Role of ectomycorrhizal colonization in enhancement of nutrients for survival of plants collected from mountainous cold stress areas.

BACKGROUND: Ectomycorrhizal (ECM and ECM-like) structures associated with plant root systems are a challenge for scientists. The dispersion pattern of roots within the soil profile and the nutritional conditions are both favourable factors to motivate the plants to make ECM associations. RESULTS: This study discusses the colonization of mycorrhizal associations in Kobresia and Polygonum species including Polygonum viviparum, Kobresia filicina, K. myosuroides, Alnus nitida, Betula pendula, Pinus sylvestris, and Trifolium repens grown naturally in cold stressed soils of Gilgit-Baltistan (high-altitude alpine Deosai plains), Hazara, Swat, Dir, and Bajaur. Sieved soil batches were exposed to +5 °C (control), -10, -20, -30, -40, -50, -125 °C for 5 h, and selected plants were sown to these soils for 10 weeks under favourable conditions for ECM colonization. Ectomycorrhizal associations were examined in the above mentioned plants. Some ECM fungi have dark mycelia that look like the mantle and Hartig net. Examples of these are Kobresia filicina, K. myosuroides, and Polygonum viviparum. Findings of this study revealed that K. myosuroides excelled in ECM root tip length, dry mass, and NH4 concentration at -125 °C. Contrarily, A. nitida demonstrated the lower values, indicated its minimum tolerance. Notably, T. repens boasted the highest nitrogen concentration (18.7 ± 1.31 mg/g), while P. sylvestris led in phosphorus (3.2 ± 0.22 mg/g). The B. pendula showed the highest potassium concentration (9.4 ± 0.66 mg/g), emphasising species-specific nutrient uptake capabilities in extreme cold conditions. The PCA analysis revealed that the parameters, e.g., NH4 in soil mix (NH4), NO3 in soil mix (NO3), phosphorus in soil in species of Polygonum viviparum, Kobresia filicina, K. myosuroides, Alnus nitida, Betula pendula, Pinus sylvestris, and Trifolium repens are most accurately represented in cases of + 5 °C, -10 °C, and -20 °C temperatures. On the other hand, the parameters for ECM root tips (ECM) and Dry Mass (DM) are best described in -40 °C, -50 °C, and - 125 °C temperatures. All parameters have a strong influence on the variability of the system indicated the efficiency of ECM. The heatmap supported the nutrients positively correlated with ECM colonization with the host plants. CONCLUSION: At lower temperatures, hyphae and spores in roots were reduced, while soluble phosphorus concentrations of leaves were increased in cold stress soils. Maximum foliar nutrient concentrations were found in K. myosuroides at the lowest temperature treatments due to efficient functioning and colonization of ECM.

A comprehensive investigation on the chemical changes of traditional Chinese medicine with classic processing technology: Polygonum multiflorum under nine cycles of steaming and sunning as a case study.

The processing of traditional Chinese medicine (TCM) plays an important role in the clinical application, which usually has the function of "increasing efficiency and reducing toxicity". Polygonum multiflorum (PM) has been reported to induce hepatotoxicity, while it is believed that the toxicity is reduced after processing. Studies have shown that the hepatotoxicity of PM is closely related to the changes in chemical components before and after processing. However, there is no comprehensive investigation on the chemical changes of PM during the processing progress. In this research, we established a comprehensive method to profile both small molecule compounds and polysaccharides from raw and different processed PM samples. In detail, an online two-dimensional liquid chromatography coupled with quadrupole-orbitrap mass spectrometry (2D-LC/Q-Orbitrap MS) was utilized to investigate the small molecules, and a total of 150 compounds were characterized successfully. After multivariate statistical analysis, 49 differential compounds between raw and processed products were screened out. Furthermore, an accurate and comprehensive method for quantification of differential compounds in PM samples was established based on ultra-high performance liquid chromatography/Q-Orbitrap-MS (UHPLC/Q-Orbitrap-MS) within 16 min. In addition, the changes of polysaccharides in different PM samples were analyzed, and it was found that the addition of black beans and steaming times would affect the content and composition of polysaccharides in PM significantly. Our work provided a reference basis for revealing the scientific connotation of the processing technology and increasing the quality control and safety of PM.

Phytochemical profiling, in vitro biological activities, and in silico (molecular docking and absorption, distribution, metabolism, excretion, toxicity) studies of Polygonum cognatum Meissn.

