Note: This page contains sample records for the topic derived plant sterol from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

The Spectrum of Plant and Animal Sterols in Different Oil-Derived Intravenous Emulsions  

Microsoft Academic Search

Intravenous lipid constituents have different effects on various biological processes. Some of these effects are protective,\\u000a while others are potentially adverse. Phytosterols, in particular, seem to be implicated with parenteral nutrition-associated\\u000a cholestasis. The aim of this study is to determine the amount of plant and animal sterols present in lipid formulations derived\\u000a from different oil sources. To this end, animal

Maria Luisa Forchielli; Germana Bersani; Sara Tala; Gabriele Grossi; Cristina Puggioli; Massimo Masi

2010-01-01

2

Serum Plant Sterol Concentration but Not the Cholesterol Precursor Sterol Concentrations in Young Children (The STRIP Study)1  

Microsoft Academic Search

Plant sterol supplementation reduces serum cholesterol concentration but may increase serum plant ste- rol concentrations, especially in children. We determined whether natural dietary plant sterols derived mainly from veg- etable oil or margarine in early childhood affect serum con- centrations of plant sterols (campesterol and sitosterol) and cholesterol precursor sterols (D-8 cholestenol, desmosterol, and lathosterol), reflecting endogenous cholesterol synthesis. We

Anne Tammi; Tapani Ronnemaa; Liisa Valsta; Ritva Seppanen; Leena Rask-Nissila; Tatu A. Miettinen; Helena Gylling; Jorma Viikari; Meri Anttolainen; Olli Simell

3

Plant sterols and the membrane environment  

Microsoft Academic Search

Sterols are essential for all eukaryotes. In contrast to animal and fungal cells, which contain only one major sterol, plant cells synthesize a complex array of sterol mixtures in which sitosterol, stigmasterol and 24-methylcholesterol often predominate. Sitosterol and 24-methylcholesterol are able to regulate membrane fluidity and permeability in a similar manner to cholesterol in mammalian cell membranes. Plant sterols can

Marie-Andrée Hartmann

1998-01-01

4

Plant Sterols in Cereals and Cereal Products  

Microsoft Academic Search

Cereal Chem. 79(1):148-154 The total plant sterol contents (free sterols and covalently bound structures) of the main cereals cultivated in Finland were determined. Furthermore, sterol contents were determined for different flour and bran fractions in the milling process of wheat and rye, as well as plant sterol contents in various milling and retail bakery products. The sample prep- aration procedure

V. Piironen; J. Toivo; A.-M. Lampi

2002-01-01

5

Metabolism of plant sterols by nematodes  

Microsoft Academic Search

Parasitic nematodes do not biosynthesize sterolsde novo and therefore possess a nutritional requirement for sterol, which must be obtained from their hosts. Consequently, the metabolism\\u000a of phytosterols by plant-parasitic nematodes is an important process with potential for selective exploitation. The sterol\\u000a compositions of several species of plant-parasitic nematodes were determined by capillary gas chromatography-mass spectrometry\\u000a and compared with the sterol

David J. Chitwood; William R. Lusby

1991-01-01

6

Monograph. Plant sterols and sterolins.  

PubMed

Sterols and sterolins, also known as phytosterols, are fats present in all plants, including fruits and vegetables. Although they are chemically similar to the animal fat, cholesterol, they have been shown to exert significant unique biochemical effects in both animals and humans. Because they are bound to the fibers of the plant, they are difficult to absorb during the transit of digested food through the gut, particularly in individuals with impaired digestive function. For this reason, and because much of the modern diet is over-processed and low in fresh plant materials, sterols and sterolins appear in the serum and tissue of healthy humans at 800-1000 times lower concentrations than that of cholesterol. Beta-sitosterol (BSS) is the major phytosterol in higher plants along with its glycoside, beta-sitosterolin (BSSG). Animal studies have demonstrated BSS and BSSG possess anti-inflammatory, antipyretic, antineoplastic, and immune-modulating properties. In other in vitro, animal, and human studies, a proprietary BSS:BSSG mixture has shown promise in normalizing T-cell function, dampening overactive antibody responses, and normalizing DHEA:cortisol ratios. Research has shown plant oils contain the highest concentration of phytosterols, nuts and seeds contain moderate amounts, and fruits and vegetables generally contain the lowest phytosterol concentrations. Because only low levels of these substances are found in humans, increased dietary intake of unprocessed fruits and vegetables or supplementation with commercial phytosterols may be of benefit in re-establishing optimal immune parameters. Restoring balance to the immune system may be of therapeutic benefit in disease processes such as chronic viral infections, stress-induced immune suppression, tuberculosis, allergies, cancer, and rheumatoid arthritis and other autoimmune conditions. PMID:11302782

2001-04-01

7

Disruption of cholesterol homeostasis by plant sterols  

PubMed Central

The ABC transporters ABCG5 and ABCG8 limit absorption and promote excretion of dietary plant sterols. It is not known why plant sterols are so assiduously excluded from the body. Here we show that accumulation of plant sterols in mice lacking ABCG5 and ABCG8 (G5G8–/– mice) profoundly perturbs cholesterol homeostasis in the adrenal gland. The adrenal glands of the G5G8–/– mice were grossly abnormal in appearance (brown, not white) due to a 91% reduction in cholesterol content. Despite the very low cholesterol levels, there was no compensatory increase in cholesterol synthesis or in lipoprotein receptor expression. Moreover, levels of ABCA1, which mediates sterol efflux, were increased 10-fold in the G5G8–/– adrenals. Adrenal cholesterol levels returned to near-normal levels in mice treated with ezetimibe, which blocks phytosterol absorption. To determine which plant sterol(s) caused the metabolic changes, we examined the effects of individual plant sterols on cholesterol metabolism in cultured adrenal cells. Addition of stigmasterol, but not sitosterol, inhibited SREBP-2 processing and reduced cholesterol synthesis. Stigmasterol also activated the liver X receptor in a cell-based reporter assay. These data indicate that selected dietary plant sterols disrupt cholesterol homeostasis by affecting two critical regulatory pathways of lipid metabolism.

Yang, Chendong; Yu, Liqing; Li, Weiping; Xu, Fang; Cohen, Jonathan C.; Hobbs, Helen H.

2004-01-01

8

Natural Sources of Dietary Plant Sterols  

Microsoft Academic Search

In this study, plant sterol contents in the most important oils and margarines and cereal products, as well as in vegetables, fruits and berries, available in Finland were determined. The samples were purchased from retail stores or market places or directly obtained from the food industry. Sterols in oils and margarines were analysed by capillary gas chromatography after sample preparation

V. Piironen; J. Toivo; A.-M. Lampi

2000-01-01

9

Dietary intake of plant sterols stably increases plant sterol levels in the murine brain  

PubMed Central

Plant sterols such as sitosterol and campesterol are frequently administered as cholesterol-lowering supplements in food. Recently, it has been shown in mice that, in contrast to the structurally related cholesterol, circulating plant sterols can enter the brain. We questioned whether the accumulation of plant sterols in murine brain is reversible. After being fed a plant sterol ester-enriched diet for 6 weeks, C57BL/6NCrl mice displayed significantly increased concentrations of plant sterols in serum, liver, and brain by 2- to 3-fold. Blocking intestinal sterol uptake for the next 6 months while feeding the mice with a plant stanol ester-enriched diet resulted in strongly decreased plant sterol levels in serum and liver, without affecting brain plant sterol levels. Relative to plasma concentrations, brain levels of campesterol were higher than sitosterol, suggesting that campesterol traverses the blood-brain barrier more efficiently. In vitro experiments with brain endothelial cell cultures showed that campesterol crossed the blood-brain barrier more efficiently than sitosterol. We conclude that, over a 6-month period, plant sterol accumulation in murine brain is virtually irreversible.

Vanmierlo, Tim; Weingartner, Oliver; van der Pol, Susanne; Husche, Constanze; Kerksiek, Anja; Friedrichs, Silvia; Sijbrands, Eric; Steinbusch, Harry; Grimm, Marcus; Hartmann, Tobias; Laufs, Ulrich; Bohm, Michael; de Vries, Helga E.; Mulder, Monique; Lutjohann, Dieter

2012-01-01

10

Current and new insights on phytosterol oxides in plant sterol-enriched food.  

PubMed

Over the past 15 years, plant sterol-enriched foods have faced a great increase in the market, due to the asserted cholesterol-lowering effect of plant sterols. However, owing to their chemical structures, plant sterols can oxidize and produce a wide variety of oxidation products with controversial biological effects. Although oxyphytosterols can derive from dietary sources and endogenous formation, their single contribution should be better defined. The following review provides an overall and critical picture on the current knowledge and future perspectives of plant sterols-enriched food, particularly focused on occurrence of plant sterol oxidation products and their biological effects. The final objective of this overview is to evince the different aspects of plant sterols-enriched food that require further research, for a better understanding of the influence of plant sterols and their oxides on consumers' health. PMID:21699886

García-Llatas, Guadalupe; Rodríguez-Estrada, María Teresa

2011-06-12

11

Plant sterols in vegetables and fruits commonly consumed in Sweden  

Microsoft Academic Search

Summary   Plant sterols are known to have serum cholesterol lowering effects. A high dietary intake might therefore have a positive\\u000a impact on health. All food items of vegetable origin contain some amount of plant sterols. The aim of this study was to analyse\\u000a the plant sterol content of vegetables and fruits commonly consumed in Sweden, and to compare fresh and

M. Johnsson; H. Andersson; Y. van Gameren; P. Dutta

1999-01-01

12

Food sources of plant sterols in the EPIC Norfolk population  

Microsoft Academic Search

Objective:To investigate the intake of plant sterols and identify major dietary sources of plant sterols in the British diet.Subjects:A total of 24 798 men and women recruited during 1993–1997, participating in the European Prospective Investigation into Cancer (EPIC-Norfolk).Interventions:A database of the plant sterol (campesterol, ?-sitosterol, stigmasterol, campestanol and ?-sitostanol) content in foods, based on gas-liquid chromatography (GLC) analyses, was linked

S Klingberg; H Andersson; A Mulligan; A Bhaniani; A Welch; S Bingham; K-T Khaw; S Andersson; L Ellegĺrd

2008-01-01

13

Determination of thermo-oxidation products of plant sterols  

Microsoft Academic Search

Plant sterols are subjected to oxidation when exposed to air and, especially, when heated at high temperatures. We developed a method to study thermo-oxidation of plant sterols. The method consisted of cold saponification, purification of oxides by solid-phase extraction and gas chromatography analysis. To compensate for losses during the procedure, an internal standard was added before saponification. The method showed

Anna-Maija Lampi; Laura Juntunen; Jari Toivo; Vieno Piironen

2002-01-01

14

Metabolic effects of plant sterols and stanols (Review)  

Microsoft Academic Search

High serum LDL cholesterol concentration is a major risk factor for cardiovascular complications. This risk can be lowered by diet. In this respect foods containing plant sterol or stanol esters can be useful for mildly- and hypercholesteraemic subjects. Plant sterols and stanols, which are structurally related to cholesterol, decrease the incorporation of dietary and biliary cholesterol into micelles. This lowers

Ariënne de Jong; Jogchum Plat; Ronald P Mensink

2003-01-01

15

Plant Sterols and Stanols: Their Role in Health and Disease  

PubMed Central

Mammalian physiological processes, and likely any organism with a biliary tree, can distinguish between dietary cholesterol and non-cholesterols, retaining very little of the non-cholesterol in their bodies. Historically, the distinction between plant sterols and cholesterol has been known about for a century or more. That plants sterols were not ‘absorbed’ has been investigated for almost half a century. Indeed, the oral of plant sterols in gram quantities was shown to interfere with cholesterol absorption and is one of the oldest pharmacological therapies for hypercholesterolemia. Although the basis for the latter was shown to be caused by exclusion of cholesterol from intestinal micelles by plant sterols, it was not until the identification of the a rare genetic disease, sitosterolemia, first described in 1974, that led to the hypothesis that specific molecular mechanism(s) governed both the entry and excretion of sterols by the body. This talk will cover the physiology of dietary sterol metabolism, genetics and pathophysiology of sitosterolemia. Additionally, the role of plant sterols in normal and abnormal metabolism in humans as well as selected animal models will be discussed.

Patel, Shailendra B.

2008-01-01

16

Transcription of sterol ? 5,6-desaturase and sterol 14?-demethylase is induced in the plant pathogenic ascomycete, Leptosphaeria maculans, during treatment with a triazole fungicide  

Microsoft Academic Search

Two genes whose derived amino acid sequences closely resemble the ergosterol biosynthetic enzymes, sterol ?5,6-desaturase (erg3) and sterol 14?-demethylase (erg11), were cloned from the plant pathogenic fungus Leptosphaeria maculans. Transcript levels of both these genes increased following exposure of L. maculans to the triazole fungicide, flutriafol, which specifically inhibits the ergosterol biosynthetic pathway. This induction may be due to a

Katherine M Griffiths; Barbara J Howlett

2002-01-01

17

Plant phloem sterol content: forms, putative functions, and implications for phloem-feeding insects  

PubMed Central

All eukaryotes contain sterols, which serve as structural components in cell membranes, and as precursors for important hormones. Plant vegetative tissues are known to contain mixtures of sterols, but very little is known about the sterol composition of phloem. Plants are food for many animals, but plant-feeding arthropods (including phloem-feeding insets) are unique among animals in that they have lost the ability to synthesize sterols, and must therefore acquire these essential nutrients from their food, or via endosymbionts. Our paper starts by providing a very brief overview of variation in plant sterol content, and how different sterols can affect insect herbivores, including those specializing on phloem. We then describe an experiment, where we bulk collected phloem sap exudate from bean and tobacco, and analyzed its sterol content. This approach revealed two significant observations concerning phloem sterols. First, the phloem exudate from each plant was found to contain sterols in three different fractions – free sterols, sterols conjugated to lipids (acylated), and sterols conjugated to carbohydrates (glycosylated). Second, for both plants, cholesterol was identified as the dominant sterol in each phloem exudate fraction; the remaining sterols in each fraction were a mixture of common phytosterols. We discuss our phloem exudate sterol profiles in a plant physiology/biochemistry context, and how it relates to the nutritional physiology/ecology of phloem-feeding insects. We close by proposing important next steps that will advance our knowledge concerning plant phloem sterol biology, and how phloem-sterol content might affect phloem-feeding insects.

Behmer, Spencer T.; Olszewski, Nathan; Sebastiani, John; Palka, Sydney; Sparacino, Gina; Sciarrno, Elizabeth; Grebenok, Robert J.

2013-01-01

18

Plant sterols and cardiovascular disease: a systematic review and meta-analysis†  

PubMed Central

The impact of increased serum concentrations of plant sterols on cardiovascular risk is unclear. We conducted a systematic review and meta-analysis aimed to investigate whether there is an association between serum concentrations of two common plant sterols (sitosterol, campesterol) and cardiovascular disease (CVD). We systematically searched the databases MEDLINE, EMBASE, and COCHRANE for studies published between January 1950 and April 2010 that reported either risk ratios (RR) of CVD in relation to serum sterol concentrations (either absolute or expressed as ratios relative to total cholesterol) or serum sterol concentrations in CVD cases and controls separately. We conducted two meta-analyses, one based on RR of CVD contrasting the upper vs. the lower third of the sterol distribution, and another based on standardized mean differences between CVD cases and controls. Summary estimates were derived by fixed and random effects meta-analysis techniques. We identified 17 studies using different designs (four case–control, five nested case–control, three cohort, five cross-sectional) involving 11 182 participants. Eight studies reported RR of CVD and 15 studies reported serum concentrations in CVD cases and controls. Funnel plots showed evidence for publication bias indicating small unpublished studies with non-significant findings. Neither of our meta-analyses suggested any relationship between serum concentrations of sitosterol and campesterol (both absolute concentrations and ratios to cholesterol) and risk of CVD. Our systematic review and meta-analysis did not reveal any evidence of an association between serum concentrations of plant sterols and risk of CVD.

Genser, Bernd; Silbernagel, Gunther; De Backer, Guy; Bruckert, Eric; Carmena, Rafael; Chapman, M. John; Deanfield, John; Descamps, Olivier S.; Rietzschel, Ernst R.; Dias, Karen C.; Marz, Winfried

2012-01-01

19

Sterols of scallop. I. Application of hydrophobic sephadex derivatives to the resolution of a complex mixture of marine sterols.  

PubMed

Column chromatography on a hydroxyalkoxypropyl derivative of Sephadex LH-20 and on Anasil B has been applied to the resolution of complex marine sterol mixture in combination with argentation thin-layer chromatography and gas chromatography. This approach permits isolation in quantity of individual sterols from a complex mixture and separation of sterol mixtures that were not resolved without the modified Sephadex step. Seventeen sterols were detected in the scallop Placopecten magellanicus. 24-Methyl-cholesterol, 24-ethyl-cholesterol, 24-methyl-22-dehydrocholesterol and 24-ethyl-22-dehydrocholesterol, i.e. sterols whose configuration at C-24 had not been definitively established, were isolated in sufficient quantities for further study by nuclear magnetic resonance spectroscopy. PMID:1202058

Patterson, G W; Khalil, M W; Idler, D R

1975-12-10

20

No Association Between Plasma Levels of Plant Sterols and Atherosclerosis in Mice and Men  

Microsoft Academic Search

Objective—Sitosterolemia is characterized by elevated plasma levels of plant sterols, hypercholesterolemia and premature coronary heart disease (CHD). CHD develops in some subjects with sitosterolemia, despite having normal plasma cholesterol levels, suggesting that high circulating levels of plant sterols may be atherogenic. We tested whether elevated plasma levels of plant sterols (sitosterol and campesterol) were associated with atherosclerosis in genetically modified

Kenneth R. Wilund; Liqing Yu; Fang Xu; Gloria L. Vega; Scott M. Grundy; Jonathan C. Cohen; Helen H. Hobbs

2010-01-01

21

Plant Sterol Levels Are Not Associated With Atherosclerosis in Mice and Men  

Microsoft Academic Search

Objective—Sitosterolemia is characterized by elevated plasma levels of plant sterols, hypercholesterolemia and premature coronary heart disease (CHD). CHD develops in some subjects with sitosterolemia, despite having normal plasma cholesterol levels, suggesting that high circulating levels of plant sterols may be atherogenic. We tested whether elevated plasma levels of plant sterols (sitosterol and campesterol) were associated with atherosclerosis in genetically modified

Kenneth R. Wilund; Liqing Yu; Fang Xu; Gloria Vega; Scott Grundy; Jonathan C. Cohen; Helen H. Hobbs

2009-01-01

22

Chromatographic analysis of plant sterols in foods and vegetable oils  

Microsoft Academic Search

This paper reviews recently published chromatographic methods for the analysis of plant sterols in various sample matrices with emphasis on vegetable oils. An overview of structural complexities and biological\\/nutritional aspects including hypocholesterolemic activities of phytosterols is provided in the Section 1. The principal themes of the review highlight the development and application of chromatographic techniques for the isolation, purification, separation

S. L. Abidi

2001-01-01

23

Plant phloem sterol content: forms, putative functions, and implications for phloem-feeding insects.  

PubMed

All eukaryotes contain sterols, which serve as structural components in cell membranes, and as precursors for important hormones. Plant vegetative tissues are known to contain mixtures of sterols, but very little is known about the sterol composition of phloem. Plants are food for many animals, but plant-feeding arthropods (including phloem-feeding insets) are unique among animals in that they have lost the ability to synthesize sterols, and must therefore acquire these essential nutrients from their food, or via endosymbionts. Our paper starts by providing a very brief overview of variation in plant sterol content, and how different sterols can affect insect herbivores, including those specializing on phloem. We then describe an experiment, where we bulk collected phloem sap exudate from bean and tobacco, and analyzed its sterol content. This approach revealed two significant observations concerning phloem sterols. First, the phloem exudate from each plant was found to contain sterols in three different fractions - free sterols, sterols conjugated to lipids (acylated), and sterols conjugated to carbohydrates (glycosylated). Second, for both plants, cholesterol was identified as the dominant sterol in each phloem exudate fraction; the remaining sterols in each fraction were a mixture of common phytosterols. We discuss our phloem exudate sterol profiles in a plant physiology/biochemistry context, and how it relates to the nutritional physiology/ecology of phloem-feeding insects. We close by proposing important next steps that will advance our knowledge concerning plant phloem sterol biology, and how phloem-sterol content might affect phloem-feeding insects. PMID:24069026

Behmer, Spencer T; Olszewski, Nathan; Sebastiani, John; Palka, Sydney; Sparacino, Gina; Sciarrno, Elizabeth; Grebenok, Robert J

2013-09-24

24

Comparison of the intestinal uptake of cholesterol, plant sterols, and stanols in mice  

Microsoft Academic Search

The recent identification of the aberrant transport proteins ABCG5 and ABCG8 resulting in sitosterolemia sug- gests that intestinal uptake of cholesterol is an unselective process, and that discrimination between cholesterol and plant sterols takes place at the level of sterol efflux from the enterocyte. Although plant sterols are structurally very simi- lar to cholesterol, differing only in their side chain

Michael Igel; Uwe Giesa; Dieter Lütjohann; Klaus von Bergmann

2003-01-01

25

Efficacy and Safety of Plant Stanols and Sterols in the Management of Blood Cholesterol Levels  

Microsoft Academic Search

Foods with plant stanol or sterol esters lower serum cho- lesterol levels. We summarize the deliberations of 32 ex- perts on the efficacy and safety of sterols and stanols. A meta-analysis of 41 trials showed that intake of 2 g\\/d of stanols or sterols reduced low-density lipoprotein (LDL) by 10%; higher intakes added little. Efficacy is similar for sterols and

MARTIJN B. KATAN; SCOTT M. GRUNDY; PETER JONES; MALCOLM LAW; TATU MIETTINEN; RODOLFO PAOLETTI

26

Non-esterified plant sterols solubilized in low fat milks inhibit cholesterol absorption  

Microsoft Academic Search

Summary.   Background: The cholesterol absorption inhibiting properties of plant sterols in milks are unknown. The milk fat globule membrane components\\u000a may enhance the absorption of cholesterol and could make plant sterols less efficient in this complex matrix. Aim of the study: To evaluate in hypercholesterolemic men the cholesterol absorption inhibiting properties of verified properly solubilized,\\u000a non-esterified plant sterols in partly

Etienne B. Pouteau; Irina E. Monnard; Christelle Piguet-Welsch; Michel J. A. Groux; Laurent Sagalowicz; Alvin Berger

2003-01-01

27

Plant sterol and stanol substrate specificity of pancreatic cholesterol esterase.  

PubMed

Consumption of plant sterols or stanols (collectively referred to as phytosterols) and their esters results in decreased low-density lipoprotein cholesterol, which is associated with decreased atherosclerotic risk. The mechanisms by which phytosterols impart their effects, however, are incompletely characterized. The objective of the present study is to determine if pancreatic cholesterol esterase (PCE; EC 3.1.1.13), the enzyme primarily responsible for cholesterol ester hydrolysis in the digestive tract, is capable of hydrolyzing various phytosterol esters and to compare the rates of sterol ester hydrolysis in vitro. We found that PCE hydrolyzes palmitate, oleate and stearate esters of cholesterol, stigmasterol, stigmastanol and sitosterol. Furthermore, we found that the rate of hydrolysis was dependent on both the sterol and the fatty acid moieties in the following order of rates of hydrolysis: cholesterol>(sitosterol=stigmastanol)>stigmasterol; oleate>(palmitate=stearate). The addition of free phytosterols to the system did not change hydrolytic activity of PCE, while addition of palmitate, oleate or stearate increased activity. Thus, PCE may play an important but discriminatory role in vivo in the liberation of free phytosterols to compete with cholesterol for micellar solubilization and absorption. PMID:19615880

Brown, Andrew W; Hang, Jiliang; Dussault, Patrick H; Carr, Timothy P

2009-07-16

28

Plant sterol-enriched margarine lowers plasma LDL in hyperlipidemic subjects with low cholesterol intake: effect of fibrate treatment.  

PubMed

Phytosterols, found in fat-soluble fractions of plants, chemically resemble cholesterol and inhibit cholesterol absorption in the small intestine. Phytosterol consumption in human subjects reduces plasma total and low density lipoprotein-cholesterol (LDL-C) levels. The primary aim of this study was to determine the efficacy of a low-fat spread enriched with plant sterols in reducing total and LDL-C concentrations in primary hypercholesterolemia. The secondary objective was to evaluate whether patients receiving a lipid-lowering drug (fibrate) might differ in their response to plant sterols. The study was a randomized, double-blind, placebo-controlled two-period cross-over trial with two treatments and three periods. Both treatment periods lasted 2 months, with a washout period (2 months) between them. Spread enriched with plant sterols was compared to non-enriched control spread. Fortified fat spread provided 1.6 g/day of plant sterols derived from edible vegetable oils and fatty acids from sunflower seed oil. The plant sterol content consisted of sitosterol esters (50%), campesterol esters (25%), stigmasterol esters (20%) and 10% of other esters. Data in 53 hypercholesterolemic patients (31 females and 22 males) who completed the study were as follows: patients were 58+/-12 years of age with mean body mass index 23.5+/-2.8 kg/m2 (mean+/-SD). No adverse side-effects of the diet were reported. Plasma total cholesterol and LDL-C concentrations were significantly reduced by 6.4% and 8.8%, respectively, after using the spread enriched in plant sterols, as compared to controls (0.0% and 1.3%, respectively). No effect on high density lipoprotein-cholesterol (HDL-C) and lipoprotein(a) concentrations was detected. When subjects were divided in two subgroups according to fibrate treatment, supplementation with phytosterols decreased plasma cholesterol and LDL-C by 8.5% and 11.1%, respectively in the subgroup of patients treated with fibrates. In the group of patients who did not receive fibrates, consumption of plant sterol margarine reduced plasma cholesterol and LDL-C by 5.5% and 7.7%, respectively. Spread enriched with plant sterol esters significantly lowers blood total and LDL-C levels without affecting HDL-C concentrations, in a hypercholesterolemic population following a strict low cholesterol diet (NCEP step1). In addition, a combination of fibrate treatment and plant sterol ester-supplemented spread offers a safe and effective measure to significantly decrease abnormally high cholesterol levels. We conclude that phytosterol-enriched spread is a useful adjunctive therapy for hypercholesterolemic patients. PMID:11522112

Nigon, F; Serfaty-Lacrosničre, C; Beucler, I; Chauvois, D; Neveu, C; Giral, P; Chapman, M J; Bruckert, E

2001-07-01

29

Molecular characterization and functional analysis of Glycine max sterol methyl transferase 2 genes involved in plant membrane sterol biosynthesis  

Microsoft Academic Search

Sterol C24 methyltransferase (SMT2) genes governing the pattern of phytosterols synthesized in higher plants have been studied in Glycine seedlings and wild-type and engineered Arabidopsis thaliana plants. The SMT2 genes of soybean (SMT2-1 and SMT2-2) previously cloned and characterized (Neelakandan et al. 2009) were shown to complement the SMT deficient cvp1 mutant Arabidopsis plants, consistent with their role in regulation

Anjanasree K. Neelakandan; Hanh T. M. Nguyen; Rajesh Kumar; Lam-Son Phan Tran; Satish K. Guttikonda; Truyen Ngoc Quach; Donovan L. Aldrich; W. David Nes; Henry T. Nguyen

2010-01-01

30

Effect of Plant Sterol Esters on the Absorption of Dietary Cholesterol1  

Microsoft Academic Search

Cholesterol absorption decreases when either free or esteri- fied plant sterols are added to the dietary fat. The effectiveness of various plant sterols, which were added to the dietary fat at the same molar con centration, in causing this decrease was determined in thoracic duct-can- nulated rats. The oleate esters of Ăź-sitosterol, campesterol, and stigmasterol, individually or in a mixture,

FRED H. MATTSON; R. A. VOLPENHEIN; ANDB. A. ERICKSON

1977-01-01

31

Plant sterols and stanols: effects on mixed micellar composition and LXR (target gene) activation  

Microsoft Academic Search

Plant stanols and sterols of the 4-desmethyl fam- ily (e.g., sitostanol and sitosterol) effectively decrease LDL cholesterol concentrations, whereas 4,4-dimethylsterols ( ? -amyrin and lupeol) do not. Serum carotenoid concentra- tions, however, are decreased by both plant sterol families. The exact mechanisms underlying these effects are not known, although effects on micellar composition have been suggested. With a liver X

Jogchum Plat; Jason A. Nichols; Ronald P. Mensink

2005-01-01

32

Differential Effects of Plant Sterols on Water Permeability and on Acyl Chain Ordering of Soybean Phosphatidylcholine Bilayers  

Microsoft Academic Search

To gain some insight into the structural and functional roles of sterols in higher plant cells, various plant sterols have been incorporated into soybean phosphatidylcholine (PtdCho) bilayers and tested for their ability to regulate water permeability and acyl chain ordering. Sitosterol was the most efficient sterol in reducing the water permeability of these vesicles and stigmasterol appeared to have no

Isabelle Schuler; Alain Milon; Yoichi Nakatani; Guy Ourisson; Anne-Marie Albrecht; Pierre Benveniste; Marie-Andree Hartman

1991-01-01

33

Economic valuation of the potential health benefits from foods enriched with plant sterols in Canada  

PubMed Central

Background Increased consumption of foods containing plant sterols has the potential to reduce the incidence of coronary heart disease (CHD) and thus reduce costs associated with treating that disease in a significant way. This paper reports the results of an investigation of the potential monetary benefits of allowing foods enriched with plant sterols to be marketed in Canada. Objective The objective of this research was to estimate the annual savings that would accrue to Canada's single-payer publicly funded health care system if plant sterols were approved for use. If foods containing plant sterols are consumed at a sufficient rate, a reduction in CHD should follow. Given the significant costs associated with CHD, approval of plant sterols in Canada has important public policy implications. Design This research employs a variation of traditional cost-of-illness analysis entailing four steps: (1) estimation of a ‘success rate’ (proportion of persons who would consume plant sterols at the necessary rate); (2) presumption of blood cholesterol reduction due to plant sterol consumption; (3) assumption of reduction in CHD that follows from blood cholesterol reduction; and (4) calculation of cost savings associated with reduced incidence of CHD. Results Calculations were carried out for four scenarios: ideal, optimistic, pessimistic, and very pessimistic. It was estimated that between $38 million (very pessimistic scenario) and $2.45 billion (ideal scenario) could be saved annually by Canada's health care system with plant sterol-enriched food products being made available for sale. Conclusion Significant expenditure reductions within Canada's publicly funded health care system could be realized with plant sterols approved for sale. Reduced CHD resulting from lower blood cholesterol levels would lessen the financial burden of disease in Canada.

Gyles, Collin L.; Carlberg, Jared G.; Gustafson, Jennifer; Davlut, David A.; Jones, Peter J.H.

2010-01-01

34

Reduction in cholesterol absorption is enhanced by stearate-enriched plant sterol esters in hamsters.  

