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At least 235 records · Page 13Linked to original sources
PubMed2002

Induction of apoptosis by 3,4'-dimethoxy-5-hydroxystilbene in human promyeloid leukemic HL-60 cells.

3, 4'-Dimethoxy-5-hydroxystilbene (DMHS) is a hydroxystilbene compound obtained by methylation and acid hydrolysis of piceid (resveratrol-3-O-glucoside) from Polygonum cuspidatum. Herein, we report that DMHS induces programmed cell death or apoptosis in human promyelocytic leukemic HL-60 cells. We found that treatment of HL-60 cells with DMHS suppressed the cell growth in a concentration-dependent manner with an IC50 value of 25 microM. DMHS increased internucleosomal DNA fragmentation in a time-dependent manner. The cell death by DMHS was partially prevented by the caspase inhibitor, zVAD-fmk. DMHS caused activation of caspases such as caspase-3, -8, and -9. Immunoblot experiments revealed that DMHS-induced apoptosis was associated with the induction of Bax expression. The release of cytochrome c from mitochondria into the cytosol was increased in response to DMHS. Taken together, our present results indicated that DMHS leads to apoptotic cell death in HL-60 cells through increased Bax expression and release of cytochrome c into cytosol and may be considered as a good candidate for a cancer chemopreventive agent in humans.

Amino Acid Chloromethyl Ketones↗
PubMed2006

Uptake and exudation behavior of perchlorate in smartweed.

Perchlorate uptake has been reported in a variety of vascular plants, but the mechanisms affecting the uptake, translocation, and exudation of ClO4(-) in plants are not well known. The uptake and transport behavior of ClO4(-) was studied in smartweed (Polygonum spp.) grown in aerated hydroponic ClO4(-) solutions with or without other common anions. Uptake followed first-order kinetics (0.017 +/- 0.003 day(-1)) and there was no apparent competitive effect on ClO4(-) uptake for up to 500 mg L(-1) of NO3(-) -N, SO4(2-), PO4(3-), or Cl(-). The net ClO4(-) mass uptake was proportional to transpiration but with some exclusion of ClO4(-) from the transpiration stream. Up to 4% of the ClO4(-) in plants after a 30-d exposure to a 10-mg/L solution of ClO4(-) was exuded from the roots within 15 d after the exposure was ended. Perchlorate exudation followed first-order kinetics with a rate coefficient of 0.0018 +/- 0.0006 (day(-1) Results obtained in this study indicate that evapotranspiration may be the critical variable to predict accumulation potential in plants and that phytoremediation strategies should take into account the re-release potential of ClO4(-) via exudation.

Biodegradation, Environmental↗
PubMed2003

Soil contamination and plant uptake of heavy metals at polluted sites in China.

We investigated heavy metal contamination in soils and plants at polluted sites in China including some with heavy industries, metal mining, smelting and untreated wastewater irrigation areas. We report our main findings in this paper. The concentrations of heavy metals, including Cd and Zn, in the soils at the investigated sites were above the background levels, and generally exceeded the Government guidelines for metals in soil. The concentrations of metals in plants served to indicate the metal contamination status of the site, and also revealed the abilities of various plant species to take up and accumulate the metals from the soil. Substantial differences in the accumulation of heavy metals were observed among the plant species investigated. Polygonum hydropiper growing on contaminated soils in a sewage pond had accumulated 1061 mg kg(-1) of Zn in its shoots. Rumex acetosa L. growing near a smelter had accumulated more than 900 mg kg(-1) of Zn both in its shoots and roots. Therefore these species have potential for phytoremediation of metal-contaminated sites. Our results indicate the need to elucidate the dynamics of soil metal contamination of plants and the onward movement of metal contaminants into the food chain. Also our results indicate that the consumption of rice grown in paddy soils contaminated with Cd, Cr or Zn may pose a serious risk to human health, because from 24 to 22% of the total metal content in the rice biomass was concentrated in the rice grain. Platanus acerifolia growing on heavily contaminated soil accumulated only very low levels of heavy metals, and this mechanism for excluding metal uptake may have value in crop improvement. Sources of metal entering the environmental matrices studied included untreated wastewater, tailings or slurries and dust depositions from metal ore mining, and sewage sludge. Pb, Zn or Cd concentrations declined with the distance from metal smelter in accordance with a good exponential correlation (R2>0.9), and this shows that metal dust deposition is an important contributor to metal contamination of soils.

