and macrophages via PD-1/IL17A pathway.

The pathogenic hyper-inflammatory response has been revealed as the major cause of the severity and death of the Corona Virus Disease 2019 (COVID-19). Xuanfei Baidu Decoction (XFBD) as one of the "three medicines and three prescriptions" for the clinically effective treatment of COVID-19 in China, shows unique advantages in the control of symptomatic transition from moderate to severe disease states. However, the roles of XFBD to against hyper-inflammatory response and its mechanism remain unclear. Here, we established acute lung injury (ALI) model induced by lipopolysaccharide (LPS), presenting a hyperinflammatory process to explore the pharmacodynamic effect and molecular mechanism of XFBD on ALI. The in vitro experiments demonstrated that XFBD inhibited the secretion of IL-6 and TNF-α and iNOS activity in LPS-stimulated RAW264.7 macrophages. In vivo, we confirmed that XFBD improved pulmonary injury via down-regulating the expression of proinflammatory cytokines such as IL-6, TNF-α and IL1-ß as well as macrophages and neutrophils infiltration in LPS-induced ALI mice. Mechanically, we revealed that XFBD treated LPS-induced acute lung injury through PD-1/IL17A pathway which regulates the infiltration of neutrophils and macrophages. Additionally, one major compound from XFBD, i.e. glycyrrhizic acid, shows a high binding affinity with IL17A. In conclusion, we demonstrated the therapeutic effects of XFBD, which provides the immune foundations of XFBD and fatherly support its clinical applications.

Polydatin Improves Sepsis-Associated Encephalopathy by Activating Sirt1 and Reducing p38 Phosphorylation.

INTRODUCTION: Our previous study confirmed that polydatin (PD) can alleviate sepsis-induced multiorgan dysfunction (in the vascular endothelium, kidney, and small intestine) by activating Sirt1 and that PD protects against traumatic brain injury in rats via increased Sirt1 and inhibition of the p38-mediated mitogen-activated protein kinase (MAPK) pathway. We aim to investigate whether PD may also attenuate sepsis-associated encephalopathy (SAE). METHODS: In this study, we constructed an SAE mouse model by cecal ligation and puncture (CLP) and measured Sirt1 protein activity, p38 phosphorylation, brain tissue pathological damage, pro-inflammatory cytokines (TNF-α, IL-1ß, and IL-6), mitochondrial function (mitochondrial membrane potential, ATP content, and reactive oxygen species), neurological function, and animal survival time. Sirt1 selective inhibitor Ex527 and p38 inhibitor SB203580 were used to explore the possible mechanism of PD in SAE. RESULTS: We confirmed that PD inhibits neuroinflammation evidenced by reduced proinflammatory cytokines. In addition, PD protects mitochondria as demonstrated by restored mitochondrial membrane potential and adenosine triphosphate (ATP) content, and decreased reactive oxygen species (ROS) level. As we expected, p38 inhibition reduces neuroinflammation and mitochondrial damage. In contrast, Sirt1 inhibition aggravates cerebral cortex mitochondrial damage and neuroinflammation and promotes phosphorylation of p38. Mechanistically, PD treatment suppressed p38 phosphorylation and consequently reduced the neuroinflammatory response, and these effects were blocked by the Sirt selective inhibitor Ex527. CONCLUSIONS: This study, to the best of our knowledge, is the first to demonstrate that PD alleviates SAE, at least partially, by upregulating Sir1-mediated neuroinflammation inhibition and mitochondrial function protection.

Polydatin combats methotrexate-induced pulmonary fibrosis in rats: Involvement of biochemical and histopathological assessment.

