Root Of Polygonum Cuspidatum Research Articles

Protein tyrosine phosphatase 1B inhibitory activities of compounds isolated from Polygonum cuspidatum

AbstractIn the search for new natural PTP1B inhibitory compounds from medicinal plants, two 9,10‐anthraquinones were isolated and structurally identified as physcion (1) and emodin (2) from the alcoholic extract of the root of Polygonum cuspidatum. Chemical structures of these isolates were identified by interpretation of spectroscopic data (1H, 13C NMR and MS) as well as comparing with reported literatures. Compounds 1–2 possessed inhibitory activity on PTP1B enzyme with IC50 values of 26.1 ± 0.7 and 13.3 ± 0.4 μM, respectively. Ursolic acid was used as positive control showing an IC50 value of 3.5 ± 0.2 μM in this assay. This result reveals that these 9,10‐anthraquinones might be considered as new natural compounds for development of antidiabetic agents.

Bioprocessed Production of Resveratrol-Enriched Rice Wine: Simultaneous Rice Wine Fermentation, Extraction, and Transformation of Piceid to Resveratrol from Polygonum cuspidatum Roots.

A new bioprocess to produce resveratrol-enriched rice wine was established and the effects of adding Polygonum cuspidatum root powder to rice wine fermentation were investigated. In this new process, piceid and resveratrol were extracted from P. cuspidatum roots to rice wine and piceid was converted to resveratrol by β-glucosidase during fermentation. After 10 days co-fermentation, rice wine with high levels of resveratrol was obtained, which contained ~14% (v/v) ethanol, 122 mg/L piceid, and 86 mg/L resveratrol. The resveratrol-enriched rice wine had enhanced antioxidant activity with significantly stronger 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric ion reducing power, and ferrous ion chelating capability. Ultrafiltration (UF) was employed in this study using hollow fibers to clarify the end product, increase shelf life without heat treatment, and maintain the quality of the phenolic compounds. The boiled and UF-treated rice wine were evaluated for ethanol, piceid, resveratrol, clarity, aerobic plate count, total acidity, pH, reducing sugars, and amino acids. The quality of the resveratrol-enriched rice wine was maintained after four weeks storage at normal refrigeration temperatures.

Polydatin Attenuates Carbachol-induced Contraction of Guinea Pig Gallbladder

The aim of this study was to determine whether polydatin, a glucoside of resveratrol isolated from the root of Polygonum cuspidatum, warranted development as a potential therapeutic for ameliorating the pain originating from gallbladder spasm disorders and the underlying mechanisms. Guinea pig gallbladder smooth muscles were treated with polydatin and specific inhibitors to explore the mechanisms underpinning polydatin-induced relaxation of carbachol-precontracted guinea pig gallbladder. Our results shown that polydatin relaxed carbachol-induced contraction in a dose-dependent manner through the nitric oxide/cyclic guanosine monophosphate/protein kinase G and the cyclic adenosine monophosphate/protein kinase A signaling pathways as well as the myosin light chain kinase and potassium channels. Our findings suggested that there was value in further exploring the potential therapeutic use of polydatin in gallbladder spasm disorders.

Protective effects of polydatin in free and nanocapsulated form on changes caused by lipopolysaccharide in hippocampal organotypic cultures.

Polydatin (PD) is a compound, originally isolated from the root and rhizome of the Chinese herb Polygonum cuspidatum. To date, various biological properties of this compound, such as analgesic, anti-pyretic or diuretic effects, have been shown. Recently, anti-oxidant and anti-inflammatory properties have been widely postulated, yet PD instability and low bioavailability limit its beneficial actions. Therefore, it has been suggested that an encapsulation process may be a promising strategy for overcoming these limitations and increasing the therapeutic efficacy of PD. We examined the effects of PD in two forms, including free and in PD-loaded polymeric nanocapsules, on lipopolysaccharide (LPS)-induced changes in hippocampal organotypic cultures. Our results indicated that free and encapsulated PD diminished cell death processes and attenuated the secretion of pro-inflammatory cytokines induced by LPS administration. Additionally, PD in both forms strongly inhibited the production of nitric oxide and down-regulated the level of iNOS enzyme in LPS-stimulated hippocampal cultures. Taken together, our study showed that PD exerts anti-inflammatory and anti-oxidant properties in LPS-treated hippocampal organotypic cultures. Furthermore, we show that the encapsulation procedure preserved the features of the free form of this compound, and therefore, the polymeric nanocapsules containing PD may be used as a novel and promising delivery system in therapeutic strategies.