Biodegradation, Environmental↗
PubMed2003

Increase in leaf mass per area benefits plant growth at elevated CO2 concentration.

An increase in leaf mass per area (MLA) of plants grown at elevated [CO2] is often accompanied by accumulation of non-structural carbohydrates, and has been considered to be a response resulting from source-sink imbalance. We hypothesized that the increase in MLA benefits plants by increasing the net assimilation rate through maintaining a high leaf nitrogen content per area (NLA). To test this hypothesis, Polygonum cuspidatum was grown at ambient (370 micro mol mol-1) and elevated (700 micro mol mol-1) [CO2] with three levels of N supply. Elevated [CO2] significantly increased MLA with smaller effects on NLA and leaf mass ratio (fLM). The effect of change in MLA on plant growth was investigated by the sensitivity analysis: MLA values observed at ambient and elevated [CO2] were substituted into a steady-state growth model to calculate the relative growth rate (R). At ambient [CO2], substitution of a high MLA (observed at elevated [CO2]) did not increase R, compared with R for a low MLA (observed at ambient [CO2]), whereas at elevated [CO2] the high MLA always increased R compared with R at the low MLA. These results suggest that the increase in MLA contributes to growth enhancement under elevated [CO2]. The optimal combination of fLM and MLA to maximize R was determined for different [CO2] and N availabilities. The optimal fLM was nearly constant, while the optimal MLA increased at elevated [CO2], and decreased at higher N availabilities. The changes in fLM of actual plants may compensate for the limited plasticity of MLA.

Algorithms↗
PubMed2006

Are heat and cold resistance of arctic species affected by successive extreme temperature events?

Extreme temperature events are projected to increase in frequency in a future climate. As successive extremes could occur more frequently, patches of vulnerable tundra vegetation were exposed to two consecutive heat waves (HWs) of 10 d each, with a 5-d recovery period in between. Surface temperatures during the HWs were increased approximately 6 degrees C using infrared irradiation sources. In three of the four target species (Pyrola grandiflora, Polygonum viviparum and Carex bigelowii), plant conditions improved upon the first exposure. Depending on species, leaf relative growth, leaf chlorophyll content or maximal photochemical efficiency was increased. In P. grandiflora the positive effects of the heat on the photosynthetic apparatus led to augmented net photosynthesis. By contrast, Salix arctica responded mainly negatively, indicating species-specific responses. During the second HW, leaf mortality suddenly increased, indicating that the heat stress induced by the extreme events lasted too long and negatively influenced the species resistance to high temperature. After the HWs, when plants were exposed to (low) ambient temperatures again, plant performance deteriorated further, indicating possible loss of cold resistance.

Arctic Regions↗
PubMedDate not supplied

Accumulation of perchlorate in aquatic and terrestrial plants at a field scale.

Previous laboratory-scale studies have documented perchlorate ClO(-)(4) uptake by different plant species, but less information is available at field scale, where ClO(-)(4) uptake may be affected by environmental conditions, such as distance to streams or shallow water tables, exposure duration, and species. This study examined uptake of ClO(-)(4) in smartweed (Polygonum spp.) and watercress (Nasturtium spp.) as well as more than forty trees, including ash (Fraxinus greggii A. Gray), chinaberry (Melia azedarach L.), elm (Ulmus parvifolia Jacq.), willow (Salix nigra Marshall), mulberry [Broussonetia papyrifera (L.) Vent.], and hackberry (Celtis laevigata Willd.) from multiple streams surrounding a perchlorate-contaminated site. Results indicate a large potential for ClO(-)(4) accumulation in aquatic and terrestrial plants, with ClO(-)(4) concentration in plant tissues approximately 100 times higher than that in bulk water. Perchlorate accumulation in leaves of terrestrial plants was also dependent on species, with hackberry, willow, and elm having a strong potential to accumulate ClO(-)(4). Generally, trees located closer to the stream had a higher ClO(-)(4) accumulation than trees located farther away from the stream. Seasonal leaf sampling of terrestrial plants indicated that ClO(-)(4) accumulation also was affected by exposure duration, with highest accumulation observed in the late growing cycle, although leaf concentrations for a given tree were highly variable. Perchlorate may be re-released into the environment via leaching and rainfall as indicated by lower perchlorate concentrations in collected leaf litter. Information obtained from this study will be helpful to understand the fate of ClO(-)(4) in macrophytes and natural systems.