Polygonum cognatum Meissn, a perennial herbaceous belonging to the Polygonaceae family, is an aromatic plant. High-performance liquid chromatography/diode array detector method was developed and validated for the phytochemical analysis of the plant. Also, various methods were used to investigate the antioxidant, antimicrobial, and cytotoxic activities of the methanolic extracts. Antioxidant activities were researched by 2,2'-diphenyl-1-picrylhydrazyl and cupric reducing antioxidant capacity methods. Among the tested standard microbial strains, Candida albicans was found to be more sensitive with a 24.60 ± 0.55 mm inhibition zone according to the diffusion tests. In the microdilution tests, the minimum inhibitory concentration and minimum bactericidal/fungicidal concentration values were 4.75 and ≥ 4.75 mg/mL, respectively, for all tested pathogens. Human colon carcinoma cells were used to investigate cytotoxicity by using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide analysis (IC50  = 2891 µg/mL for Plant A, IC50  = 3291 µg/mL for Plant B). Molecular docking and absorption, distribution, metabolism, excretion, and toxicity analysis were used to explain inhibition mechanisms of major phenolic compounds of plants against Tankyrase 1, Tankyrase 2 enzymes, and deoxyribonucleic acid gyrase subunit B and found compatible with experimental results.

Screening anti-anaphylactoid components in Polygonum cuspidatum via cell membrane chromatography with LC-MS targeting Mas-related G protein-coupled receptor X2.

Mas-related G protein-coupled receptor X2 (MrgprX2) is acknowledged as a mast cell-specific receptor, playing a crucial role in orchestrating anaphylactoid responses through mast cell degranulation. It holds promise as a target for regulating allergic and inflammatory diseases mediated by mast cells. Polygonum cuspidatum (PC) has shown notable anti-anaphylactoid effects, while its pharmacologically active components remain unclear. In this study, we successfully utilized MrgprX2 high-expressing cell membrane chromatography (CMC), in conjunction with liquid chromatography-mass spectrometry (LC-MS), to identify active anti-anaphylactoid components in PC. Our study pinpointed polydatin, resveratrol, and emodin-8-O-ß-d-glucoside as potential anti-anaphylactoid compounds in PC. Their anti-anaphylactoid activities were evaluated through ß-aminohexosidase and histamine release assays, demonstrating a concentration-dependent inhibition for both ß-aminohexosidase and histamine release. This approach, integrating MrgprX2 high-expression CMC with LC-MS, proves effective in screening potential anti-anaphylactoid ingredients in natural herbal medicines. The findings from this study illuminated the anti-anaphylactoid properties of specific components in PC and provided an efficient method for the drug development of natural products.

Evaluation of antidiabetic and antioxidant effects of Polygonum cognatum Meisn. and phytochemical analysis of effective extracts.

Polygonum cognatum Meisn. (Polygonaceae) is used both as food and as a folk medicine to treat diabetes. This study aimed to evaluate the effect of the extracts, along with isolated compounds, from P. cognatum aerial parts on diabetes. In vitro studies were conducted using an α-glucosidase inhibitory assay, while in vivo antidiabetic studies were carried out on streptozotocin-induced diabetic rats. Effective extracts were subjected to isolation studies, and structures of the compounds were elucidated by spectroscopic methods. The ethyl acetate and n-butanol extracts had the highest effect in both in vitro and in vivo experiments. They also decreased aspartate transaminase, alanine transaminase and malondialdehyde levels, while increasing glutathione and superoxide dismutase activity in rats. From the active extracts, 11 phenolic compounds were isolated and characterized. Among the isolated compounds, quercetin was found to be the most active according to α-glucosidase inhibitory activity studies. This study provided scientific evidence for the traditional use of P. cognatum as a folk medicine for treating diabetes. The findings suggest that the ethyl acetate and n-butanol extracts, as well as quercetin, have the potential for development as antidiabetic agents.

Thrombin-targeted screening of anticoagulant active components from Polygonum amplexicaule D. Don var. sinense Forb by affinity ultrafiltration coupled with UPLC-Q-TOF-MS.

