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PubMed2002

Submergence research using Rumex palustris as a model; looking back and going forward.

Flooding is a phenomenon that destroys many crops worldwide. During evolution several plant species evolved specialized mechanisms to survive short- or long-term waterlogging and even complete submergence. One of the plant species that evolved such a mechanism is Rumex palustris. When flooded, this plant species is capable to elongate its petioles to reach the surface of the water. Thereby it restores normal gas exchange which leads to a better survival rate. Enhanced levels of ethylene, due to physical entrapment, is the key signal for the plant that its environment has changed from air to water. Subsequently, a signal transduction cascade involving at least four (classical) plant hormones, ethylene, auxin, abscisic acid, and gibberellic acid, is activated. This results in hyponastic growth of the leaves accompanied by a strongly enhanced elongation rate of the petioles enabling them to reach the surface. Other factors, among them cell wall loosening enzymes have been shown to play a role as well.

Abscisic Acid↗
PubMed2001

Resveratrol isolated from Polygonum cuspidatum root prevents tumor growth and metastasis to lung and tumor-induced neovascularization in Lewis lung carcinoma-bearing mice.

Resveratrol is a naturally occurring phytoalexine found in medicinal plants. We found that resveratrol, at doses of 2.5 and 10 mg/kg, significantly reduced the tumor volume (42%), tumor weight (44%) and metastasis to the lung (56%) in mice bearing highly metastatic Lewis lung carcinoma (LLC) tumors, but not at a dose of 0.6 mg/kg. Resveratrol did not affect the number of CD4(+), CD8(+) and natural killer (NK)1.1.(+) T cells in the spleen. Therefore, the inhibitory effects of resveratrol on tumor growth and lung metastasis could not be explained by natural killer or cytotoxic T-lymphocyte activation. In addition, resveratrol inhibited DNA synthesis most strongly in LLC cells; its 50% inhibitory concentration (IC(50)) was 6.8 micromol/L. Resveratrol at 100 micromol/L increased apoptosis to 20.6 +/- 1.35% from 12.1 +/- 0.36% (P < 0.05) in LLC cells, and decreased the S phase population to 22.1 +/- 1.03% and 29.2 +/- 0.27% from 35.2 +/- 1.72% (P < 0.05) at concentrations of 50 and 100 micromol/L, respectively. Resveratrol inhibited tumor-induced neovascularization at doses of 2.5 and 10 mg/kg in an in vivo model. Moreover, resveratrol significantly inhibited the formation of capillary-like tube formation from human umbilical vein endothelial cells (HUVEC) at concentrations of 10-100 micromol/L; the degree of the inhibition of capillary-like tube formation by resveratrol was 45.5% at 10 micromol/L, 50.2% at 50 micromol/L and 52.6% at 100 micromol/L. Resveratrol inhibited the binding of vascular endothelial growth factor (VEGF) to HUVEC at concentrations of 10-100 micromol/L, but not at concentrations of 1 and 5 micromol/L. The degree of inhibition of VEGF binding to HUVEC by resveratrol was 16.9% at 10 micromol/L, 53.2% at 50 micromol/L and 47.8% at 100 micromol/L. We suggest that the antitumor and antimetastatic activities of resveratrol might be due to the inhibition of DNA synthesis in LLC cells and the inhibition of LLC-induced neovascularization and tube formation (angiogensis) of HUVEC by resveratrol

Angiogenesis Inhibitors↗
PubMed1997

beta-Glucosidase in the indigo plant: intracellular localization and tissue specific expression in leaves.