PubMed

Consumption of plant sterol esters reduces plasma LDL cholesterol concentration by inhibiting intestinal cholesterol absorption. Commercially available plant sterol esters are prepared by esterifying free sterols to fatty acids from edible plant oils such as canola, soybean, and sunflower. To determine the influence of the fatty acid moiety on cholesterol metabolism, plant sterol esters were made with fatty acids from soybean oil (SO), beef tallow (BT), or purified stearic acid (SA) and fed to male hamsters for 4 wk. A control group fed no plant sterol esters was also included. Hamsters fed BT and SA had significantly lower cholesterol absorption and decreased concentrations of plasma non-HDL cholesterol and liver esterified cholesterol, and significantly greater fecal sterol excretion than SO and control hamsters. Cholesterol absorption was lowest in hamsters fed SA (7.5%), whereas it was 72.9% in control hamsters. Cholesterol absorption was correlated with fecal sterol excretion (r = -0.72, P < 0.001), liver cholesterol concentration (r = 0.88, P < 0.001), and plasma non-HDL cholesterol concentration (r = 0.85, P < 0.001). A multiple regression model that included each sterol ester type vs. cholesterol absorption indicated that intake of steryl stearate was the only dietary component that contributed significantly to the model (R2 = -0.75, P < 0.001). Therefore, our results demonstrate that BT and SA are more effective than SO in reducing cholesterol absorption, liver cholesterol, and plasma non-HDL cholesterol concentration, suggesting that cardioprotective benefits can be achieved by consuming stearate-enriched plant sterol esters. PMID:17056791

Rasmussen, Heather E; Guderian, David M; Wray, Curtis A; Dussault, Patrick H; Schlegel, Vicki L; Carr, Timothy P

2006-11-01

35

Plant sterols lower LDL cholesterol without improving endothelial function in prepubertal children with familial hypercholesterolaemia  

Microsoft Academic Search

In adults with familial hypercholesterolaemia (FH), cholesterol lowering with statins has been shown to improve the endothelial\\u000a function, a hallmark of early atherogenesis. Currently, therapeutic options for treating high cholesterol levels in FH children\\u000a are limited. Plant sterols safely and effectively reduce serum cholesterol concentrations by inhibiting cholesterol absorption.\\u000a Therefore, we evaluated the effect of plant sterols on cholesterol and

S. De Jongh; M. N. Vissers; P. Rol; H. D. Bakker; J. J. P. Kastelein; E. S. G. Stroes

2003-01-01

36

Safety of long-term consumption of plant sterol esters-enriched spread  

Microsoft Academic Search

Objective: To evaluate both efficacy and safety in humans of long-term consumption of spreads containing plant sterol esters.Design: Randomized double-blind placebo-controlled parallel trial.Subjects: Hundred and eighty-five healthy volunteers (35–64 y).Interventions: Volunteers daily consumed 20 g spread enriched with 1.6 g plant sterols as fatty acid esters or a control spread for 1 y. They continued their habitual diet and lifestyle.

H F J Hendriks; E J Brink; G W Meijer; H M G Princen; F Y Ntanios

2003-01-01

37

Plant sterols/stanols as cholesterol lowering agents: A meta-analysis of randomized controlled trials  

PubMed Central

Background Consumption of plant sterols has been reported to reduce low density lipoprotein (LDL) cholesterol concentrations by 5–15%. Factors that affect plant sterol efficacy are still to be determined. Objectives To more precisely quantify the effect of plant sterol enriched products on LDL cholesterol concentrations than what is reported previously, and to identify and quantify the effects of subjects’ characteristics, food carrier, frequency and time of intake on efficacy of plant sterols as cholesterol lowering agents. Design Fifty-nine eligible randomized clinical trials published from 1992 to 2006 were identified from five databases. Weighted mean effect sizes were calculated for net differences in LDL levels using a random effect model. Results Plant sterol containing products decreased LDL levels by 0.31 mmol/L (95% CI, –0.35 to –0.27, P=?plant sterols were incorporated into fat spreads, mayonnaise and salad dressing, milk and yoghurt comparing with other food products such as croissants and muffins, orange juice, non-fat beverages, cereal bars, and chocolate. Plant sterols consumed as a single morning dose did not have a significant effect on LDL cholesterol levels. Conclusion Plant sterol containing products reduced LDL concentrations but the reduction was related to individuals’ baseline LDL levels, food carrier, and frequency and time of intake.

AbuMweis, Suhad S.; Barake, Roula; Jones, Peter J.H.

2008-01-01

38

Efficacy and safety of plant stanols and sterols in the management of blood cholesterol levels.  

PubMed

Foods with plant stanol or sterol esters lower serum cholesterol levels. We summarize the deliberations of 32 experts on the efficacy and safety of sterols and stanols. A meta-analysis of 41 trials showed that intake of 2 g/d of stanols or sterols reduced low-density lipoprotein (LDL) by 10%; higher intakes added little. Efficacy is similar for sterols and stanols, but the food form may substantially affect LDL reduction. Effects are additive with diet or drug interventions: eating foods low in saturated fat and cholesterol and high in stanols or sterols can reduce LDL by 20%; adding sterols or stanols to statin medication is more effective than doubling the statin dose. A meta-analysis of 10 to 15 trials per vitamin showed that plasma levels of vitamins A and D are not affected by stanols or sterols. Alpha carotene, lycopene, and vitamin E levels remained stable relative to their carrier molecule, LDL. Beta carotene levels declined, but adverse health outcomes were not expected. Sterol-enriched foods increased plasma sterol levels, and workshop participants discussed whether this would increase risk, in view of the marked increase of atherosclerosis in patients with homozygous phytosterolemia. This risk is believed to be largely hypothetical, and any increase due to the small increase in plasma plant sterols may be more than offset by the decrease in plasma LDL. There are insufficient data to suggest that plant stanols or sterols either prevent or promote colon carcinogenesis. Safety of sterols and stanols is being monitored by follow-up of samples from the general population; however, the power of such studies to pick up infrequent increases in common diseases, if any exist, is limited. A trial with clinical outcomes probably would not answer remaining questions about infrequent adverse effects. Trials with surrogate end points such as intima-media thickness might corroborate the expected efficacy in reducing atherosclerosis. However, present evidence is sufficient to promote use of sterols and stanols for lowering LDL cholesterol levels in persons at increased risk for coronary heart disease. PMID:12911045

Katan, Martijn B; Grundy, Scott M; Jones, Peter; Law, Malcolm; Miettinen, Tatu; Paoletti, Rodolfo

2003-08-01

39

Transcription of sterol Delta(5,6)-desaturase and sterol 14alpha-demethylase is induced in the plant pathogenic ascomycete, Leptosphaeria maculans, during treatment with a triazole fungicide.  

PubMed

Two genes whose derived amino acid sequences closely resemble the ergosterol biosynthetic enzymes, sterol Delta(5,6)-desaturase (erg3) and sterol 14alpha-demethylase (erg11), were cloned from the plant pathogenic fungus Leptosphaeria maculans. Transcript levels of both these genes increased following exposure of L. maculans to the triazole fungicide, flutriafol, which specifically inhibits the ergosterol biosynthetic pathway. This induction may be due to a decrease in ergosterol content or to abnormal levels of the ergosterol precursor, 24-methylene dihydrolanosterol. PMID:12445649

Griffiths, Katherine M; Howlett, Barbara J

2002-11-19

40

START lipid\\/sterol-binding domains are amplified in plants and are predominantly associated with homeodomain transcription factors  

Microsoft Academic Search

BACKGROUND: In animals, steroid hormones regulate gene expression by binding to nuclear receptors. Plants lack genes for nuclear receptors, yet genetic evidence from Arabidopsis suggests developmental roles for lipids\\/sterols analogous to those in animals. In contrast to nuclear receptors, the lipid\\/sterol-binding StAR-related lipid transfer (START) protein domains are conserved, making them candidates for involvement in both animal and plant lipid\\/sterol

Kathrin Schrick; Diana Nguyen; Wojciech M Karlowski; Klaus FX Mayer

2004-01-01

41

Plant Sterols as Anticancer Nutrients: Evidence for Their Role in Breast Cancer  

PubMed Central

While many factors are involved in the etiology of cancer, it has been clearly established that diet significantly impacts one’s risk for this disease. More recently, specific food components have been identified which are uniquely beneficial in mitigating the risk of specific cancer subtypes. Plant sterols are well known for their effects on blood cholesterol levels, however research into their potential role in mitigating cancer risk remains in its infancy. As outlined in this review, the cholesterol modulating actions of plant sterols may overlap with their anti-cancer actions. Breast cancer is the most common malignancy affecting women and there remains a need for effective adjuvant therapies for this disease, for which plant sterols may play a distinctive role.

Grattan, Bruce J.

2013-01-01

42

Plasma levels of plant sterols and the risk of coronary artery disease: the prospective EPIC-Norfolk Population Study  

Microsoft Academic Search

Some studies have suggested that a modest in- crease of plant sterol levels is a risk factor for coronary artery disease (CAD). We studied the relationship between plant sterol levels and CAD risk in a prospective nested case- control study consisting of 373 cases and 758 controls. Sitosterol and campesterol concentrations did not differ between cases and controls (sitosterol, 0.21

Sabine Pinedo; Maud N. Vissers; Klaus von Bergmann; Karim Elharchaoui; Dieter Lutjohann; Robert Luben; Nicholas J. Wareham; John J. P. Kastelein; Kay-Tee Khaw; S. Matthijs Boekholdt

2006-01-01

43

Oxidized plant sterols in human serum and lipid infusions as measured by combined gas-liquid chromatography-mass spectrometry  

Microsoft Academic Search

Some oxidized forms of cholesterol (oxysterols) are thought to be atherogenic and cytotoxic. Because plant sterols are structurally related to cholesterol, we examined whether oxidized plant sterols (oxyphytosterols) could be identified in human serum and soy-based lipid emulsions. We first prepared both deuterated and nondeuterated reference compounds. We then analyzed by gas-liquid chromatography- mass spectrometry the oxyphytosterol concentrations in serum

Jogchum Plat; Harald Brzezinka; Dieter Lütjohann; Ronald P. Mensink; Klaus von Bergmann

44

Plasma plant sterols serve as poor markers of cholesterol absorption in man.  

PubMed

The validation of the use of plasma plant sterols as a marker of cholesterol absorption is frail. Nevertheless, plant sterol concentrations are routinely used to describe treatment-induced changes in cholesterol absorption. Their use has also been advocated as a clinical tool to tailor cholesterol-lowering therapy. Prior to wider implementation, however, the validity of plant sterols as absorption markers needs solid evaluation. Therefore, we compared plasma plant sterol concentrations to gold-standard stable isotope-determined cholesterol absorption. Plasma campesterol/TC concentrations (camp/TC) were measured in a population of 175 mildly hypercholesterolemic individuals (age: 59.7 ± 5.6 years; BMI: 25.5 ± 2.9 kg/m(2); LDL-C: 4.01 ± 0.56 mmol/l). We compared cholesterol absorption according to the plasma dual-isotope method in subjects with the highest camp/TC concentrations (N = 41, camp/TC: 2.14 ± 0.68 ?g/mg) and the lowest camp/TC concentrations (N = 39, camp/TC: 0.97 ± 0.22 ?g/mg). Fractional cholesterol absorption did not differ between the groups (24 ± 12% versus 25 ± 16%, P = 0.60), nor was it associated with plasma camp/TC concentrations in the total population of 80 individuals (? = 0.13; P = 0.30, adjusted for BMI and plasma triglycerides). Our findings do not support a relation between plasma plant sterol concentrations and true cholesterol absorption and, therefore, do not favor the use of these sterols as markers of cholesterol absorption. This bears direct consequences for the interpretation of earlier studies, as well as for future studies targeting intestinal regulation of cholesterol metabolism. PMID:23178226

Jakulj, Lily; Mohammed, Hussein; van Dijk, Theo H; Boer, Theo; Turner, Scott; Groen, Albert K; Vissers, Maud N; Stroes, Erik S G

2012-11-25

45

Plant sterols alter bile acid metabolism and reduce cholesterol absorption in hamsters fed a beef-based diet  

Microsoft Academic Search

This study examined the cholesterol-lowering properties of dietary plants sterols (PS) when consumed in a beef-based diet. Male Syrian hamsters were fed freeze-dried ground beef supplemented with maltodextrin, vegetable oil, vitamins, minerals, and soybean sterol esters at 0.0, 0.3, 1.0, or 3.0% sterol by weight of the diet. After 4 weeks, plasma and liver total cholesterol concentrations were significantly and

Timothy P Carr; Roxana M Cornelison; Blake J Illston; Cindy L Stuefer-Powell; Daniel D Gallaher

2002-01-01

46

Effect of plant sterols and tannins on Phytophthora ramorum growth and sporulation.  

PubMed

Elicitin-mediated acquisition of plant sterols is required for growth and sporulation of Phytophthora spp. This study examined the interactions between elicitins, sterols, and tannins. Ground leaf tissue, sterols, and tannin-enriched extracts were obtained from three different plant species (California bay laurel, California black oak, and Oregon white oak) in order to evaluate the effect of differing sterol/tannin contents on Phytophthora ramorum growth. For all three species, high levels of foliage inhibited P. ramorum growth and sporulation, with a steeper concentration dependence for the two oak samples. Phytophthora ramorum growth and sporulation were inhibited by either phytosterols or tannin-enriched extracts. High levels of sterols diminished elicitin gene expression in P. ramorum; whereas the tannin-enriched extract decreased the amount of 'functional' or ELISA-detectable elicitin, but not gene expression. Across all treatment combinations, P. ramorum growth and sporulation correlated strongly with the amount of ELISA-detectable elicitin (R (2)?= 0.791 and 0.961, respectively). PMID:23689874

Stong, Rachel A; Kolodny, Eli; Kelsey, Rick G; González-Hernández, M P; Vivanco, Jorge M; Manter, Daniel K

2013-05-21

47

Factors affecting sample preparation in the gas chromatographic determination of plant sterols in whole wheat flour  

Microsoft Academic Search

A fractional factorial experimental design was applied to study factors affecting sample preparation prior to a gas chromatographic determination of total plant sterols in cereal samples. Whole wheat flour was chosen for the representative matrix. Altogether six factors were studied at two levels. The most affecting factors were a type of hydrolysis (combined acid hydrolysis and alkaline hydrolysis over alkaline

Jari Toivo; Anna-Maija Lampi; Satu Aalto; Vieno Piironen

2000-01-01

48

Plasma Plant Sterols Do Not Reflect Cholesterol Absorption in Smith-Lemli-Opitz Syndrome Children  

PubMed Central

Objective In adults, the ratio of plant sterols to cholesterol in plasma correlates with dietary cholesterol absorption. We hypothesized that this correlation could be validated in children with Smith Lemli-Opitz syndrome (SLOS), a cholesterol synthesis disorder. Study design We obtained measurements of cholesterol absorption by a direct radioisotope cholesterol absorption method during 9 SLOS subject visits. We measured plasma sterols in 22 SLOS subjects and 16 controls, as well as dietary intake of cholesterol and sitosterol (n=11 SLOS). Results The correlations of 2 plasma plant sterol ratios (sitosterol/cholesterol and campesterol/cholesterol) with direct cholesterol absorption measurement were poor (R= ?0.33 and R= ?0.25, respectively), significantly lower than the published correlation in adults (R=+0.73) (P<0.02). Conclusions Although the ratios of plant sterols to cholesterol in plasma has been used as a surrogate for cholesterol absorption in adults and children, these ratios may not accurately reflect cholesterol absorption in children with SLOS. These ratios should not be used as a surrogate for cholesterol absorption in children without further validation.

Merkens, Louise S.; Jordan, Julia M.; Penfield, Jennifer A.; Lutjohann, Dieter; Connor, William E.; Steiner, Robert D.

2011-01-01

49

Cell-free transfer of sterols by plant fractions  

SciTech Connect

Microsomes from etiolated hypocotyls of soybean or leaves of light-grown spinach radiolabeled in vivo with ({sup 3}H)acetate or in vitro with ({sup 3}H)squalene or ({sup 3}H)cholesterol as donor transferred radioactivity to unlabeled acceptor membranes immobilized on nitrocellulose. Most efficient transfer was with plasma membrane or tonoplast as the acceptor. The latter were highly purified by aqueous two-phase partition (plasma membrane) and preparative free-flow electrophoresis (tonoplast and plasma membrane). Plasma membrane- and tonoplast-free microsomes and purified mitochondria were less efficient acceptors. Sterol transfer was verified by thin-layer chromatography of extracted lipids. Transfer was time- and temperature-dependent, required ATP but was not promoted by cytosol. The nature of the donor (endoplasmic reticulum, Golgi apparatus or both) and of the transfer mechanism is under investigation.

Morre, D.J.; Wilkinson, F.E.; Morre, D.M. (Purdue Univ., West Lafayette, IN (USA)); Moreau, P. (CNRS, Boreaux (France)); Sandelius, A.S. (Univ. of Goteborg (Sweden)); Penel, C.; Greppin, H. (Univ. of Geneva (Switzerland))

1990-05-01

50

Differential effects on inhibition of cholesterol absorption by plant stanol and plant sterol esters in apoE-/- mice  

PubMed Central

Aims ‘Functional foods’ supplemented with plant sterol esters (PSE) and plant stanol esters (PSA) are therapeutic options for the management of hypercholesterolaemia. However, their effects on blood monocytes, endothelial function, atherogenesis, and sterol tissue concentrations are poorly understood. Methods and results Male apoE?/? mice (n= 30) were randomized to three different diets for 6 weeks (n= 10 per group): high-cholesterol (1.25%) western-type diet (WTD), WTD + 2% PSE, and WTD + 2% PSA. Both supplements reduced serum cholesterol. WTD + PSE resulted in increased plant sterol serum concentrations and increased inflammatory Ly-6C(high) monocyte numbers. WTD + PSA increased plant stanol serum concentrations and Ly-6C-monocyte numbers, but decreased vascular superoxide release, lipid hydroperoxides, and inflammatory cytokines in aortic tissue, in plasma, and in circulating monocytes. Despite reduced serum cholesterol concentrations, both supplements impaired endothelial vasodilation compared with WTD. WTD + PSA reduced the development of atherosclerotic lesions compared with WTD alone (12.7 ± 3.7 vs. 28.3 ± 3.5%), and WTD + PSE was less effective (17.5 ± 3.7%). WTD + PSE and WTD + PSA reduced the cholesterol content in the liver, but not in the brain. However, WTD + PSE and WTD + PSA increased plant sterol and plant stanol concentrations in the liver as well as in the brain. Conclusion PSE and PSA supplementation reduced serum cholesterol, but increased plant sterol and plant stanol concentrations. Elevated levels of PSE and PSA were associated with endothelial dysfunction and increased central nervous system depositions. Atherosclerotic lesion retardation was more pronounced in WTD + PSA, coinciding with higher regenerative monocyte numbers, decreased oxidative stress, and decreased inflammatory cytokines compared with WTD + PSE.

Weingartner, Oliver; Ulrich, Christof; Lutjohann, Dieter; Ismail, Kenan; Schirmer, Stephan H.; Vanmierlo, Tim; Bohm, Michael; Laufs, Ulrich

2011-01-01

51

Effect of plant sterols, fatty acids and lecithin on cholesterol absorption in vivo in the rat  

Microsoft Academic Search

The inhibitory effect of plant sterols, fatty acids and lecithin on cholesterol intestnal absorption was studied in the unanesthetized\\u000a rat using a single pass perfusion technique. Bile was excluded from the perfused intestine. Cholesterol absorption did not\\u000a change following the additions of cholestanol, cholestanone, lanosterol, stigmasterol and ?-sitosterol. A 3-fold increase\\u000a in the molarity of cholestanol and ?-sitosterol or the

Daniel Hollander; Donna Morgan

1980-01-01

52

Plant sterol esters lower plasma lipids and most carotenoids in mildly hypercholesterolemic adults  

Microsoft Academic Search

The ability of plant sterol esters (PSE) in salad dressing to modify plasma lipids and carotenoids was determined in 26 men\\u000a and 27 women fed controlled, weight-maintaining, isocaloric diets. Diets contained typical American foods that provided 32%\\u000a of energy from fat. Dressings contained 8 g (ranch) or 4 g (Italian) of fat per serving. PSF (3.6 g\\/d) were provided in

Joseph T. Judd; David J. Baer; Shirley C. Chen; Beverly A. Clevidence; Richard A. Muesing; Matthew Kramer; Gert W. Meijer

2002-01-01

53

The effect of combining plant sterols, soy protein, viscous fibers, and almonds in treating hypercholesterolemia  

Microsoft Academic Search

Reductions in low-density lipoprotein-cholesterol (LDL-C) result from diets containing almonds, or diets that are either low in saturated fat or high in viscous fibers, soy proteins, or plant sterols. We have therefore combined all of these interventions in a single diet (portfolio diet) to determine whether cholesterol reductions could be achieved of similar magnitude to those reported in recent statin

David J. A Jenkins; Cyril W. C Kendall; Augustine Marchie; Dorothea Faulkner; Edward Vidgen; Karen G Lapsley; Elke A Trautwein; Tina L Parker; Robert G Josse; Lawrence A Leiter; Philip W Connelly

2003-01-01

54

Bendigoles D-F, bioactive sterols from the marine sponge-derived Actinomadura sp. SBMs009.  

PubMed

Marine derived actinomycetes have become an important source of bioactive natural products. Here we report the structure and bioactivity of the bendigoles D-F (1-3), 3-keto sterols isolated from the new marine sponge derived bacterium, Actinomadura sp. SBMs009. The isolation of these compounds was guided by a novel high-content screen for NF-?B and glucocorticoid receptor (GR) activity, and cytotoxicity assays. The structures of 1-3 were determined by detailed analysis of NMR, MS, and single crystal X-ray diffraction data. Interestingly, 1 displayed cytotoxicity against the L929 (mouse fibroblast) cell line with an IC(50) approximated to 30 ?M and was the most active inhibitor of GR-translocation, while 3 was the most effective inhibitor of NF-?B nuclear translocation with an IC(50) of 71 ?M. PMID:21684166

Simmons, Luke; Kaufmann, Katrin; Garcia, Ronald; Schwär, Gertrud; Huch, Volker; Müller, Rolf

2011-05-30

55

Sterol composition of mycelia of the plant pathogenic ascomycete Leptosphaeria maculans  

Microsoft Academic Search

Analysis of sterols in mycelia of the ascomycete, Leptosphaeria maculans by gas chromatography–mass spectrometry revealed that ergosterol comprised 95% of the total sterols, with eight other sterols comprising the remaining 5%. Six of these latter sterols were putative precursors of ergosterol and their presence suggested a pathway for ergosterol biosynthesis in this fungus. Ergosterol biosynthesis in fungi is inhibited by

K. M Griffiths; A Bacic; B. J Howlett

2003-01-01

56

Role of membrane sterols and cortical microtubules in gravity resistance in plants  

NASA Astrophysics Data System (ADS)

Resistance to the gravitational force is a principal graviresponse in plants comparable to gravitropism Nevertheless only limited information has been obtained for this graviresponse We have examined mechanisms of signal perception transformation and transduction of the perceived signal and response to the transduced signal in gravity resistance using hypergravity conditions produced by centrifugation In Arabidopsis hypocotyls hypergravity treatment greatly increased the expression level of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase HMGR which catalyzes a reaction producing mevalonic acid a key precursor of terpenoids such as membrane sterols Geranyl diphosphate synthase gene was also up-regulated by hypergravity whereas the expression of other genes involved in membrane lipid metabolism was not influenced Hypergravity caused an increase in sterol content in azuki bean epicotyls but not in phospholipid glycolipid or fatty acid content Also hypergravity did not influence fatty acid composition in any lipid class Thus the effect of hypergravity on membrane lipid metabolism was specific for sterol synthesis On the other hand alpha- and beta-tubulin genes were up-regulated by hypergravity treatment in Arabidopsis hypocotyls Hypergravity also induced reorientation of cortical microtubules in azuki epicotyls the percentage of epidermal cells with transverse microtubles was decreased whereas that with longitudinal microtubules was increased Inhibitors of HMGR action and microtubule-disrupting agents completely prevented the gravity resistance

Hoson, T.; Koizumi, T.; Matsumoto, S.; Kumasaki, S.; Soga, K.; Wakabayashi, K.; Sakaki, T.

57

START lipid/sterol-binding domains are amplified in plants and are predominantly associated with homeodomain transcription factors  

PubMed Central

Background In animals, steroid hormones regulate gene expression by binding to nuclear receptors. Plants lack genes for nuclear receptors, yet genetic evidence from Arabidopsis suggests developmental roles for lipids/sterols analogous to those in animals. In contrast to nuclear receptors, the lipid/sterol-binding StAR-related lipid transfer (START) protein domains are conserved, making them candidates for involvement in both animal and plant lipid/sterol signal transduction. Results We surveyed putative START domains from the genomes of Arabidopsis, rice, animals, protists and bacteria. START domains are more common in plants than in animals and in plants are primarily found within homeodomain (HD) transcription factors. The largest subfamily of HD-START proteins is characterized by an HD amino-terminal to a plant-specific leucine zipper with an internal loop, whereas in a smaller subfamily the HD precedes a classic leucine zipper. The START domains in plant HD-START proteins are not closely related to those of animals, implying collateral evolution to accommodate organism-specific lipids/sterols. Using crystal structures of mammalian START proteins, we show structural conservation of the mammalian phosphatidylcholine transfer protein (PCTP) START domain in plants, consistent with a common role in lipid transport and metabolism. We also describe putative START-domain proteins from bacteria and unicellular protists. Conclusions The majority of START domains in plants belong to a novel class of putative lipid/sterol-binding transcription factors, the HD-START family, which is conserved across the plant kingdom. HD-START proteins are confined to plants, suggesting a mechanism by which lipid/sterol ligands can directly modulate transcription in plants.

Schrick, Kathrin; Nguyen, Diana; Karlowski, Wojciech M; Mayer, Klaus FX

2004-01-01

58

Involvement of membrane sterols in hypergravity-induced modifications of growth and cell wall metabolism in plant stems  

NASA Astrophysics Data System (ADS)

Organisms living on land resist the gravitational force by constructing a tough body Plants have developed gravity resistance responses after having first went ashore more than 500 million years ago The mechanisms of gravity resistance responses have been studied under hypergravity conditions which are easily produced on earth by centrifugation In Arabidopsis hypocotyls hypergravity treatment greatly increased the expression level of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase HMGR which is involved in synthesis of terpenoids such as membrane sterols In the present study we examined the role of membrane sterols in gravity resistance in plants by analyzing sterol levels of stem organs grown under hypergravity conditions and by analyzing responses to hypergravity of the organs whose sterol level was modulated Hypergravity inhibited elongation growth but stimulated lateral expansion of Arabidopsis hypocotyls and azuki bean epicotyls Under hypergravity conditions sterol levels were kept high as compared with 1 g controls during incubation Lovastatin an inhibitor HMGR prevented lateral expansion as the gravity resistance response in azuki bean epicotyls Similar results were obtained in analyses with loss of function mutants of HMGR in Arabidopsis It has been shown that sterols play a role in cellulose biosynthesis probably as the primer In wild type Arabidopsis hypocotyls hypergravity increased the cellulose content but it did not influence the content in HMGR mutants These results suggest that hypergravity increases

Koizumi, T.; Soga, K.; Wakabayashi, K.; Suzuki, M.; Muranaka, T.; Hoson, T.

59

Cholesterol-lowering effects of plant sterol esters and non-esterified stanols in margarine, butter and low-fat foods  

Microsoft Academic Search

Objectives: To determine the efficacy on plasma cholesterol-lowering of plant sterol esters or non-esterified stanols eaten within low-fat foods as well as margarine.Design: Randomised, controlled, single-blind study with sterol esters and non-esterified plant stanols provided in breakfast cereal, bread and spreads. Study 1 comprised 12 weeks during which sterol esters (2.4 g) and stanol (2.4 g) -containing foods were eaten

P Nestel; M Cehun; S Pomeroy; M Abbey; G Weldon

2001-01-01

60

The Metabolic Effects of Omega3 Plant Sterol Esters in Mixed Hyperlipidemic Subjects  

Microsoft Academic Search

Purpose  The aim of the current study was to evaluate the therapeutic effects of omega-3 plant sterol esters (n-3-PSE) on lipid profile\\u000a and other coronary heart disease risk factors in subjects with mixed hyperlipidemia.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Ninety-one patients with mixed hyperlipidemia were randomized in a double blind fashion to receive either placebo (corn oil)\\u000a or n-3-PSE. Twenty four patients dropped out or were

Rafael Bitzur; Hofit Cohen; Tzafra Cohen; Tali W. Dror; Yael Herzog; Yael Lifshitz; Tamar Lubish; Dror Harats; Ardon Rubinstein

2010-01-01

61

Unique pathways of sterol metabolism in the Mexican bean beetle, a plant-feeding insect  

Microsoft Academic Search

Radiolabeled sterols,14C-cholesterol,14C-cholestanol,3H-stigmasterol,3H-stigmastanol, and3H-sitosterol, were fed to larvae of the Mexican bean beetle,Epilachna varivestis Mulsant, by coating soybean leaves. Free sterol and sterol ester fractions from treated insects were isolated and analyzed,\\u000a and in each case nearly 30% or more of total radiolabeled sterols retained by the insect were found in the sterol ester fraction\\u000a after 8 days. ?5 sterols were

J. A. Svoboda; M. J. Thompson; W. E. Robbins; T. C. Elden

1975-01-01

62

Cholesterol lowering effect of a soy drink enriched with plant sterols in a French population with moderate hypercholesterolemia  

PubMed Central

Background Plant sterols are an established non-pharmacological means to reduce total and LDL blood cholesterol concentrations and are therefore recommended for cholesterol management by worldwide-renown health care institutions. Their efficacy has been proven in many types of foods with the majority of trials conducted in spreads or dairy products. As an alternative to dairy products, soy based foods are common throughout the world. Yet, there is little evidence supporting the efficacy of plant sterols in soy-based foods. The objective of this study was to investigate the effect of a soy drink enriched with plant sterols on blood lipid profiles in moderately hypercholesterolemic subjects. Methods In a randomized, placebo-controlled double-blind mono-centric study, 50 subjects were assigned to 200 ml of soy drink either enriched with 2.6 g plant sterol esters (1.6 g/d free plant sterol equivalents) or without plant sterols (control) for 8 weeks. Subjects were instructed to maintain stable diet pattern and physical activity. Plasma concentrations of lipids were measured at initial visit, after 4 weeks and after 8 weeks. The primary measurement was the change in LDL cholesterol (LDL-C). Secondary measurements were changes in total cholesterol (TC), non-HDL cholesterol (non-HDL-C), HDL cholesterol (HDL-C) and triglycerides. Results Regular consumption of the soy drink enriched with plant sterols for 8 weeks significantly reduced LDL- C by 0.29 mmol/l or 7% compared to baseline (p < 0.05). TC and non-HDL-C concentrations decreased by 0.26 mmol/l and 0.31 mmol/l (each p < 0.05), respectively. Mean reductions in total, LDL and non-HDL cholesterol were significantly greater than in the placebo group (p < 0.05). HDL-C and triglycerides were not affected. Compliance was very high (>96%), and products were well tolerated. Conclusion Daily consumption of a plant sterol-enriched soy drink significantly decreased total, non-HDL and LDL cholesterol and is therefore an interesting and convenient aid in managing mild to moderate hypercholesterolemia.

Weidner, Christina; Krempf, Michel; Bard, Jean-Marie; Cazaubiel, Murielle; Bell, Doris

2008-01-01

63

Sterol composition of mycelia of the plant pathogenic ascomycete Leptosphaeria maculans.  

PubMed

Analysis of sterols in mycelia of the ascomycete, Leptosphaeria maculans by gas chromatography-mass spectrometry revealed that ergosterol comprised 95% of the total sterols, with eight other sterols comprising the remaining 5%. Six of these latter sterols were putative precursors of ergosterol and their presence suggested a pathway for ergosterol biosynthesis in this fungus. Ergosterol biosynthesis in fungi is inhibited by the triazole antifungal agent flutriafol. When L. maculans was grown in the presence of flutriafol, ergosterol content decreased while two 14 alpha-methylated sterols, 24-methylene dihydrolanosterol and obtusifoliol, accumulated. PMID:12482449

Griffiths, K M; Bacic, A; Howlett, B J

2003-01-01

64

Sterols as ecological indicators  

Microsoft Academic Search

Plots of the C-27, C-28 and C-29 sterol contents of marine plankton, higher plants, soils, and lacustrine and marine sediments form discrete areas in a triangular diagram. Because the positions of these plots of the various samples are relatable to biological sources, sterol analyses may be used to define ecological systems.