INTRODUCTION: Polygonum amplexicaule D. Don var. sinense Forb (PAF), a medicinal plant, has the effect of promoting blood circulation and removing blood stasis. However, the active compounds and targets of its anticoagulant effect are still unclear. OBJECTIVES: This study aims to establish an effective reversely thrombin-targeted screening method for anticoagulant active components in PAF by affinity ultrafiltration (AUF) coupled with ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectroscopy (UPLC-Q-TOF-MS). METHODS: Different polar parts of PAF were screened for potential thrombin ligands by AUF-HPLC and identified by UPLC-Q-TOF-MS. After studying the affinity between ligands and thrombin by molecular docking, the antithrombotic activity of ligands was detected in vivo by zebrafish thrombus model, and in vitro by chromogenic substrate method. The mechanism of such ligands on thrombin was further studied by coagulation factor assay. RESULTS: Eleven potential thrombin ligands from PAF were screened by the AUF-UPLC-Q-TOF-MS method, and two compounds (butyl gallate and ß-sitosterol) with significant anticoagulant activity were discovered via in vitro and in vivo activity testing. CONCLUSION: A method system based on AUF-UPLC-Q-TOF-MS, molecular docking and in vivo and in vitro experiments also provided a powerful tool for further exploration of anticoagulant active components in PAF.

Screening of Key Components for Melanogenesis Inhibition of Polygonum cuspidatum Extract Based on the Spectrum-Effect Relationship and Molecular Docking.

Polygonum cuspidatum (PC) extract has been listed in the "Catalog of Used Cosmetic Ingredients (2021 Edition)", which can inhibit melanogenesis, thus exerting a whitening effect, and has been widely used in cosmetics. However, there are currently no quality standards for PC extract used in cosmetics, and the bioactive components associated with anti-melanogenesis remain unclear. In view of this, the present study was the first to investigate the spectrum-effect relationship between fingerprints of PC extract and melanogenesis inhibition. Ten batches of PC extract fingerprints were established by HPLC. Pearson's correlation analysis, gray correlation analysis (GRA) and orthogonal partial least squares regression analysis (OPLSR) were used to screen out resveratrol, emodin and physcion as the main whitening active ingredients using the inhibition of tyrosinase in B16F10 cells as the pharmacological index. Then, the melanogenesis inhibitory effects of the above three components were verified by tyrosinase inhibition and a melanin content assay in B16F10 cells. The interaction between small molecules and proteins was investigated by the molecular docking method, and it was confirmed by quantitative real-time PCR (qRT-PCR) that resveratrol, emodin and physcion significantly down-regulated the transcript levels of melanogenesis-related factors. In conclusion, this study established a general model combining HPLC fingerprinting and melanogenesis inhibition and also analyzed the spectrum-effect relationship of PC extract, which provided theoretical support for the quality control of PC extract in whitening cosmetics.

Total Mineral Content in Raw Materials of Ten Medicinal Plants from Roadside Biotopes of Voronezh Oblast.

The total mineral content was studied in medicinal plants from roadside and railside biotopes of the Voronezh region. Pharmacopoeial plant raw materials of 10 species were evaluated: roots of Taraxacum officinale F.H. Wigg and Arctium lappa L.; herb of Polygonum aviculare L., Artemisia absinthium L., Leonurus quinquelobatus Gilib., and Achillea millefolium L.; leaves of Urtica dioica L. and Plantago major L.; and flowers of Tanacetum vulgare L. and Tilia cordata Mill. Plant raw materials were collected near roads and railways of various types in the periods specified in regulatory documents. The total ash content in plant material was used to determine the minimum allowable distances from various roads and railways for collecting plant material. The minimum allowable distance from heavy-traffic motorways was recommended to be 210 m in the forest zone, 240 m in the forest-steppe zone, and 380 m in the steppe zone. A distance of at least 80 m was recommended for secondary low-speed roads and railways.

The relative impact of parental and current environment on plant transcriptomes depends on type of stress and genotype.

Through developmental plasticity, an individual organism integrates influences from its immediate environment with those due to the environment of its parents. While both effects on phenotypes are well documented, their relative impact has been little studied in natural systems, especially at the level of gene expression. We examined this issue in four genotypes of the annual plant Persicaria maculosa by varying two key resources-light and soil moisture-in both generations. Transcriptomic analyses showed that the relative effects of parent and offspring environment on gene expression (i.e. the number of differentially expressed transcripts, DETs) varied both for the two types of resource stress and among genotypes. For light, immediate environment induced more DETs than parental environment for all genotypes, although the precise proportion of parental versus immediate DETs varied among genotypes. By contrast, the relative effect of soil moisture varied dramatically among genotypes, from 8-fold more DETs due to parental than immediate conditions to 10-fold fewer. These findings provide evidence at the transcriptomic level that the relative impacts of parental and immediate environment on the developing organism may depend on the environmental factor and vary strongly among genotypes, providing potential for the interplay of these developmental influences to evolve.