beta-Glucosidase of indigo plant (Polygonum tinctorium) has a high substrate specificity for indican (indoxyl beta-D-glucoside). To examine the localization of this beta-glucosidase, we fractionated the cells of the leaves and analysed them immunocytochemically. Immunoelectron micrographs with specific antibodies against the beta-glucosidase clearly showed that the beta-glucosidase was localized in the stroma of the chloroplasts in mesophyll cells, but not in the thylakoid membrane. Chloroplasts were isolated from the crude homogenate of the fresh leaves by Percoll density gradient centrifugation and then subjected to suborganellar fractionation. beta-Glucosidase activity was specifically detected in the stromal fraction, but not in the thylakoid membrane. This was also supported by the result of an immunoblot of the fraction with anti-beta-glucosidase antibodies. The beta-glucosidase was immunocytochemically localized in the chloroplasts of mesophyll cells, but not in any chloroplasts in marginal cells of the vascular bundle or epidermal cells; ribulose 1,5-bisphosphate carboxylase (Rubisco), a typical stromal protein, was observed in all chloroplasts in these cells. These results suggest that beta-glucosidase is tissue specific in its expression in the leaves of the indigo plant.

Plant Leaves↗
PubMed2000

Tissue and intracellular localization of indican and the purification and characterization of indican synthase from indigo plants.

Indican (indoxyl beta-D-glucoside) was found to accumulate only in green leaves of the indigo plant, and not in any other tissues. Comparisons of the indican content of protoplasts and vacuoles showed that indican was stored only in the vacuole of the cell. Indican content appeared and increased with the appearance and growth of leaves. In mature plants, the younger leaves contained larger amounts of indican than the older ones. Cell extracts of young leaves of indigo plant catalyzed the synthesis of indican from UDP-glucose and indoxyl. Indican synthase was extracted and purified from young leaves. The enzyme was separated into two fractions by anion-exchange chromatography. The enzyme in the fraction which was eluted by 0.1 M NaCl had a molecular weight of 53,000 by SDS-PAGE. Optimum pH of the enzyme was at about 10.0, indicating that the enzyme is likely localized in a different intracellular compartment from that of indican storage. The enzyme showed normal Michaelis-Menten kinetics and a K(m) value of 0.13 mM for UDP-glucose.

Glucosyltransferases↗
PubMed2000

Molecular cytogenetic analysis of supernumerary heterochromatic segments in Rumex acetosa.

The dioecious plant Rumex acetosa shows intraspecific karyotype variation, caused by supernumerary heterochromatic segments or DAPI (4',6-diamidino-2 phenylindole)-bands at the ends of the short arms of three pairs of autosomes. A DNA sequence (RAE730) specific to the supernumerary heterochromatic segments was cloned and sequenced. RAE730 was about 730 bp and AT-rich (71% AT-content). Using fluorescence in situ hybridization (FISH), RAE730 was localized in the supernumerary DAPI-positive heterochromatic segments on several mitotic chromosomes and chromocenters in interphase nuclei, but not in the DAPI-bands of Y or B chromosomes. RAE730 was tandemly arranged in the genome, and the copy number varied between plants from 40000 to 304000 copies per 2C, corresponding to the relative amount of supernumerary heterochromatic segments per genome. These results indicate that the karyotype variation caused by the supernumerary heterochromatic segment was generated by amplification or reduction of the tandem repeats of RAE730.

Base Sequence↗
PubMed2000

Antifibrotic effects of the methanol extract of Polygonum aviculare in fibrotic rats induced by bile duct ligation and scission.

The antifibrotic effect of the methanol extract from Polygonum aviculare (PA), Artemisia capillaris (AC) and an aqueous solution of biphenyl dimethyl dicarboxylate (DDB) on liver fibrosis were studied. Liver fibrosis was induced by a bile duct ligation and scission (BDL/S) operation, duration of 4 weeks in rats. In BDL/S rats, the levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin in serum and hydroxyproline content in liver were dramatically increased. The PA treatment in BDL/S rats reduced the serum AST, ALT and ALP levels significantly (p<0.01). Liver hydroxyproline content in PA treated BDL/S group was also reduced to 40% that of BDL/S control group (p<0.01). The morphological characteristics of fibrotic liver, which appeared in BDL/S control group were improved in the PA treated BDL/S group. But neither AC nor DDB treatment improved any parameters in fibrotic rats induced by BDL/S. These results indicate that PA has an antifibrotic effect on fibrotic rats induced by BDL/S.

Animals↗
PubMed2003

A new naphthopyrone from the root of Pleuropterus ciliinervis.