2-Ethoxystypandrone, a novel small-molecule STAT3 signaling inhibitor from Polygonum cuspidatum, inhibits cell growth and induces apoptosis of HCC cells and HCC Cancer stem cells

BackgroundSignal transducer and activator of transcription 3 (STAT3) is an oncogene constitutively activated in hepatocellular carcinoma (HCC) cells and HCC cancer stem cells (CSCs). Constitutively activated STAT3 plays a pivotal role in holding cancer stemness of HCC CSCs, which are essential for hepatoma initiation, relapse, metastasis and drug resistance. Therefore, STAT3 has been validated as a novel anti-cancer drug target and the strategies targeting HCC CSCs may bring new hopes to HCC therapy. This study aimed to isolate and identify small-molecule STAT3 signaling inhibitors targeting CSCs from the ethyl acetate (EtOAc) extract of the roots of Polygonum cuspidatum and to evaluate their in vitro anti-cancer activities.MethodsThe chemical components of the EtOAc extract and the subfractions of P. cuspidatum were isolated by using various column chromatographies on silical gel, Sephadex LH-20, and preparative HPLC. Their chemical structures were then determined on the basis of spectroscopic data including NMR, MS and IR analysis and their physicochemical properties. The inhibitory effects of the isolated compounds against STAT3 signaling were screened by a STAT3-dependent luciferase reporter gene assay. The tyrosine phosphorylation of STAT3 was examined by Western Blot analysis. In vitro anti-cancer effects of the STAT3 pathway inhibitor were further evaluated on cell growth of human HCC cells by a MTT assay, on self-renewal capacity of HCC CSCs by the tumorsphere formation assay, and on cell cycle and apoptosis by flow cytometry analysis, respectively.ResultsThe EtOAc extract of the roots of P. cuspidatum was investigated and a novel juglone analogue 2-ethoxystypandrone (1) along with seven known compounds (2–8) was isolated. Among the eight isolated compounds 1–8, 2-ethoxystypandrone was a novel and potent STAT3 signaling inhibitor (IC50 = 7.75 ± 0.18 μM), and inhibited the IL-6-induced and constitutive activation of phosphorylation of STAT3 in HCC cells. Moreover, 2-ethoxystypandrone inhibited cell survival of HCC cells (IC50 = 3.69 ± 0.51 μM ~ 20.36 ± 2.90 μM), blocked the tumorspheres formation (IC50 = 2.70 ± 0.28 μM), and induced apoptosis of HCC CSCs in a dose-dependent manner.ConclusionA novel juglone analogue 2-ethoxystypandrone was identified from the EtOAc extract of the roots of P. cuspidatum and was demonstrated to be a potent small-molecule STAT3 signaling inhibitor, which strongly blocked STAT3 activation, inhibited proliferation, and induced cell apoptosis of HCC cells and HCC CSCs. 2-Ethoxystypandrone as a STAT3 signaling inhibitor might be a promising lead compound for further development into an anti-CSCs drug.

Polydatin protects H9c2 cells from hypoxia-induced injury via up-regulating long non-coding RNA DGCR5.