Paenibacillus polygoni sp. nov., an endophytic bacterium isolated from Polygonum lapathifolium L. in wetland.

A Gram-stain-positive, aerobic, rod-shaped, non-motile, yellowish and glossy strain, C31T, was isolated from a wetland plant Polygonum lapathifolium L. located south of Poyang Lake, Jiangxi Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain C31T showed similarity values of lower than 97.0 % to other type species belonging to the genus Paenibacillus. The genomic average nucleotide identity values between strain C31T and its reference type species ranged from 68.9-70.9 % and the digital DNA-DNA hybridization values were lower than 27.8 %. The genomic DNA G+C content of strain C31T was 41.9 mol%. The optimal growth temperature, pH and NaCl concentration were 37 °C, pH 7 and 0.5 %, respectively. The major cellular fatty acids (>5.0 %) of strain C31T were anteiso-C15 : 0 (73.7 %), anteiso-C17 : 0 (8.4 %) and iso-C15 : 0 (5.2 %). The polar lipids of strain C31T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unidentified phospholipids. The respiratory quinone was MK-7. Based on these phylogenetic and phenotypic characterizations, strain C31T represents a novel species within the genus Paenibacillus. Therefore, the proposed name for this newly identified species is Paenibacillus polygoni sp. nov. and the type strain is C31T (=CCTCC AB 2022349T=KCTC 43565T).

Molecular cloning and in silico analysis of chalcone isomerase from Polygonum minus.

BACKGROUND: Chalcone isomerase (CHI; EC 5.5.1.6) is one of the key enzymes in the flavonoid biosynthetic pathway that is responsible for the intramolecular cyclization of chalcones into specific 2S-flavanones. METHODS AND RESULTS: In this study, the open reading frame (ORF) of CHI was successfully isolated from the cDNA of Polygonum minus at 711-bp long, encoding for 236 amino acid residues, with a predicted molecular weight of 25.4 kDa. Multiple sequence alignment and phylogenetic analysis revealed that the conserved residues (Thr50, Tyr108, Asn115, and Ser192) in the cleft of CHI enzyme group active site are present in PmCHI protein sequence and classified as type I. PmCHI comprises more hydrophobic residues without a signal peptide and transmembrane helices. The three-dimensional (3D) structure of PmCHI predicted through homology modeling was validated by Ramachandran plot and Verify3D, with values within the acceptable range of a good model. PmCHI was cloned into pET-28b(+) plasmid, expressed in Escherichia coli BL21(DE3) at 16 °C and partially purified. CONCLUSION: These findings contribute to a deeper understanding of the PmCHI protein and its potential for further characterization of its functional properties in the flavonoid biosynthetic pathway.

Ultra-high performance liquid chromatography-quadrupole/time-of-flight mass spectrometry-based lipidomics reveals key lipid molecules as potential therapeutic targets of Polygonum cuspidatum against hyperlipidemia in a hamster model.

Polygonum cuspidatum is a homology of traditional medicine and functional food widely distributed around the world. Our previous study on the hyperlipidemic animal model demonstrated that Polygonum cuspidatum was effective in ameliorating hyperlipidemia, which is characterized by lipid disorders. Herein, the regulatory effect of Polygonum cuspidatum on lipid metabolism needs to be known if its hypolipidemic mechanism is desired to clarify. In this study, an ultra-high performance liquid chromatography-quadrupole/time-of-flight mass spectrometry-based lipidomic strategy was first applied to investigate the lipidomic patterns of high-fat diet-induced hyperlipidemic hamsters when treated with Polygonum cuspidatum. The results showed that Polygonum cuspidatum improved the lipidomic profile of hyperlipidemia. A total of 65 differential lipids related to the hypolipidemic effect of Polygonum cuspidatum were screened out and identified, and these differential lipids covered various categories, such as phosphatidylcholines, phosphatidylethanolamines, triacylglycerols, sphingomyelins and so on. Orally administrated Polygonum cuspidatum restored these differential lipids back to normal or nearly normal levels. This study adopted lipidomics to reveal the key lipid molecules as potential therapeutic targets of Polygonum cuspidatum against hyperlipidemia, which would provide a scientific basis for its clinical application.