Wen-Yen Huang; W. G. Meinschein

1979-01-01

65

The lipid lowering effect of plant sterol ester capsules in hypercholesterolemic subjects  

PubMed Central

Background Foods enriched with phytosterols have been proven to be an effective therapy to improve blood lipid profiles. However, none of the studies have investigated the efficacy in lipid lowering of plant sterol esters (PSE) in capsule form. The objective of this study is to determine if the plant sterol esters (PSE) in capsule form (1.3 grams of PSE/day) lowered plasma cholesterol levels and lipid ratios in free-living hypercholesterolemic subjects during a 4-week intervention period. Methods Sixteen subjects participated in a double-blind, placebo-controlled, sequential study with a 4-week placebo phase followed by a 2-week wash-out period and a 4-week treatment phase. Subjects were instructed to maintain stable diet pattern and physical activities. Blood samples were collected at 7, 21 and 28 days of each phase. The primary measurements were change in plasma total cholesterol (TC), HDL-cholesterol (HDL) and LDL-cholesterol (LDL) between phases and within each phase. The secondary measurements were change in triglycerides, lipoprotein ratios (TC/HDL, LDL/HDL) and C-reactive protein (CRP). Results In comparison to placebo, LDL-cholesterol was significantly reduced by 7% and 4% (P < 0.05) at both week 3 and week 4; HDL at week 3 of the treatment was significantly increased by 9% (P < 0.01), but not at week 4 (4%); total cholesterol was not significantly different from placebo throughout the period, TC/HDL and LDL/HDL were significantly reduced by (8%, 8%, 6%, 10%, respectively) (P < 0.01) at both week 3 and week 4. CRP and triglycerides did not differ either between the two phases or during the treatment phase. Conclusion In conclusion, plant sterol ester capsule is effective in improving lipid profiles among hypercholesterolemic subjects in a free-living setting at the minimum dosage recommended by FDA. The significant improved lipid profiles were reached after three weeks of administration. To achieve better lipid lowering results, higher dosages and combination with diets low in saturated fat and cholesterol are recommended.

Acuff, Robert V; Cai, David J; Dong, Zhi-Ping; Bell, Doris

2007-01-01

66

Gonopodial morphogenesis in female mosquitofish, Gambusia affinis affinis , masculinized by exposure to degradation products from plant sterols  

Microsoft Academic Search

Female mosquitofish,Gambusia affinis affinis, were masculinized by exposure to degradation products (presumably steroids) of the plant sterol, stigmastanol. Masculinization was indicated by the induction of a male-like gonopodium in each specimen. The morphogenetic stages of gonopodial development are discussed as are the anatomical specializations produced in the mature gonopodial tip.

W. Mike Howell; Thomas E. Denton

1989-01-01

67

Cholesterol lowering effect of a soy drink enriched with plant sterols in a French population with moderate hypercholesterolemia  

Microsoft Academic Search

BACKGROUND: Plant sterols are an established non-pharmacological means to reduce total and LDL blood cholesterol concentrations and are therefore recommended for cholesterol management by worldwide-renown health care institutions. Their efficacy has been proven in many types of foods with the majority of trials conducted in spreads or dairy products. As an alternative to dairy products, soy based foods are common

Christina Weidner; Michel Krempf; Jean-Marie Bard; Murielle Cazaubiel; Doris Bell

2008-01-01

68

A dietary portfolio approach to cholesterol reduction: Combined effects of plant sterols, vegetable proteins, and viscous fibers in hypercholesterolemia  

Microsoft Academic Search

Plant sterols, soy proteins, and viscous fibers are advised for cholesterol reduction but their combined effect has never been tested. We therefore assessed their combined effect on blood lipids in hyperlipidemic subjects who were already consuming a low[ndash ]saturated fat, low-cholesterol diet before starting the study. The test (combination) diet was 1 month in duration and was very low in

David J. A. Jenkins; Cyril W. C. Kendall; Dorothea Faulkner; Edward Vidgen; Elke A. Trautwein; Tina L. Parker; Augustine Marchie; George Koumbridis; Karen G. Lapsley; Robert G. Josse; Lawrence A. Leiter; Philip W. Connelly

2002-01-01

69

Synthesis of deuterium-labeled plant sterols and analysis of their side-chain mobility by solid state deuterium NMR  

SciTech Connect

Sitosterol and stigmasterol, plant sterols, were deuterated at specific positions. Orientation and mobility of the deuterated sitosterol and stigmasterol (and two of their diasteromers) on oriented lipid bilayers were analyzed by deuterium NMR spectroscopy. Orientation and mobility of the side chains was revealed by these studies.

Marsan, M.P.; Muller, I.; Milon, A. [CNRS, Toulouse (France)] [and others

1996-06-28

70

Beyond cholesterol-lowering effects of plant sterols: clinical and experimental evidence of anti-inflammatory properties.  

PubMed

Inflammation is a strong risk factor for cardiovascular disease. Dietary plant sterols are known to reduce plasma cholesterol levels and thereby reduce cardiovascular risk. Recent observations from animal and human studies have demonstrated anti-inflammatory effects of phytosterols. For example, several animal and human studies report reductions in the levels of proinflammatory cytokines, including C-reactive protein, after consumption of dietary plant sterols. Although the cholesterol-lowering effects of phytosterols in humans are well documented, studies on the effects of phytosterols on inflammatory markers have produced inconsistent results. This review summarizes and discusses findings from recent animal and human studies with regard to the potential anti-inflammatory effects of dietary phytosterols. Findings on the effects of plant sterols on inflammation remain limited and confounding. Future research using better-designed and well-controlled laboratory studies and clinical trials are needed to fully understand the mechanisms through which phytosterols influence inflammation. Additional well-designed placebo-controlled studies are needed to better understand how and to what extent dietary plant sterols may modify the immune system and the production of inflammatory markers. PMID:21729090

Othman, Rgia A; Moghadasian, Mohammed H

2011-06-30

71

SHORT-TERM EFFICACY OF PLANT STEROLS CONSUMED AT BREAKFAST OR AT EACH MEAL IN LOWERING BLOOD CHOLESTEROL LEVELS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Objective: To compare under controlled conditions the effect of plant sterol consumed as a single morning dose or divided through the day on blood lipid profile. Method: A randomized, placebo-controlled, crossover-feeding, single blind trial was conducted in 19 subjects with LDL- cholesterol level...

72

Serum Retinol, ?-Tocopherol, and ?-Carotene Levels Are Not Altered by Excess Ingestion of Diacylglycerol-Containing Plant Sterol Esters  

Microsoft Academic Search

Background: Diacylglycerol (DAG) suppresses the postprandial increase in serum triglycerides, and has antiobesity effects. On the other hand, plant sterol esters (PSE) lower serum cholesterol levels in hypercholesterolemia. Thus, DAG-containing PSE (PSE\\/DAG) would be expected to maintain an appropriate serum cholesterol level and decrease the risk of arteriosclerotic disorders. Several recent studies, however, report negative effects of PSE on serum

Shinichiro Saito; Kazuichi Tomonobu; Naoto Kudo; Daisuke Shiiba; Tadashi Hase; Ichiro Tokimitsu

2006-01-01

73

935. Anti-PI3K\\/Akt Cell Survival Pathway Gene Therapy Supplemented with Plant Sterol Diet for Prostate Cancer Treatment  

Microsoft Academic Search

Prostate cancer is the most frequently diagnosed malignancy and the second leading cause of cancer deaths in American men today. The dietary animal and plant sterols appear to play critical roles in prostate cancer formation\\/progression, or prevention, respectively. Cholesterol, the animal sterol that is enriched in red meat and dietary fat, is implicated in promoting prostate cancer formation and progression.

Jun Zhang; Yi Lu

2006-01-01

74

Identification of plant sterols in plasma and red blood cells of man and experimental animals  

Microsoft Academic Search

Direct gas liquid chromatography (GLC) of total plasma lipids showed small peaks (0.5–1.5% of total free sterol area) corresponding\\u000a to free C28 and C29 sterols in ca. 50% of some 3,000 normal subjects and patients with hyperlipemia. Comparable proportions of similar peaks\\u000a were present in the sterol fraction isolated from the red blood cells of many of these subjects. The

A. Kuksis; L. Marai; J. J. Myher; K. Geher

1976-01-01

75

Cholesterol-lowering efficacy of plant sterols/stanols provided in capsule and tablet formats: results of a systematic review and meta-analysis.  

PubMed

Plant sterols/stanols-enriched foods possess well-documented low-density lipoprotein (LDL)-cholesterol-lowering effect. However, the relative efficacy of plant sterols/stanols as supplements (tablets/capsules) compared with other dietary forms still needs to be determined. Our aim was to precisely identify and quantify the LDL-cholesterol-lowering effect of plant sterols/stanols as supplements in contrast to food-based approaches. Eight eligible clinical trials published from January 1992 to April 2013 were identified from five databases. A random effect model was used to calculate weighted mean effect sizes for net differences in LDL-cholesterol concentrations. Among the included trials with the duration between 4 and 6 weeks, plant sterol/stanol dose ranged from 1.0 to 3.0 g/day administrated mainly with the main meals (2 or 3 times/day). Intake of plant sterol/stanol supplements decreased LDL-cholesterol concentrations by 12 mg/dL (0.31 mmol/L) (95% CI -0.39 to -0.23; P<0.000) compared with placebo. The test of heterogeneity was not significant (?(2) , P=0.50, I(2)=0%). Further analysis showed no significant difference between the LDL-cholesterol-lowering action of plant sterols/stanols supplements (-12 mg/dL [-0.31 mmol/L]; 95% CI -0.39 to -0.24; P<0.0001) vs foods enriched with plant sterols/stanols (-12 mg/dL [-0.31 mmol/L]; 95% CI -0.35 to -0.27; P<0.0001). Plant sterol/stanol supplements as part of a healthy diet represent an effective means of delivering LDL-cholesterol-lowering similar to plant sterols/stanols delivered in various food formats. PMID:24144075

Amir Shaghaghi, Mandana; Abumweis, Suhad S; Jones, Peter J H

2013-11-01

76

Dietary intake of naturally occurring plant sterols is related to a lower risk of a first myocardial infarction in men but not in women in northern sweden.  

PubMed

Dietary intake of naturally occurring plant sterols is inversely related to serum cholesterol concentrations. Elevated serum cholesterol increases the risk of myocardial infarction (MI), but it is unknown if this can be reduced by dietary intake of naturally occurring plant sterols. Our aim was to investigate if a high intake of naturally occurring plant sterols is related to a lower risk of contracting a first MI. The analysis included 1005 prospective cases (219 women, 786 men) and 3148 matched referents (723 women, 2425 men), aged 29-73 y at baseline, from the population-based Northern Sweden Health and Disease Study. A food frequency questionnaire (FFQ) was completed at baseline. Absolute plant sterol intake was inversely related to the risk of a first MI in men (OR highest vs. lowest quartile = 0.70; 95% CI: 0.53, 0.85; P-trend = 0.006) but not in women. After adjustment for confounders, the estimated risk was somewhat attenuated (OR highest vs. lowest quartile = 0.71; 95% CI: 0.55, 0.92; P-trend = 0.067), suggesting that increasing sterol intake from 150 to 340 mg/d reduces the risk of a first MI by 29%. Energy-adjusted plant sterol intake was not related to the risk of a first MI in either men or women. In conclusion, the findings of this observational study show that a high absolute intake of naturally occurring plant sterols is significantly related to a lower risk of a first MI in men in northern Sweden, whereas no significant relation was seen for energy-adjusted plant sterol intake. In women, no significant associations were found. The results from this study show that intake of plant sterols may be important in prevention of MI. PMID:23925940

Klingberg, Sofia; Ellegĺrd, Lars; Johansson, Ingegerd; Jansson, Jan-Hĺkan; Hallmans, Göran; Winkvist, Anna

2013-08-07

77

Plant sterols regulate rat vascular smooth muscle cell growth and prostacyclin release in culture.  

PubMed

Cardiovascular disease (CVD) is the leading cause of death in the USA and other industrialized countries. A large number of epidemiological studies have established a direct correlation between diet and the development and progression of atherosclerosis. Several studies have shown the incidence of CVD to be lower in populations consuming a predominantly plant-based diet, as compared to meat-based diets. Besides being low in fat and cholesterol, vegetarian and Asian diets contain a large variety of phytochemicals, which may function in the body. For example, phytosterols (PS) are plant sterols that interfere with the absorption of cholesterol from the intestine when present in adequate amounts. Although PS may also function at a cellular level in the body, there are few studies examining the action of PS on cells involved in atherosclerosis. The purpose of this study was to examine the effect of dietary PS on vascular smooth muscle cell (VSMC) growth and function, since VSMC play a central role in the development of atherosclerosis. VSMC were treated with 16 microM cholesterol, 25-hydroxycholesterol, campesterol and beta-sitosterol (SIT) using an ethanol as a vehicle. Cell growth was determined by cell counting and cell proliferation by DNA synthesis, which was measured by [(3)H]-thymidine incorporation. Cholesterol supplementation had no effect on cell growth and proliferation. 25-Hydroxycholesterol decreased cell growth by 68% and DNA synthesis by 99%. SIT was found to inhibit VSMC growth more effectively than campesterol. Of the two PS, campesterol decreased cell growth by 16% and SIT decreased cell growth by 30%. DNA synthesis was decreased 25% by SIT supplementation but was not influenced by campesterol or cholesterol supplementation. Cholesterol, campesterol and SIT were not cytotoxic to VSMC and did not significantly alter cell viability. 25-Hydroxycholesterol, however, was cytotoxic and decreased cell viability by 45% as determined by lactate dehydrogenase release and a trypan blue dye exclusion test. De novo cholesterol synthesis was decreased 28% by campesterol, 49% by SIT and 23% by cholesterol. Beta-sitosterol exhibited a greater effect on cholesterol synthesis than campesterol or cholesterol supplementation. Measurement of cell sterol content demonstrated incorporation of PS into VSMC at the expense of cholesterol. Campesterol decreased VSMC cholesterol content by 36%, representing 40% of the total sterol content following treatment. Beta-sitosterol decreased VSMC cholesterol by 41% following supplementation and represented 49% of the total sterol amount. Cholesterol treatment did not alter the cholesterol content of the cells. Prostacyclin production was significantly altered by PS treatment. Basal prostacyclin release was increased 43% by campesterol and 81% by SIT. A23187 stimulated prostacyclin release was increased 25% by campesterol and 54% by SIT. SIT supplementation induced a greater effect on prostacyclin release from VSMC than cholesterol or campesterol supplementation. The in vitro results presented here suggest that dietary PS, especially SIT, may offer protection from the VSMC hyperproliferation found in atherosclerosis. Further in vivo research is needed to support these observations. PMID:11427042

Awad, A B; Smith, A J; Fink, C S

2001-06-01

78

The effect of methyl jasmonate on triterpene and sterol metabolisms of Centella asiatica, Ruscus aculeatus and Galphimia glauca cultured plants.  

PubMed

Considering that exogenously applied methyl jasmonate can enhance secondary metabolite production in a variety of plant species and that 2,3-oxidosqualene is a common precursor of triterpenes and sterols in plants, we have studied Centella asiatica and Galphimia glauca (both synthesizing triterpenoid secondary compounds) and Ruscus aculeatus (which synthesizes steroidal secondary compounds) for their growth rate and content of free sterols and respective secondary compounds, after culturing with or without 100 microM methyl jasmonate. Our results show that elicited plantlets of G. glauca and to a higher degree C. asiatica (up to 152-times more) increased their content of triterpenoids directly synthesized from 2,3-oxidosqualene (ursane saponins and nor-seco-friedelane galphimines, respectively) at the same time as growth decreased. In contrast, the free sterol content of C. asiatica decreased notably, and remained practically unaltered in G. glauca. However, in the case of R. aculeatus, which synthesizes steroidal saponins (mainly spirostane type) indirectly from 2,3-oxidosqualene after the latter is converted to the plant phytosterol-precursor cycloartenol, while the growth rate and free sterol content clearly decreased, the spirostane saponine content was virtually unchanged (aerial part) or somewhat lower (roots) in presence of the same elicitor concentration. Our results suggest that while methyl jasmonate may be used as an inducer of enzymes involved in the triterpenoid synthesis downstream from 2,3-oxidosqualene in both C. asiatica and G. glauca plantlets, in those of C. asiatica and R. aculeatus it inhibited the enzymes involved in sterol synthesis downstream from cycloartenol. PMID:16876832

Mangas, Susana; Bonfill, Mercč; Osuna, Lidia; Moyano, Elisabeth; Tortoriello, Jaime; Cusido, Rosa M; Pińol, M Teresa; Palazón, Javier

2006-07-28

79

Sterol and n-alkane biomarker composition of modern fen plants - potential application for palaeoecological analyses  

NASA Astrophysics Data System (ADS)

Acute and contemporary questions related to human-induced changes in climate have emphasized the importance of peatland research because peatlands store large quantities of carbon. Historically, pristine mires have been long-term sinks for atmospheric carbon because of a slow decomposition rate of the organic matter once below the water table. However, the net carbon balance of mires is highly sensitive and reflects changes in moisture conditions and consequent changes in vegetation assemblages. Historical variations in climate and hydrology are recorded in peat layers as alteration in the assemblages of different biological organisms. Past vegetation assemblages are in a key role when reconstructing the past moisture conditions that control peatland carbon dynamics. In order to evaluate the role of northern peatlands as carbon sinks or sources in changing future climate, it is important to understand the past mechanisms: how mires have earlier responded to climate forcing. An especially useful proxy method to reconstruct past environmental changes is the plant macrofossil method. Large parts of northern peatlands are fens, where, as a result of fast surface decay, major parts of the peat below the surface layer is highly humified. Bog peats, in turn, usually contain relatively well preserved plant material for palaeoecological examination, but highly humified layers can also be found underneath the top layers of bog peats. A high degree of humification constrains palaeo-botanical and -climatical studies because reliable identification of different fossil vegetation components is difficult. Previous work has shown that plant biomarkers (compounds that can be linked to specific plant types) can be successfully applied to indentify modern and fossil plant groups from less-humified bog peat. In this study we apply selected organic geochemistry methods to fen plant species to investigate the potential for biomarkers to characterise different fen plants. We focus on plant types that would give insight into major palaeoecological challenges (e.g. Sphagnum subsecundum, Warnstorfia exannulata, Carex livida). We report n-alkane and sterol distributions and concentrations in shoots, stems and roots from 12 plant species common to fens. The primary results are promising, confirming some previously established relationships in peat-forming plants e.g. n-alkane chain length differs between the main plant types (e.g. Sphagnum versus non-Sphagnum). However, we also find that biomarker composition, and thus interpretation of the chemical fingerprints of fen plants, is not as straightforward as in bog plants. The implications of these results for palaeo-ecological investigations are discussed.

Ronkainen, T.; McClymont, E. L.; Väliranta, M.; Tuittila, E.

2011-12-01

80

Intake of dietary plant sterols is inversely related to serum cholesterol concentration in men and women in the EPIC Norfolk population: a cross-sectional study  

Microsoft Academic Search

Objective: We examined the relation between intake of natural dietary plant sterols and serum lipid concentrations in a free-living population.Design, setting and participants: Cross-sectional population-based study of 22 256 men and women aged 39–79 y resident in Norfolk, UK, participating in the European Prospective Investigation into Cancer (EPIC-Norfolk).Main exposure and outcome measures: Plant sterol intake from foods and concentrations of

S W Andersson; J Skinner; L Ellegĺrd; A A Welch; S Bingham; A Mulligan; H Andersson; K-T Shaw; K-T Khaw

2004-01-01

81

Impact of margarine enriched with plant sterols on blood lipids, platelet function, and fibrinogen level in young men  

Microsoft Academic Search

The effects of margarines enriched with ?-6 polyunsaturated fatty acids (PUFA), as well as those containing plant sterols or stanols, on reduction of plasma low-density lipoprotein-cholesterol (LDL-C) have been extensivly studied. However, their impact on fibrinogen (Fb) concentration and blood platelet function is much less known. Our research involved 42 healthy male students (average age, 23.7 ± 1.6) who during

Ma?gorzata Koz?owska-Wojciechowska; Maria Jastrz?bska; Marek Naruszewicz; Anna Folty

2003-01-01

82

Plant sterol ester-enriched spread lowers plasma total and LDL cholesterol in children with familial hypercholesterolemia1,2  

Microsoft Academic Search

Background: Naturally occurring plant sterol esters (SEs) favor- ably affect serum cholesterol concentrations in humans and could aid in the treatment of children with familial hypercholes- terolemia (FH). Objective: We studied the effect of SE-enriched spread on serum lipids, lipoproteins, carotenoids, fat-soluble vitamins, and physi- ologic variables in children with FH aged 7-12 y. Design: In a randomized, double-blind crossover

Ĺgot L Amundsen; Leiv Ose; Marit S Nenseter; Fady Y Ntanios

83

Effect of free plant sterols in low-fat milk on serum lipid profile in hypercholesterolemic subjects  

Microsoft Academic Search

Objective: To determine the effect of nonesterified, nonhydrogenated plant sterols solubilized in a partly vegetable oil-filled low-fat milk on serum low-density lipoprotein cholesterol (LDL) in mildly hypercholesterolemic patients.Design: Double-blind, randomized, placebo-controlled three-arm crossover study.Setting: Outpatient clinical trial.Subjects: A total of 138 patients were screened, providing 81 patients for randomization; 71 patients completed the study.Interventions: The study product was a 500

A B Thomsen; H B Hansen; C Christiansen; H Green; A Berger

2004-01-01

84

Additive effect of plant sterol-ester margarine and cerivastatin in lowering low-density lipoprotein cholesterol in primary hypercholesterolemia  

Microsoft Academic Search

The objective of this study was to evaluate whether plant sterol-ester margarine has an additive or interactive effect on low-density lipoprotein (LDL) cholesterol reduction when ingested in combination with a statin drug. This was a multicenter, randomized, double-blind study with 4 parallel treatment arms in a balanced 2 × 2 factorial design. The 4 daily treatment options were: (1) placebo

Leon A Simons

2002-01-01

85

Oxidised plant sterols as well as oxycholesterol increase the proportion of severe atherosclerotic lesions in female LDL receptor+/ - mice.  

PubMed

Oxysterols (oxidised cholesterol) may play a role in the pathogenesis of CVD. Similar to cholesterol, plant sterols are susceptible to oxidation. However, less is known about the potential atherogenicity of oxidised plant sterols (oxyphytosterols). In the present study, the atherogenicity of a mixture of oxyphytosterols was examined by feeding female LDL receptor-deficient (LDLR+/ -) mice for 35 weeks a control diet (atherogenic high-fat diet; n 9), an oxysterol diet (control diet+0·025 % (w/w) oxysterols; n 12) or an oxyphytosterol diet (control diet+0·025 % (w/w) oxyphytosterols; n 12). In the LDLR+/ - mice, serum levels of cholesterol, lipoprotein profiles, cholesterol exposure and inflammatory markers at the end of the experiment were comparable between the three diet groups. Nevertheless, the proportion of severe atherosclerotic lesions was significantly higher after oxysterol (41 %; P= 0·004) and oxyphytosterol (34 %; P= 0·011) diet consumption than after control diet consumption (26 %). Oxyphytosterol levels in the lesions were the highest in the oxyphytosterol group. Here, we show that not only dietary oxysterols but also dietary oxyphytosterols increase the proportion of severe atherosclerotic lesions. This suggests that plant sterols when oxidised may increase atherosclerotic lesion severity instead of lowering the size and severity of lesions when fed in their non-oxidised form. Therefore, this finding might give an indication as to where to find the answer in the current hot debate about the potential atherogenicity of plant sterols. However, to what extent these results can be extrapolated to the human situation warrants further investigation. PMID:23773414

Plat, Jogchum; Theuwissen, Elke; Husche, Constanze; Lütjohann, Dieter; Gijbels, Marion J J; Jeurissen, Mike; Shiri-Sverdlov, Ronit; van der Made, Ingeborg; Mensink, Ronald P

2013-06-18

86

Plant sterol-enriched spread enhances the cholesterol-lowering potential of a fat-reduced diet  

Microsoft Academic Search

Objective: To determine the effect of a plant sterol-enriched spread on plasma cholesterol concentrations when replacing butter or a standard polyunsaturated spread in a diet containing 30% of energy fat.Design: Parallel butter phase followed by double-blind, randomized, cross-over polyunsaturated spread phases.Setting: General community.Subjects: Volunteer sample of 50 free-living men and women with mean age (s.d.) 46.7 y (10.5), moderately elevated

C L Cleghorn; C M Skeaff; J Mann; A Chisholm

2003-01-01

87

Synthesis of novel ring B Abeo-sterol derivatives and their antiproliferative activities.  

PubMed

Using cholesterol, ?-sitosterol, dehydroisoandrosterone and pregnenolone as starting materials, a series of 6- hydroximino analogs of ring B abeo-sterols were synthesized and characterized. The antiproliferative activity of analogs was evaluated against SGC 7901 (human gastric carcinoma), HeLa (human cervical carcinoma) and Bel 7404 (human liver carcinoma) cells. The results showed that the presence of a alkyl side chain was very important for their cytotoxicity. However, the presence of 6-hydroximino cannot increase the cytotoxicity of compounds compared with 6-hydroxy group. The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs. PMID:23061600

Gan, Chunfang; Fan, Lianghua; Huang, Yanmin; Liu, Zhiping; Cui, Jianguo

2013-09-01

88

Effects of sterol-binding agent nystatin on wheat roots: The changes in membrane permeability, sterols and glycoceramides  

Microsoft Academic Search

Plant sterols are important multifunctional lipids, which are involved in determining membrane properties. Biophysical characteristics of model lipid and isolated animal membranes with altered sterol component have been intensively studied. In plants however, the precise mechanisms of involvement of sterols in membrane functioning remain unclear. In present work the possible interactions between sterols and other membrane lipids in plant cells

Julia N. Valitova; Farida V. Minibayeva; Ekaterina R. Kotlova; Alexander V. Novikov; Alexey L. Shavarda; Lyaisan I. Murtazina; Irina S. Ryzhkina

2011-01-01

89

Plant Stanols and Plant Sterols and Blood LDL-Cholesterol Scientific Opinion of the Panel on Dietetic Products Nutrition and Allergies on a request from the European Commission and a similar request from France in relation to the authorization procedure for health claims on plant stanols and plant sterols and lowering\\/reducing blood LDL-cholesterol  

Microsoft Academic Search

SUMMARY Following a request from the European Commission and a similar request from France, the Panel on Dietetic Products, Nutrition and Allergies was asked to deliver a scientific advice in relation to the authorisation procedure for health claims on plant stanols and plant sterols and lowering\\/reducing blood cholesterol pursuant to Article 14 of Regulation (EC) No 1924\\/2006. The quantities of

Jean-Louis Bresson; Albert Flynn; Marina Heinonen; Karin Hulshof; Hannu Korhonen; Pagona Lagiou; Rosangela Marchelli; Ambroise Martin; Bevan Moseley; Hildegard Przyrembel; Seppo Salminen; Stephan Strobel; Inge Tetens; Henk van den Berg; Hendrik van Loveren; Hans Verhagen

2009-01-01

90

Stearate-enriched plant sterol esters lower serum LDL cholesterol concentration in normo- and hypercholesterolemic adults.  

PubMed

Studies in our laboratory have previously demonstrated in hamsters a superior cholesterol-lowering ability of plant sterol (PS) esters enriched in stearate compared with linoleate. We therefore conducted a randomized, double-blind, 2-group parallel, placebo-controlled study to test the cholesterol-lowering properties of stearate-enriched PS esters in normo- and hypercholesterolemic adults. Thirty-two adults, 16 per group with equal number of males and females in each group, participated in the 4-wk study. Participants consumed 3 g/d (1 g three times per day with meals) of either PS esters or placebo delivered in capsules. Serum LDL cholesterol concentration significantly decreased 0.42 mmol/L (11%) and the LDL:HDL cholesterol ratio decreased 10% with PS ester supplementation, whereas LDL particle size and lipoprotein subclass particle concentrations (as measured by NMR) were not affected. The percent change in LDL cholesterol was positively correlated with baseline lathosterol concentration (r = 0.729; P = 0.0014), indicating an association between the magnitude of LDL change and the rate of whole-body cholesterol synthesis. Serum campesterol (but not sitosterol) concentration significantly increased in the PS ester group. Serum tocopherol, retinol, and beta-carotene concentrations were not affected by PS ester supplementation. Thus, our findings demonstrate the usefulness of a novel stearate-enriched PS ester compound in decreasing LDL cholesterol in both normo- and hypercholesterolemic adults. The extent to which PS ester fatty acid composition affects intestinal micelle formation and cholesterol absorption in humans requires further study. PMID:19535421

Carr, Timothy P; Krogstrand, Kaye L Stanek; Schlegel, Vicki L; Fernandez, Maria Luz

2009-06-17

91

Prevention of Endotoxin-Induced Uveitis in Rats by Plant Sterol Guggulsterone  

PubMed Central

Purpose. To investigate the anti-inflammatory effects of guggulsterone, an antioxidant and antitumor agent, in endotoxin-induced uveitis (EIU) in rats and to elucidate the underlying molecular mechanism or mechanisms related to ocular inflammation. Methods. EIU was induced by subcutaneous injection of lipopolysaccharide (LPS; 150 ?g) into Lewis rats treated with guggulsterone (30 mg/kg body weight, intraperitoneally) or its carrier. After 24 hours the rats were killed, eyes were enucleated, and aqueous humor (AqH) was collected. Numbers of infiltrating cells and levels of matrix metalloproteinase-2 (MMP-2), nitric oxide (NO), and prostaglandin E2 (PGE2) were determined in AqH by specific ELISAs. An antibody array was used to measure the expression of various inflammatory cytokines in AqH. The expression of MMP-2, iNOS, Cox-2, phospho-I?B, and phospho-NF-?B was determined immunohistochemically. Human primary nonpigment ciliary epithelial cells (HNPECs) were used to determine the in vitro efficacy of guggulsterone on the LPS-induced inflammatory response. Results. Compared with control, the EIU rat eye AqH had a significantly higher number of infiltrating cells, total protein, and inflammatory markers, such as MMP-2, NO, and PGE2, and the treatment of guggulsterone prevented EIU-induced increases. Guggulsterone also prevented the expression of MMP-2, iNOS, and Cox-2 proteins and of I?B and NF-?B in various eye tissues. Moreover, in cultured HNPECs, guggulsterone inhibited LPS-induced expression of inflammatory proteins. Conclusions. These results for the first time demonstrate that the plant sterol guggulsterone suppresses ocular inflammation in EIU, suggesting that the supplementation of guggulsterone could be a novel approach for the treatment of ocular inflammation.

Kalariya, Nilesh M.; Shoeb, Mohammad; Reddy, Aramati B. M.; Zhang, Min; van Kuijk, Frederik J. G. M.

2010-01-01

92

Efficacy of plant sterols is not influenced by dietary cholesterol intake in hypercholesterolemic individuals.  

PubMed

Plant sterols (PSs) reduce plasma total and low-density lipoprotein cholesterol (LDL-C) levels by reducing cholesterol absorption; however, it is not known whether the level of dietary cholesterol intake has an impact on the efficacy of PSs on blood lipids. The purpose of this study was to determine the effect of high vs low dietary cholesterol levels on the lipid-lowering efficacy of free PSs. The study was a semirandomized, double-blind, crossover trial consisting of four 28-day feeding phases each separated by a 4-week washout period. Otherwise healthy hypercholesterolemic subjects (n = 22) consumed each of (a) low-cholesterol control (C(-)S(-)), (b) high-cholesterol control (C(+)S(-)), (c) 22 mg PSs per kilogram of body weight with a low-cholesterol diet (C(-)S(+)), and (d) 22 mg PSs per kilogram of body weight with a high-cholesterol diet (C(+)S(+)). Blood was drawn on the first and last 2 days of each phase to measure plasma total cholesterol, LDL-C, high-density lipoprotein cholesterol, and triacylglycerols as well as plasma campesterol and beta-sitosterol concentrations. Dietary cholesterol had no effect on PS efficacy as a cholesterol-lowering agent because no interaction was found between the 2 factors. However, dietary cholesterol and PS intake had significant independent effects on plasma total cholesterol, LDL-C, and high-density lipoprotein cholesterol levels. beta-Sitosterol levels in plasma increased (P < .0001) as a result of PS supplementation. Data from the present study indicate that, although PSs and dietary cholesterol exert independent effects on plasma cholesterol, PS efficacy is not affected by varying levels of cholesterol intake. PMID:18249205

Kassis, Amira N; Vanstone, Catherine A; AbuMweis, Suhad S; Jones, Peter J H

2008-03-01

93

Increased plasma plant sterol levels in heterozygotes with sitosterolemia and xanthomatosis  

Microsoft Academic Search

Plasma sterol levels in a family of sitosterolemia and xanthomatosis were determined by a high performance liquid chromatography. Three affected siblings manifested marked xanthomatosis including subcutaneous soft tissues and general- ized atherosclerosis. Two other siblings as well as children of the patients did not show such clinical symptoms and signs. Plasma levels of cholesterol, sitosterol, campesterol, and cholestanol in three

Hideki Hidaka; Takaaki Nakamura; Takahiko Aoki; Hideto Kojima; Yuzuru Nakajima; Keisuke Kosugi; Ikuo Hatanaka; Masaki Harada; Masashi Kobayashi; Akira Tamura; Tatsuzo Fujii; Yukio Shigeta

94

The ABCA2 transporter: intracellular roles in trafficking and metabolism of LDL-derived cholesterol and sterol-related compounds.  