Polydatin (PD), a monocrystalline polyphenolic drug mainly found in the roots of Polygonum cuspidatum, has various pharmacological activities. Long non-coding RNAs (lncRNA) DiGeorge syndrome critical region gene 5 (DGCR5) was found to participate in the suppression of multiple cancers. Here, we proposed to study the effect of PD on myocardial infarction (MI) by inducing DGCR5. CCK-8 assay was performed to detect the viability of H9c2 cells. Flow cytometry was utilized to test apoptosis of H9c2 cells. These results determined the optimal concentration and effect time of hypoxia as well as PD. Si-DGCR5 was transfected into cells and the expression level was determined by qRT-PCR. Western blot was utilized to evaluate the expression of apoptosis-related proteins, Bcl-2, Bax, and cleaved-caspase-3, as well as autophagy-associated proteins including Beclin-1, p62, and LC3-II/LC3-I. As a result, PD efficiently attenuated hypoxia-induced apoptosis and autophagy in H9c2 cells. The expression of DGCR5 was down-regulated by hypoxia and up-regulated by PD. Besides, knocking-down the expression of DGCR5 inhibited the protection of PD in H9c2 cells. In addition, PD up-regulated the accumulation of DGCR5, DGCR5 decreased the expression of Bcl-2 and p62, raised the expression of Bax and cleaved-caspase-3, and the proportion of LC3-II/LC3-I. PD stimulated the PI3K/AKT/mTOR and MEK/ERK signaling pathways via up-regulating the expression of DGCR5. Our data demonstrated that PD reduced cell apoptosis and autophagy induced by hypoxia in cardiomyocytes. Moreover, PD activated PI3K/AKT/mTOR and MEK/ERK signaling pathways by up-regulating the expression of DGCR5.

Effect of resveratrol and Regrapex-R-forte on Trichosporon cutaneum biofilm.

Microorganisms that cause chronic infections exist predominantly as surface-attached stable communities known as biofilms. Microbial cells in biofilms are highly resistant to conventional antibiotics and other forms of antimicrobial treatment; therefore, modern medicine tries to develop new drugs that exhibit anti-biofilm activity. We investigated the influence of a plant polyphenolic compound resveratrol (representative of the stilbene family) on the opportunistic pathogen Trichosporon cutaneum. Besides the influence on the planktonic cells of T. cutaneum, the ability to inhibit biofilm formation and to eradicate mature biofilm was studied. We have tested resveratrol as pure compound, as well as resveratrol in complex plant extract-the commercially available dietary supplement Regrapex-R-forte, which contains the extract of Vitis vinifera grape and extract of Polygonum cuspidatum root. Regrapex-R-forte is rich in stilbenes and other biologically active substances. Light microscopy imaging, confocal microscopy, and crystal violet staining were used to quantify and visualize the biofilm. The metabolic activity of biofilm-forming cells was studied by the tetrazolium salt assay. Amphotericin B had higher activity against planktonic cells; however, resveratrol and Regrapex-R-forte showed anti-biofilm effects, both in inhibition of biofilm formation and in the eradication of mature biofilm. The minimum biofilm eradicating concentration (MBEC80) for Regrapex-R-forte was found to be 2222mg/L (in which resveratrol concentration is 200mg/L). These methods demonstrated that Regrapex-R-forte can be employed as an anti-biofilm agent, as it has similar effect as amphotericin B (MBEC80 = 700mg/L), which is routinely used in clinical practice.

Synthesis of Biotinylated 2-methoxystypandrone and Identification of JAK2 and IKK as its Targets.

2-Methoxystypandrone (2-MS), isolated from the roots of Polygonum cuspidatum, is a potent dual inhibitor of the STAT3 and NF-κB pathways. To investigate the molecular targets and mechanisms of 2-MS. A biotin-conjugated 2-MS analog, named 2-MS-Biotin, was designed and synthesized. The effects of 2-MS-Biotin on the STAT3 and NF-κB pathways were examined by Western blotting. The cytotoxicity of 2- MS-Biotin was evaluated using real-time cell analysis system. Proteins directly bound to 2-MS-Biotin were pulled down through streptavidin agarose beads and were detected using Western blotting. 2-MS-Biotin retained the inhibition activities of the parent compound 2-MS on the STAT3 and NF-κB pathways as well as on cancer cell growth. Also, JAK2 and IKK proteins can be effectively pulled down by 2- MS-Biotin. Using 2-MS-Biotin as a tool, both JAK2 and IKK were identified as the targets of 2-MS.