A new naphthopyrone, pleuropyrone A (1), together with (-)-lyoniresinol 3a-O-beta-D-glucopyranoside (2) and (+)-lyoniresinol 3a-O-beta-D-glucopyranoside (3) was isolated from the roots of Pleuropterus ciliinervis. The structure of pleuropyrone A (1) was determined to be 2,5-dimethyl-8-hydroxynaphthopyrone 10-O-beta-D-glucopyranoside by spectroscopic methods including 2D-NMR. Compounds 2 and 3 showed moderate antioxidant activity.

Animals↗
PubMed2006

Studies on nepalese crude drugs. XXVIII. Chemical constituents of Bhote Khair, the underground parts of Eskemukerjea megacarpum HARA.

From the underground parts of Eskemukerjea megacarpum HARA, two new stilbenes (14, 15) were isolated, together with a known coumarin, 5,7-dihydroxycoumarin (1), a tyramine derivative, trans-feruloyltyramine (2), two pyrogallol derivatives, gallic acid (3) and beta-glucogallin (4), four flavonoids, trifolin (5), hyperin (6), myricetin 3-O-beta-D-galactopyranoside (7), and myricitrin (8), five stilbenes, resveratorol (9), astringenin (10), piceid (11) astringin (12), and resveratorol 3-O-beta-D-(6-O-galloyl)glucopyranoside (13), a flavan-3-ol, (-)-epigallocatechin 3-O-gallate (16), two proanthocyanidins, catechin-(4alpha-->8)-epigallocatechin 3-O-gallate (17) and epicatechin 3-O-gallate-(4beta-->8)-epigallocatechin 3-O-gallate (18), and an anthocyanin, idaein (19). Compounds 14 and 15 were identified as (E)-3,5,3',4'-tetrahydroxystilbene 3-O-beta-D-(6-O-galloyl)glucopyranoside and (E)-3,5,4'-trihydroxystilbene 3-O-beta-D-(6-O-galloyl)glucopyranoside, respectively, based on spectral and chemical data.

Coumarins↗
PubMed2003

[Inhibition of tumor growth in vitro by the extract of Fagopyrum cymosum].

OBJECTIVE: Fagopyrum cymosum (Trev.) Meisn has long been used in China to treat various ailments of the lung, including lung tumors. This study investigated whether Fagopyrum cymosum extract (Fago-c) has effects on other organs. METHODS: Human cancer cells derived from 10 different organs were employed, and their growths as affected by Fago-c were investigated. RESULTS: It was found that the growth of cancer cells from lung, liver, colon, leukocytes and bone is inhibited by Fago-c. However, cancer cells derived from prostate, cervix, ovary and brain are not sensitive to Fago-c, and the extract stimulates the growth of cancer cells from breast (MCF-7). Synergistic inhibition effect of Fago-c and daunomycin was observed in human lung cancer cells (H460). Cellular proteins from H460 cells treated with Fago-c were analyzed by 2D-gel electrophoresis. A protein (M.W./pI=20 K/5.9) was induced. The Fago-c extract was analyzed by High Performance Liquid Chromatography (HPLC). Four major and twenty minor components were identified. CONCLUSION: These studies indicate the effect of Fago-c in inhibiting the growth of cell lines derived from certain organs.

Antibiotics, Antineoplastic↗
PubMedDate not supplied

The investigations into the interferon-like activity of Polygonum L. genus.

The interferon inducing abilities of eleven ethanolic extracts obtained from nine taxons of Polygonum L. genus, were tested in the cell culture of monkey kidney. The extracts from the herb of Polygonum amphibium L. and the rhizome and fruit of Polygonum bistorta L. induced a substance showing an interferon-like activity. Biological activity studies showed that the protective titre (the highest dilution which protected cells by 50% against virus infection) of the interferon-like materials was 1:10-1:15.

Antiviral Agents↗
PubMed1997

[Chemical composition of Fagopyrum cymosum (Trev.) Meisn].