Nasturtium↗
PubMed1998

[Pharmacognostical identification on Chinese drug zhizhuliao].

In this paper, 2 kinds of Zhizhuliao that original plants are Polygonum suffultum Maxim., P. amplexicaule D. Don. var. sinense Forb. et Hemal. are made an initial study on the characteristics, microscopical and physichemical sides. It provides scientific basis for its comprehensive development and ultilization, and to use in clinical.

Chromatography, Thin Layer↗
PubMed1997

[Pharmacognostical identification on the Chinese drug quanshen].

In this paper, 5 kinds of Quanshen that original plants are Polygonum bistorta L., P. viviparum L., P. paleacum Wall., P. sphaerostachyum Meisn., P. macrophyllum D. Don. are made an initial study on the characteristics, microscopical and physichemistical sides. It provide scientific basis for its comprehensive development and ultilization, and to use in clinical.

Chromatography, Thin Layer↗
PubMed2003

[Study on the metabolite of stilbene glucoside in mice by liquid chromatography tandem-mass spectrometry].

AIM: To study the metabolite of stilbene glucoside in the Chinese traditional medicine Polygonum multiflornm in mice and elucidate its chemical structure by liquid chromatography tandem-mass spectrometry. METHODS: The stilbene glucoside was injected into the tail vein of mice. Blood samples were collected from artery in the eyepit. The methanol-protein-precipitated plasma sample was introduced into the liquid chromatography-tandem mass spectrometer directly. The analytical column was C18 column (250 mm x 4.6 mm ID, 5 microns). The mobile phase consisted of acetonitrile-methanol-water-formic acid (15:18:66:1) for ES+, acetonitrile-methanol-water (15:18:67) for ES-. The UV detection wavelength was set at 320 nm. The mass ion source type was ESI. HV capillary was 3 kV. The dry gas was nitrogen gas and the flow rate was set at 318 L.h-1. The ion source temperature was 150 degrees C. RESULTS: The stilbene glucoside and its metabolite were separated completely under the chromatography condition. The ions at m/z 600 and m/z 605 were detected under positive ion polarity while the ions at m/z 581 and m/z 402 were detected under negative ion polarity. CONCLUSION: It was proposed that the metabolite of stilbene glucoside injected in vein was its glucuronide conjugate.

Animals↗
PubMed2003

[Studies on the extraction of ingredients from Chinese traditional medicine with CO2 supercritical fluid].

OBJECTIVE: To study the extraction technology with CO2 supercritical fluid in Chinese Traditional Medicine by extracting the anthraquinones ingredients from Salvia miltiorrhiza and Polygonum caspidatum. METHOD: Extractions were made under different pressure, temperature, extraction time, entrainer, and the extracts were analyzied by TLC and HPLC. RESULT: The technology could be used in extraction and isolation. Under certain conditions, different contents of the extracts could be obtained. CONCLUSION: CO2 supercritical fluid is good at extracing low polarity ingredients, and it shows the evident individurity in extraction of Chinese herb. The technological factors in industrial usage must be thought of all over.

Abietanes↗
PubMedDate not supplied

New anticancer agents: in vitro and in vivo evaluation of the antitumor and antimetastatic actions of various compounds isolated from medicinal plants.