Anti-Proliferative and Apoptotic Effects of Polygonum cuspidatum and its Bioactive Compound, Emodin, in Colorectal Carcinoma HT-29 cells

Antiproliferative and apoptotic effects of ethyl acetate from the root of Polygonum cuspidatum (EAPC) and its bioactive compound, emodin, in colorectal adenocarcinoma HT-29 cells were investigated. HPLC analysis of major compounds, cell viability by MTT assay, the Comet assay, determination of reactive oxygen species (ROS) levels, apoptosis assay by flow cytometry and Western blot analysis were conducted. The results show significant antiproliferative effects of EAPC, IC50 = 141.4 μg/mL, and emodin isolated from EAPC, IC50 = 73.0 μg/mL, on HT-29 cells. HT-29 cells which were exposed to EAPC and emodin exerted apoptosis, after annexin V FITC/PI staining. EAPC (at 200 μg/mL) and emodin (at 100 μg/mL) increase DNA damage in HT-29 cells by 75.6% and 67.8%, respectively, supporting that apoptosis occurred when the cells were treated with EAPC and emodin. Cells treated with EAPC and emodin generated intracellular ROS. In addition, emodin at tested doses of 25-100 μg/mL suppressed nuclear factor κB (NFκB) and enhanced activator protein 1 (AP-1), which are involved in both proliferation and apoptosis events. EAPC and emodin demonstrated significant anti-proliferation of HT-29 cells through their pro-oxidant activity and contribution to oxidative stress, which in turn leads to cell death. EPAC and emodin inhibited HT-29 cell growth via apoptosis and could be considered as potential candidates for anti-colorectal cancer treatment.

The antimicrobial effects of three phenolic extracts from Rosmarinus officinalis L., Vitis vinifera L. and Polygonum cuspidatum L. on food pathogens

In this study three phenolic extracts were examined, without volatile fraction, against common food pathogens. The samples, all suitable for food application, were from the leaves of Rosmarinus officinalis L., Vitis vinifera L., and the root of Polygonum cuspidatum L. The microorganisms tested were Escherichia coli O157:H7, Salmonella Enteritidis, Salmonella Typhi, Yersinia enterocolitica and Listeria monocytogenes, well-known as important food pathogens. The results demonstrated a microbicidal activity of all the tested compounds at different concentrations; the rosemary extract showed greater efficacy than the other compounds against the tested microorganisms. In particular, the best results were obtained with rosemary extract against E. coli O157:H7 and L. monocytogenes with values of 200 and 270 μg/mL, respectively. Our results show that rosemary extract, often present as a natural antioxidant in food, can also be proposed as a natural disinfectant in the food field.

Production of Resveratrol by Piceid Deglycosylation Using Cellulase

Resveratrol is a dietary polyphenolic compound widely used in medicine, food, and cosmetic products. The glycoside form of resveratrol, piceid, is also present in several plant materials but is less bioavailable. In this study, enzymatic transformation of piceid into resveratrol using inexpensive cellulase was investigated. Response surface methodology was used to evaluate the effect of reaction parameters, including reaction temperature, reaction time, enzyme amount and pH. The optimal conditions for biotransformation of piceid to resveratrol are: a reaction temperature of 50 °C, reaction time of 4.75 h, enzyme amount of 2.5 fungal β-glucanase (FBG) units and pH of 4.3. In addition, the extracts from Polygonum cuspidatum root contained high amounts of piceid were treated with cellulase in order to deglycosylation that increased resveratrol yield. After treatment, the resveratrol yield significantly increased from 2.72 to 9.49 mg/g, while the piceid contents decreased from 8.60 to 0 mg/g. The result provides an efficient method to convert piceid in the extracts of P. cuspidatum root into resveratrol by cellulase.

Plant–soil interactions regulate the identity of soil carbon in invaded ecosystems: implication for legacy effects