Discovery of the potential neuraminidase inhibitors from Polygonum cuspidatum by ultrafiltration combined with mass spectrometry guided by molecular docking.

Neuraminidase is an important target in the treatment of the influenza A virus. Screening natural neuraminidase inhibitors from medicinal plants is crucial for drug research. This study proposed a rapid strategy for identifying neuraminidase inhibitors from different crude extracts (Polygonum cuspidatum, Cortex Fraxini, and Herba Siegesbeckiae) using ultrafiltration combined with mass spectrometry guided by molecular docking. Firstly, the main component library of the three herbs was established, followed by molecular docking between the components and neuraminidase. Only the crude extracts with numbers of potential neuraminidase inhibitors identified by molecular docking were selected for ultrafiltration. This guided approach reduced experimental blindness and improved efficiency. The results of molecular docking indicated that the compounds in Polygonum cuspidatum demonstrated good binding affinity with neuraminidase. Subsequently, ultrafiltration-mass spectrometry was employed to screen for neuraminidase inhibitors in Polygonum cuspidatum. A total of five compounds were fished out, and they were identified as trans-polydatin, cis-polydatin, emodin-1-O-ß-D-glucoside, emodin-8-O-ß-D-glucoside, and emodin. The enzyme inhibitory assay showed that they all had neuraminidase inhibitory effects. In addition, the key residues of the interaction between neuraminidase and fished compounds were predicted. In all, this study could provide a strategy for the rapid screening of the potential enzyme inhibitors from medicinal herbs.

Polygonum sibiricum polysaccharides exert the antidepressant-like effects in chronic unpredictable mild stress-induced depressive mice by modulating microbiota-gut-brain axis.

Polygonum sibiricum polysaccharides (PSP) are one of the main active components of Polygonatum sibiricum, which is a traditional Chinese medicine with food and drug homologies. Recent studies have revealed the antidepressant-like effects of PSP. However, the precise mechanisms have not been clarified. Therefore, the present study was conducted to explore that whether PSP could exert the antidepressant-like effects via microbiota-gut-brain (MGB) axis in chronic unpredictable mild stress (CUMS)-induced depressive mice by transplantation of fecal microbiota (FMT) from PSP administration mice. FMT markedly reversed the depressive-like behaviors of CUMS-induced mice in the open field, the sucrose preference, the tail suspension, the forced swimming, and the novelty-suppressed feeding tests. FMT significantly increased the levels of 5-hydroxytryptamine and norepinephrine, decreased the levels of the pro-inflammatory cytokines in the hippocampus and reduced the levels of corticosterone, an adrenocorticotropic-hormone, in the serum of CUMS-induced mice. In addition, administration of PSP and FMT significantly increased the expressions of ZO-1 and occludin in the colon and decreased the levels of lipopolysaccharide and interferon-γ in the serum of CUMS-induced mice. Moreover, administration of PSP and FMT regulated the signaling pathways of PI3K/AKT/TLR4/NF-κB and ERK/CREB/BDNF. Taken together, these findings indicated that PSP exerted antidepressant-like effects via the MGB axis.

Polygonum orientale L. Alleviates Myocardial Ischemia-Induced Injury via Activation of MAPK/ERK Signaling Pathway.

Although Polygonum orientale L. (PO) has a beneficial effect on treatment of myocardial ischemia (MI), its mechanism remains unclear. This study aimed to explore the pharmacological mechanism of PO against MI through MAPK signaling pathways. Firstly, the therapeutic effect of PO was evaluated for treatment of MI mice. Using Western blot and immunohistochemistry, the influence of PO on MAPK signaling pathways and cell apoptosis was investigated. Subsequently, one key pathway (ERK) of MAPK signaling pathways was screened out, on which PO posed the most obvious impact. Finally, an inhibitor of ERK1/2 was utilized to further verify the regulatory effect of PO on the MAPK/ERK signaling pathway. It was found that PO could reduce the elevation of the ST segment; injury of heart tissue; the activity of LDH, CK, NOS, cNOS and iNOS and the levels of NO, BNP, TNF-α and IL-6. It is notable that PO could significantly modulate the protein content of p-ERK/ERK in mice suffering from MI but hardly had an effect on p-JNK/JNK and p-p38/p38. Additionally, the expressions of bax, caspase3 and caspase9 were inhibited in heart tissue in the PO-treated group. To evaluate whether ERK1/2 inhibitor (PD98059) could block the effect of PO on treatment of MI, both PO and PD98059 were given to mice with MI. It was discovered that the inhibitor indeed could significantly reverse the regulatory effects of PO on the above indicators, indicating that PO could regulate p-ERK/ERK. This study provides experimental evidence that PO extenuates MI injury, cardiomyocyte apoptosis and inflammation by activating the MAPK/ERK signaling pathway.