Polydatin (PD) is a polyphenolic compound found naturally in many fruits such as grapes. It has anti-oxidant and anti-inflammatory activities that are of paramount importance for its pharmacological actions. This study aimed to explore possible protective effects of PD against methotrexate (MTX)-induced pulmonary fibrosis in rats. A single oral dose of MTX (14 mg/kg) per week for 2 weeks caused a significant decrease in glutathione (GSH) content with a marked increase in transforming growth factor-beta (TGF-ß), alpha-smooth muscle actin (α-SMA), pulmonary content of malondialdehyde (MDA), interleukin-1ß (IL-1ß), Hydroxyproline, tumor necrosis factor-alpha (TNF-α), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) as compared with the control group. Contrarily, daily administration of PD (25, 50, and 100 mg/kg, p.o.) for 14 days concomitantly with MTX ameliorated MTX-induced pulmonary fibrosis as indicated by mitigation of the previously mentioned biochemical parameters and histopathological changes in a dose-dependent manner. In conclusion, the protective effect of PD against pulmonary fibrosis induced by MTX in rats might be attributed to its anti-oxidant, anti-inflammatory as well as anti-fibrotic effects.

Polydatin alleviates DSS- and TNBS-induced colitis by suppressing Th17 cell differentiation via directly inhibiting STAT3.

Inflammatory bowel disease (IBD) is a non-specific chronic intestinal inflammatory disease, often presenting with abdominal pain, diarrhea, bloody stool, anorexia, and body loss. It is difficult to cure completely and a promising treatment is urgently needed. Natural compounds can offer promising chemical agents for treatment of diseases. Polydatin is a natural ingredient extracted from the dried rhizome of Polygonum cuspidatum, which has anti-inflammatory, anti-tumor, and dementia protection activities. The purpose of this study was to evaluate the therapeutic effect of polydatin on IBD and explore its possible mechanism. We found that polydatin could effectively suppress the differentiation of Th17 cells in vitro, but had no effect on the differentiation of Treg cells. Polydatin significantly alleviated colitis induced by dextran sulfate sodium (DSS) and 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) in mice, and dramatically decreased the proportion of Th17 cells in spleen and mesenteric lymph nodes. Mechanism investigations revealed that polydatin specifically inhibited signal transducer and activator of transcription 3 (STAT3) phosphorylation by directly binding to STAT3, leading to Th17 cell reduction and thereby alleviating colitis. These findings provide novel insights into the anti-colitis effect of polydatin, which may be a promising drug candidate for the treatment of IBD.

Old dog, new tricks: Polydatin as a multitarget agent for current diseases.

Polydatin (PD) is a natural single-crystal product that is primarily extracted from the traditional plant Polygonum cuspidatum Sieb. et Zucc. Early research showed that PD exhibited a variety of biological activities. PD has attracted increasing research interest since 2014, but no review comprehensively summarized the new findings. A great gap between its biological activities and drug development remains. It is necessary to summarize new findings on the pharmacological effects of PD on current diseases. We propose that PD will most likely be used in cardiac and cerebral ischaemia/reperfusion-related diseases and atherosclerosis in the future. The present work classified these new findings according to diseases and summarized the main effects of PD via specific mechanisms of action. In summary, we found that PD played a therapeutic role in a variety of diseases, primarily via five mechanisms: antioxidative effects, antiinflammatory effects, regulation of autophagy and apoptosis, maintenance of mitochondrial function, and lipid regulation.

Polydatin ameliorates hepatic ischemia-reperfusion injury by modulating macrophage polarization.

BACKGROUND: Polydatin, a glucoside of resveratrol, has been shown to have protective effects against various diseases. However, little is known about its effect on hepatic ischemia-reperfusion (I/R) injury. This study aimed to elucidate whether polydatin protects liver against I/R-induced injury and to explore the underlying mechanism. METHODS: After gavage feeding polydatin once daily for a week, mice underwent a partial hepatic I/R procedure. Serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST), hematoxylin-eosin (H&E) and TdT-mediated dUTP nick-end labeling (TUNEL) staining were used to evaluate liver injury. The severity related to the inflammatory response and reactive oxygen species (ROS) production was also investigated. Furthermore, immunofluorescence and Western blotting were used to detect macrophage polarization and the NF-κB signaling pathway in macrophages. RESULTS: Compared with the I/R group, polydatin pretreatment significantly attenuated I/R-induced liver damage and apoptosis. The oxidative stress marker (dihydroethidium fluorescence, malondialdehyde, superoxide dismutase and glutathione peroxidase) and I/R related inflammatory cytokines (interleukin-1ß, interleukin-10 and tumor necrosis factor-α) were significantly suppressed after polydatin treatment. In addition, the result of immunofluorescence indicated that polydatin reduced the polarization of macrophages toward M1 macrophages both in vivo and in vitro. Western blotting showed that polydatin inhibited the pro-inflammatory function of RAW264.7 via down-regulating the NF-κB signaling pathway. CONCLUSIONS: Polydatin protects the liver from I/R injury by remodeling macrophage polarization via NF-κB signaling.