PubMed

ATP-binding cassette (ABC) transporters comprise a family of critical membrane bound proteins functioning in the translocation of molecules across cellular membranes. Substrates for transport include lipids, cholesterol and pharmacological agents. Mutations in ABC transporter genes cause a variety of human pathologies and elicit drug resistance phenotypes in cancer cells. ABCA2, the second member the A subfamily to be identified, was highly expressed in ovarian carcinoma cells resistant to the anti-cancer agent, estramustine, and more recently, in human vestibular schwannomas. Cells expressing elevated levels of ABCA2 show resistance to variety of compounds, including estradiol, mitoxantrone and a free radical initiator, 2,2'-azobis-(2-amidinopropane). ABCA2 is expressed in a variety of tissues, with greatest abundance in the central nervous system and macrophages. This transporter, along with other proteins that have a high degree of homology to ABCA2, including ABCA1 and ABCA7, are up-regulated in human macrophages during cholesterol import. Recent studies have shown ABCA2 also plays a role in the trafficking of low-density lipoprotein (LDL)-derived free cholesterol and to be coordinately expressed with sterol-responsive genes. A single nucleotide polymorphism in exon 14 of the ABCA2 gene was shown to be linked to early onset Alzheimer disease (AD) in humans, supporting an earlier study showing ABCA2 expression influences levels of APP and beta-amyloid peptide, the primary component of senile plaques. Studies thus far implicate ABCA2 as a sterol transporter, the deregulation of which may affect a cellular phenotype conducive to the pathogenesis of a variety of human diseases including AD, atherosclerosis and cancer. PMID:17266523

Mack, Jody T; Townsend, Danyelle M; Beljanski, Vladimir; Tew, Kenneth D

2007-01-01

95

Fish-oil esters of plant sterols differ from vegetable-oil sterol esters in triglycerides lowering, carotenoid bioavailability and impact on plasminogen activator inhibitor-1 (PAI-1) concentrations in hypercholesterolemic subjects  

Microsoft Academic Search

BACKGROUND: Consumption of plant sterol (PS) esters lower low-density lipoprotein (LDL)-cholesterol levels by suppressing intestinal absorption of cholesterol. Commercially available PS are mainly esterified to omega-6 fatty acid (FA), such as sunflower oil (SO) FA. Emerging trends include using other sources such as olive oil (OO) or omega-3 FA from fish oil (FO), known to exert potent hypotriglyceridemic effects. Our

Peter JH Jones; Isabelle Demonty; Yen-Ming Chan; Yael Herzog; Dori Pelled

2007-01-01

96

Cholesterol-lowering effects of plant sterol esters differ in milk, yoghurt, bread and cereal  

Microsoft Academic Search

Objective: To measure the relative effects of each of four phytosterol ester-enriched low-fat foods (bread, breakfast cereal, milk and yoghurt) on serum lipids, plasma phytosterols and carotenoids.Design: Three research centres undertook a randomised, incomplete crossover, single-blind study consisting of four treatment periods of 3 weeks each, one of which was a control period. Each sterol-enriched test food provided 1.6 g\\/day

P M Clifton; M Noakes; D Sullivan; N Erichsen; D Ross; G Annison; A Fassoulakis; M Cehun; P Nestel

2004-01-01

97

Plant derived veterinary vaccines  

Microsoft Academic Search

Infectious diseases remain one of the main causes of death and economic losses in animals despite the fact that prophylactic\\u000a vaccination has been extremely successful in disease prevention. New effective viral, bacterial and parasitic vaccines are\\u000a needed, but unfortunately production costs still remain prohibitive. In this respect plants can offer a valid alternative.\\u000a Production of antigenic proteins in plants relies

L. Santi

2009-01-01

98

A dietary portfolio approach to cholesterol reduction: combined effects of plant sterols, vegetable proteins, and viscous fibers in hypercholesterolemia.  

PubMed

Plant sterols, soy proteins, and viscous fibers are advised for cholesterol reduction but their combined effect has never been tested. We therefore assessed their combined effect on blood lipids in hyperlipidemic subjects who were already consuming a low-saturated fat, low-cholesterol diet before starting the study. The test (combination) diet was 1 month in duration and was very low in saturated fat and high in plant sterols (1 g/1,000 kcal), soy protein (23 g/1,000 kcal), and viscous fibers (9 g/1,000 kcal) obtained from foods available in supermarkets and health food stores. One subject also completed 2 further diet periods: a low-fat control diet and a control diet plus 20 mg/d lovastatin. Fasting blood lipids, blood pressure, and body weight were measured prior to and at weekly intervals during the study. The combination diet was rated as acceptable and very filling. The diet reduced low-density lipoprotein (LDL)-cholesterol by 29.0% +/- 2.7% (P <.001) and the ratio of LDL-cholesterol to high-density lipoprotein (HDL)-cholesterol by 26.5% +/- 3.4% (P <.001). Near maximal reductions were seen by week 2. In the subject who took Mevacor and control diets each for 4 weeks, the reduction in LDL:HDL-cholesterol on Mevacor was similar to the combination diet. We conclude that acceptable diets of foods from supermarkets and health food stores that contain recognized cholesterol-lowering dietary components in combination (a dietary portfolio) may be as effective as the starting dose of older first-line drugs in managing hypercholesterolemia. PMID:12489074

Jenkins, David J A; Kendall, Cyril W C; Faulkner, Dorothea; Vidgen, Edward; Trautwein, Elke A; Parker, Tina L; Marchie, Augustine; Koumbridis, George; Lapsley, Karen G; Josse, Robert G; Leiter, Lawrence A; Connelly, Philip W

2002-12-01

99

Plant-derived wildlife repellents  

US Patent & Trademark Office Database

Products from the plant species Nerium oleander and, Urginea maritima, are prepared and tested as wildlife repellents comparing them with digitalis products. Chemical compounds derived from these plants including oleandrin, oleandrigenin, scillirosidin, digitoxigenin and digoxigenin are shown to cause nausea and emesis at low doses in pigeons and to repel, mice, rats, gophers, meadow voles and mountain beavers. After ingestion these animals quickly learn to avoid targets treated with the plant-derived repellents. When the remembrance of a treated food or other target lasts for an extended period of time it can be termed an aversion conditioning agent. Such products can be used for the protection of other plants, seeds, buildings, structures, communication cables and animals exposed to wildlife.

Verbiscar; Anthony J. (Sierra Madre, CA)

1994-10-18

100

Effect of low-fat, fermented milk enriched with plant sterols on serum lipid profile and oxidative stress in moderate hypercholesterolemia13  

Microsoft Academic Search

Background: Plant sterol (PS)-enriched foods have been shown to reduce plasma LDL-cholesterol concentrations. In most studies, however, PSs were incorporated into food products of high fat content. Objective: We examined the effect of daily consumption of PS- supplemented low-fat fermented milk (FM) on the plasma lipid profile and on systemic oxidative stress in hypercholesterolemic subjects. Design: Hypercholesterolemic subjects (LDL-cholesterol concen-

Boris Hansel; Catherine Nicolle; Florent Lalanne; Francoise Tondu; Taous Lassel; Yves Donazzolo; Jean Ferričres; Michel Krempf; Jean-Louis Schlienger; Bruno Verges; M John Chapman; Eric Bruckert

101

Evaluating potential applications of faecal sterols in distinguishing sources of faecal contamination from mixed faecal samples.  

PubMed

Faecal samples from humans, herbivores, carnivores and birds as well as samples from septic tanks and effluents from a sewage treatment plant (STP) were extracted and analyzed by gas chromatography-mass spectrometry for faecal sterols including coprostanol, epicoprostanol, cholestanol, cholesterol, stigmasterol, campesterol, 24-ethylcoprostanol and beta-sitosterol. Coprostanol was observed in the highest concentrations from the human derived samples, but it was also present in substantial quantities in a range of herbivores. There was no unique marker of human faecal contamination. Multivariate analyses revealed that the faecal sterol profiles were significantly different between the four groups of animals (Wilks' lambda=0.007, P<0.002), and coprostanol and 24-ethylcoprostanol were the major discriminant factors. However, when faecal samples were mixed, the confounding of faecal sterol levels prevented accurate identification of contributing species. Conversely, faecal sterol ratios were highly efficient at identifying which mixtures contained human contribution, but could not appropriately determine percentage contributions of sources. PMID:17614115

Shah, Vikaskumar G; Dunstan, R Hugh; Geary, Phillip M; Coombes, Peter; Roberts, Timothy K; Von Nagy-Felsobuki, Ellak

2007-07-05

102

Cholesterol absorption efficiency and sterol metabolism in obesity  

Microsoft Academic Search

Role of enterohepatic cholesterol metabolism in obesity-induced increase of cholesterol synthesis was studied in healthy lean (BMI 31) subjects by measuring serum lipids (including plant sterols, cholestanol and cholesterol precursors), cholesterol absorption % (double-label method), sterol balance and biliary lipids. New aspects of sterol metabolism in obesity were as follows: low efficiency of cholesterol absorption, reduced ratios to cholesterol of

Tatu A. Miettinen; Helena Gylling

2000-01-01

103

Role of membrane sterols and cortical microtubules in gravity resistance in plants  

Microsoft Academic Search

Resistance to the gravitational force is a principal graviresponse in plants comparable to gravitropism Nevertheless only limited information has been obtained for this graviresponse We have examined mechanisms of signal perception transformation and transduction of the perceived signal and response to the transduced signal in gravity resistance using hypergravity conditions produced by centrifugation In Arabidopsis hypocotyls hypergravity treatment greatly increased

T. Hoson; T. Koizumi; S. Matsumoto; S. Kumasaki; K. Soga; K. Wakabayashi; T. Sakaki

2006-01-01

104

Plant sterols the better cholesterol in Alzheimer's disease? A mechanistical study.  

PubMed

Amyloid-? (A?), major constituent of senile plaques in Alzheimer's disease (AD), is generated by proteolytic processing of the amyloid precursor protein (APP) by ?- and ?-secretase. Several lipids, especially cholesterol, are associated with AD. Phytosterols are naturally occurring cholesterol plant equivalents, recently been shown to cross the blood-brain-barrier accumulating in brain. Here, we investigated the effect of the most nutritional prevalent phytosterols and cholesterol on APP processing. In general, phytosterols are less amyloidogenic than cholesterol. However, only one phytosterol, stigmasterol, reduced A? generation by (1) directly decreasing ?-secretase activity, (2) reducing expression of all ?-secretase components, (3) reducing cholesterol and presenilin distribution in lipid rafts implicated in amyloidogenic APP cleavage, and by (4) decreasing BACE1 internalization to endosomal compartments, involved in APP ?-secretase cleavage. Mice fed with stigmasterol-enriched diets confirmed protective effects in vivo, suggesting that dietary intake of phytosterol blends mainly containing stigmasterol might be beneficial in preventing AD. PMID:24107941

Burg, Verena K; Grimm, Heike S; Rothhaar, Tatjana L; Grösgen, Sven; Hundsdörfer, Benjamin; Haupenthal, Viola J; Zimmer, Valerie C; Mett, Janine; Weingärtner, Oliver; Laufs, Ulrich; Broersen, Laus M; Tanila, Heikki; Vanmierlo, Tim; Lütjohann, Dieter; Hartmann, Tobias; Grimm, Marcus O W

2013-10-01

105

Metabolism of conjugated sterols in eggplant. Part 1. UDP-glucose : sterol glucosyltransferase.  

PubMed

A membrane-bound UDP-glucose : sterol glucosyltransferase from Solanum melongena (eggplant) leaves was partially purified and its specificity as well as molecular and kinetic properties were defined. Among a wide spectrum of 3-OH steroids (i.e. typical plant sterols, androstane, pregnane and cholestane derivatives, steroidal alkaloids and sapogenins) and triterpenic alcohols, the highest activity was found with 22-oxycholesterol. UDP-glucose appeared to be the best sugar donor. The enzyme preparation was also able to utilize UDP-galactose, TDP-glucose and CDP-glucose as a sugar source for sterol glucosylation, however, at distinctly lower rates. The investigated glucosyltrasferase was stimulated by 2-mercaptoethanol, Triton X-100 and negatively charged phospholipids, and inhibited in the presence of UDP, mono-, di- and triacylglycerols, divalent cations such as Zn(2+), Co(2+), high ionic strength, cholesteryl glucoside, galactoside and xyloside and some amino acid-modifying reagents (SITS, DIDS, PLP, DEPC, pCMBS, NEM, WRK and HNB). Our results suggest that unmodified residues of lysine, tryptophan, cysteine, histidine and dicarboxylic amino acids are essential for full enzymatic activity and indicate that a glutamic (or aspartic) acid residue is necessary for the binding of sugar donor, i.e. UDP-glucose in the active site of the GT-ase while histidine and cysteine residues are both important for the binding of the nucleotide-sugar as well as of the steroidal aglycone. PMID:18196184

Potocka, Anna; Zimowski, Jan

2008-01-16

106

Mississippi River Basin Sterol Assay Project Report. Coprostanol, A Positive Molecular Marker of Domestic and Run-Off Pollution. Sterol Assay of Raw Sewage, Wastewater Plant Effluent and Surface Waters in the Burlington, Iowa Area on the Mississippi River.  

National Technical Information Service (NTIS)

Several studies have recently emphasized the merits of using coprostanol, a major human fecal sterol as a positive molecular marker of domestic pollution in addition to the standard method for enumeration of fecal coliforms. Bunch and his coworkers (1967)...

H. H. Tabak R. L. Bunch

1970-01-01

107

Deciphering the Molecular Functions of Sterols in Cellulose Biosynthesis  

PubMed Central

Sterols play vital roles in plant growth and development, as components of membranes and as precursors to steroid hormones. Analysis of Arabidopsis mutants indicates that sterol composition is crucial for cellulose biosynthesis. Sterols are widespread in the plasma membrane (PM), suggesting a possible link between sterols and the multimeric cellulose synthase complex. In one possible scenario, molecular interactions in sterol-rich PM microdomains or another form of sterol-dependent membrane scaffolding may be critical for maintaining the correct subcellular localization, structural integrity and/or activity of the cellulose synthase machinery. Another possible link may be through steryl glucosides, which could act as primers for the attachment of glucose monomers during the synthesis of ??(1???4) glucan chains that form the cellulose microfibrils. This mini-review examines genetic and biochemical data supporting the link between sterols and cellulose biosynthesis in cell wall formation and explores potential approaches to elucidate the mechanism of this association.

Schrick, Kathrin; DeBolt, Seth; Bulone, Vincent

2012-01-01

108

Food labeling: health claims; plant sterol/stanol esters and coronary heart disease. Interim final rule; notice of extension of period for issuance of final rule.  

PubMed

The Food and Drug Administration (FDA) is extending to July 25, 2001, the period for issuance of a final rule in response to its interim final rule of September 8, 2000, entitled " Food Labeling: Health Claims; Plant Sterol/Stanol Esters and Coronary Heart Disease." FDA's regulations require the agency to issue a notice of such extension if it finds, for cause, that it is unable to issue a final rule within 270 days from the date of publication of the interim final rule. The complexity of the issues raised by the comments to the interim final rule and the lack of agency resources to complete the final rule within the specified 270 days have persuaded the agency of the need to extend the deadline to publish the final rule. PMID:11724074

2001-06-01

109

Wastewater treatment plants (WWTPs) as a source of sediment contamination by toxic organic pollutants and fecal sterols in a semi-enclosed bay in Korea.  

PubMed

Toxic organic contaminants and a macrobenthic community were assayed in sediments collected near a wastewater treatment plant (WWTP) outfall to assess the impact of WWTP discharges on an aquatic environment. Average concentrations of toxic organic contaminants in sediments from 20 locations were 96.7ng TEQ/kg dry matter for PCDD/Fs, 1.84ng TEQ/kg dry matter for dioxin-like PCBs, 29.1microg/kg dry matter for PBDEs, 411microg/kg dry matter for nonylphenols, 1021microg/kg dry matter for fecal sterols, and 928microg/kg dry matter for PAHs. Concentrations of all the organic contaminants and fecal sterols varied widely and there was a clear decrease in concentration gradients with increasing distances from the WWTP outfall. This result suggests that WWTP activities contribute to contamination by organic chemicals. A survey of benthic organisms showed the dominance of a few polychaete species, indicating a deterioration of the macrobenthic community by the WWTP discharge. Non-parametric multidimensional scaling (MDS) ordination and Spearman correlation analyses showed that organic contamination is associated with the benthic community structure. For polychaete species, the sensitive species for organic contaminants was Paraprionospio pinnata, while contaminant-tolerant species were Spiochaetopterus koreana and Capitella capitata. BIOENV analyses of all locations suggested PCDDs and PCDFs as the major contaminants influencing the structure of the macrobenthic community. The present study highlights that continuous WWTP discharges contribute to severe organic contamination and risks for the benthic community in an aquatic ecosystem. PMID:18727999

Moon, Hyo-Bang; Yoon, Sang-Pil; Jung, Rae-Hong; Choi, Minkyu

2008-08-24

110

Serum noncholesterol sterols during inhibition of cholesterol synthesis by statins  

Microsoft Academic Search

We studied changes in serum cholestanol and plant sterols (indexes of cholesterol absorption) and cholesterol precursors (indexes of cholesterol synthesis) in response to cholesterol reduction by way of 1 year's treatment with atorvastatin (n = 102) and simvastatin (n = 105) treatments in patients with coronary heart disease. Serum cholesterol levels and ratios of the precursor sterols to cholesterol after

Tatu A. Miettinen; Helena Gylling; Nina Lindbohm; Tatu E. Miettinen; Radhakrishnan A. Rajaratnam; Heikki Relas

2003-01-01

111

Mediation of Elicitin Activity on Tobacco Is Assumed by Elicitin-Sterol Complexes  

Microsoft Academic Search

Elicitins secreted by phytopathogenic Phytophthora spp. are proteinaceous elicitors of plant de- fense mechanisms and were demonstrated to load, carry, and transfer sterols between mem- branes. The link between elicitor and sterol-loading properties was assessed with the use of site-directed mutagenesis of the 47 and 87 cryptogein tyrosine residues, postulated to be involved in sterol binding. Mutated cryptogeins were tested

Hanan Osman; Sebastien Vauthrin; Vladimir Mikes; Marie-Louise Milat; Franck Panabieres; Antoine Marais; Simone Brunie

2001-01-01

112

Fungal cytochrome P450 sterol 14?-demethylase (CYP51) and azole resistance in plant and human pathogens.  

PubMed

Azoles have been applied widely to combat pathogenic fungi in medicine and agriculture and, consequently, loss of efficacy has occurred in populations of some species. Often, but not always, resistance was found to result from amino acid substitutions in the molecular target of azoles, 14?-sterol demethylase (CYP51 syn. ERG11). This review summarizes CYP51 function, evolution, and structure. Furthermore, we compare the occurrence and contribution of CYP51 substitutions to azole resistance in clinical and field isolates of important fungal pathogens. Although no crystal structure is available yet for any fungal CYP51, homology modeling using structures from other origins as template allowed deducing models for fungal orthologs. These models served to map amino acid changes known from clinical and field isolates. We conclude with describing the potential consequences of these changes on the topology of the protein to explain CYP51-based azole resistance. Knowledge gained from molecular modeling and resistance research will help to develop novel azole structures. PMID:22684327

Becher, Rayko; Wirsel, Stefan G R

2012-06-12

113

Screening of synthetic and plant-derived compounds for (anti)estrogenic and (anti)androgenic activities.  

PubMed

Recently we constructed yeast cells that either express the human estrogen receptor alpha or the human androgen receptor in combination with a consensus ERE or ARE repeat in the promoter region of a green fluorescent protein (yEGFP) read-out system. These bioassays were proven to be highly specific for their cognate agonistic compounds. In this study the value of these yeast bioassays was assessed for analysis of compounds with antagonistic properties. Several pure antagonists, selective estrogen receptor modulators (SERMs) and plant-derived compounds were tested. The pure antiestrogens ICI 182,780 and RU 58668 were also classified as pure ER antagonists in the yeast estrogen bioassay and the pure antiandrogen flutamide was also a pure AR antagonist in the yeast androgen bioassay. The plant-derived compounds flavone and guggulsterone displayed both antiestrogenic and antiandrogenic activities, while 3,3'-diindolylmethane (DIM) and equol combined an estrogenic mode of action with an antiandrogenic activity. Indol-3-carbinol (I3C) only showed an antiandrogenic activity. Coumestrol, genistein, naringenin and 8-prenylnaringenin were estrogenic and acted additively, while the plant sterols failed to show any effect. Although hormonally inactive, in vitro and in vivo metabolism of the aforementioned plant sterols may still lead to the formation of active metabolites in other test systems. PMID:18188547

Bovee, Toine F H; Schoonen, Willem G E J; Hamers, Astrid R M; Bento, Marta Jorge; Peijnenburg, Ad A C M

2008-01-11

114

A Spread Enriched with Plant Sterol-Esters Lowers Blood Cholesterol and Lipoproteins without Affecting Vitamins A and E in Normal and Hypercholesterolemic Japanese Men and Women1,2  

Microsoft Academic Search

The objective of the study was to investigate whether different initial baseline cholesterol levels modulate the efficacy of a spread enriched with plant sterol-esters (PS) in lowering blood cholesterol in a Japanese population consuming their usual diet. Healthy adults with a mean age of 45 y and mean plasma total cholesterol (TC) level of 6.5 mmol\\/L were recruited to participate

Fady Y. Ntanios; Yasuhiko Homma; Soichiro Ushiro

115

Lipid-altering effects of a dietary supplement tablet containing free plant sterols and stanols in men and women with primary hypercholesterolaemia: a randomized, placebo-controlled crossover trial  

PubMed Central

This randomized, placebo-controlled, crossover trial assessed the lipid-altering efficacy of a dietary supplement (tablet form) providing 1.8g/day free (non-esterified) plant sterols and stanols versus placebo for 6 weeks as part of a therapeutic lifestyle changes (TLC) diet in 32 men and women with primary hypercholesterolaemia. Mean ± SE baseline (end of a 5-week TLC diet lead-in) lipid concentrations (mmol/1) were total cholesterol (TC), 5.88 ± 0.08; non-high-density lipoprotein cholesterol (non-HDL-C), 4.71 ± 0.09; low-density lipoprotein cholesterol (LDL-C), 4.02 ± 0.08; HDL-C, 1.17 ± 0.06 and triglycerides (TGs), 1.51 ± 0.12. Differences from control in responses (plant sterol/stanol — control) were significant (p < 0.05) for LDL-C (? 4.9%), non-HDL-C (? 3.6%) and TC (? 2.8%). HDL-C and TG responses were not significantly different between treatment conditions. These results indicate that 1.8g/day free plant sterols/stanols administered in a tablet produced favourable lipoprotein lipid changes in men and women with hypercholesterolaemia.

Maki, Kevin C; Lawless, Andrea L; Reeves, Matthew S; Dicklin, Mary R; Jenks, Belinda H; Shneyvas, ED; Brooks, James R

2012-01-01

116

Sterols and oxysterols in immune cell function.  

PubMed

Intermediates in the cholesterol-biosynthetic pathway and oxysterol derivatives of cholesterol regulate diverse cellular processes. Recent studies have expanded the appreciation of their roles in controlling the functions of cells of the innate and adaptive immune systems. Here we review recent literature reporting on the biological functions of sterol intermediates and oxysterols, acting through transcription factors such as the liver X receptors (LXRs), sterol regulatory element-binding proteins (SREBPs) and the G protein-coupled receptor EBI2, in regulating the differentiation and population expansion of cells of the innate and adaptive immune systems, their responses to inflammatory mediators, their effects on the phagocytic functions of macrophages and their effects on antiviral activities and the migration of immune cells. Such findings have raised many new questions about the production of endogenous bioactive sterols and oxysterols and their mechanisms of action in the immune system. PMID:23959186

Spann, Nathanael J; Glass, Christopher K

2013-08-20

117

Biochemicat studies of the excitable membrane of Paramecium tetraurelia. VI I. Sterols and other neutral lipids of cells and cilia  

Microsoft Academic Search

The neutral lipid content of cells and cilia of Par- amecium tetraurelia was determined as a function of growth stage and of growth medium composition. The major sterol(s) of deciliated cells and of cilia were the sterol provided in the growth medium (e.g., stigmasterol) and its 7-dehydro deriv- ative. Body sterol esters and triglycerides accumulated during exponential cell growth and

Todd M. Hennessey; Douglas Andrews; David L. Nelson

118

Steroid and sterol 7-hydroxylation: ancient pathways.  

PubMed

B-ring hydroxylation is a major metabolic pathway for cholesterols and some steroids. In liver, 7 alpha-hydroxylation of cholesterols, mediated by CYP7A and CYP39A1, is the rate-limiting step of bile acid synthesis and metabolic elimination. In brain and other tissues, both sterols and some steroids including dehydroepiandrosterone (DHEA) are prominently 7 alpha-hydroxylated by CYP7B. The function of extra-hepatic steroid and sterol 7-hydroxylation is unknown. Nevertheless, 7-oxygenated cholesterols are potent regulators of cell proliferation and apoptosis; 7-oxygenated derivatives of DHEA, pregnenolone, and androstenediol can have major effects in the brain and in the immune system. The receptor targets involved remain obscure. It is argued that B-ring modification predated steroid evolution: non-enzymatic oxidation of membrane sterols primarily results in 7-oxygenation. Such molecules may have provided early growth and stress signals; a relic may be found in hydroxylation at the symmetrical 11-position of glucocorticoids. Early receptor targets probably included intracellular sterol sites, some modern steroids may continue to act at these targets. 7-Hydroxylation of DHEA may reflect conservation of an early signaling pathway. PMID:12398993

Lathe, Richard

2002-11-01

119

Identification and Characterization of an S-Adenosyl-L-methionine: D24-Sterol-C-methyltransferase cDNA from Soybean  

Microsoft Academic Search

In plants, the dominant sterols are 24-alkyl sterols, which play multiple roles in plant growth and develop- ment, i.e. as membrane constituents and as precursors to steroid growth regulators such as brassinosteroids. The initial step in the conversion of the phytosterol intermediate cycloartenol to the 24-alkyl sterols is cata- lyzed by S-adenosyl-L-methionine:D24-sterol-C-methyl- transferase (SMT), a rate-limiting enzyme for phytoste- rol

Jinrui Shi; Robert A. Gonzales; Madan K. Bhattacharyya

120

Sterols of the cultured dinoflagellate Pyrocystis lunula.  

PubMed

Eighteen components of the sterol fraction of Pyrocystis lunula have been identified. In addition to 4 alpha-methyl sterols (typical dinoflagellate sterols), regular sterols, both with a saturated and delta 5-unsaturated skeleton, were isolated, together with delta 4-3-keto steroids including the hitherto unknown 23,24R-dimethyl-4,22E-cholestadien-3-one. PMID:6892172

Kokke, W C; Fenical, W; Djerassi, C

1982-09-01

121

Plasma membrane sterol complexation, generated by filipin, triggers signaling responses in tobacco cells  

Microsoft Academic Search

The effects of changes in plasma membrane (PM) sterol lateral organization and availability on the control of signaling pathways have been reported in various animal systems, but rarely assessed in plant cells. In the present study, the pentaene macrolide antibiotic filipin III, commonly used in animal systems as a sterol sequestrating agent, was applied to tobacco cells. We show that

Laurent Bonneau; Patricia Gerbeau-Pissot; Dominique Thomas; Christophe Der; Jeannine Lherminier; Stéphane Bourque; Yann Roche; Françoise Simon-Plas

2010-01-01

122

Sterol Lipid Metabolism in Down Syndrome Revisited: Down Syndrome Is Associated with a Selective Reduction in Serum Brassicasterol Levels  

PubMed Central

Over the past 15 years, insights into sterol metabolism have improved our understanding of the relationship between lipids and common conditions such as atherosclerosis and Alzheimer's Disease (AD). A better understanding of sterol lipid metabolism in individuals with Down Syndrome (DS) may help elucidate how this population's unique metabolic characteristics influence their risks for atherosclerosis and AD. To revisit the question of whether sterol lipid parameters may be altered in DS subjects, we performed a pilot study to assess traditional serum sterol lipids and lipoproteins, as well as markers of sterol biosynthesis, metabolites, and plant sterols in 20 subjects with DS compared to age-matched controls. Here we report that the levels of nearly all lipids and lipoproteins examined are similar to control subjects, suggesting that trisomy 21 does not lead to pronounced general alterations in sterol lipid metabolism. However, the levels of serum brassicasterol were markedly reduced in DS subjects.

Tansley, Gavin; Holmes, Daniel T.; Lutjohann, Dieter; Head, Elizabeth; Wellington, Cheryl L.

2012-01-01

123

Plant-derived medicines: a novel class of immunological adjuvants.  

PubMed

Plant-derived medicines have a long history of use for the prevention and treatment of human disease. Today, many pharmaceuticals currently approved by the Food and Drug Administration (FDA) have origins to plant sources. A major role for plant-derived compounds based on the reported immunomodulatory effects has emerged in recent times and has led to the rigorous scientific examination to determine efficacy and safety. The discovery of novel plant compounds with immune system modulating activities has become an increasingly important area of research, particularly in the search for new-generation vaccine adjuvants. This review discusses the important role of plant-derived medicines as immunomodulators and provides evidence in support of the continued investigation of this new class of drugs for the maintenance of human health. The identification and characterization of plant compounds that augment new or existing vaccines, and in particular mucosally administered vaccines, will be of significant interest to vaccinologists and immunologists. PMID:21056709

Licciardi, Paul V; Underwood, John R

2010-11-05

124

Sterols as Complex-forming Species  

NASA Astrophysics Data System (ADS)

The formation of complexes of sterols with different compounds determines the biological properties of both sterols and various natural substances such as saponins and polyene antibiotics. Complex formation by sterols with phospholipids, steroid saponins, and polyene antibiotics is determined by the same characteristic features of the structure of the sterol molecule. The principal role in complex formation is played by the hydrophobic reaction of the cyclopentanoperhydrophenanthrene ring. The formation of a hydrogen bond between the hydroxyl group of the sterol and a proton acceptor, which is assumed in most complexes, has been proved only in the complexes of sterols with water and acids. The bibliography contains 122 references.

Ioffe, D. V.