Preparation of Solid Dispersion of Polygonum Cuspidatum Extract by Hot Melt Extrusion to Enhance Oral Bioavailability of Resveratrol.

The aim of this study was to improve the solubility, bioavailability, and stability of resveratrol (RES-SD) Solid Dispersion in Polygonum cuspidatum extract (PCE) by hot melt extrusion (HME). In addition, the role of the auxiliary substances in PCE was also studied. The solid dispersion of Polygonum cuspidatum extract was prepared by hot-melt extrusion. The optimum formula was selected by single factor design and orthogonal test. The optimum formula was barrel temperature 140 °C, screw rotation speed 40 rpm/min, and the ratio of Polygonum cuspidatum extract to HPMCAS was 1:2. The dissolution test showed that PCE-SD increased the dissolution of RES from 46.75 ± 0.47% to 130.06 ± 0.12%. The pharmacokinetics curve of rats showed that PCE-SD increased AUC0-t of RES from 111,471.22 ± 11.4% to 160,458.968 ± 15.7%, indicating an approximately 1.44-fold increase in absorption. In addition, the rotation speed of PCE-SD screw is less than that of RES-SD screw. The bioavailability of PCE-SD was slightly better than that of RES-SD. PCE-SD is more hygroscopic than RES-SD. PCE-SD increased the solubility and oral bioavailability of RES. The auxiliary substances in Polygonum cuspidatum extract have influence on its preparation technology, stability, and bioavailability.

Evaluation of the Biological Properties of an Optimized Extract of Polygonum cuspidatum Using Ultrasonic-Assisted Extraction.

Phytochemicals are natural compounds found in plants that have potential health benefits such as antioxidants, anti-inflammatory and anti-cancer properties, and immune reinforcement. Polygonum cuspidatum Sieb. et Zucc. is a source rich in resveratrol, traditionally consumed as an infusion. In this study, P. cuspidatum root extraction conditions were optimized to increase antioxidant capacity (DPPH, ABTS+), extraction yield, resveratrol concentration, and total polyphenolic compounds (TPC) via ultrasonic-assisted extraction using a Box-Behnken design (BBD). The biological activities of the optimized extract and the infusion were compared. The optimized extract was obtained using a solvent/root powder ratio of 4, 60% ethanol concentration, and 60% ultrasonic power. The optimized extract showed higher biological activities than the infusion. The optimized extract contained 16.6 mg mL-1 resveratrol, high antioxidant activities (135.1 µg TE mL-1 for DPPH, and 230.4 µg TE mL-1 for ABTS+), TPC (33.2 mg GAE mL-1), and extraction yield of 12.4%. The EC50 value (effective concentration 50) of the optimized extract was 0.194 µg mL-1, which revealed high cytotoxic activity against the Caco-2 cell line. The optimized extract could be used to develop functional beverages with high antioxidant capacity, antioxidants for edible oils, functional foods, and cosmetics.

Ethanolic Extract of Polygonum minus Protects Differentiated Human Neuroblastoma Cells (SH-SY5Y) against H2O2-Induced Oxidative Stress.