Conductive polymer sorbent for extraction and determination of resveratrol and polydatin in Polygonum cuspidatum root samples.

INTRODUCTION: The quantitative analysis of trace resveratrol and polydatin in plant tissues is suitable for elucidation of the compounds' mechanisms of action. OBJECTIVES: The main objective of this work was to develop a feasible and effective sample pretreatment method to measure the concentrations of resveratrol and polydatin in complex samples. METHODOLOGY: A polymer sorbent, poly(2-mercaptobenzimidazole), was electrochemically prepared and utilized for selective extraction, while resveratrol and polydatin were used as target analytes. The sorbent was characterized by cyclic voltammetry, scanning electron microscopy and Fourier transform infrared spectroscopy. After extraction and elution, the analytes were analyzed by a Thermo U3000 HPLC system. Several affecting parameters, including the volume of elution solution, sample pH value, sample flow rate and sample volume, were evaluated and optimized. RESULTS: The proposed method showed good linearity with low limits of detection (from 0.5 to 0.8 ng·mL-1 ) and ideal accuracy with spiked recoveries from 81.30% to 99.16%. A good enrichment factor (more than 200-fold) together with good sensitivity was obtained with this method. Analysis of resveratrol and polydatin in Polygonum cuspidatum samples by this method is efficient. CONCLUSION: The method developed in this work exhibits several significant merits, including easy operation and high extraction efficiency, indicating that electrochemically prepared polymer sorbent is useful for sample pretreatment and analysis of traditional Chinese medicine samples.

Influence of Polydatin on the Tumor Microenvironment In Vitro: Studies with a Colon Cancer Cell Model.

The tumor microenvironment of colon carcinoma, the site at which tumor cells and the host immune system interact, is influenced by signals from tumor cells, immunocompetent cells, and bacterial components, including LPS. A large amount of LPS is available in the colon, and this could promote inflammation and metastasis by enhancing tumor cell adhesion to the endothelium. Polydatin (PD), the 3-ß-D-glucoside of trans-resveratrol, is a polyphenol with anti-cancer, anti-inflammatory, and immunoregulatory effects. This study was designed to explore whether PD is able to produce antiproliferative effects on three colon cancer lines, to reduce the expression of adhesion molecules that are upregulated by LPS on endothelial cells, and to decrease the proinflammatory cytokines released in culture supernatants. Actually, we investigated the effects of PD on tumor growth in a coculture model with human mononuclear cells (MNCs) that mimics, at least in part, an in vitro tumor microenvironment. The results showed that PD alone or in combination with MNC exerts antiproliferative and proapoptotic effects on cancer cells, inhibits the production of the immunosuppressive cytokine IL-10 and of the proinflammatory cytokines upregulated by LPS, and reduces E-selectin and VCAM-1 on endothelial cells. These data provide preclinical support to the hypothesis that PD could be of potential benefit as a therapeutic adjuvant in colon cancer treatment and prevention.

Application of ß-Glucosidase in a Biphasic System for the Efficient Conversion of Polydatin to Resveratrol.

Resveratrol, an ingredient of traditional Chinese medicine, has beneficial effects on human health and huge potential for application in modern medicine. Polydatin is extracted from plants and then deglycosylated into resveratrol; enzymatic methods are preferred for this reaction. In this study, a ß-D-glucosidase from Sphingomonas showed high efficiency in transforming polydatin into resveratrol and was tolerant toward organic solvents. Applying this enzyme in a biphasic transformation system resulted in 95.3% conversion of 20% concentration crude polydatin to resveratrol in 4 h. We thus report a new method for high-efficiency, clean production of resveratrol.