1986-02-01

125

Phylogenomics of Sterol Synthesis: Insights into the Origin, Evolution, and Diversity of a Key Eukaryotic Feature  

PubMed Central

The availability of complete genomes from a wide sampling of eukaryotic diversity has allowed the application of phylogenomics approaches to study the origin and evolution of unique eukaryotic cellular structures, but these are still poorly applied to study unique eukaryotic metabolic pathways. Sterols are a good example because they are an essential feature of eukaryotic membranes. The sterol pathway has been well dissected in vertebrates, fungi, and land plants. However, although different types of sterols have been identified in other eukaryotic lineages, their pathways have not been fully characterized. We have carried out an extensive analysis of the taxonomic distribution and phylogeny of the enzymes of the sterol pathway in a large sampling of eukaryotic lineages. This allowed us to tentatively indicate features of the sterol pathway in organisms where this has not been characterized and to point out a number of steps for which yet-to-discover enzymes may be at work. We also inferred that the last eukaryotic common ancestor already harbored a large panel of enzymes for sterol synthesis and that subsequent evolution over the eukaryotic tree occurred by tinkering, mainly by gene losses. We highlight a high capacity of sterol synthesis in the myxobacterium Plesiocystis pacifica, and we support the hypothesis that the few bacteria that harbor homologs of the sterol pathway have likely acquired these via horizontal gene transfer from eukaryotes. Finally, we propose a potential candidate for the elusive enzyme performing C-3 ketoreduction (ERG27 equivalent) in land plants and probably in other eukaryotic phyla.

Desmond, Elie

2009-01-01

126

Insect molting hormone and sterol biosynthesis in spinach  

SciTech Connect

Insect molting hormones, which are produced by plants and are effective molecules in the control of insect crop pests, are biosynthesized in developing spinach leaves (Spinacia oleracea L.). The major sterols biosynthesized by spinach are avenasterol (24{alpha}-ethyl-5{alpha}-cholesta-7,24(28)-dien-3{beta}-ol), spinasterol (24{alpha}-ethyl-5{alpha}-cholesta-7,22-dien-3{beta}-ol), and 22-dihydrospinasterol (24{alpha}-ethyl-5{alpha}-cholest-7-en-3{beta}-ol). The major ecdysteroids biosynthesized are ecdysterone (2{beta},3{beta},14{alpha},20R,22R,25-hexahydroxy-5{beta}-cholest-7-en-6-one) and polypodine B (2{beta},3{beta},5{beta},14{alpha},20R,22R,25-heptahycroxycholest-7-en-6-one) and polypodine B (2{beta},3{beta},5{beta},14{alpha},20R,22R,25-heptahydroxycholest-7-en-6-one). When labeled 2-{sup 14}C-mevalonic acid was incorporated into young leaves isolated squalene, sterols and ecdysteroids contained the label. During a short (16 h) incorporation period in intact young leaves of 100 day old plants, the avenasterol has the highest specific activity in counts per minute per {mu}g of sterol followed by 22-dihydrospinasterol which is more highly labeled than spinasterol. The ecdysteroids synthesized, on an entire plant basis, account for 20% of the total steroid (sterol and ecdysteroid) isolated from the plant.

Grebenok, R.J.; Adler, J.H. (Michigan Technological Univ., Houghton (USA))

1990-05-01

127

Yeast metabolic engineering--targeting sterol metabolism and terpenoid formation.  

PubMed

Terpenoids comprise various structures conferring versatile functions to eukaryotes, for example in the form of prenyl-anchors they attach proteins to membranes. The physiology of eukaryotic membranes is fine-tuned by another terpenoid class, namely sterols. Evidence is accumulating that numerous membrane proteins require specific sterol structural features for function. Moreover, sterols are intermediates in the synthesis of steroids serving as hormones in higher eukaryotes. Like steroids many compounds of the terpenoid family do not contribute to membrane architecture, but serve as signalling, protective or attractant/repellent molecules. Particularly plants have developed a plenitude of terpenoid biosynthetic routes branching off early in the sterol biosynthesis pathway and, thereby, forming one of the largest groups of naturally occurring organic compounds. Many of these aromatic and volatile molecules are interesting for industrial application ranging from foods to pharmaceuticals. Combining the fortunate situation that sterol biosynthesis is highly conserved in eukaryotes with the amenability of yeasts to genetic and metabolic engineering, basically all naturally occurring terpenoids might be produced involving yeasts. Such engineered yeasts are useful for the study of biological functions and molecular interactions of terpenoids as well as for the large-scale production of high-value compounds, which are unavailable in sufficient amounts from natural sources due to their low abundance. PMID:23567752

Wriessnegger, Tamara; Pichler, Harald

2013-04-06

128

Biopharmaceuticals derived from genetically modified plants  

Microsoft Academic Search

Summary Modern biotechnology has resulted in a resurgence of interest in the production of new therapeutic agents using botanical sources. With nearly 500 biotechnology products approved or in develop- ment globally, and with production capacity lim- ited, the need for efficient means of therapeutic protein production is apparent. Through genetic engineering, plants can now be used to produce pharmacologically active

D. A. Goldstein; J. A. THOMAS

2004-01-01

129

Plant damage by pollution derived from automobiles  

Microsoft Academic Search

Emissions from motor vehicles are now known to be the principal source of the raw materials contributing to photochemical air pollution in California. Some of the products of the reaction, ozone, peroxyacyl nitrates, and the unidentified products of ozone-olefin reactions, are very damaging to the leaves of a variety of crop plants. The injury that was once confined to Los

E. F. Darley; W. M. Dugger; J. B. Mudd; L. Ordin; O. C. Taylor; E. R. Stephens

1963-01-01

130

Chromosomal behavior of anther culture derived plants of rice  

Microsoft Academic Search

Cytological examination of anther-culture-derived plants of rice showed that the regenerants were predominantly diploids and haploids. Haploid meiosis indicated that the earlier hypothesis of rice being an ancient polyploid is unlikely. Diploids generally were normal and fertile. The low frequency of polyploids (1.5%) probably was due to rapid regeneration of plants from short term callus cultures.

S. T. Mercy; F. J. Zapata

1986-01-01

131

Plant-derived triterpenoid sweetness inhibitors.  

PubMed

Considerable recent attention has been focused on naturally occurring compounds with taste-modifying activity, which are of potential use in both dietary sweetness management and in gaining a better understanding of the sweet taste sensation. This review summarizes information on the phytochemistry and biological activity of more than 40 triterpenoid sweetness inhibitors that have been isolated from the leaves of three medicinal plants, namely, Gymnema sylvestre R.Br. (Asclepiadaceae), Ziziphus jujuba P. Miller (Rhamnaceae), and Hovenia dulcis Thunb. (Rhamnaceae). PMID:7564423

Suttisri, R; Lee, I S; Kinghorn, A D

1995-06-23

132

Relationship between the rate of hepatic sterol synthesis and the incorporation of (3H)water  

SciTech Connect

The true rate of sterol synthesis in liver cells was determined by measurement of the weight of desmosterol produced over a given time period during incubations in the presence of triparanol. The simultaneous presence of tritiated water (/sup 3/H/sub 2/O) during the incubations permitted a direct observation of the weight of tritium incorporated into a given mass of newly synthesized sterol. The incorporation of tritium per atom of sterol carbon (H/C ratio) was lower than some previously reported values and suggests that a sizeable proportion of the reducing equivalents (NADPH) required for sterol synthesis arises via the pentose phosphate pathway. The H/C ratio changed significantly with length of the incubation period. The value of the ratio was also dependent upon whether the acetyl-CoA units utilized for sterol synthesis were derived predominantly from a carbohydrate or a fatty acid source.

Pullinger, C.R.; Gibbons, G.F.

1983-10-01

133

Sterols of the phylum Zygomycota: Phylogenetic implications  

Microsoft Academic Search

The sterol composition of 42 fungal species representing six of the eight orders of the Zygomycota was determined using gas-liquid\\u000a chromatography-mass spectrometry to assess whether the distribution of major sterols in this phylum has taxonomic or phylogenetic\\u000a relevance. Ergosterol, 22-dihydroergosterol, 24-methyl cholesterol, cholesterol, and desmosterol were detected as the major\\u000a sterols among the species studied. Ergosterol was the major sterol

J. D. Weete; S. R. Gandhi

1997-01-01

134

Alternative pathways of sterol synthesis in yeast  

Microsoft Academic Search

Yeast produce traces of aberrant sterols by minor alternative pathways, which can become significant when normal metabolism is blocked by inhibitors or mutations. We studied sterols generated in the absence of the ?8–?7 isomerase (Erg2p) or ?5 desaturase (Erg3p) by incubating three mutant strains of Saccharomyces cerevisiae with 5?-cholest-8-en-3?-ol, 8-dehydrocholesterol (?5,8 sterol), or isodehydrocholesterol (?6,8 sterol), together with the corresponding

Benfang Ruan; Peggy S Lai; Christine W Yeh; William K Wilson; Jihai Pang; Ran Xu; Seiichi P. T Matsuda; George J Schroepfer Jr.

2002-01-01

135

Unusual tetraene sterols in some phytoplankton  

Microsoft Academic Search

Sterols were analyzed from four phytoplankton strains which are under investigation as possible sources of food for oysters\\u000a in culture. One strain ofPyramimonas contained only 24-methylenecholesterol as a major sterol component.Pyramimonas grossii, Chlorella autotrophica andDunaliella tertiolecta each contained a complex mixture of C28 and C29 sterols with ?7, ?5,7 and ?5,7,9(11) nuclear double bond systems. Sterols were found both with

G. W. Patterson; P. K. Gladu; G. H. Wikfors; W. R. Lusby

1992-01-01

136

Sterols in pumpkin seed oil  

Microsoft Academic Search

and summary  The sterol fraction of unsaponifiable matter obtained from a Yugoslav pumpkin seed ripening was investigated by gas liquid\\u000a chromatography on a glass capillary column. It contained at least 14 different sterols ten of which were identified primarily\\u000a by combined gas chromatography-mass spectrometry as cholesterol, brassicasterol, campesterol, stigmasterol, 24-methylcholest-7-en-3?-ol,\\u000a ?7,22,25-stimastatrien-3?-ol, ?-spinasterol, ?7,25-stigmastadien-3?-ol, ?7,25-stigmastenol, and ?7-avenasterol. It was shown that the

M. Basti?; Lj. Basti?; J. A. Jovanovi?; G. Spiteller

1977-01-01

137

Sterol/steroid metabolism and absorption in a generalist and specialist caterpillar: effects of dietary sterol/steroid structure, mixture and ratio.  

PubMed

Insects cannot synthesize sterols de novo, so they typically require a dietary source. Cholesterol is the dominant sterol in most insects, but because plants contain only small amounts of cholesterol, plant-feeding insects generate most of their cholesterol by metabolizing plant sterols. Plants almost always contain mixtures of different sterols, but some are not readily metabolized to cholesterol. Here we explore, in two separate experiments, how dietary phytosterols and phytosteroids, in different mixtures, ratios, and amounts, affect insect herbivore sterol/steroid metabolism and absorption; we use two caterpillars species - one a generalist (Heliothis virescens), the other a specialist (Manduca sexta). In our first experiment caterpillars were reared on two tobacco lines - one expressing a typical phystosterol profile, the other expressing high amounts/ratios of stanols and 3-ketosteroids. Caterpillars reared on the control tobacco contained mostly cholesterol, but those reared on the modified tobacco had reduced amounts of cholesterol, and lower total sterol/steroid body profiles. In our second experiment, caterpillars were reared on artificial diets containing known amounts of cholesterol, stigmasterol, cholestanol and/or cholestanone, either singly or in various combinations and ratios. Cholesterol and stigmasterol-reared moths were mostly cholesterol, while cholestanol-reared moths were mostly cholestanol. Moth tissue cholesterol concentration tended to decrease as the ratio of dietary cholestanol and/or cholestanone increased. In both moths cholestanone was metabolized into cholestanol and epicholestanol. Interestingly, M. sexta generated much more cholestanol than epicholestanol, while H. virescens did the opposite. Finally, total tissue steroid levels were significantly reduced in moths reared on diets containing very high levels of cholestanol. We discuss how dietary sterol/steroid structural differences are important with respect to sterol/steroid metabolism and uptake, including species-specific differences. PMID:23567589

Jing, Xiangfeng; Grebenok, Robert J; Behmer, Spencer T

2013-04-06

138

Sterols with antileishmanial activity isolated from the roots of Pentalinon andrieuxii  

PubMed Central

A new cholesterol derivative, pentalinonsterol (cholest-4,20,24-trien-3-one, 1), and a new polyoxygenated pregnane sterol glycoside, pentalinonside (2), together with 18 known compounds, including 14 sterols (3–16), three coumarins (17–19), and a triterpene (20), were isolated from a n-hexane partition of a methanol extract of the roots of the Mexican medicinal plant Pentalinon andrieuxii. Structure elucidation of compounds 1 and 2 was accomplished by spectroscopic data interpretation. All isolates were evaluated in vitro for their antileishmanial activity. Among these compounds, 6,7-dihydroneridienone (15) was found to be the most potent principle against promastigotes of Leishmania mexicana (L. mexicana). The cholesterol analogue, pentalinonsterol (1), together with two known sterols, 24-methylcholest-4,24(28)-dien-3-one (3) and neridienone (16), also exhibited significant leishmanicidal activity in this same bioassay. Compounds 1, 3, 15, 16, cholest-4-en-3-one (4), and cholest-5,20,24-trien-3?-ol (7), showed strong antileishmanial activity against amastigotes of L. mexicana, and 4 was found to be the most potent agent with an IC50 value of 0.03 ?M. All the isolates were also evaluated for their cytotoxicity in non-infected bone marrow-derived macrophages, but none of these compounds was found active towards this cell line. The intracellular parasites treated with compounds 1, 3, 4, 15, and 16 were further studied by electron microscopy; morphological abnormalities and destruction of the amastigotes were observed, as a result of treatment with these compounds.

Pan, Li; Lezama-Davila, Claudio M.; Isaac-Marquez, Angelica P.; Calomeni, Edward P.; Fuchs, James R.; Satoskar, Abhay R.; Kinghorn, A. Douglas

2012-01-01

139

Sterols with antileishmanial activity isolated from the roots of Pentalinon andrieuxii.  

PubMed

A new cholesterol derivative, pentalinonsterol (cholest-4,20,24-trien-3-one, 1), and a new polyoxygenated pregnane sterol glycoside, pentalinonside (2), together with 18 known compounds, including 14 sterols (3-16), three coumarins (17-19), and a triterpene (20), were isolated from a n-hexane partition of a methanol extract of the roots of the Mexican medicinal plant Pentalinon andrieuxii. Structure elucidation of compounds 1 and 2 was accomplished by spectroscopic data interpretation. All isolates were evaluated in vitro for their antileishmanial activity. Among these compounds, 6,7-dihydroneridienone (15) was found to be the most potent principle against promastigotes of Leishmania mexicana (L. mexicana). The cholesterol analogue, pentalinonsterol (1), together with two known sterols, 24-methylcholest-4,24(28)-dien-3-one (3) and neridienone (16), also exhibited significant leishmanicidal activity in this same bioassay. Compounds 1, 3, 15, 16, cholest-4-en-3-one (4), and cholest-5,20,24-trien-3?-ol (7), showed strong antileishmanial activity against amastigotes of L. mexicana, and 4 was found to be the most potent agent with an IC(50) value of 0.03?M. All the isolates were also evaluated for their cytotoxicity in non-infected bone marrow-derived macrophages, but none of these compounds was found active towards this cell line. The intracellular parasites treated with compounds 1, 3, 4, 15, and 16 were further studied by electron microscopy; morphological abnormalities and destruction of the amastigotes were observed, as a result of treatment with these compounds. PMID:22840389

Pan, Li; Lezama-Davila, Claudio M; Isaac-Marquez, Angelica P; Calomeni, Edward P; Fuchs, James R; Satoskar, Abhay R; Kinghorn, A Douglas

2012-07-26

140

Sterol lipids in finger millet (Eleusine coracana)  

Microsoft Academic Search

Neutral lipids, glycolipids, and phospholipids (1.3%, 0.25%, and 0.10% of seed weight) were isolated from the total lipids\\u000a (chloroform-methanol) of finger millet seeds(Eleusine coracana), and four sterol-containing lipids further isolated from neutral and glycolipids by preparative column and thin layer chromatography.\\u000a On seed weight, these comprised: free sterols (S) 0.091%, sterol esters (SE) 0.013%, sterol glycosides (SG) 0.025%, acyl sterol

V. G. Mahadevappa; P. L. Raina

1978-01-01

141

[Safety assessment of foods derived from genetically modified plants].  

PubMed

The placing of genetically modified plants and derived food on the market falls under Regulation (EC) No. 1829/2003. According to this regulation, applicants need to perform a safety assessment according to the Guidance Document of the Scientific Panel on Genetically Modified Organisms of the European Food Safety Authority (EFSA), which is based on internationally agreed recommendations. This article gives an overview of the underlying legislation as well as the strategy and scientific criteria for the safety assessment, which should generally be based on the concept of substantial equivalence and carried out in relation to an unmodified conventional counterpart. Besides the intended genetic modification, potential unintended changes also have to be assessed with regard to potential adverse effects for the consumer. All genetically modified plants and derived food products, which have been evaluated by EFSA so far, were considered to be as safe as products derived from the respective conventional plants. PMID:20449554

Pöting, A; Schauzu, M

2010-06-01

142

Comparison of the effects of plant sterol ester and plant stanol ester-enriched margarines in lowering serum cholesterol concentrations in hypercholesterolaemic subjects on a low-fat diet  

Microsoft Academic Search

Objective: To investigate cholesterol-lowering effects of stanol ester (STAEST) and sterol ester (STEEST)-enriched margarines as part of a low-fat diet.Design: According to a Latin square model randomized double-blind repeated measures design with three test margarines and three periods.Setting: Outpatient clinical trial with free-living subjects.Subjects: Thirty-four hypercholesterolaemic subjects completed the study.Interventions: Subjects consumed three rapeseed oil-based test margarines (STAEST, STEEST and

MA Hallikainen; ES Sarkkinen; H Gylling; AT Erkkilä; MIJ Uusitupa

2000-01-01

143

Plant-derived virus-like particles as vaccines.  

PubMed

Virus-like particles (VLPs) are self-assembled structures derived from viral antigens that mimic the native architecture of viruses but lack the viral genome. VLPs have emerged as a premier vaccine platform due to their advantages in safety, immunogenicity, and manufacturing. The particulate nature and high-density presentation of viral structure proteins on their surface also render VLPs as attractive carriers for displaying foreign epitopes. Consequently, several VLP-based vaccines have been licensed for human use and achieved significant clinical and economical success. The major challenge, however, is to develop novel production platforms that can deliver VLP-based vaccines while significantly reducing production times and costs. Therefore, this review focuses on the essential role of plants as a novel, speedy and economical production platform for VLP-based vaccines. The advantages of plant expression systems are discussed in light of their distinctive posttranslational modifications, cost-effectiveness, production speed, and scalability. Recent achievements in the expression and assembly of VLPs and their chimeric derivatives in plant systems as well as their immunogenicity in animal models are presented. Results of human clinical trials demonstrating the safety and efficacy of plant-derived VLPs are also detailed. Moreover, the promising implications of the recent creation of "humanized" glycosylation plant lines as well as the very recent approval of the first plant-made biologics by the U. S. Food and Drug Administration (FDA) for plant production and commercialization of VLP-based vaccines are discussed. It is speculated that the combined potential of plant expression systems and VLP technology will lead to the emergence of successful vaccines and novel applications of VLPs in the near future. PMID:22995837

Chen, Qiang; Lai, Huafang

2012-09-20

144

Polymeric derivatives of plant growth regulators: synthesis and properties  

Microsoft Academic Search

The polymeric formulations of plant growth regulators (PGRs) are high molecular weight systems in which the PGR unit is attached to the polymeric chain by a hydrolysable chemical bond. These polymeric derivatives (esters, ethers, or else) of PGRs are characterised by the ability to release the active compound (PGR) from their solutions (mainly aqueous) in certain conditions. The release of

Aristidis M. Tsatsakis; Michail I. Shtilman

1994-01-01

145

Plant-derived, synthetic and endogenous cannabinoids as neuroprotective agents  

Microsoft Academic Search

There is good evidence that plant-derived and synthetic cannabinoids possess neuroprotective properties. These compounds, as a result of effects upon CB1 cannabinoid receptors, reduce the release of glutamate, and in addition reduce the influx of calcium following NMDA receptor activation. The major obstacle to the therapeutic utilization of such compounds are their psychotropic effects, which are also brought about by

Christopher J. Fowler

2003-01-01

146

Daidzein Sulfoconjugates Are Potent Inhibitors of Sterol Sulfatase (EC 3.1.6.2)  

Microsoft Academic Search

Recent studies have associated high dietary isoflavone intake with low incidence of breast cancer. Since estrogenic steroids are important factors in the evolution of breast cancer, and in breast tumors they are derived mainly from the sterol sulfatase pathway, we have therefore investigated effects of the isoflavone daidzein and its sulfoconjugates, daidzein-4?-O-sulfate and daidzein-7,4?-di-O-sulfate, on sterol sulfatase acitivity using dehydroepiandrosterone

Chun-Kwok Wong; Wing Ming Keung

1997-01-01

147

Analysis of unsaturated c27 sterols by nuclear magnetic resonance spectroscopy  

Microsoft Academic Search

Complete 'H and IsC nuclear magnetic reso- nance (NMR) signal assignments have been established for 5a-cholestan-3P-01, 22 unsaturated C27 sterols, and their ace- tate derivatives. Assignments were made from a combination of 1D and 2D spectra and include stereochemical 'H assign- ments for the C-22 and C-23 protons of 5a-cholesta-8,24dien- 3p-01 and other A*' sterols with a Cg side chain.

William K. Wilson; Rhea M. Sumpter; Joshua J. Warren; Peter S. Rogers; Benfang Ruan; George J. Schroepfer

148

Plant-derived pharmaceuticals for the developing world.  

PubMed

Plant-produced vaccines and therapeutic agents offer enormous potential for providing relief to developing countries by reducing the incidence of infant mortality caused by infectious diseases. Vaccines derived from plants have been demonstrated to effectively elicit an immune response. Biopharmaceuticals produced in plants are inexpensive to produce, require fewer expensive purification steps, and can be stored at ambient temperatures for prolonged periods of time. As a result, plant-produced biopharmaceuticals have the potential to be more accessible to the rural poor. This review describes current progress with respect to plant-produced biopharmaceuticals, with a particular emphasis on those that target developing countries. Specific emphasis is given to recent research on the production of plant-produced vaccines toward human immunodeficiency virus, malaria, tuberculosis, hepatitis B virus, Ebola virus, human papillomavirus, rabies virus and common diarrheal diseases. Production platforms used to express vaccines in plants, including nuclear and chloroplast transformation, and the use of viral expression vectors, are described in this review. The review concludes by outlining the next steps for plant-produced vaccines to achieve their goal of providing safe, efficacious and inexpensive vaccines to the developing world. PMID:23857915

Hefferon, Kathleen

2013-07-15

149

Studies on the sterols and sterol esters of the intracellular organelles of maize shoots  

PubMed Central

1. The composition of the esterified and unesterified sterols of the nuclear, chloroplastidic, mitochondrial and microsomal fractions of 21-day-old maize shoots was examined. 2. The microsomal and mitochondrial fractions contain the bulk of the sterols of the tissue. 3. Only 1% of the sterol isolated from all the organelles is esterified. 4. The nuclear fraction has the greatest proportion of esterified sterol and the microsomal fraction the least. 5. 4-Demethyl sterols constitute the bulk of both esterified and unesterified sterols in all organelle fractions. 6. Cholesterol is the major esterified 4-demethyl sterol of the nuclear and chloroplastidic fractions, but only the nuclear fraction has an appreciable proportion of unesterified cholesterol. 7. Sterol esters of linolenic acid are more abundant in the mitochondrial and microsomal fractions than in the other two fractions.

Kemp, R. J.; Mercer, E. I.

1968-01-01

150

The protective ability of Mediterranean dietary plants against the oxidative damage: The role of radical oxygen species in inflammation and the polyphenol, flavonoid and sterol contents  

Microsoft Academic Search

Ten hydroalcoholic extracts of edible plants from the Calabria region (Italy) were evaluated for their in vitro antioxidant and antiradical properties and in vivo topical anti-inflammatory activity. All the extracts had radical-scavenging and\\/or antioxidant properties, the most active plants being hawkweed oxtongue and viper’s bugloss. The best free radical (DPPH·)-scavenging activity was found in hawkweed oxtongue and chicory leaves extracts

Filomena Conforti; Silvio Sosa; Mariangela Marrelli; Federica Menichini; Giancarlo A. Statti; Dimitar Uzunov; Aurelia Tubaro; Francesco Menichini

2009-01-01

151

Special relationship between sterols and oxygen: Were sterols an adaptation to aerobic life?  

Microsoft Academic Search

A fascinating link between sterols and molecular oxygen (O2) has been a common thread running through the fundamental work of Konrad Bloch, who elucidated the biosynthetic pathway for cholesterol, to recent work supporting a role of sterols in the sensing of O2. Synthesis of sterols by eukaryotes is an O2-intensive process. In this review, we argue that increased levels of

Anne M. Galea; Andrew J. Brown

2009-01-01

152

Response of ?? T cells to plant-derived tannins  

PubMed Central

Many pharmaceutical drugs are isolated from plants used in traditional medicines. Through screening plant extracts, both traditional medicines and compound libraries, new pharmaceutical drugs continue to be identified. Currently, two plant-derived agonists for ?? T cells are described. These plant-derived agonists impart innate effector functions upon distinct ?? T cell subsets. Plant tannins represent one class of ?? T cell agonist and preferentially activate the mucosal population. Mucosal ?? T cells function to modulate tissue immune responses and induce epithelium repair. Select tannins, isolated from apple peel, rapidly induce immune gene transcription in ?? T cells, leading to cytokine production and increased responsiveness to secondary signals. Activity of these tannin preparations tracks to the procyanidin fraction, with the procyanidin trimer (C1) having the most robust activity defined to date. The response to the procyanidins is evolutionarily conserved in that responses are seen with human, bovine, and murine ?? T cells. Procyanidin-induced responses described in this review likely account for the expansion of mucosal ?? T cells seen in mice and rats fed soluble extracts of tannins. Procyanidins may represent a novel approach for treatment of tissue damage, chronic infection, and autoimmune therpies.

Holderness, Jeff; Hedges, Jodi F.; Daughenbaugh, Katie; Kimmel, Emily; Graff, Jill; Freedman, Brett; Jutila, Mark A.

2008-01-01

153

Analysis of Sterol Glycosides in Biodiesel and Biodiesel Precipitates  

Microsoft Academic Search

Biodiesel is produced by the transesterification of vegetable oils with short chain alcohols, usually in the presence of an\\u000a alkali catalyst. Minor components in biodiesel exist as a result of unreacted reagents, by-products, additives, and auto-oxidation\\u000a products, such as water, free glycerin, bonded glycerin, free fatty acids, catalysts, residual alcohol, unsaponifiable matter\\u000a (plant sterols, antioxidants, and hydrocarbons), soaps and polymers.

Huali Wang; Haiying Tang; Steven Salley; K. Y. Simon Ng

2010-01-01

154

Use of capillary gas chromatography for measuring fecal-derived sterols application to stormwater, the sea-surface microlayer, beach greases, regional studies, and distinguishing algal blooms and human and non-human sources of sewage pollution  

Microsoft Academic Search

The sterol composition, including the fecal biomarker coprostanol, from a variety of sample types was determined by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The coprostanol concentration in field samples readily provided an estimate of human fecal pollution. The technique was successfully used for stormwater, the sea-surface microlayer, beach sands and greases, and in regional studies of coastal

Peter D. Nichols; Rhys Leeming; Mark S. Rayner; Val Latham

1996-01-01

155

The sterols of calcareous sponges (Calcarea, Porifera).  

PubMed

Sponges are sessile suspension-feeding organisms whose internal phylogenetic relationships are still the subject of intense debate. Sterols may have the potential to be used as independent markers to test phylogenetic hypotheses. Twenty representative specimens of calcareous sponges (class Calcarea, phylum Porifera) with a broad coverage within both subclasses Calcinea and Calcaronea were analysed for their sterol content. Two major pseudohomologous series were found, accompanied by some additional sterols. The first series encompassing conventional C(27) to C(29)Delta(5,7,22) sterols represented the major sterols, with ergosterol (ergosta-5,7,22-trien-3beta-ol, C(28)Delta(5,7,22)) being most prominent in many species. The second series consisted of unusual C(27) to C(29)Delta(5,7,9(11),22) sterols. Cholesterol occurred sporadically, mostly in trace amounts. The sterol patterns did not resolve intraclass phylogenetic relationships, namely the distinction between the subclasses, Calcinea and Calcaronea. This pointed towards major calcarean lipid traits being established prior to the separation of subclasses. Furthermore, calcarean sterol patterns clearly differ from those found in Hexactinellida, whereas partial overlap occurred with some Demospongiae. Hence, sterols only partly reflect the phylogenetic separation of Calcarea from both of the other poriferan classes that was proposed by recent molecular work and fatty acid analyses. PMID:18671957

Hagemann, Andrea; Voigt, Oliver; Wörheide, Gert; Thiel, Volker

2008-07-10

156

Effect of Sterol Alterations on Conjugation in Saccharomyces Cerevisiae.  

National Technical Information Service (NTIS)

Sterol auxotrophic strains of Saccharomyces cerevisiae were grown and allowed to conjugate on media supplemented with various sterols. The mating efficiency of the auxotrophs is perturbed by the replacement of the normal yeast sterol, ergosterol. with oth...

M. E. Tomeo G. Fenner S. R. Tove L. W. Parks

1992-01-01

157

Regeneration of peach plants from callus derived from immature embryos  

Microsoft Academic Search

Peach plants were repeatedly regenerated from immature embryos but not from callus derived from mature embryos. A white, nodular, highly regenerative callus was obtained when friable, primary callus from immature embryos was transferred from medium containing 4.5 µM 2,4-dichlorophenoxyacetic acid and 0.44 µM benzyladenine (BA) to media containing 0.27 µM a-naphthaleneacetic acid (NAA) and 2.2 µM BA. This callus retained

F. A. Hammerschlag; G. Bauchan; R. Scorza

1985-01-01

158

Cameroonian Medicinal Plants: Pharmacology and Derived Natural Products  

PubMed Central

Many developing countries including Cameroon have mortality patterns that reflect high levels of infectious diseases and the risk of death during pregnancy and childbirth, in addition to cancers, cardiovascular diseases and chronic respiratory diseases that account for most deaths in the developed world. Several medicinal plants are used traditionally for their treatment. In this review, plants used in Cameroonian traditional medicine with evidence for the activities of their crude extracts and/or derived products have been discussed. A considerable number of plant extracts and isolated compounds possess significant antimicrobial, anti-parasitic including antimalarial, anti-proliferative, anti-inflammatory, anti-diabetes, and antioxidant effects. Most of the biologically active compounds belong to terpenoids, phenolics, and alkaloids. Terpenoids from Cameroonian plants showed best activities as anti-parasitic, but rather poor antimicrobial effects. The best antimicrobial, anti-proliferative, and antioxidant compounds were phenolics. In conclusion, many medicinal plants traditionally used in Cameroon to treat various ailments displayed good activities in vitro. This explains the endeavor of Cameroonian research institutes in drug discovery from indigenous medicinal plants. However, much work is still to be done to standardize methodologies and to study the mechanisms of action of isolated natural products.

Kuete, Victor; Efferth, Thomas

2010-01-01

159

Plant-derived bioactive compounds produced by endophytic fungi.  