Neuronal models are an important tool in neuroscientific research. Hydrogen peroxide (H2O2), a major risk factor of neuronal oxidative stress, initiates a cascade of neuronal cell death. Polygonum minus Huds, known as 'kesum', is widely used in traditional medicine. P. minus has been reported to exhibit a few medicinal and pharmacological properties. The current study aimed to investigate the neuroprotective effects of P. minus ethanolic extract (PMEE) on H2O2-induced neurotoxicity in SH-SY5Y cells. LC-MS/MS revealed the presence of 28 metabolites in PMEE. Our study showed that the PMEE provided neuroprotection against H2O2-induced oxidative stress by activating the Nrf2/ARE, NF-κB/IκB and MAPK signaling pathways in PMEE pre-treated differentiated SH-SY5Y cells. Meanwhile, the acetylcholine (ACH) level was increased in the oxidative stress-induced treatment group after 4 h of exposure with H2O2. Molecular docking results with acetylcholinesterase (AChE) depicted that quercitrin showed the highest docking score at -9.5 kcal/mol followed by aloe-emodin, afzelin, and citreorosein at -9.4, -9.3 and -9.0 kcal/mol, respectively, compared to the other PMEE's identified compounds, which show lower docking scores. The results indicate that PMEE has neuroprotective effects on SH-SY5Y neuroblastoma cells in vitro. In conclusion, PMEE may aid in reducing oxidative stress as a preventative therapy for neurodegenerative diseases.

Antiviral activities of Polygonum perfoliatum L. extract and related phenolic acid constituents against hepatitis B virus.

Chronic hepatitis B virus (HBV) infection is an important public health problem. Polygonum perfoliatum L. is a traditional medicinal herb and has been reported to have pharmacological activities such as anti-inflammatory, antibacterial, and antiviral. In this study, the antiviral activities and mechanisms of Polygonum perfoliatum L. extract against HBV and the effective components were investigated. The results showed that the total extract of Polygonum perfoliatum L. reduced the levels of HBV e antigen (HBeAg) secretion and the viral covalently closed circular DNA (CCC DNA) formation, but had little or no negative effects on viral capsid assembly and pregenomic RNA packaging. Further fractionation showed that the water extract (WE) fraction exerted comparable anti-HBV activities with the total extract, especially in inhibiting the CCC DNA formation and HBeAg production, indicating that the effective antiviral components are mainly distributed in this fraction. Further study showed that the phenolic acids constituents, protocatechuic acid, and gallic acid, but not ethyl caffeate, which is reported enriched in the WE fraction, showed strong anti-HBV activities in inhibiting viral core DNA synthesis, CCC DNA formation, and HBeAg production. These results suggested that the Polygonum perfoliatum L. total extract and the related phenolic acids like protocatechuic acid and gallic acid could inhibit HBV replication and also indicated the potential utility of Polygonum perfoliatum L. and related constituents as sources of novel antivirals against HBV.

Attraction of the Biocontrol Agent, Galerucella placida Towards Volatile Blends of Two Polygonaceae Weeds, Rumex dentatus and Polygonum glabrum.

The Polygonaceae weed, Rumex dentatus L. grows in association with wheat, mustard and potato, while Polygonum glabrum Willd. grows in association with rice in India. Both larvae and adults of Galerucella placida Baly (Coleoptera: Chrysomelidae) voraciously consume these weeds. Applications of synthetic herbicides to control weeds are harmful to the environment including beneficial organisms. We propose to find volatile organic compounds (VOCs) from both weeds causing attraction of the biocontrol agent, G. placida, in order to attempt to use the insect as a biological weed control. Behavioral responses of G. placida towards volatile blends characteristic of undamaged (UD), insect-damaged (ID), jasmonic acid-treated (JA) or mechanically-damaged (MD) plants were conducted by Y-tube olfactometer bioassays. Cuminaldehyde was predominant in VOCs of UD R. dentatus, ID P. glabrum, and both JA and MD R. dentatus and P. glabrum. Geraniol was predominant in VOCs of UD P. glabrum, while 1,3-diethylbenzene predominated in VOCs of ID R. dentatus. Females were more attracted towards volatile blends of ID plants compared to UD or JA plants. Females did not show attraction towards volatile blends of JA plants. We identified two bioactive synthetics blends, one comprised of seven compounds - 16.65 µg 1,3-diethylbenzene, 10.72 µg acetophenone, 6.52 µg 2,6-(E,Z)-nonadienal, 2.46 µg 1-nonanol, 4.19 µg decanal, 9.86 µg 4-ethylacetophenone and 3.34 µg 1-hexadecene dissolved in 25 µl CH2Cl2 and the other containing five compounds - 2.50 µg 2-octanol, 6.84 µg limonene, 0.64 µg dodecane, 6.63 µg 4-ethylacetophenone and 0.24 µg geranyl acetone dissolved in 25 µl CH2Cl2. These two blends of volatile compounds could be used to attract the biocontrol agent during early vegetative period of these two weeds, which could lead to eradication of weeds from crop fields.