Summary Introduced, invasive plants can alter local soil chemistry and microbial communities, but the underlying mechanisms and extent of these changes are largely unknown. Based on characteristics associated with invasiveness in plants, it was hypothesized that introduced species that produce large amounts of litter with distinctive secondary compounds can a) alter the chemistry of both extractable and bulk carbon in the soil, b) shift microbial communities towards microbes better able to metabolize the compounds in the litter and c) cause soil carbon chemistry and microbial communities to shift to relatively uniform, novel states at multiple sites. Composition of phenolics in senescent tissues (leaves and roots) of Polygonum cuspidatum was compared to the composition of extractable phenolics and non‐extractable bulk organic carbon in soils under and adjacent to large, long‐established stands of P. cuspidatum at four sites in the eastern U.S. Rates of degradation of phenolics, activities of enzymes associated with the breakdown of phenolics and shifts in microbial community composition were also measured at the sites. Soils under P. cuspidatum stands contained twice as much phenolics as adjacent soils, but the composition of phenolics differed greatly between soils under stands and senescent tissues of P. cuspidatum. Flavonoids and proanthocyanidins constituted >90% of the identified phenolics in P. cuspidatum tissues, whereas monophenolic compounds accounted for >90% of the phenolics in soils under stands. Soils under and adjacent to stands also exhibited distinctive compositions of relatively persistent bulk organic carbon; composition differed less between soils under stands at different sites than between soils under and adjacent to stands at the same site. Soils under P. cuspidatum had 2·8 times greater abundance of fungi than soils adjacent to stands, and fungal markers showed clear separation of soils under and adjacent to P. cuspidatum. However, the potential activity of enzymes that degrade polyphenols was lower in soils under stands. Exogenously applied, chemically complex polyphenols persisted in both P. cuspidatum‐invaded and adjacent non‐invaded soils, whereas less complex compounds rapidly disappeared from both soils. Synthesis. Results suggest that interactions between plant inputs, abiotic reactions and biotic transformations may create and maintain new states in invaded soils that are chemically and biologically less diverse. In the case of polyphenol‐rich, fast‐growing invasive species, these interactions may alter the composition of bulk soil organic matter that has relatively slower turnover rates, resulting in legacy effects. Restoration could thus require, not just removal of the species, but also post‐removal interventions such as soil amendments.

Determination of polydatin by gold nanoparticle-enhanced chemiluminescence of silver nitrate and luminol

ABSTRACTA novel flow injection method for the determination of polydatin is reported based on the inhibition of silver nitrate, luminol, and gold nanoparticles chemiluminescence. Under the optimum condition, the decrease in chemiluminescence was proportional to the concentration of polydatin from 1.0 × 10−8 to 1.0 × 10−5 mol/L. The detection limit was 2.1 × 10−9 mo1/L and the relative standard deviation was 2.1% for the determination of 1.0 × 10−6 mol/L polydatin. This method was successfully employed for the determination of polydatin in Polygonum cuspidatum roots and human urine.

Extraction of polydatin and resveratrol from Polygonum cuspidatum root: Kinetics and modeling

The biochemical activities of polydatin and resveratrol have been proven to own considerable medicinal potential. However, the extraction processes are yet to be fully characterized. This study explores particularly the optimization and kinetics of polydatin and resveratrol extraction from Rhizoma Et Radix Polygoni Cuspidati (the root of Polygonum cuspidatum) in agitation extractions by ethanol and water mixtures. The effects of the parameters on several extraction processes have been fully investigated. The optimized condition for polydatin was found at 0.4 mole fraction of ethanol as the extraction solvents, temperature 323K, agitation speed 500rpm and solid to solvent ratio of 1:90. However, the optimized condition for resveratrol was 0.4 mole fraction of ethanol, temperature 323K, agitation speed 800rpm, solid to solvent ratio of 1:120. Furthermore, the extraction kinetics behavior of polydatin and resveratrol follows a first order kinetics with diffusion coefficient ranging from 3.59×10−11 to 7.53×10−11m2s−1 and 3.90×10−11 to 10.10×10−11m2s−1 for polydatin and resveratrol respectively. The values of activation energy for the extraction were found to be 3.96kJmol−1 for polydatin and 17.83kJmol−1 for resveratrol.

Inhibition of Epstein-Barr Virus Lytic Cycle by an Ethyl Acetate Subfraction Separated from Polygonum cuspidatum Root and Its Major Component, Emodin

Polygonum cuspidatum is widely used as a medicinal herb in Asia. In this study, we examined the ethyl acetate subfraction F3 obtained from P. cuspidatum root and its major component, emodin, for their capacity to inhibit the Epstein-Barr virus (EBV) lytic cycle. The cell viability was determined by the MTT [3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyltetrazolium bromide] method. The expression of EBV lytic proteins was analyzed by immunoblot, indirect immunofluorescence and flow cytometric assays. Real-time quantitative PCR was used to assess the EBV DNA replication and the transcription of lytic genes, including BRLF1 and BZLF1. Results showed that the F3 and its major component emodin inhibit the transcription of EBV immediate early genes, the expression of EBV lytic proteins, including Rta, Zta, and EA-D and reduces EBV DNA replication, showing that F3 and emodin are potentially useful as an anti-EBV drug.