PubMed

Plant endophytic fungi are an important and novel resource of natural bioactive compounds with their potential applications in agriculture, medicine and food industry. In the past two decades, many valuable bioactive compounds with antimicrobial, insecticidal, cytotoxic, and anticancer activities have been successfully discovered from endophytic fungi. During the long period of co-evolution, a friendly relationship was formed between each endophyte and its host plant. Some endophytes have the ability to produce the same or similar bioactive compounds as those originated from their host plants. This review mainly deals with the research progress on endophytic fungi for producing plant-derived bioactive compounds such as paclitaxel, podophyllotoxin, camptothecine, vinblastine, hypericin, and diosgenin. The relations between endophytic fungi and their host plants, biological activities and action mechanisms of these compounds from endophytic fungi, some available strategies for efficiently promoting production of these bioactive compounds, as well as their potential applications in the future will also be discussed. It is beneficial for us to better understand and take advantage of plant endophytic fungi. PMID:21222580

Zhao, J; Shan, T; Mou, Y; Zhou, L

2011-02-01

160

Andrographolide: A New Plant-Derived Antineoplastic Entity on Horizon  

PubMed Central

Plant-derived natural products occupy an important position in the area of cancer chemotherapy. Molecules such as vincristine, vinblastine, paclitaxel, camptothecin derivatives, epipodophyllotoxin, and so forth, are invaluable contributions of nature to modern medicine. However, the quest to find out novel therapeutic compounds for cancer treatment and management is a never-ending venture; and diverse plant species are persistently being studied for identification of prospective anticancer agents. In this regard, Andrographis paniculata Nees, a well-known plant of Indian and Chinese traditional system of medicines, has drawn attention of researchers in recent times. Andrographolide, the principal bioactive chemical constituent of the plant has shown credible anticancer potential in various investigations around the globe. In vitro studies demonstrate the capability of the compound of inducing cell-cycle arrest and apoptosis in a variety of cancer cells at different concentrations. Andrographolide also shows potent immunomodulatory and anti-angiogenic activities in tumorous tissues. Synthetic analogues of the compound have also been created and analyzed, which have also shown similar activities. Although it is too early to predict its future in cancer chemotherapy, the prologue strongly recommends further research on this molecule to assess its potential as a prospective anticancer agent.

Varma, Astha; Padh, Harish; Shrivastava, Neeta

2011-01-01

161

Metabolic engineering of sugars and simple sugar derivatives in plants.  

PubMed

Carbon captured through photosynthesis is transported, and sometimes stored in plants, as sugar. All organic compounds in plants trace to carbon from sugars, so sugar metabolism is highly regulated and integrated with development. Sugars stored by plants are important to humans as foods and as renewable feedstocks for industrial conversion to biofuels and biomaterials. For some purposes, sugars have advantages over polymers including starches, cellulose or storage lipids. This review considers progress and prospects in plant metabolic engineering for increased yield of endogenous sugars and for direct production of higher-value sugars and simple sugar derivatives. Opportunities are examined for enhancing export of sugars from leaves. Focus then turns to manipulation of sugar metabolism in sugar-storing sink organs such as fruits, sugarcane culms and sugarbeet tubers. Results from manipulation of suspected 'limiting' enzymes indicate a need for clearer understanding of flux control mechanisms, to achieve enhanced levels of endogenous sugars in crops that are highly selected for this trait. Outcomes from in planta conversion to novel sugars and derivatives range from severe interference with plant development to field demonstration of crops accumulating higher-value sugars at high yields. The differences depend on underlying biological factors including the effects of the novel products on endogenous metabolism, and on biotechnological fine-tuning including developmental expression and compartmentation patterns. Ultimately, osmotic activity may limit the accumulation of sugars to yields below those achievable using polymers; but results indicate the potential for increases above current commercial sugar yields, through metabolic engineering underpinned by improved understanding of plant sugar metabolism. PMID:23043616

Patrick, John W; Botha, Frikkie C; Birch, Robert G

2012-10-08

162

The sterols of calcareous sponges (Calcarea, Porifera)  

Microsoft Academic Search

Sponges are sessile suspension-feeding organisms whose internal phylogenetic relationships are still the subject of intense debate. Sterols may have the potential to be used as independent markers to test phylogenetic hypotheses. Twenty representative specimens of calcareous sponges (class Calcarea, phylum Porifera) with a broad coverage within both subclasses Calcinea and Calcaronea were analysed for their sterol content. Two major pseudohomologous

Andrea Hagemann; Oliver Voigt; Gert Wörheide; Volker Thiel

2008-01-01

163

Antioxidant kinetics of plant-derived substances and extracts.  

PubMed

The antioxidant activity (AA) of substances present in several plant species has been widely studied which reflects their fundamental role in the protection of skin tissue against the harmful action of reactive oxygen species. Given the importance of effective and long-lasting protection against ultraviolet radiation, we studied the AA of several plant derivatives and extracts over time. Several chemical in vitro methods may be used to evaluate antioxidant capability, among which the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method stands out, despite its unspecificity, as the most cited and described method in the literature. In this work the AA was evaluated by measuring their capacity to reduce DPPH in 30 min, which is suggested in the literature, and additionally at different times up to 8 h from the baseline reading. The methodology used to evaluate the AA over time was validated. It is important to emphasize that this study proposes to modify the conventional DPPH method, although considered to be non-specific, to be used to test new antioxidant agents. This represents a considerable advantage because some substances show no significant activity during the first 30 min of reaction. Among other plant products, we tested a proantocyanidin-rich grapeseed extract, a hesperidin derivative, a rutin-containing ginkgo extract, a polyphenol-containing yerba maté extract and tocopheryl acetate, all of which were properly standardized. As they have different antioxidant profiles, each ingredient showed a specific behaviour over time, which may promote the selection of anti-radical compounds capable of offering protection against external agents. Combining extracts and plant derivatives that present fast, medium and slow antioxidant kinetic it is possible to create complexes capable of offering an effective protection from the moment of application up to several hours later. It is a perfectly feasible method, and such combinations prove to be more effective and have more durable effect. PMID:19818087

Silva, A R; Menezes, P F C; Martinello, T; Novakovich, G F L; Praes, C E O; Feferman, I H S

2009-10-10

164

Sterol homeostasis requires regulated degradation of squalene monooxygenase by the ubiquitin ligase Doa10/Teb4.  

PubMed

Sterol homeostasis is essential for the function of cellular membranes and requires feedback inhibition of HMGR, a rate-limiting enzyme of the mevalonate pathway. As HMGR acts at the beginning of the pathway, its regulation affects the synthesis of sterols and of other essential mevalonate-derived metabolites, such as ubiquinone or dolichol. Here, we describe a novel, evolutionarily conserved feedback system operating at a sterol-specific step of the mevalonate pathway. This involves the sterol-dependent degradation of squalene monooxygenase mediated by the yeast Doa10 or mammalian Teb4, a ubiquitin ligase implicated in a branch of the endoplasmic reticulum (ER)-associated protein degradation (ERAD) pathway. Since the other branch of ERAD is required for HMGR regulation, our results reveal a fundamental role for ERAD in sterol homeostasis, with the two branches of this pathway acting together to control sterol biosynthesis at different levels and thereby allowing independent regulation of multiple products of the mevalonate pathway. DOI:http://dx.doi.org/10.7554/eLife.00953.001. PMID:23898401

Foresti, Ombretta; Ruggiano, Annamaria; Hannibal-Bach, Hans K; Ejsing, Christer S; Carvalho, Pedro

2013-07-23

165

Free, esterified and residual bound sterols in Black Sea Unit I sediments  

NASA Astrophysics Data System (ADS)

Detailed compositional data for the sterols isolated from a surface, Unit I, sediment from the Black Sea are reported. A procedure based on digitonin precipitation has been used to separate the more abundant free sterols from those occurring in esterified forms. Saponification of the solvent extracted sediment residue liberated only a small quantity of residual bound sterols in contrast to studies of other sediments. 4-Methylsterols are much more abundant than 4-desmethylsterols in both the free and esterified sterol fractions which we attribute to a major dinoflagellate input, as in deeper Unit II sediment. The desmethylsterol fraction appears to derive from a variety of sources including dinoflagellates, coccolithophores, diatoms, terrigenous detritus and perhaps invertebrates. 5?(H)-Stanols are particularly abundant in the free sterol fraction. An analysis of the stanol/stenol ratios suggests that the 4-desmethyl-5?(H)-stanols are the result of specific microbial reductions of ? 5-sterols and/or the reflection of a contribution of stanol containing source organisms.

de Leeuw, J. W.; Rijpstra, W. Irene C.; Schenck, P. A.; Volkman, J. K.

1983-03-01

166

In Vitro and In Vivo Anticancer Effects of Sterol Fraction from Red Algae Porphyra dentata  

PubMed Central

Porphyra dentata, an edible red macroalgae, is used as a folk medicine in Asia. This study evaluated in vitro and in vivo the protective effect of a sterol fraction from P. dentata against breast cancer linked to tumor-induced myeloid derived-suppressor cells (MDSCs). A sterol fraction containing cholesterol, ?-sitosterol, and campesterol was prepared by solvent fractionation of methanol extract of P. dentata??in silica gel column chromatography. This sterol fraction in vitro significantly inhibited cell growth and induced apoptosis in 4T1 cancer cells. Intraperitoneal injection of this sterol fraction at 10 and 25?mg/kg body weight into 4T1 cell-implanted tumor BALB/c mice significantly inhibited the growth of tumor nodules and increased the survival rate of mice. This sterol fraction significantly decreased the reactive oxygen species (ROS) and arginase activity of MDSCs in tumor-bearing mice. Therefore, the sterol fraction from P. dentata showed potential for protecting an organism from 4T1 cell-based tumor genesis.

Kazlowska, Katarzyna; Lin, Hong-Ting Victor; Chang, Shun-Hsien

2013-01-01

167

Formation of micella containing solubilized sterols during rehydration of active dry yeasts improves their fermenting capacity.  

PubMed

During their rehydration in aqueous media, active dry yeasts (ADY) may be supplemented with inactive yeasts, yeast derivatives, or other optional complementary nutrients to improve their fermentation capacity. We found that yeast sterols solubilized in situ during ADY rehydration were particularly efficient for stimulating the fermenting capacity of ADY. Spontaneous solubilization of sterols during rehydration occurred by the formation of micelles by membrane phospholipids and specific cell wall polysaccharides and sterols, both compounds being provided by inactive dry yeasts (IDY). These micelles contained a specific distribution of the initial sterols from the inactive yeasts. Above a concentration of 100 mg L(-1) in the rehydration medium, these micelles acted as emulsifiers. Their critical micellar concentration (cmc) was found to be about 4 g L(-1). During rehydration, purified micelles, at a concentration near the cmc, were able to interact quickly with yeast cell membranes by modifying the yeast plasma membrane order [monitored by steady-state fluorescence anisotropy of 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene-p-toluenesulfonate (TMA-DPH) probe] and by increasing the sterol contents of ADY. Such an enrichment of ADY by very low concentrations of solubilized sterols was very efficient for the completion of fermentations. This is useful when musts are limited in available phytosterols or when micro-oxygenation is not desirable during fermentation. PMID:16190666

Soubeyrand, Virginie; Luparia, Valeria; Williams, Pascale; Doco, Thierry; Vernhet, Aude; Ortiz-Julien, Anne; Salmon, Jean-Michel

2005-10-01

168

Effects of high molecular weight alcohols from sugar cane fed alone or in combination with plant sterols on lipid profile and antioxidant status of Wistar rats.  

PubMed

The effect of feeding a mixture of high molecular weight alcohols derived from sugarcane (SCA), both alone and in combination with phytosterols (PS), on changes in plasma lipids, organ cholesterol accumulation, and antioxidant status of Wistar rats was undertaken. Three separate experiments were conducted and each experiment had 3 subsets. In experiment 1, rats were fed on an AIN-76, semi-synthetic diet supplemented with 0%, 0.5%, and 5% SCA w/w. The second experiment consisted of feeding rats an atherogenic diet (AIN-76+0.5% cholesterol) containing 0%, 0.5%, and 5% SCA w/w. The third experiment consisted of feeding rats an atherogenic diet that contained 2% PS in combination with 0%, 0.5%, and 5% SCA. Rats fed the atherogenic diet exhibited significant elevations in total and low-density lipoprotein cholesterol, and significant reductions in the high-density lipoprotein/total cholesterol ratio, regardless of the presence of 0.5% or 5% SCA mixture. Serum cholesterol increased 29% to 35% in these animals compared with animals fed the nonatherogenic diets. In contrast, animals fed atherogenic diets that contained 2% PS exhibited no difference in serum lipids compared with counterparts fed nonatherogenic diets. The combined presence of SCA with PS had no effect on further lowering plasma cholesterol. No changes in C-reactive protein were observed, but plasma oxygen radical scavenging capacity values significantly (p < 0.05) decreased when rats were fed the atherogenic diets that contained the combination of PS and SCA. This result corresponded to an apparent greater (p < 0.05) susceptibility of red blood cells to oxidative stress. PMID:22803783

Kitts, David D; Kopec, Aneta; Zawistowski, Jerzy; Popovich, David G

2012-07-17

169

Sterol chemotaxonomy of marine pelagophyte algae.  

PubMed

Several marine algae of the class Pelagophyceae produce the unusual marine sterol 24-propylidenecholesterol, mainly as the (24E)-isomer. The (24Z)-isomer had previously been considered as a specific biomarker for Aureococcus anophagefferens, the 'brown tide' alga of the Northeast coast of the USA. To test this hypothesis and to generate chemotaxonomic information, the sterol compositions of 42 strains of pelagophyte algae including 17 strains of Aureococcus anophagefferens were determined by GC analysis. A more comprehensive sterol analysis by HPLC and (1)H-NMR was obtained for 17 selected pelagophyte strains. All strains analyzed contained 24-propylidenecholesterol. In all strains belonging to the order Sarcinochrysidales, this sterol was found only as the (E)-isomer, while all strains in the order Pelagomonadales contained the (Z)-isomer, either alone or together with the (E)-isomer. The occurrence of Delta(22) and 24alpha-sterols was limited to the Sarcinochrysidales. The first occurrence of Delta(22)-24-propylcholesterol in an alga, CCMP 1410, was reported. Traces of the rare sterol 26,26-dimethyl-24-methylenecholesterol were detected in Aureococcus anophagefferens, and the (25R)-configuration was proposed, based on biosynthetic considerations. Traces of a novel sterol, 24-propylidenecholesta-5,25-dien-3beta-ol, were detected in several species. PMID:19623555

Giner, José-Luis; Zhao, Hui; Boyer, Gregory L; Satchwell, Michael F; Andersen, Robert A

2009-07-01

170

Plant growth regulation activity of steviol and derivatives.  

PubMed

This work describes the preparation of tetracyclic diterpenoids and determination of their plant growth regulator properties. Stevioside (2) was used as starting material and the derivatives 13-hydroxy-ent-kaur-16-en-19-oic acid (steviol, 3), ent-7alpha,13-dihydroxy-kaur-16-en-19-oic acid (4), 13-hydroxy, ent-kaur-16,17-epoxi-19-oic acid (steviol epoxide, 5), 17-hydroxy-16-ketobayeran-19-oic acid (17-hydroxyisosteviol, 6), 17-hydroxy-16-hydroxyiminobayeran-19-oic acid (7), 16-ketobayeran-19-oic acid (isosteviol, 9), 16,17-dihydroxybeyeran-19-oic acid (8), and 16-hydroxyiminobayeran-19-oic acid (isosteviol oxime, 10) were obtained by simple chemical procedures. Another derivative, ent-7alpha,13-dihydroxycaur-15-en-19-oic acid (4), was obtained by biotransformation of steviol (3) by Penicillium citrinum. In order to determine the plant growth regulator activity the compounds were submitted to the lettuce hypocotyl and barley aleurone bioassays. All compounds showed significant activities in both bioassays. Steviol (3) and isosteviol (9) were also tested in field-grown grapes resulting in an increase in berry weight and size. PMID:18329674

de Oliveira, Brás Heleno; Stiirmer, Júlio César; de Souza Filho, José D; Ayub, Ricardo Antonio

2008-03-10

171

40 CFR 180.1179 - Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Plant extract derived from Opuntia lindheimeri...Exemptions From Tolerances § 180.1179 Plant extract derived from Opuntia lindheimeri...tolerance. The biochemical pesticide plant extract derived from Opuntia...

2011-07-01

172

40 CFR 180.1179 - Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Plant extract derived from Opuntia lindheimeri...Exemptions From Tolerances § 180.1179 Plant extract derived from Opuntia lindheimeri...tolerance. The biochemical pesticide plant extract derived from Opuntia...

2012-07-01

173

40 CFR 180.1179 - Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus...180.1179 Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica...biochemical pesticide plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus...

2010-07-01

174

40 CFR 180.1179 - Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus...180.1179 Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica...biochemical pesticide plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus...

2009-07-01

175

Low and moderate-fat plant sterol fortified soymilk in modulation of plasma lipids and cholesterol kinetics in subjects with normal to high cholesterol concentrations: report on two randomized crossover studies  

PubMed Central

Background Although consumption of various plant sterol (PS)-enriched beverages is effective in lowering plasma cholesterol, the lipid-lowering potential of PS in a soymilk format has not been investigated thoroughly. Therefore, to evaluate the efficacy of PS-enriched soy beverages on plasma lipids and cholesterol kinetics, we conducted two separate 28 d dietary controlled cross-over studies. In study 1, the cholesterol-lowering efficacy of a low-fat (2 g/serving) PS enriched soy beverage was examined in 33 normal cholesterolemic subjects in comparison with 1% dairy milk. In study 2, we investigated the efficacy of a moderate-fat (3.5 g/serving) PS-enriched soy beverage on plasma cholesterol concentrations and cholesterol kinetic responses in 23 hypercholesterolemic subjects compared with 1% dairy milk. Both the low and moderate-fat PS-enriched soymilk varieties provided 1.95 g PS/d. Endpoint plasma variables were analyzed by repeated-measures ANOVA using baseline values as covariates for plasma lipid measurements. Results In comparison with the 1% dairy milk control, the low-fat soy beverage reduced (P < 0.05) total and LDL-cholesterol by 10 and 13%, respectively. Consumption of the moderate-fat PS-enriched soy beverage reduced (P < 0.05) plasma total and LDL-cholesterol by 12 and 15% respectively. Fasting triglycerides were reduced by 9.4% following consumption of the moderate-fat soy beverage in comparison with the 1% dairy milk. Both low and moderate-fat PS-enriched soy varieties reduced (P < 0.05) LDL:HDL and TC:HDL ratios compared with the 1% dairy milk control. Consumption of the moderate-fat PS-enriched soymilk reduced (P < 0.05) cholesterol absorption by 27%, but did not alter cholesterol synthesis in comparison with 1% dairy milk. Conclusion We conclude that, compared to 1% dairy milk, consumption of low and moderate-fat PS-enriched soy beverages represents an effective dietary strategy to reduce circulating lipid concentrations in normal to hypercholesterolemic individuals by reducing intestinal cholesterol absorption. Trial registration (clinicaltrials.gov) NCT00923403 (Study 1), NCT00924391 (Study 2).

Rideout, Todd C; Chan, Yen-Ming; Harding, Scott V; Jones, Peter JH

2009-01-01

176

Fibroblast membrane sterol kinetic domains: modulation by sterol carrier protein-2 and liver fatty acid binding protein  

Microsoft Academic Search

The mechanism(s) of intracellular sterol traffick- ing among subcellular organelle membranes is not well un- derstood. Relative contributions of vesicular, sterol carrier protein, and membrane sterol domain pathways are not re- solved. A sterol kinetic assay was used to resolve multiple sterol domains in microsome (MICRO), mitochondria (MITO), and plasma (PM) membrane: exchangeable, 20-40% of total; non-exchangeable, 60-80% of total.

Andrey Frolov; Judith K. Woodford; Eric J. Murphy; Jeffrey T. Billheher; Friedhelm Schroederl

177

Steroid and sterol 7-hydroxylation: ancient pathways  

Microsoft Academic Search

B-ring hydroxylation is a major metabolic pathway for cholesterols and some steroids. In liver, 7?-hydroxylation of cholesterols, mediated by CYP7A and CYP39A1, is the rate-limiting step of bile acid synthesis and metabolic elimination. In brain and other tissues, both sterols and some steroids including dehydroepiandrosterone (DHEA) are prominently 7?-hydroxylated by CYP7B. The function of extra-hepatic steroid and sterol 7-hydroxylation is

Richard Lathe

2002-01-01

178

Universal Behavior of Membranes with Sterols  

Microsoft Academic Search

Lanosterol is the biosynthetic precursor of cholesterol and ergosterol, sterols that predominate in the membranes of mammals and lower eukaryotes, respectively. These three sterols are structurally quite similar, yet their relative effects on membranes have been shown to differ. Here we study the effects of cholesterol, lanosterol, and ergosterol on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine lipid bilayers at room temperature. Micropipette aspiration is used

J. Henriksen; A. C. Rowat; Y. W. Hsueh; J. L. Thewalt; M. J. Zuckermann; J. H. Ipsen

2006-01-01

179

Gas chromatographic analysis of plant sterols  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phytosterols are well-known for their ability to lower blood cholesterol by competing with absorption of cholesterol from the diet and reabsorption of bile cholesterol. Phytosterols as food ingredients are “Generally Recognized As Safe” (GRAS) by the FDA, and they are increasingly incorporated into ...

180

Sterol synthesis in the human arterial intima  

PubMed Central

Intimal sterol synthesis was examined in isolated human arterial segments obtained at surgery or at postmortem examination. The tissues were incubated with acetate-1-14C and mevalonate-2-14C and the incorporation of these precursors into sterols was determined. Intimal sterols were isolated by multiple chromatographic techniques and purified by bromination and oxidation procedures. The results indicate that the arterial intima can incorporate acetate and mevalonate into cholesterol, cholestanol, and squalene. Cholestanol was the major sterol synthesized by the arterial wall, but cholesterol production was also consistently observed. The findings suggest that local synthesis is a potential source of sterol accumulation within the arterial wall. The conversion of cholesterol to other sterols was also studied in terminally ill patients receiving labeled cholesterol before death. Tissue analyses revealed the presence of labeled cholestanol as well as cholesterol in the tissue 5-104 days after labeled cholesterol administration. The results demonstrate the conversion of cholesterol to cholestanol in man and suggest that the exchange of cholestanol between the blood and tissues is similar to that of cholesterol.

Chobanian, Aram V.

1968-01-01

181

Sterol regulatory element binding proteins (SREBP)-1a and SREBP-2 are linked to the MAP-kinase cascade  

Microsoft Academic Search

The classic sterol regulatory cis element ( sre -1) in the LDL receptor promoter mediates sterol regulatory ele- ment binding protein (SREBP)-binding and the effects of insulin and platelet derived growth factor (PDGF). To eluci- date whether SREBP-1a and SREBP-2 play a direct role in insulin and PDGF action, stable cell lines of HepG2 defi- cient in either SREBP-1 or

Jörg Kotzka; Dirk Müller-Wieland; Gunther Roth; Lorena Kremer; Martina Munck; Sandra Schürmann; Birgit Knebel; Wilhelm Krone

182

Molecular and biochemical classification of plant-derived food allergens.  

PubMed

Molecular biology and biochemical techniques have significantly advanced the knowledge of allergens derived from plant foods. Surprisingly, many of the known plant food allergens are homologous to pathogenesis-related proteins (PRs), proteins that are induced by pathogens, wounding, or certain environmental stresses. PRs have been classified into 14 families. Examples of allergens homologous to PRs include chitinases (PR-3 family) from avocado, banana, and chestnut; antifungal proteins such as the thaumatin-like proteins (PR-5) from cherry and apple; proteins homologous to the major birch pollen allergen Bet v 1 (PR-10) from vegetables and fruits; and lipid transfer proteins (PR-14) from fruits and cereals. Allergens other than PR homologs can be allotted to other well-known protein families such as inhibitors of alpha-amylases and trypsin from cereal seeds, profilins from fruits and vegetables, seed storage proteins from nuts and mustard seeds, and proteases from fruits. As more clinical data and structural information on allergenic molecules becomes available, we may finally be able to answer what characteristics of a molecule are responsible for its allergenicity. PMID:10887301

Breiteneder, H; Ebner, C

2000-07-01

183

How Plants Sense Wounds: Damaged-Self Recognition Is Based on Plant-Derived Elicitors and Induces Octadecanoid Signaling  

Microsoft Academic Search

BackgroundAnimal-derived elicitors can be used by plants to detect herbivory but they function only in specific insect–plant interactions. How can plants generally perceive damage caused by herbivores? Damaged-self recognition occurs when plants perceive molecular signals of damage: degraded plant molecules or molecules localized outside their original compartment.Methodology\\/Principal FindingsFlame wounding or applying leaf extract or solutions of sucrose or ATP to

Martin Heil; Enrique Ibarra-Laclette; Rosa M. Adame-Álvarez; Octavio Martínez; Enrique Ramirez-Chávez; Jorge Molina-Torres; Luis Herrera-Estrella

2012-01-01

184

Identification of ergosterol and inhibition of sterol synthesis by. Delta. sup 5 -sterols in GL7, an auxotrophic mutant of yeast  

SciTech Connect

Synthesis of ergosterol was demonstrated in the GL7 mutant of Saccharomyces cerevisiae. This sterol auxotroph has been thought to lack the ability to synthesize sterols due both to the absence of 2,3-oxidosqualene cyclase and to a heme deficiency eliminating cytochrome P-450 which is required in demethylation at C-14. However, when the exogenous sterol was 5{alpha}-cholestan-3{beta}-ol, 5{alpha}-cholest-8(14)-en-3{beta}-ol, or 24{beta}-methyl-5{alpha}-cholest-8(14)-en-3{beta}-ol, sterol synthesis was found to proceed yielding 1-3 fg/cell of ergosterol. Ergosterol was identified by mass spectroscopy, gas and high performance liquid chromatography, ultraviolet spectroscopy, and radioactive labelling from ({sup 3}H)acetate. Except for some cholest-5-en-3{beta}-ol (cholesterol) which was derived from the 5{alpha}-cholestan-3{beta}-ol, the stanol and the two 8(14)-stenols were not significantly metabolized confirming the absence of an isomerase for migration of the double bond from C-8(14) to C-7. Drastic reduction of ergosterol synthesis to not more than 0.06 fg/cell was observed when the exogenous sterol either had a double bond at C-5, as in the case of cholesterol, or could be metabolized to a sterol with such a bond. Thus, both 5{alpha}-cholest-8(9)-en-3{beta}-ol and 5{alpha}-cholest-7-en-3{beta}-ol (lathosterol) were converted to cholesta-5,7-dien-3{beta}-ol (7-dehydrocholesterol), and the presence of the latter dienol depressed the level of ergosterol.

Dhanuka, I.C.

1988-01-01

185

Effects of sterols on the development and aging of caenorhabditis elegans  

Technology Transfer Automated Retrieval System (TEKTRAN)

Because Caenorhabditis elegans lacks several components of the de novo sterol biosynthesis pathway, it requires sterols as essential nutrients. Supplemented cholesterol undergoes extensive enzymatic modification in C. elegans to form other sterols of unknown function. Because sterol metabolism in ...

186

Phosphoproteome exploration reveals a reformatting of cellular processes in response to low sterol biosynthetic capacity in Arabidopsis.  

PubMed

Sterols are membrane-bound isoprenoid lipids that are required for cell viability and growth. In plants, it is generally assumed that 3-hydroxy-3-methylglutaryl-CoA-reductase (HMGR) is a key element of their biosynthesis, but the molecular regulation of that pathway is largely unknown. In an attempt to identify regulators of the biosynthetic flux from acyl-CoA toward phytosterols, we compared the membrane phosphoproteome of wild-type Arabidopsis thaliana and of a mutant being deficient in HMGR1. We performed a N-terminal labeling of microsomal peptides with a trimethoxyphenyl phosphonium (TMPP) derivative, followed by a quantitative assessment of phosphopeptides with a spectral counting method. TMPP derivatization of peptides resulted in an improved LC-MS/MS detection due to increased hydrophobicity in chromatography and ionization efficiency in electrospray. The phosphoproteome coverage was 40% higher with this methodology. We further found that 31 proteins were in a different phosphorylation state in the hmgr1-1 mutant as compared with the wild-type. One-third of these proteins were identified based on novel phosphopeptides. This approach revealed that phosphorylation changes in the Arabidopsis membrane proteome targets major cellular processes such as transports, calcium homeostasis, photomorphogenesis, and carbohydrate synthesis. A reformatting of these processes appears to be a response of a genetically reduced sterol biosynthesis. PMID:22182420

Heintz, Dimitri; Gallien, Sebastien; Compagnon, Vincent; Berna, Anne; Suzuki, Masashi; Yoshida, Shigeo; Muranaka, Toshiya; Van Dorsselaer, Alain; Schaeffer, Christine; Bach, Thomas J; Schaller, Hubert

2012-01-11

187

Assessment of plant-derived hydrocarbons. Final report  

SciTech Connect

A number of hydrocarbon producing plants are evaluated as possible sources of rubber, liquid fuels, and industrial lubricants. The plants considered are Euphorbia lathyris or gopher plant, milkweeds, guayule, rabbit brush, jojoba, and meadow foam. (ACR)

McFadden, K.; Nelson, S.H.

1981-09-30

188

Advances in analytical methods to study cholesterol metabolism: the determination of serum noncholesterol sterols.  

PubMed

Cholesterol biosynthesis precursors and plant sterols are noncholesterol sterols currently used as relative surrogate markers of cholesterol synthesis and absorption, respectively. Its determination in serum samples is a way of diagnosing inherited disorders and also a tool for health evaluation during lipid-lowering lifestyle/drug therapy monitoring. This approach is the only one that can be used for large-scale clinical trials or population based studies, but, nevertheless, there is no reference method for the quantification of noncholesterol sterols in human serum samples and only analysis by GC-FID and GC-MS has been reported to be completely validated. Although there has been a wider use of noncholesterol sterols for the measurement and characterization of cholesterol metabolism, there is a lack of harmonization of measurements and of standardization of the methodology, which is essential for routine measurements of diagnostic utility. New recent advances in analytical methods for the determination of serum noncholesterol sterols are highlighted, focusing on the sample preparation, separation and detection techniques, which will enhance the range of applications in clinical practice. Copyright © 2012 John Wiley & Sons, Ltd. PMID:23165328

Andrade, Isabel; Santos, Lčlita; Ramos, Fernando

2012-11-20

189

Field evaluation of micropropagated bananas derived from plants containing Banana Bunchy-Top Virus  

Microsoft Academic Search

Micropropagated bananas derived from Banana Bunchy-Top Virus (BBTV) infected plants, but displaying no symptoms of the disease, were established in the field. They were grown for three years and produced a plant crop and ratoon crops. No disease symptoms were observed. There was uncertainty as to whethermicropropagation eliminated the virus from the material,the plants were symptomlessly infected, orthe plants were

R. A. Drew; M. K. Smith; D. W. Anderson

1992-01-01

190

Assessing anthropogenic contamination in surface sediments of Niger Delta, Nigeria with fecal sterols and n-alkanes as indicators.  

PubMed

The occurrence of sterols and n-alkanes in surface sediments from rivers and canals in the Niger Delta, Nigeria, determined with a gas chromatography-mass spectrometry method, was used to assess the impacts of anthropogenic activities in the area. The concentrations of total sterols (??Sterol) and n-alkanes (???n-alkane) in the sediments ranged from 133 to 2040 ng/g and 474 to 79,200 ng/g, respectively. An evaluation of the source diagnostic indices indicated that petroleum related sources (petrogenic) were the main contributor of n-alkanes in the samples, with minor contribution from higher plants waxes (biogenic), while the sterols were mainly of biogenic origin. The ratio of ?-cholestanone/(?-cholestanone+?-cholestanone), a commonly used source diagnostic index, implicated no fecal contamination in most of the sediment samples under investigation. These results have established the occurrence of anthropogenic contamination in Niger Delta sediments with significant contributions from petrogenic sources. PMID:23137973

Sojinu, Samuel O; Sonibare, Oluwadayo O; Ekundayo, O; Zeng, Eddy Y

2012-11-06

191

An Oxysterol-derived Positive Signal for 3Hydroxy 3-methylglutaryl-CoA Reductase Degradation in Yeast  

Microsoft Academic Search

Sterol synthesis by the mevalonate pathway is modu- lated, in part, through feedback-regulated degradation of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR). In mammals, both a non-sterol isoprenoid signal derived from farnesyl diphosphate (FPP) and a sterol-derived signal appear to act together to positively regulate the rate of HMGR degradation. Although the nature and number of sterol-derived signals are not clear, there is growing

Richard G. Gardner; Hui Shan; Seiichi P. T. Matsuda; Randolph Y. Hampton

2001-01-01

192

An update on plant derived anti-androgens.  