In this review, in the search for the development of new anticancer drugs, the effects of compounds isolated from various medicinal plants on tumor growth and metastasis, using mice bearing a highly metastatic drug-resistant mouse tumor, were studied. The antitumor and antimetastatic actions of stilbene derivatives isolated from Polygonum and Cassia species were examined. Among the stilbene derivatives, resveratrol and cassiagrol A (stilbene dimer) displayed antitumor and antimetastatic actions through the inhibition of tumor-induced neovascularization in in vitro and in vivo models. It was found that two chalcone derivatives from Angelica keiskei roots also inhibited tumor growth and metastasis in tumor-bearing mice through the inhibition of tumor-induced neovascularization and/or the inhibition of immune suppression caused by tumors. Recently, basidiomycete fungi have been used for the treatment of cancer. Then, the low molecular weight substances were isolated from Agaricus blazei and Ganoderma lucidum as antitumor and antimetastatic substances. It is suggested that these substances of basidiomycete also inhibited tumor growth and metastasis to the lung through the inhibition of tumor-induced neovascularization and/or the inhibition of immune suppression caused by tumors.

Agaricus↗
PubMed2005

Toxicological study of plant extracts on termite and laboratory animals.

Toxic activity of leaf extracts of Polygonum hydropiper L. and Pogostemon parviflorus Benth. were tested in the laboratory against tea termite, Odontotermes assamensis Holm. Both the tested extracts caused mortality of the termite. The highest toxic activity (100%) was found in the 2.0% chloroform extracts of P. hydropiper. The chloroform extract of P. hydropiper was explored for possible mammalian toxicological effects. The LD50 was 758.58 mg/kg in male albino mice. Subcutaneous injection of sub-lethal dose of extract into male mice once a week for 6 weeks failed to express any significant influence on WBC, RBC count and blood cholesterol.

Animals↗
PubMed2006

[Pharmacodynamic study of Relinqing granules on bacterial pyelonephritis model in rats].

OBJECTIVE: To observe the effects of Relinqing granules (powder of Polygonum capitatum extract) on the bacterial pyelonephritis model in rats. METHOD: The rat bacterial pyelonephritis model was induced by injecting the escherichia coli ATCC-25922 into kidney parenchyma. The rats were divided ramdamly into Relinqing groups(52.32, 26.16 g x kg(-1)), norflorin group (0.03 g x kg(-1)), model group and normal control group, and were given experimental drugs by gastrogavage. The contents of leucocytes (WBC), occult bloo (BLD), glucose (GLU), protein (PRO), ketones, bilirubin and urobilinagen in urine were determined. RESULT: As compared with the model group, Relinqing granules 6.0 g x kg(-1) (crude drug 52.32 g x kg(-1)) could decrease significantly the contents of WBC and BLD in urine and, however, had no markedly effects on the other biochemical parameters of urine. CONCLUSION: Relinqqing granule has significant effects of decreasing urine WBC and BLD on the bacterial pyolonephritis in rats.

Animals↗
PubMed2000

The ameliorating effects of the cognitive-enhancing Chinese herbs on scopolamine-induced amnesia in rats.

Ameliorating effects were investigated of the cognitive-enhancing Chinese herbs administered orally for 1 week-Panax ginseng (PG), Panax notoginseng (PNG), Dioscorea opposita (DO), Gastrodia elata (GE), Salvia miltiorrhiza (SM), Acorus gramineus (AG), Coptis chinensis (CC), Polygonum multiflorum (PM), Cyperus rotundus (CR) and Psoralea corylifolia (PC)-on the scopolamine (SCOP)-induced amnesia by using a passive avoidance task in rats. Of ten Chinese herbs, only PG, PNG, GE and CC prolonged the SCOP-shortened STL. These results revealed that PG, PNG GE and CC administered orally for 1 week improved the SCOP-induced learning and memory deficit in rats.

Administration, Oral↗
PubMed2005

Herbicide-resistant crops and weed resistance to herbicides.