In Vitro and in Vivo Studies of the Inhibitory Effects of Emodin Isolated from Polygonum cuspidatum on Coxsakievirus B4

The lack of effective therapeutics for Coxsackievirus B4 (CVB4) infection underscores the importance of finding novel antiviral compounds. Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is one of the natural anthraquinone derivatives obtained from the root and rhizome of Polygonum cuspidatum. In the present study, the possibility of using emodin as a potential antiviral to treat CVB4 infection was explored in vitro and in mice. Emodin reduced CVB4 entry and replication on Hep-2 cells in a concentration- and time-dependent manner, with a 50% effective concentration (EC50) of 12.06 μM and selectivity index (SI) of 5.08, respectively. The inhibitory effect of emodin for CVB4 entry and replication was further confirmed by a quantitative real time PCR (qPCR) assay. The results further showed that the mice orally treated with different dosages of emodin displayed a dose dependent increase of survival rate, body weight and prolonged mean time of death (MTD), accompanied by significantly decreased myocardial virus titers and pathologic scores/lesions. Moreover, emodin could inhibit CVB4-induced apoptosis in vitro and in vivo. Our results indicated that emodin could be used as potential antiviral in the post-exposure prophylaxis for CVB4 infection.

Biotransformation of polydatin to resveratrol in Polygonum cuspidatum roots by highly immobilized edible Aspergillus niger and Yeast

A new biotransformation method of producing resveratrol with co-immobilized edible Aspergillus niger and Yeast (AY) was investigated. The biotransformation conditions were optimized for the resveratrol production under 30°C, pH 6.5, 2days, liquid–solid ratio 12:1 (mL/g), the yield of resveratrol reached 33.45mg/g, which increased 11-fold to that of untreated one. The conversion rate of polydatin reached 96.7%. The residual activity of immobilized microorganism was 83.2% after used for 15 runs. The developed method could be an effectively alternative biotransformation method for producing resveratrol from the plants.

Cardiovascular effects of resveratrol

nema

Ultrasonic-Assisted Extraction of the Botanical Dietary Supplement Resveratrol and Other Constituents of Polygonum cuspidatum

The roots of Polygonum cuspidatum produce several phenolic compounds, including trans-resveratrol (1), trans-piceid (2), and emodin (3), and are a commercial source of the botanical dietary supplement 1. Ultrasonic-assisted extraction technology and conventional shaking extraction procedures were compared for the extraction of 1-3 from P. cuspidatum roots, using 50% ethanol as a food grade solvent. These compounds were extracted successfully, and their mass transfer coefficients were calculated by fitting the experimental results to a model derived from Fick's second law. The results indicated that ultrasonic-assisted extraction had higher mass transfer efficacies and extraction yields for 1-3 as compared with conventional shaking extraction. Under the extraction conditions used (extraction temperature 50 °C; ultrasonic power 150 W), yields of 3.5, 9.2, and 7.8 mg/g were obtained for 1-3, respectively.

Small-molecule STAT3 Signaling Pathway Modulators from Polygonum cuspidatum

Constitutively activated STAT3 plays a pivotal role in oncogenesis and metastasis in many human cancers, and STAT3 has been validated as a novel anticancer drug target. Thus, the identification of small molecules that modulate STAT3 activity could be of great therapeutic importance. The aim of this study was to isolate novel modulators of the STAT3 signaling pathway from the roots of Polygonum cuspidatum by bioassay-guided fractionation using a STAT3 reporter gene assay. 2-Methoxystypandrone (1), as well as three anthraquinones (2-4), were identified as major active components of P. cuspidatum. Compound 1 demonstrated a potent inhibitory effect on STAT3 activation and significantly inhibited cell proliferation of human breast cancer cells, especially those with constitutively activated STAT3 (IC₅₀ = 2.7-3.1 µM). The SAR analysis of quinone analogues suggested that the phenolic and carbonyl groups are the key structures contributing to their inhibitory activities against the STAT3 signaling.