PubMed

Anti-androgens are an assorted group of drugs and compounds that reduce the levels or activity of androgen hormones within the human body. Disease states in which this is relevant include polycystic ovarian syndrome, hirsutism, acne, benign prostatic hyperplasia, and endocrine related cancers such as carcinoma of the prostate. We provide an overview and discussion of the use of anti-androgen medications in clinical practice and explore the increasing recognition of the benefits of plant-derived anti-androgens, for example, spearmint tea in the management of PCOS, for which some evidence about efficacy is beginning to emerge. Other agents covered include red reishi, which has been shown to reduce levels 5-alpha reductase, the enzyme that facilitates conversion of testosterone to dihydrotestosterone (DHT); licorice, which has phytoestrogen effects and reduces testosterone levels; Chinese peony, which promotes the aromatization of testosterone into estrogen; green tea, which contains epigallocatechins and also inhibits 5-alpha reductase, thereby reducing the conversion of normal testosterone into the more potent DHT; black cohosh, which has been shown to kill both androgenresponsive and non-responsive human prostate cancer cells; chaste tree, which has a reduces prolactin from the anterior pituitary; and saw palmetto extract, which is used as an anti-androgen although it shown no difference in comparison to placebo in clinical trials. PMID:23843810

Grant, Paul; Ramasamy, Shamin

2012-04-20

193

Quinuclidine Derivatives as Potential Antiparasitics  

Microsoft Academic Search

There is an urgent need for the development of new drugs for the treatment of tropical parasitic diseases such as Chagas' disease and leishmaniasis. One potential drug target in the organisms that cause these diseases is sterol biosynthesis. This paper describes the design and synthesis of quinuclidine derivatives as potential inhibitors of a key enzyme in sterol biosynthesis, squalene synthase

Simon B. Cammerer; Carmen Jimenez; Simon Jones; Ludovic Gros; Silvia Orenes Lorente; Carlos Rodrigues; Juliany C. F. Rodrigues; Aura Caldera; Luis Miguel Ruiz Perez; Wanderley da Souza; Marcel Kaiser; Reto Brun; Julio A. Urbina; Dolores Gonzalez Pacanowska; Ian H. Gilbert

2007-01-01

194

Sterol composition of shellfish species commonly consumed in the United States  

PubMed Central

Background Shellfish can be a component of a healthy diet due to a low fat and high protein content, but the cholesterol content of some species is often cited as a reason to limit their consumption. Data on levels of non-cholesterol sterols in commonly consumed species are lacking. Objective Shellfish were sampled and analyzed to update sterol data in the United States Department of Agriculture (USDA) National Nutrient Database for Standard Reference. Design Using a nationwide sampling plan, raw shrimp and sea scallops, canned clams, and steamed oysters, blue crab, and lobster were sampled from 12 statistically selected supermarkets across the United States in 2007–08. For each species, four composites were analyzed, each comprised of samples from three locations; shrimp and scallops from six single locations were also analyzed separately. Using validated analytical methodology, 14 sterols were determined in total lipid extracts after saponification and derivatization to trimethylsilyethers, using gas chromatography for quantitation and mass spectrometry for confirmation of components. Results Crab, lobster, and shrimp contained significant cholesterol (96.2–27 mg/100 g); scallops and clams had the lowest concentrations (23.4–30.1 mg/100 g). Variability in cholesterol among single-location samples of shrimp was low. The major sterols in the mollusks were brassicasterol (12.6–45.6 mg/100 g) and 24-methylenecholesterol (16.7–41.9 mg/100 g), with the highest concentrations in oysters. Total non-cholesterol sterols were 46.5–75.6 mg/100 g in five single-location scallops samples, but 107 mg/100 g in the sixth, with cholesterol also higher in that sample. Other prominent non-cholesterol sterols in mollusks were 22-dehydrocholesterol, isofucosterol, clionasterol, campesterol, and 24-norcholesta-5,22-diene-3?-ol (4–21 mg/100 g). Conclusions The presence of a wide range of sterols, including isomeric forms, in shellfish makes the analysis and quantitation of sterols in marine species more complex than in animal and plant tissues. The detailed sterol composition reported herein provides data that may be useful in research on the impact of shellfish consumption on dietary risk factors.

Phillips, Katherine M.; Ruggio, David M.; Exler, Jacob; Patterson, Kristine Y.

2012-01-01

195

Ecological significance of sterols in aquatic food webs  

Microsoft Academic Search

\\u000a Sterols are indispensable for a multitude of physiological processes in all eukaryotic organisms. In most eukaryotes, sterols\\u000a are synthesized de novo from low molecular weight precursors. Some invertebrates (e.g., all arthropods examined to date),\\u000a however, are incapable of synthesizing sterols de novo, and therefore have to acquire sterols from their diet. Here, we aim\\u000a to demonstrate that such nutritional requirements

Dominik Martin-Creuzburg; Eric von Elert

196

Some important aspects of sterol analysis of vegetable oils  

Microsoft Academic Search

The content and composition of the sterol fraction is an important indicator of the value of vegetable oils, mainly due to the cholesterol-lowering effect of certain sterol compounds. Although many methods have been described in the literature, various steps may still cause errors during sample preparation. The present article covers some of the key steps in sterol analysis that are

Erkki Mäeorga; Peeter Läänistea; Juhan Jőudua; Uno Mäeorgb

197

Characterization of sterol uptake in leaf tissues of sugar beet.  

PubMed

The uptake of cholesterol has been characterized in leaf discs from mature leaves of sugar beet ( Beta vulgaris L.). This transport system exhibited a simple saturable phase with an apparent Michaelis constant ranging from 30 to 190 microM depending on the sample. When present at 10 M excess, other sterols were able to inhibit cholesterol uptake. Moreover, binding assays demonstrated the presence of high-affinity binding sites for cholesterol in purified plasma membrane vesicles. In the range 1-60 microM, cholesterol uptake showed an active component evidenced by action of the protonophore carbonyl cyanide m-chlorophenylhydrazone. Energy was required as shown by the inhibition of uptake induced by respiration inhibitors (NaN(3)), darkness and photosynthesis inhibitors [3-(3,4-dichlorophenyl)-1,1-dimethylurea, methyl viologen]. Moreover, the process was strongly dependent on the experimental temperature. Uptake was optimal at acidic pH (4.0), sensitive to ATPase modulators, inhibited by thiol reagents (N-ethylmaleimide, p-chloromercuribenzenesulfonic acid, Mersalyl) and by the histidyl-group reagent diethyl pyrocarbonate. The addition of cholesterol did not modify H(+) flux from tissues, indicating that H(+)-co-transport was unlikely to be involved. MgATP did not increase the uptake, arguing against involvement of an ABC cassette-type transporter. By contrast, cryptogein, a sterol carrier protein from the Oomycete Phytophtora cryptogea, greatly increased absorption. Taken together, the results reported in this work suggest that plant cells contain a specific plasma membrane transport system for sterols. PMID:12920595

Rossard, Stéphanie; Bonmort, Janine; Guinet, Frédéric; Ponchet, Michel; Roblin, Gabriel

2003-08-15

198

Molecular changes in protoplast-derived rice plants  

Microsoft Academic Search

To determine whether regeneration of rice plants from protoplast culture induces DNA polymorphisms, progeny plants from direct regenerants of such cultures were examined for restriction fragment length polymorphisms (RFLP analysis). Significantly increased levels of DNA polymorphism were found compared with those in non-tissue culture control plants. Analysis with gene sequences representative of different functional domains, revealed that such polymorphisms are

P. T. H. Brown; J. Kyozuka; Y. Sukekiyo; Y. Kimura; K. Shimamoto; H. Lörz

1990-01-01

199

Molecular cloning and characterization of one member of 3beta-hydroxy sterol glucosyltransferase gene family in Withania somnifera.  

PubMed

Sterol glycosides are constituents of plant cell membranes. Glucosylations of the sterols are catalyzed by sterol glucosyltransferases (SGTs), which are members of family 1 glycosyltransferases. We have identified the family of SGT genes expressed in the leaves of a medicinal plant Withania somnifera. One member (SGTL1) of this gene family was cloned. The full-length cDNA sequence of SGTL1 represents 2532 bp, comprising untranslated regions (UTRs) of 337 and 89 bp at the 5' and 3' ends, respectively. The amino acid sequence deduced from the 2103 bp open reading frame (ORF) showed homology (67-45%) to the reported plant SGTs. The presence of two putative transmembrane domains suggested the association of SGTL1 with membrane. The SGTL1 was expressed in Escherichia coli and recombinant enzyme from the supernatant was partially purified and biochemically characterized. The relative activity and kinetic properties of SGTL1 for different sterols were compared with a recombinant SGT (GenBank Accession No. Z83833) of Arabidopsis thaliana (AtSGT). Both the recombinant enzymes showed activity with 3-beta-OH sterols. The distribution of SGTL1 transcript in W. somnifera, as determined by quantitative PCR, showed higher expression in roots and mature leaves. Expression of the SGTL1 transcript in the leaves of W. somnifera was enhanced following the application of salicylic acid. In contrast, it decreased rapidly on exposure of the plants to heat shock, suggesting functional role of the enzyme in biotic and abiotic stresses. PMID:17324374

Sharma, Lokendra Kumar; Madina, Bhaskara Reddy; Chaturvedi, Pankaj; Sangwan, Rajender Singh; Tuli, Rakesh

2007-02-12

200

Novel guggulsterone derivative GG52 inhibits NF-?B signaling in intestinal epithelial cells and attenuates acute murine colitis  

Microsoft Academic Search

We already showed that the plant sterol guggulsterone has been reported to inhibit nuclear factor-?B (NF-?B) signaling in intestinal epithelial cells (IECs) and to attenuate dextran sulfate sodium (DSS)-induced colitis. This study investigates the anti-inflammatory effects of novel guggulsterone derivatives on IEC and preventive and therapeutic murine models of DSS-induced colitis. Novel guggulsterone derivates with high lipophilicity were designed and

Jung Mogg Kim; Hyoun Woo Kang; Mi Yeon Cha; Doyoung Yoo; Nayoung Kim; In-Kyoung Kim; Jeounghun Ku; Sunil Kim; Sang-Ho Ma; Hyun Chae Jung; In Sung Song; Joo Sung Kim

2010-01-01

201

Changes in membrane lipid composition in azuki bean epicotyls under hypergravity conditions: Possible role of membrane sterols in gravity resistance  

NASA Astrophysics Data System (ADS)

Seedlings of azuki bean ( Vigna angularis Ohwi et Ohashi) were cultivated under hypergravity conditions, and changes in membrane lipid composition in their epicotyls were analyzed. Under hypergravity conditions at 300 g, the levels of total sterols, phospholipids, and fatty acids per fresh weight were kept higher, as compared with 1 g controls. In particular, sterol levels were prominently increased by hypergravity. On the other hand, hypergravity did not clearly influence the levels of each phospholipid and glycolipid class, or their fatty acid compositions. Thus, the effect of hypergravity on membrane lipid metabolism was specific for sterol biosynthesis. In various regions of azuki epicotyls, high growth rate was associated with high sterol levels. Hypergravity suppressed elongation growth and stimulated lateral expansion of azuki epicotyls. In the presence of lovastatin, an inhibitor of sterol biosynthesis, at 30 ?M, such changes in growth parameters occurred even under 1 g conditions, suggesting that lovastatin made epicotyls hypersensitive to the gravitational force. These results support the hypothesis that membrane sterols are involved in maintenance of normal growth capacity of plant organs against gravity.

Koizumi, T.; Sakaki, T.; Usui, S.; Soga, K.; Wakabayashi, K.; Hoson, T.

202

Using Theoretical Correction Factors for Quantitative Analysis of Sterols and Sterol Concentrates  

Microsoft Academic Search

A common detector for the analysis of sterols and sterol concentrates by gas chromatography is the flame ionization detector\\u000a (FID). The detector measures the response of ions from a molecule as it is pyrolyzed in a hydrogen flame. The response is\\u000a relative to the number of hydrogen and carbon atoms in a molecule and it gives different responses for the

Colin D. Costin; Steven L. Hansen; Daniel P. Chambers

2009-01-01

203

Transport of Newly Synthesized Sterol to the Sterol-Enriched Plasma Membrane Occurs via Nonvesicular Equilibration †  

Microsoft Academic Search

The mechanism by which newly synthesized sterols are transported from their site of synthesis, the endoplasmic reticulum (ER), to the sterol-enriched plasma membrane (PM) is not fully understood. Studies in mammalian cells suggest that newly synthesized cholesterol is transported to the PM in Golgi- bypassing vesicles and\\/or via a nonvesicular process. Using the yeast Saccharomyces cereVisiae as a model system,

Nikola A. Baumann; David P. Sullivan; Henna Ohvo-Rekilä; Cedric Simonot; Anita Pottekat; Zachary Klaassen; Christopher T. Beh; Anant K. Menon

2005-01-01

204

Antibodies to nystatin demonstrate polyene sterol specificity and allow immunolabeling of sterols in Saccharomyces cerevisiae.  

PubMed Central

Polyclonal antibodies elicited by injection into rabbits of a nystatin-bovine serum albumin conjugate were reactive with both nystatin and amphotericin B. Upon labeling of polyene-treated Saccharomyces cerevisiae sterol auxotrophs grown on various sterols, nystatin reacted specifically with ergosterol, while amphotericin B did not react preferentially with ergosterol, cholesterol, or cholestanol. Time course labeling experiments demonstrated the rate of ergosterol transport into cholesterol-grown cells. Images

Walker-Caprioglio, H M; MacKenzie, J M; Parks, L W

1989-01-01

205

Cycads: evolutionary innovations and the role of plant-derived neurotoxins  

Microsoft Academic Search

Cycads are an important relic from the past and represent the oldest living seed plants. Cycads have been instrumental in our understanding the evolution of angiosperms and gymnosperms because they have recognizable morphological characteristics intermediate between less-recently evolved plants such as ferns and more-derived (advanced) plants including the angiosperms. Cycads also produce several compounds that are carcinogenic and neurotoxic. Because

Eric D. Brenner; Dennis W. Stevenson; Richard W. Twigg

2003-01-01

206

Field performance characterization of strawberry ( Fragaria × ananassa Duch.) plants derived from cryopreserved apices  

Microsoft Academic Search

This study compares agronomic traits of two cultivars of strawberry in plants derived from conventional propagation, micropropagation and cryopreserved apices. The agronomic traits evaluated were fruit production and fruit quality. Differences were found in some of the fruit production traits studied in the plants post-micropropagation and post-cryopreservation when compared to conventionally propagated plants of the cultivar ‘Andana’; showing the first

Juan Jesús Medina; Isabel Clavero-Ramírez; María Elena González-Benito; Josefa Gálvez-Farfán; José Manuel López-Aranda; Carmen Soria

2007-01-01

207

Lectin cDNA and transgenic plants derived therefrom  

DOEpatents

Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties. GOVERNMENT RIGHTS This application was funded under Department of Energy Contract DE-AC02-76ER01338. The U.S. Government has certain rights under this application and any patent issuing thereon. .

Raikhel, N.V.

1994-01-04

208

Statement of Policy - Foods Derived from New Plant Varieties  

Center for Food Safety and Applied Nutrition (CFSAN)

... For example, animals consume whole cottonseed meal, whereas humans consume only cotton seed oil. Gossypol, a plant ... More results from www.fda.gov/food/guidanceregulation/guidancedocumentsregulatoryinformation

209

A new triazole, voriconazole (UK-109,496), blocks sterol biosynthesis in Candida albicans and Candida krusei.  

PubMed Central

Voriconazole (UK-109,496) is a novel triazole derivative with potent broad-spectrum activity against various fungi, including some that are inherently resistant to fluconazole, such as Candida krusei. In this study we compared the effect of subinhibitory concentrations of voriconazole and fluconazole on sterol biosynthesis of fluconazole-resistant and -susceptible Candida albicans strains, as well as C. krusei, in an effort to delineate the precise mode of action of voriconazole. Voriconazole MICs ranged from 0.003 to 4 microg/ml, while fluconazole MICs ranged from 0.25 to >64 microg/ml. To investigate the effects of voriconazole and fluconazole on candidal sterols, yeast cells were grown in the absence and presence of antifungals. In untreated C. albicans controls, ergosterol was the major sterol (accounting for 53.6% +/- 2.2% to 71.7% +/- 7.8% of the total) in C. albicans and C. krusei strains. There was no significant difference between the sterol compositions of the fluconazole-susceptible and -resistant C. albicans isolates. Voriconazole treatment led to a decrease in the total sterol content of both C. albicans strains tested. In contrast, exposure to fluconazole did not result in a significant reduction in the total sterol content of the three candidal strains tested (P > 0.5). Gas-liquid chromatographic analysis revealed profound changes in the sterol profiles of both C. albicans strains and of C. krusei in response to voriconazole. This antifungal agent exerted a similar effect on the sterol compositions of both fluconazole-susceptible and -resistant C. albicans strains. Interestingly, a complete inhibition of ergosterol synthesis and accumulation of its biosynthetic precursors were observed in both strains treated with voriconazole. In contrast, fluconazole partially inhibited ergosterol synthesis. Analysis of sterols obtained from a fluconazole-resistant C. albicans strain grown in the presence of different concentrations of voriconazole showed that this agent inhibits ergosterol synthesis in a dose-dependent manner. In C. krusei, voriconazole significantly inhibited ergosterol synthesis (over 75% inhibition). C. krusei cells treated with voriconazole accumulated the following biosynthetic intermediates: squalene, 4,14-dimethylzymosterol, and 24-methylenedihydrolanosterol. Accumulation of these methylated sterols is consistent with the premise that this agent functions by inhibiting fungal P-450-dependent 14alpha-demethylase. As expected, treating C. krusei with fluconazole minimally inhibited ergosterol synthesis. Importantly, our data indicate that voriconazole is more effective than fluconazole in blocking candidal sterol biosynthesis, consistent with the different antifungal potencies of these compounds.

Sanati, H; Belanger, P; Fratti, R; Ghannoum, M

1997-01-01

210

Immunization against Rabies with Plant-Derived Antigen  

Microsoft Academic Search

We previously demonstrated that recombinant plant virus particles containing a chimeric peptide representing two rabies virus epitopes stimulate virus neutralizing antibody synthesis in immunized mice. We show here that mice immunized intraperitoneally or orally (by gastric intubation or by feeding on virus-infected spinach leaves) with engineered plant virus particles containing rabies antigen mount a local and systemic immune response. After

Anna Modelska; Bernard Dietzschold; N. Sleysh; Zhen Fang Fu; Klaudia Steplewski; D. Craig Hooper; Hilary Koprowski; Vidadi Yusibov

1998-01-01

211

Foliar fatty acids and sterols of soybean field fumigated with SO/sub 2/  

SciTech Connect

Sixty-day-old soybean plants were exposed in the field to 78.7 parts per one-hundred million of SO/sub 2/ in an open-air fumigation system for 20 days. Leaves from the top one-fourth and bottom one-fourth of the plants were analyzed for chlorophyll, free fatty acids, fatty acid esters, polar lipid fatty acids, and sterols. Fumigated plants had a lower chlorophyll, free fatty acid, and polar lipid content, but a higher fatty acid ester content. Of the individual fatty acids, linolenic and linolenic acid increased with SO/sub 2/ fumigation while palmitic acid decreased. SO/sub 2/ fumigations had only a minor effect on leaf sterols. In general, the lower, more mature leaves showed a greater response to SO/sub 2/ exposure.

Grunwald, C.

1981-01-01

212

Mechanisms and genetic determinants regulating sterol absorption, circulating LDL levels, and sterol elimination: implications for classification and disease risk  

PubMed Central

This review integrates historical biochemical and modern genetic findings that underpin our understanding of the low-density lipoprotein (LDL) dyslipidemias that bear on human disease. These range from life-threatening conditions of infancy through severe coronary heart disease of young adulthood, to indolent disorders of middle- and old-age. We particularly focus on the biological aspects of those gene mutations and variants that impact on sterol absorption and hepatobiliary excretion via specific membrane transporter systems (NPC1L1, ABCG5/8); the incorporation of dietary sterols (MTP) and of de novo synthesized lipids (HMGCR, TRIB1) into apoB-containing lipoproteins (APOB) and their release into the circulation (ANGPTL3, SARA2, SORT1); and receptor-mediated uptake of LDL and of intestinal and hepatic-derived lipoprotein remnants (LDLR, APOB, APOE, LDLRAP1, PCSK9, IDOL). The insights gained from integrating the wealth of genetic data with biological processes have important implications for the classification of clinical and presymptomatic diagnoses of traditional LDL dyslipidemias, sitosterolemia, and newly emerging phenotypes, as well as their management through both nutritional and pharmaceutical means.

Calandra, Sebastiano; Tarugi, Patrizia; Speedy, Helen E.; Dean, Andrew F.; Bertolini, Stefano; Shoulders, Carol C.

2011-01-01

213

Using faecal sterols from humans and animals to distinguish faecal pollution in receiving waters  

Microsoft Academic Search

The sterol content of faeces from humans and 14 species of animals common to rural or urban environments were examined. The major human faecal sterol was the 5?-stanol, coprostanol which constituted ? 60% of the total sterols found in human faeces. The sterol profiles of herbivores were dominated by C29 sterols and 5?-stanols were generally in equal or greater abundance

R. Leeming; A. Ball; N. Ashbolt; P. Nichols

1996-01-01

214

Daidzein sulfoconjugates are potent inhibitors of sterol sulfatase (EC 3.1.6.2).  

PubMed

Recent studies have associated high dietary isoflavone intake with low incidence of breast cancer. Since estrogenic steroids are important factors in the evolution of breast cancer, and in breast tumors they are derived mainly from the sterol sulfatase pathway, we have therefore investigated effects of the isoflavone daidzein and its sulfoconjugates, daidzein-4'-O-sulfate and daidzein-7,4'-di-O-sulfate, on sterol sulfatase acitivity using dehydroepiandrosterone sulfate as substrate. While daidzein does not affect sterol sulfatase, its sulfoconjugates are potent inhibitors of this enzyme. Kinetic analyses reveal that daidzein-4'-O-sulfate and daidzein-7,4'-di-O-sulfate inhibit sterol sulfatase competitively with respect to the steroid substrate and with Ki values of 5.9 and 1 microM, respectively. Daidzein sulfo-conjugates also inhibit hydroxysteroid and phenol sulfotransferases but at much higher concentrations. These results provide a biochemical basis for the putative chemopreventive role of dietary isoflavones against breast cancer. PMID:9168894

Wong, C K; Keung, W M

1997-04-28

215

Sterols and sterolins: new drugs for the immune system?  

PubMed

Since the discovery of glucocorticoids, we have had a single strategy for manipulating the immune system in cases of destructive diseases mediated by uncontrolled immune responses. However, long-term use of immunosuppressive drugs can lead to the threat of opportunistic infections and malignancies. As we learn more about regulatory subsets of T lymphocytes and their cytokine profiles, the thrust has been on developing new ligands that ultimately give us more site-specific control. Our group has developed a patented mixture of plant sterols and sterolins that has anti-inflammatory properties and profound immune modulating effects on subsets of CD4+ T cells. We have tested this mixture in several clinical entities and we believe that it has wide applications in reverting immune abnormalities. PMID:12547034

Bouic, Patrick J D

2002-07-15

216

Sterol Molecular Modifications Influencing Membrane Permeability 1  

PubMed Central

Various sterols and related steroids were tested for their ability to influence ethanol-induced electrolyte leakage from Hordeum vulgare roots. Cholesterol had the greatest influence and, depending on concentration, it stimulated or inhibited the loss of electrolyte. Cholesterol, however, was ineffective if the roots were pretreated with ethanol. These data suggest that sterols protect rather than restore membrane structure. First, modifications in the cholesterol perhydrocyclopentanophenanthrene ring system suggest that at least one double bond is required for membrane activity. Second, increasing the bulkiness of the C17 side chain of cholesterol, as shown with campesterol, stigmasterol, and sitosterol, decreased its activity. Apparently for maximum effectiveness the sterol molecule should have a relatively flat configuration. Third, the C3-hydroxyl group is required for membrane activity since cholesteryl methyl ether, cholest-5-ene-3?-thiol and cholesteryl halogens were without activity. Exception to the foregoing rule was cholestane which was slightly active but which has neither a C3-hydroxyl group nor a double bond in the ring system.

Grunwald, Claus

1974-01-01

217

Incorporation of L Cell Sterols into Vesicular Stomatitis Virus  

PubMed Central

The incorporation of host cell sterol into vesicular stomatitis virus can be effectively studied in an L cell system. The end product of de novo sterol synthesis in the L cell is desmosterol, and as the concentration of cholesterol in the medium is increased the cells incorporate the exogenous cholesterol and the synthesis of desmosterol decreases. L cells which contained desmosterol as their sole sterol produced virus whose sterol content was similarly composed of only desmosterol. Virus grown in L cells which had a constantly changing sterol ratio also contained a mixture of cholesterol and desmosterol, but the virus was found to be more enriched in cholesterol than in the L cells in which it was grown. Viral stability, growth, and plaquing efficiency were tested and found not to be affected by the alteration of its sterol composition, i.e., by partially or completely replacing cholesterol with desmosterol.

Bates, Sandra R.; Rothblat, George H.

1972-01-01

218

How Plants Sense Wounds: Damaged-Self Recognition Is Based on Plant-Derived Elicitors and Induces Octadecanoid Signaling  

PubMed Central

Background Animal-derived elicitors can be used by plants to detect herbivory but they function only in specific insect–plant interactions. How can plants generally perceive damage caused by herbivores? Damaged-self recognition occurs when plants perceive molecular signals of damage: degraded plant molecules or molecules localized outside their original compartment. Methodology/Principal Findings Flame wounding or applying leaf extract or solutions of sucrose or ATP to slightly wounded lima bean (Phaseolus lunatus) leaves induced the secretion of extrafloral nectar, an indirect defense mechanism. Chemically related molecules that would not be released in high concentrations from damaged plant cells (glucose, fructose, salt, and sorbitol) did not elicit a detectable response, excluding osmotic shock as an alternative explanation. Treatments inducing extrafloral nectar secretion also enhanced endogenous concentrations of the defense hormone jasmonic acid (JA). Endogenous JA was also induced by mechanically damaging leaves of lima bean, Arabidopsis, maize, strawberry, sesame and tomato. In lima bean, tomato and sesame, the application of leaf extract further increased endogenous JA content, indicating that damaged-self recognition is taxonomically widely distributed. Transcriptomic patterns obtained with untargeted 454 pyrosequencing of lima bean in response to flame wounding or the application of leaf extract or JA were highly similar to each other, but differed from the response to mere mechanical damage. We conclude that the amount or concentration of damaged-self signals can quantitatively determine the intensity of the wound response and that the full damaged-self response requires the disruption of many cells. Conclusions/Significance Numerous compounds function as JA-inducing elicitors in different plant species. Most of them are, contain, or release, plant-derived molecular motifs. Damaged-self recognition represents a taxonomically widespread mechanism that contributes to the perception of herbivore feeding by plants. This strategy is independent of insect-derived elicitors and, therefore, allows plants to maintain evolutionary control over their interaction with herbivores.

Heil, Martin; Ibarra-Laclette, Enrique; Adame-Alvarez, Rosa M.; Martinez, Octavio; Ramirez-Chavez, Enrique; Molina-Torres, Jorge; Herrera-Estrella, Luis

2012-01-01

219

Toxicological Actions of Plant-Derived and Anthropogenic Methylenedioxyphenyl-Substituted Chemicals in Mammals and Insects  

Microsoft Academic Search

The methylenedioxyphenyl (MDP) substituent is a structural feature present in many plant chemicals that deter foraging by predatory insects and herbivores. With increasing use of herbal extracts in alternative medicine, human exposure to MDP-derived plant chemicals may also be significant. Early studies found that most MDP agents themselves possess relatively low intrinsic toxicity, but strongly influence the actions of other

Michael Murray

2012-01-01

220

Human-derived, plant-produced monoclonal antibody for the treatment of anthrax  

Microsoft Academic Search

The unpredictable nature of bio-terrorism compels us to develop medical countermeasures that will enable authorities to treat individuals exposed to agents such as anthrax. We report the feasibility of producing a protective, human-derived, monoclonal antibody directed against the protective antigen (PA) of Bacillus anthracis in plants. This was achieved by transient expression using agroinfiltration of Nicotiana benthamiana plants. The resulting

Anna K. Hull; Carolyn J. Criscuolo; Vadim Mett; Herman Groen; Wilma Steeman; Hans Westra; Gail Chapman; Bart Legutki; Les Baillie; Vidadi Yusibov

2005-01-01

221

Regeneration of fertile plants from protoplasts derived from embryogenic cell suspensions of barley ( Hordeum vulgare L.)  

Microsoft Academic Search

We report regeneration of fertile plants from barley (Hordeum vulgare L. cv. Igri) protoplasts isolated from regenerable suspension cultures initiated from anther-derived embryogenic callus. Plants were routinely regenerated from these suspension cultures, which maintained their regenerative capacity for several months. It was first possible to isolate protoplasts from suspensions after three months of culture and after four months protoplasts capable

A. Jähne; P. A. Lazzeri; H. Lörz

1991-01-01

222

Artificial inoculation of banana tissue culture plantlets with indigenous endophytes originally derived from native banana plants  

Microsoft Academic Search

Fusarium wilt disease of banana is one of the most harmful fungal diseases affecting banana production worldwide. We hypothetically proposed that the loss of indigenous endophytes in tissue culture propagation of banana might be related to increased disease severity on banana plants. In the present study, a mixture of uncultivated endophytes, which was originally derived from native healthy banana plant

Lian Jie; Wang Zifeng; Cao Lixiang; Tan Hongming; Inderbitzin Patrik; Jiang Zide; Zhou Shining

2009-01-01

223

Efficient production of doubled haploid plants through colchicine treatment of anther-derived maize callus  

Microsoft Academic Search

A chromosome doubling technique, involving colchicine treatment of an embryogenic, haploid callus line of maize (Zea mays L., derived through anther culture), was evaluated. Two colchicine levels (0.025% and 0.05%) and three treatment durations (24, 48, and 72 h) were used and compared to untreated controls. Chromosome counts and seed recovery from regenerated plants were determined. No doubled haploid plants

Y. Wan; J. F. Petolino; J. M. Widholm

1989-01-01

224

Immunization against Rabies with Plant-Derived Antigen  

NASA Astrophysics Data System (ADS)

We previously demonstrated that recombinant plant virus particles containing a chimeric peptide representing two rabies virus epitopes stimulate virus neutralizing antibody synthesis in immunized mice. We show here that mice immunized intraperitoneally or orally (by gastric intubation or by feeding on virus-infected spinach leaves) with engineered plant virus particles containing rabies antigen mount a local and systemic immune response. After the third dose of antigen, given intraperitoneally, 40% of the mice were protected against challenge infection with a lethal dose of rabies virus. Oral administration of the antigen stimulated serum IgG and IgA synthesis and ameliorated the clinical signs caused by intranasal infection with an attenuated rabies virus strain.