From the ethanolic extracts of the aerial parts of Fagopyrum cymosum, eleven compounds were isolated, of which eight have been identified as benzoic acid(1), beta-sitosterol(2),5,5'-di-alpha-furaldehyde dimethyl ether(3), p-hydroxybenzoic acid(4), rutin(5), quercetin(6), daucosterol(7), succinic acid(8) by spectroscopic methods. Compound 3 is obtained from the genus for the first time.

Drugs, Chinese Herbal↗
PubMed1998

[Analysis of isoenzymes in six kinds of caulis drug by means of polyacrylamide gel slab electrophoresis].

OBJECTIVE: To probe into the possibility of application of electrophoresis in the identification of caulis drugs. METHOD: The isoenzymes of peroxidase, esterase and amylase in six kinds of caulis drug with similar characteristics were analyzed by means of polyacrylamide gel slab electrophoresis. RESULT: The bands of isoenzymogram of peroxidase are the clearest of all, and band number and mobility rates of the six drugs differ from one another, showing a remarkable interspecific distinction. CONCLUSION: Electrophoresis of isoenzymes of peroxidase can be employed as one of the effective means in differentiating caulis drugs.

Drugs, Chinese Herbal↗
PubMedDate not supplied

Prevention of azoxymethane-induced intestinal tumors by a crude ethyl acetate-extract and tryptanthrin extracted from Polygonum tinctorium Lour.

The effect of a crude ethyl acetate (AcOEt)-extract and tryptanthrin extracted from the Indigo plant (Polygonum tinctorium Lour.) on azoxymethane (AOM)-induced intestinal tumors was examined in F344 rats. The rats were given subcutaneous (s.c.) injections of either AOM (15 mg/kg body weight (b.w.)) once a week for 3 weeks to induce atypical crypt foci (ACF) as a known cancer precursor, or AOM (7.5 mg/kg b.w.) once a week for 10 weeks to induce intestinal tumors. The rats were also administered the AcOEt-extract (500 mg/kg b.w.) or tryptanthrin (50 mg/kg b.w.) orally, 5 days a week, for 7 or 30 weeks, starting two days before the first administration of AOM. All rats were killed 4 or 20 weeks after the last treatment. In the short-term experiment, the incidence of ACE and atypical crypts (AC) in the groups receiving the AcOEt-extract and tryptanthrin was significantly lower than in the control group. In the tumor-inducing experiment, intestinal tumor incidence in the tryptanthrin group was lower than in the AOM-control group (5% versus 26%), and small intestine tumor incidence in the AcOEt-extract and tryptanthrin groups were lower than in the AOM-control group (0% and 0% versus 23%). These results show that the AcOEt-extract of Indigo and tryptanthrin have cancer chemopreventive activity.

Acetates↗
PubMed2002

Gastroprotective and antiulcerogenic effects of Rumex patientia L. extract.

Gastroprotective and antiulcerogenic effects of the aqueous extract of Rumex patientia L. roots (D-1) were investigated in rats and compared to non-steroidal antiinflammatory drugs (NSAIDs). Whereas oral administration of high doses of NSAIDs caused stomach damage, D-1 (aqueous extract of Rumex patientia roots, 150 and 500 mg/kg) and nimesulid (100 and 300 mg/kg) did not cause any damage. In rats, the number of stress ulcers induced by the administration of 150 mg/kg of D-1 were identical to that of the control group. However, compared to the control group, the number of stress ulcers decreased 1.9 times and the size of ulceration areas decreased 1.1 times in the group treated with 500 mg/kg of D-1.

Animals↗
PubMed2002

[Hairy-root culture of Polygonium multiflorum Thunb. and the production of its active constituents-anthraquinones].

Transformed hairy roots of Polygonium multiflorum Thunb. were obtained by the transformation of Agrobacterium rhizogenes LBA9402. It was clearly demonstrated that T-DNA of A. Rhizogenes Ri plasmid was integrated into the cells of hairy roots by the experiments of PCR and Southern hybridization. Through the screen of basic medium and the research of growth curve of hairy roots, the optimum inoculum time was selected in 30 days or so in the optimum condition-MS medium. On the condition, the content of rhein was 2.85 folds higher in hairy roots than that of natural plants by means of HPLC.

Anthraquinones↗