The adoption of genetically modified (GM) crops has increased dramatically during the last 3 years, and currently over 52 million hectares of GM crops are planted world-wide. Approximately 41 million hectares of GM crops planted are herbicide-resistant crops, which includes an estimated 33.3 million hectares of herbicide-resistant soybean. Herbicide-resistant maize, canola, cotton and soybean accounted for 77% of the GM crop hectares in 2001. However, sugarbeet, wheat, and as many as 14 other crops have transgenic herbicide-resistant cultivars that may be commercially available in the near future. There are many risks associated with the production of GM and herbicide-resistant crops, including problems with grain contamination, segregation and introgression of herbicide-resistant traits, marketplace acceptance and an increased reliance on herbicides for weed control. The latter issue is represented in the occurrence of weed population shifts, the evolution of herbicide-resistant weed populations and herbicide-resistant crops becoming volunteer weeds. Another issue is the ecological impact that simple weed management programs based on herbicide-resistant crops have on weed communities. Asiatic dayflower (Commelina cumminus L) common lambsquarters (Chenopodium album L) and wild buckwheat (Polygonum convolvulus L) are reported to be increasing in prominence in some agroecosystems due to the simple and significant selection pressure brought to bear by herbicide-resistant crops and the concomitant use of the herbicide. Finally, evolution of herbicide-resistant weed populations attributable to the herbicide-resistant crop/herbicide program has been observed. Examples of herbicide-resistant weeds include populations of horseweed (Conyza canadensis (L) Cronq) resistant to N-(phosphonomethyl)glycine (glyphosate). An important question is whether or not these problems represent significant economic issues for future agriculture.

Adaptation, Physiological↗
PubMed2006

Evaluation of oriental medicinal herbs for estrogenic and antiproliferative activities.

Herb extracts commercially used in Asia were screened for their estrogenic activity with a recombinant yeast system with both a human estrogen receptor (ER) expression plasmid and a reporter plasmid. Pueraria lobata (flower) had the highest estrogenic relative potency (RP, 17-estradiol = 1.00) (7.8e-3) (RP for + control), followed by Amomum xanthioides (1.3e-3), Glycyrrhiza uralensis, Zingiber officinale, Rheum palmatum, Curcuma aromatica, Eriobotrya japonica, Sophora flavescens, Anemarrhena asphodeloides, Polygonum multiflorum and Pueraria lobata (root) (9.5e-4-1.0e-4), and Prunus persica, Lycoppus lucidus and Adenophora stricta (9.0e-5-8.0e-5). In the antiproliferative assay, five human cancer cell lines representing different tissues (breast, lung and ovary) were used. Eriobotrya japonica showed strong cytotoxicity in ER-negative breast cancer (MDA-MB-231), cervix epitheloid (HeLa) and lung (A549) carcinoma cell lines.

Asia↗
PubMed2004

Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction.

Here we describe a liquid chromatography/mass spectrometry (LC/MS) method with automated online extraction (LC/LC/MS) to simultaneously determine the in vitro inhibitory potency of herbal extracts on six major human drug-metabolising cytochrome P450 enzymes. Substrates were incubated with a commercially available mixture of CYP1A2/2C8/2C9/2C19/2D6 and 3A4 from baculovirus-infected insect cells and the resulting metabolites were quantified with LC/LC/MS using electrospray ionisation in the selected ion monitoring mode. Consistent inhibitory activities were obtained for known inhibitors and plant extracts using the enzyme/substrate cocktail and the individual enzymes/substrates. Popular herbal remedies including devil's claw root (Harpagophytum procumbens), feverfew herb (Tanacetum parthenium), fo-ti root (Polygonum multiflorum), kava-kava root (Piper methysticum), peppermint oil (Mentha piperita), eucalyptus oil (Eucalyptus globulus), red clover blossom (Trifolium pratense) and grapefruit juice (GJ; Citrus paradisi) could be identified as inhibitors of the applied CYP enzymes with IC(50) values between 20 and 1000 microg/mL.

Chemical Fractionation↗
PubMed1997

Extractability and nutritional value of leaf protein from tropical aquatic plants.

In a study conducted on the extraction of protein from the leaves of 30 freshwater aquatic plants, the highest standing crop fresh yield was found in Typha latifolia (2650 g/m2). The Bio-Medical Data Processing (BMDP) K-means clustering program with K = 2 showed that 11 of the 30 plants had a high protein nitrogen extractability as well as a high nitrogen content of the extracted protein. Among these, leaf protein from Allmania nodiflora had the highest content of crude protein (62.7%) and beta-carotene (782.4 micrograms/g). Leaf protein prepared from Hygrophila spinosa, Ottelia alismoides and Polygonum barbatum had low in-vitro digestibility. The levels of alkaloids and polyphenols were lower in the extracted protein compared to that present in the original leaf sample.

Dietary Proteins↗