Modelska, Anna; Dietzschold, Bernard; Sleysh, N.; Fu, Zhen Fang; Steplewski, Klaudia; Hooper, D. Craig; Koprowski, Hilary; Yusibov, Vidadi

1998-03-01

225

Fertile Indica rice plants regenerated from protoplasts isolated from microspore derived cell suspensions  

Microsoft Academic Search

Rice plants (Oryza sativa L., Chinsurah Boro II var. Indica) were regenerated from protoplasts isolated from microspore derived cell suspensions. A simple procedure for the establishment of such cell suspension cultures from embryogenic microcallus derived from cultured isolated microspores of Indica-type rice is described. Regenerating protoplasts could readily be isolated from 5–12 months old cell suspensions showing visible colony formation

Swapan K. Datta; Karabi Datta; Ingo Potrykus

1990-01-01

226

Sterol Structure Determines Miscibility versus Melting Transitions in Lipid Vesicles  

Microsoft Academic Search

Lipid bilayer membranes composed of DOPC, DPPC, and a series of sterols demix into coexisting liquid phases below a miscibility transition temperature. We use fluorescence microscopy to directly observe phase transitions in vesicles of 1:1:1 DOPC\\/DPPC\\/sterol within giant unilamellar vesicles. We show that vesicles containing the “promoter” sterols cholesterol, ergosterol, 25-hydroxycholesterol, epicholesterol, or dihydrocholesterol demix into coexisting liquid phases as

Mary Elizabeth Beattie; Sarah L. Veatch; Benjamin L. Stottrup; Sarah L. Keller

2005-01-01

227

Technological Factors Affecting Sterols in Australian Olive Oils  

Microsoft Academic Search

Sterols are important lipids related to the quality of olive oil and broadly used for checking its genuineness. Recent analyses\\u000a have identified that some Australian olive oils would not meet international standards for total content of sterols or for\\u000a certain individual components. Several research works indicate that there are some significant correlations between cultural\\u000a and processing practices and sterols content

Claudia Guillaume; Leandro Ravetti; Debashree Lala Ray; Joshua Johnson

228

Sterol-polyene antibiotic complexation: Probe of membrane structure  

Microsoft Academic Search

Polyene antibiotics are useful tools for studying the role of sterols in biological membranes. The interaction of polyene\\u000a antibiotics with membrane-bound sterols in artificial membrane systems, prokaryotic and eukaryotic cells, and lipid-containing\\u000a viruses is reviewed. The pentaene macrolide, filipin, is shown to serve as a probe of phosphatidylcholine-sterol interaction\\u000a and of the localization of cholesterol in the membrane of mycoplasmas.

Robert Bittman

1978-01-01

229

Plants' use of leachate derived from municipal solid waste  

SciTech Connect

Leachate was collected from a watertight pit at a landfill center dealing mainly with household refuse and plant waste. This effluent was characterized by a moderate organic matter content, a pH slightly higher than neutral and strong electrical conductivity. This latter was due to the presence of chlorides, Na, K, and ammonium. The organic content could be divided into two fractions: Fraction A consisting of large molecules and Fraction B of smaller, more acidic molecules. The presence of phenols could be identified in the leachate as a whole. A biological treatment of this leachate, involving methanization followed by aerated lagooning, was set up on the site: this led to a reduction of nearly 60% in the organic content and almost total elimination of the ammonium. This treatment was not however sufficient to allow direct evacuation of the resulting effluent into the surface ground water. As heavy metals were absent from this effluent, the leachates from this landfill site could possibly be envisaged in the fertilization of soil-grown crops or for furrow irrigation-fertilization of tree plantations. The effect of irrigating soil-grown plants with a solution of leachate was examined using pots of ryegrass (Lolium sp.). Application of solutions containing dilutions of 1 to 400 mL L{sup {minus}1} of this effluent had a highly favorable effect on plant growth. Toxicity phenomena were apparent above this concentration. The optimum effect on ryegrass growth, under the conditions of this trial, was obtained by watering each pot with 30 mL of a solution containing 400 mL L{sup {minus}1} of leachate, every 2 d. This solution improved water and N nutrition in these plants.

Revel, J.C.; Morard, P.; Bailly, J.R.; Labbe, H.; Berthout, C.; Kaemmerer, M.

1999-08-01

230

Plant derivatives in the treatment of alcohol dependency  

Microsoft Academic Search

The present review summarizes the findings of the effects of extracts of purified compounds from several plants on alcohol intake in alcohol-preferring rats. These include St. John's wort (Hypericum perforatum, HPE), kudzu (Pueraria lobata) and ibogaine (Tabernanthe iboga). Alcohol-preferring (P), Marchigian Sardinian (msP), high-alcohol-drinking (HAD), Fawn-Hooded (FH) rats were allowed to drink alcohol or water voluntarily to establish baseline levels.

Amir H Rezvani; David H Overstreet; Marina Perfumi; Maurizio Massi

2003-01-01

231

Plant-growth inhibitory activity of heliannuol derivatives.  

PubMed

In addition to (+)-, (-)- and (+/-)-heliannuol E, growth-inhibitory activities of five synthetic chromans and four tetrahydrobenzo[b]oxepins were examined against oat and cress. All heliannuol E isomers exhibited similar biological activities against cress, whereas when tested against oat roots, the unnatural optical isomer (+) showed no inhibitory activity. Four brominated chromans and two tetrahydrobenzo[b]oxepin derivatives also showed apparent inhibition against both cress and oat. PMID:15231414

Doi, Fuminao; Ohara, Taiga; Ogamino, Takahisa; Sugai, Takeshi; Higashinakasu, Keiko; Yamada, Kosumi; Shigemori, Hideyuki; Hasegawa, Koji; Nishiyama, Shigeru

2004-05-01

232

Sterols and the Sensitivity of Pythium Species to Filipin1  

PubMed Central

Schlosser, Eckart (University of Illinois, Urbana), and David Gottlieb. Sterols and the sensitivity of Pythium species to filipin. J. Bacteriol. 91:1080–1084. 1966.—The growth of several Pythium species was not affected by filipin. No leakage of inorganic phosphate was observed after treatment with the antibiotic. No sterol could be detected in 1 g (dry weight) of mycelium. Thus, the insensitivity of these fungi to the antibiotic may be explained by the lack of sterols, the postulated reaction site for filipin in the cell membrane. Though not capable of synthesizing sterols, Pythium species can incorporate exogeneous sterols, which renders them sensitive to filipin; such treatment causes a lag in growth and leakage of inorganic phosphate. The leakage after filipin treatment is indirect evidence that the sterols have been incorporated into the cell membrane. Induced sensitivity to filipin was reversible; it was lost when the sterols were diluted out by one transfer through a medium free from sterols. The hypothesis that the primary site of interaction of filipin is the sterol located in the cell membrane was strengthened by these studies. The experiments further demonstrated a change in sensitivity of a fungus to a toxic agent due to nutritional conditions.

Schlosser, Eckart; Gottlieb, David

1966-01-01

233

Insulin-induced gene protein (INSIG)-dependent sterol regulation of Hmg2 endoplasmic reticulum-associated degradation (ERAD) in yeast.  

PubMed

Insulin-induced gene proteins (INSIGs) function in control of cellular cholesterol. Mammalian INSIGs exert control by directly interacting with proteins containing sterol-sensing domains (SSDs) when sterol levels are elevated. Mammalian 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase (HMGR) undergoes sterol-dependent, endoplasmic-reticulum (ER)-associated degradation (ERAD) that is mediated by INSIG interaction with the HMGR SSD. The yeast HMGR isozyme Hmg2 also undergoes feedback-regulated ERAD in response to the early pathway-derived isoprene gernanylgeranyl pyrophosphate (GGPP). Hmg2 has an SSD, and its degradation is controlled by the INSIG homologue Nsg1. However, yeast Nsg1 promotes Hmg2 stabilization by inhibiting GGPP-stimulated ERAD. We have proposed that the seemingly disparate INSIG functions can be unified by viewing INSIGs as sterol-dependent chaperones of SSD clients. Accordingly, we tested the role of sterols in the Nsg1 regulation of Hmg2. We found that both Nsg1-mediated stabilization of Hmg2 and the Nsg1-Hmg2 interaction required the early sterol lanosterol. Lowering lanosterol in the cell allowed GGPP-stimulated Hmg2 ERAD. Thus, Hmg2-regulated degradation is controlled by a two-signal logic; GGPP promotes degradation, and lanosterol inhibits degradation. These data reveal that the sterol dependence of INSIG-client interaction has been preserved for over 1 billion years. We propose that the INSIGs are a class of sterol-dependent chaperones that bind to SSD clients, thus harnessing ER quality control in the homeostasis of sterols. PMID:23306196

Theesfeld, Chandra L; Hampton, Randolph Y

2013-01-10

234

Agro-morphological characterization of ovary culture-derived plants of rice (Oryza sativa L.)  

Microsoft Academic Search

Plants derived from unpollinated ovary culture of ten rice genotypes showed significant variability in agro-morphological\\u000a characteristics. The ovary-derived plant (H1) populations were completely haploid, doubled haploid or haploid-doubled haploid\\u000a mixture. Haploids had very drastic reduction in plant height, panicle length, grain length, breadth and number and spikelet\\u000a fertility (0.0%–2.1%). Doubled haploids from the hybrid of UPRI 95–121 UPRI 95–165 were

Li Rongbai; M. P. Pandey; S. K. Pandey; D. K. Dwivedi

1999-01-01

235

Lack of requirement for sterol carrier protein-2 in the intracellular trafficking of lysosomal cholesterol  

Microsoft Academic Search

Previous work has established that the absence of peroxisomes, as occurs in Zellweger syndrome, is accompanied by the absence of cellular sterol carrier protein-2 (SCPz). In the present study, Zellweger-syndrome fibroblasts and peroxisome- deficient CHO-ZR78 cells were used to study the role of SCPz in the intracellular transport of low density lipoprotein (LDL)- derived lysosomal cholesterol. By immunoblotting, peroxisome- deficient

William J. Johnson; Michael P. Reinhart

236

Sterols and Oxidized Sterols in Feed Ingredients Obtained from Chemical and Physical Refining Processes of Fats and Oils  

Microsoft Academic Search

The by-products obtained from conventional chemical and physical refining processes for edible fats and oils are important\\u000a sources of valuable fatty components such as sterols, tocopherols, fatty acids, etc., and are also used as ingredients in\\u000a animal feed formulations. Reports on sterol composition and content are limited, and the levels of oxidized sterols in these\\u000a valuable by-products are unknown. This

Sarojini J. K. A. Ubhayasekera; Paresh C. Dutta

2009-01-01

237

Development of field-grown potato plants derived from meristem plants multiplied with different methods  

Microsoft Academic Search

In the current multiplication technique first-generation seed tubers produced in the field by transplanting plants raised on peat in plastic rolls from plants cultured by repetitive multiplication using tip- and stem-cuttings and truncated plants are compared with in vitro micro-plants from the aspect of obtaining optimal-sized, disease-free seed tubers.The objective of the study is to compare the dynamics of total

Marje Särekanno; Jüri Kadaja; Katrin Kotkas; Viive Rosenberg; Viacheslav Eremeev

2011-01-01

238

Development of field-grown potato plants derived from meristem plants multiplied with different methods  

Microsoft Academic Search

In the current multiplication technique first-generation seed tubers produced in the field by transplanting plants raised on peat in plastic rolls from plants cultured by repetitive multiplication using tip- and stem-cuttings and truncated plants are compared with in vitro micro-plants from the aspect of obtaining optimal-sized, disease-free seed tubers.The objective of the study is to compare the dynamics of total

Marje Särekanno; Jüri Kadaja; Katrin Kotkas; Viive Rosenberg; Viacheslav Eremeev

2012-01-01

239

A search for mosquito larvicidal compounds by blocking the sterol carrying protein, AeSCP-2, through computational screening and docking strategies  

PubMed Central

Background: Sterol is a very vital compound for most of the insects and mosquitoes to complete their life cycle. Unfortunately mosquitoes cannot synthesize the sterol, it depends on mammals for the same. Mosquitoes take the sterol from the plant decays during their larval stage in the form of phytosterol, which is then converted to cholesterol for further growth and reproduction. This conversion occurs with the help of the sterol carrier protein 2(SCP2). Methods: Mosquito populations are controlled by plant-based inhibitors, which inhibit sterol carrier protein (SCPI-Sterol carrier protein inhibitor) activity. In this article, we explain the methods of inhibiting Aedes aegypti SCP2 by insilico methods including natural inhibitor selection and filtrations by virtual screening and interaction studies. Results: In this study protein-ligand interactions were carried out with various phytochemicals, as a result of virtual screening Alpha-mangostin and Panthenol were found to be good analogs, and were allowed to dock with the mosquito cholesterol carrier protein AeSCP-2. Conclusion: Computational selections of SCPIs are highly reliable and novel methods for discovering new and more effective compounds to control mosquitoes.

Kumar, R. Barani; Shanmugapriya, B.; Thiyagesan, K.; Kumar, S. Raj; Xavier, Suresh M.

2010-01-01

240

Substrate Preferences and Catalytic Parameters Determined by Structural Characteristics of Sterol 14[alpha]-Demethylase (CYP51) from Leishmania infantum  

SciTech Connect

Leishmaniasis is a major health problem that affects populations of {approx}90 countries worldwide, with no vaccine and only a few moderately effective drugs. Here we report the structure/function characterization of sterol 14{alpha}-demethylase (CYP51) from Leishmania infantum. The enzyme catalyzes removal of the 14{alpha}-methyl group from sterol precursors. The reaction is essential for membrane biogenesis and therefore has great potential to become a target for antileishmanial chemotherapy. Although L. infantum CYP51 prefers C4-monomethylated sterol substrates such as C4-norlanosterol and obtusifoliol (V{sub max} of {approx}10 and 8 min{sup -1}, respectively), it is also found to 14{alpha}-demethylate C4-dimethylated lanosterol (V{sub max} = 0.9 min{sup -1}) and C4-desmethylated 14{alpha}-methylzymosterol (V{sub max} = 1.9 min{sup -1}). Binding parameters with six sterols were tested, with K{sub d} values ranging from 0.25 to 1.4 {mu}m. Thus, L. infantum CYP51 is the first example of a plant-like sterol 14{alpha}-demethylase, where requirements toward the composition of the C4 atom substituents are not strict, indicative of possible branching in the postsqualene portion of sterol biosynthesis in the parasite. Comparative analysis of three CYP51 substrate binding cavities (Trypanosoma brucei, Trypanosoma cruzi, and L. infantum) suggests that substrate preferences of plant- and fungal-like protozoan CYP51s largely depend on the differences in the enzyme active site topology. These minor structural differences are also likely to underlie CYP51 catalytic rates and drug susceptibility and can be used to design potent and specific inhibitors.

Hargrove, Tatiana Y.; Wawrzak, Zdzislaw; Liu, Jialin; Nes, W. David; Waterman, Michael R.; Lepesheva, Galina I. (Vanderbilt); (TTU); (NWU)

2012-05-14

241

Plant derivatives in the treatment of alcohol dependency.  

PubMed

The present review summarizes the findings of the effects of extracts of purified compounds from several plants on alcohol intake in alcohol-preferring rats. These include St. John's wort (Hypericum perforatum, HPE), kudzu (Pueraria lobata) and ibogaine (Tabernanthe iboga). Alcohol-preferring (P), Marchigian Sardinian (msP), high-alcohol-drinking (HAD), Fawn-Hooded (FH) rats were allowed to drink alcohol or water voluntarily to establish baseline levels. Pure compounds (puerarin, daidzin, daidzein or analogs) isolated from kudzu, extracts from HPE or ibogaine and its analog were given by either intraperitoneal or oral administration. After acute administration, all agents dose-dependently reduced alcohol intake with minimal effects on food intake. Puerarin and HPE were also effective following chronic treatment. Overall, it is clear that pure compounds (daidzin, puerarin), extracts from St. John's wort, ibogaine and an ibogaine analog suppress alcohol intake in animal models of excessive drinking with minimal effects on other appetitive behaviors. Although the true mechanisms of action of these compounds on alcohol intake are not fully understood, with the current information, it appears that these compounds exert their effects by modulating several neuronal systems implicated in drinking behavior. However, their role in the future of pharmacotherapy for alcoholism will depend upon the outcome of carefully conducted clinical trials. PMID:12895677

Rezvani, Amir H; Overstreet, David H; Perfumi, Marina; Massi, Maurizio

2003-06-01

242

Adult sterol metabolism is not affected by a positive sterol balance in the neonatal Golden Syrian hamster.  

PubMed

Dietary components impact metabolism early in life. Some of the diet-induced effects are long lasting and can lead to various adult-based diseases. In the current studies, we examined the short-term effects of dietary cholesterol on neonatal hepatic sterol metabolism and the long-term effects that those early-life diets had on sterol metabolism in adulthood. Neonatal hamsters began consuming solid food as a supplement to milk by 5 days of age; diets contained 0 or 2% added cholesterol (wt/wt). By 10 days of age, plasma and liver cholesterol concentrations were 3.2- and 2.5-fold greater, respectively, in the neonates fed cholesterol. Hepatic sterol synthesis rates were suppressed 65% in cholesterol-fed neonates compared with control neonates. By 20 days of age, plasma and liver cholesterol concentrations were still greater and sterol synthesis rates were now suppressed maximally in neonates fed cholesterol compared with control neonates. The expression level of an apolipoprotein B-containing lipoprotein receptor (low-density lipoprotein receptor-related protein) was greater and the mature form of the sterol regulatory element-binding protein-2 was similar in livers of 20-day-old control neonates compared with control neonates at 10 days of age. To test whether the change in sterol balance in the neonatal period had a lasting effect on hepatic sterol metabolism, all animals were weaned on a low-cholesterol diet. At 70 days of age, hepatic sterol synthesis rates, plasma lipoprotein and liver cholesterol concentrations, and bile acid pool sizes and compositions were measured. Sterol balance in the adults was similar between animals fed either diet early in life, as demonstrated by a lack of difference in any parameter measured. Thus, even though dietary cholesterol suppressed hepatic sterol synthesis rates dramatically in the neonatal hamster, the change has little impact on sterol balance later in life. PMID:15550619

Yao, Lihang; Woollett, Laura A

2004-11-18

243

Regulation of sterol transport in human microvascular endothelial cells  

Microsoft Academic Search

In cultured human dermal microvessel endothelial cells, the rate of efflux (about twofold greater than for fibroblasts under equivalent conditions) was coupled to an equivalent high rate of sterol net transport from the cells to the medium. This net transport was linked with esterification via lecithin:cholesterol acyltransferase. Since the use of free sterol by plasma transferase is constant, such increased

PHOEBE E. FIELDING; PAMELA M. DAVISON; MARVIN A. KARASEK; CHRISTOPHER J. FIELDING

1982-01-01

244

STARD4 abundance regulates sterol transport and sensing  

PubMed Central

Nonvesicular transport of cholesterol plays an essential role in the distribution and regulation of cholesterol within cells, but it has been difficult to identify the key intracellular cholesterol transporters. The steroidogenic acute regulatory-related lipid-transfer (START) family of proteins is involved in several pathways of nonvesicular trafficking of sterols. Among them, STARD4 has been shown to increase intracellular cholesteryl ester formation and is controlled at the transcriptional level by sterol levels in cells. We found that STARD4 is very efficient in transporting sterol between membranes in vitro. Cholesterol levels are increased in STARD4-silenced cells, while sterol transport to the endocytic recycling compartment (ERC) and to the endoplasmic reticulum (ER) are enhanced upon STARD4 overexpression. STARD4 silencing attenuates cholesterol-mediated regulation of SREBP-2 activation, while its overexpression amplifies sterol sensing by SCAP/SREBP-2. To analyze STARD4's mode of action, we compared sterol transport mediated by STARD4 with that of a simple sterol carrier, methyl-?-cyclodextrin (MCD), when STARD4 and MCD were overexpressed or injected into cells. Interestingly, STARD4 and cytosolic MCD act similarly by increasing the rate of transfer of sterol to the ERC and to the ER. Our results suggest that cholesterol transport mediated by STARD4 is an important component of the cholesterol homeostasis regulatory machinery.

Mesmin, Bruno; Pipalia, Nina H.; Lund, Frederik W.; Ramlall, Trudy F.; Sokolov, Anna; Eliezer, David; Maxfield, Frederick R.

2011-01-01

245

Comprehensive and definitive structural identities of Pneumocystis carinii sterols  

Microsoft Academic Search

Pneumocystis causes a type of pneumonia in im- munodeficient mammals, such as AIDS patients. Mammals cannot alkylate the C-24 position of the sterol side chain, nor can they desaturate C-22. Thus, the reactions leading to these sterol modifications are particularly attractive targets for the development of drugs against fungal and protozoan pathogens that make them. In the present study, the

José-Luis Giner; Hui Zhao; David H. Beach; Edward J. Parish; Koka Jayasimhulu; Edna S. Kaneshiro

2002-01-01

246

Sterol-Rich Plasma Membrane Domains in Fungi  

Microsoft Academic Search

Concepts regarding the eukaryotic plasma membrane have been evolving in light of growing evidence that it is segregated into distinct lateral domains known as lipid rafts. These sterol- and sphingolipid-rich raft domains are thought to play impor- tant roles in dynamic processes, including protein sorting, cell polarity, and signal transduction. Because of this, it has been very intriguing that sterol-rich

Francisco J. Alvarez; Lois M. Douglas; James B. Konopka

2007-01-01

247

Prevention of bubonic and pneumonic plague using plant-derived vaccines.  

PubMed

Yersinia pestis, the causative agent of bubonic and pneumonic plague, is an extremely virulent bacterium but there are currently no approved vaccines for protection against this organism. Plants represent an economical and safer alternative to fermentation-based expression systems for the production of therapeutic proteins. The recombinant plague vaccine candidates produced in plants are based on the two most immunogenic antigens of Y. pestis: the fraction-1 capsular antigen (F1) and the low calcium response virulent antigen (V) either in combination or as a fusion protein (F1-V). These antigens have been expressed in plants using all three known possible strategies: nuclear transformation, chloroplast transformation and plant-virus-based expression vectors. These plant-derived plague vaccine candidates were successfully tested in animal models using parenteral, oral, or prime/boost immunization regimens. This review focuses on the recent research accomplishments towards the development of safe and effective pneumonic and bubonic plague vaccines using plants as bioreactors. PMID:19931370

Alvarez, M Lucrecia; Cardineau, Guy A

248

Bacterial source tracking from diverse land use catchments by sterol ratios.  

PubMed

Water samples from sites potentially impacted by septic tanks, cattle, sewage treatment plant (STP) and natural forests were collected at regular monthly intervals and within 48 h of rainfall events between October 2004 and June 2006. All samples (n=296) were analysed for faecal coliforms and faecal sterols including coprostanol, epicoprostanol, cholestanol, cholesterol and 24-ethylcoprostanol. Faecal sterol ratios were used to assign human and/or herbivore contamination sources and to estimate their percentage relative contributions in water samples. The catchments had significantly different profiles of designated contamination origins (p<0.05), which were consistent with land use patterns. The STP impacted site had the highest incidence of human contamination assignations and the highest mean levels of coprostanol, whilst the forested site had the highest incidence of uncontaminated samples and the lowest mean concentration of coprostanol. Coprostanol concentrations were not always correlated with faecal coliform counts. PMID:17433407

Shah, Vikaskumar G; Hugh Dunstan, R; Geary, Phillip M; Coombes, Peter; Roberts, Timothy K; Rothkirch, Tony

2007-04-11

249

Fluorescent sterols as tools in membrane biophysics and cell biology.  

PubMed

Cholesterol is an important constituent of cellular membranes playing a fundamental role in many biological processes. This sterol affects membrane permeability, lateral lipid organization, signal transduction and membrane trafficking. Intracellular sterol transport modes and pathways as well as the regulation of sterol metabolism and disposition in various tissues are areas of intense research. Progress is intimately linked to development and use of appropriate analogs, which closely mimic the properties of cholesterol while allowing to be detected by spectroscopic or microscopic methods. This review provides an overview of various fluorescent sterols used in membrane biophysics and cell biology including analogs of cholesterol and cholesteryl esters. Attention is paid to the natural fluorescent sterol dehydroergosterol (DHE). A survey of the many applications of DHE in biological research is presented. Special emphasis is on recent developments in fluorescence microscopy instrumentation to visualize DHE as an intrinsically fluorescent analog of cholesterol in living cells. PMID:17241621

Wüstner, Daniel

2006-12-30

250

Terrestrial Plant-Derived Anticancer Agents and Plant Species Used in Anticancer Research  

Microsoft Academic Search

Cancer is a major cause of death and the number of new cases, as well as the number of individuals living with cancer, is expanding continuously. Due to the enormous propensity of plants that synthesize mixtures of structurally diverse bioactive compounds, the plant kingdom is potentially a very diverse source of chemical constituents with tumor cytotoxic activity. Despite the successful

Spiridon E. Kintzios

2006-01-01

251

Use of plant fatty acyl hydroxylases to produce hydroxylated fatty acids and derivatives in plants  

DOEpatents

The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds. 35 figs.

Somerville, C.; Loo, F. van de

1998-09-01

252

Analysis of plant-derived miRNAs in animal small RNA datasets  

PubMed Central

Background Plants contain significant quantities of small RNAs (sRNAs) derived from various sRNA biogenesis pathways. Many of these sRNAs play regulatory roles in plants. Previous analysis revealed that numerous sRNAs in corn, rice and soybean seeds have high sequence similarity to animal genes. However, exogenous RNA is considered to be unstable within the gastrointestinal tract of many animals, thus limiting potential for any adverse effects from consumption of dietary RNA. A recent paper reported that putative plant miRNAs were detected in animal plasma and serum, presumably acquired through ingestion, and may have a functional impact in the consuming organisms. Results To address the question of how common this phenomenon could be, we searched for plant miRNAs sequences in public sRNA datasets from various tissues of mammals, chicken and insects. Our analyses revealed that plant miRNAs were present in the animal sRNA datasets, and significantly miR168 was extremely over-represented. Furthermore, all or nearly all (>96%) miR168 sequences were monocot derived for most datasets, including datasets for two insects reared on dicot plants in their respective experiments. To investigate if plant-derived miRNAs, including miR168, could accumulate and move systemically in insects, we conducted insect feeding studies for three insects including corn rootworm, which has been shown to be responsive to plant-produced long double-stranded RNAs. Conclusions Our analyses suggest that the observed plant miRNAs in animal sRNA datasets can originate in the process of sequencing, and that accumulation of plant miRNAs via dietary exposure is not universal in animals.

2012-01-01

253

Bacterial biofilm formation inhibitory activity revealed for plant derived natural compounds.  

PubMed

Use of herbal plant remedies to treat infectious diseases is a common practice in many countries in traditional and alternative medicine. However to date there are only few antimicrobial agents derived from botanics. Based on microbiological screening tests of crude plant extracts we identified four compounds derived from Krameria, Aesculus hippocastanum and Chelidonium majus that showed a potentially interesting antimicrobial activity. In this work we present an in depth characterization of the inhibition activity of these pure compounds on the formation of biofilm of Staphylococcus aureus as well as of Staphylococcus epidermidis strains. We show that two of these compounds possess interesting potential to become active principles of new drugs. PMID:22182580

Artini, M; Papa, R; Barbato, G; Scoarughi, G L; Cellini, A; Morazzoni, P; Bombardelli, E; Selan, L

2011-12-01

254

Cultivation of Chlorella emersonii with flue gas derived from a cement plant  

Microsoft Academic Search

The present study reviews the options of cultivating the green alga, Chlorella emersonii, under photoautotrophic conditions with flue gas derived from a cement plant. It was conducted in the Lafarge Perlmooser\\u000a plant in Retznei, Austria, where stone coal and various surrogate fuels such as used tyres, plastics and meat-and-bone meal\\u000a are incinerated for heating limestone. During 30 days of cultivation, flue

Clemens G. Borkenstein; Josef Knoblechner; Heike Frühwirth; Michael Schagerl

2011-01-01

255

Variable use of plant- and soil-derived carbon by microorganisms in agricultural soils  

Microsoft Academic Search

In this study we used compound specific 13C and 14C isotopic signatures to determine the degree to which recent plant material and older soil organic matter (SOM) served as carbon substrates for microorganisms in soils. We determined the degree to which plant-derived carbon was used as a substrate by comparison of the 13C content of microbial phospholipid fatty acids (PLFA)

Christiane Kramer; Gerd Gleixner

2006-01-01

256

Polysubstituted Isochroman Derivatives with Plant Growth Regulating Properties on Wheat ( Triticum aestivum L. cv Klein Escorpion)  

Microsoft Academic Search

The synthesis of isochroman derivatives 4–9 from \\u0009?-hydroxylactone 3 is reported. These heterocycles, carrying different substituents on C-3, C-4, and C-8, exhibited different degrees of inhibition\\u000a of the vegetative growth of wheat (Triticum aestivum cv Klein Escorpion) plants, whereas plant developmental patterns such as their protein profile, carotenes\\/chlorophylls ratio,\\u000a and weight\\/length relationship were not significantly affected. Microscopic observation of transverse

Darío A. Bianchi; Luciano Brambilla; Martha A. Gattuso; Teodoro S. Kaufman

2006-01-01

257

Heterogeneous plastid genomes in anther culture-derived albino rice plants  

Microsoft Academic Search

Large-scale deletions in the plastid genome of albino plants derived fromanther culture of japonica rice have in previous studies been detected bySouthern blot analysis. In the present study, PCR was applied to detectlarge-scale deletions in the plastid genome of albino and green plantsgenerated from the anther culture of japonica-indica hybrid-derived DHlines. The rice plastid genome (134.5 kbp) was separated into

Masumi Yamagishi

2002-01-01

258

Molecular Aspects of Polyene- and Sterol-Dependent Pore Formation in Thin Lipid Membranes  

PubMed Central

Amphotericin B modifies the permeability properties of thin lipid membranes formed from solutions containing sheep red cell phospholipids and cholesterol. At 10-6 M amphotericin B, the DC membrane resistance fell from ?108 to ?102 ohm-cm2, and the membranes became Cl--, rather than Na+-selective; the permeability coefficients for hydrophilic nonelectrolytes increased in inverse relationship to solute size, and the rate of water flow during osmosis increased 30-fold. These changes may be rationalized by assuming that the interaction of amphotericin B with membrane-bound sterol resulted in the formation of aqueous pores. N-acetylamphotericin B and the methyl ester of N-acetylamphotericin B, but not the smaller ring compounds, filipin, rimocidin, and PA-166, produced comparable permeability changes in identical membranes, and amphotericin B and its derivatives produced similar changes in the properties of membranes formed from phospholipid-free sterol solutions. However, amphotericin B did not affect ionic selectivity or water and nonelectrolyte permeability in membranes formed from solutions containing phospholipids and no added cholesterol, or when cholesterol was replaced by either cholesterol palmitate, dihydrotachysterol, epicholesterol, or ?5-cholesten-3-one. Phospholipid-free sterol membranes exposed to amphotericin B or its derivatives were anion-selective, but the degree of Cl- selectivity varied among the compounds, and with the aqueous pH. The data are discussed with regard to, first, the nature of the polyene-sterol interactions which result in pore formation, and second, the functional groups on amphotericin B responsible for membrane anion selectivity.

Dennis, Vincent W.; Stead, Nancy W.; Andreoli, Thomas E.

1970-01-01

259

Inhibitors of delta24(25) sterol methyltransferase block sterol synthesis and cell proliferation in Pneumocystis carinii.  

PubMed Central

Detailed analysis of the endogenous sterol content of purified Pneumocystis carinii preparations by gas-liquid chromatography coupled to mass spectrometry suggested that this parasite can both synthesize de novo steroid skeletons (to produce delta7 sterols) and take them from the infected host (leading to delta5 sterols). In both cases the final products are 24-alkyl sterols, resulting from the action of delta24(25) and delta24(24') sterol methyltransferases, enzymes not present in vertebrates. To investigate the physiological significance of these sterols, cultures of P. carinii in embryonic lung cells were exposed to 22,26-azasterol (20-piperidin-2-yl-5alpha-pregnan-3beta-20(R)-diol), a compound previously shown to inhibit both enzymes and to halt cell proliferation in fungi and protozoa. This compound produced a dose-dependent reduction in the parasite proliferation, with a 50% inhibitory concentration of 0.3 microM and 80% reduction of growth after 96 h at 10 microM. Correspondingly, parasites treated with the azasterol at 10 microM for 48 h accumulated 24-desalkyl sterols such as zymosterol (cholesta-8,24-dien-3beta-ol) and cholesta-8,14,24-trien-3beta-ol to ca. 40% of the total mass of endogenous sterols. This is the first report on the antiproliferative effects of a sterol biosynthesis inhibitor on P. carinii and indicate that sterol methyltransferase inhibitors could be the basis of a novel and specific chemotherapeutic approach to the treatment of P. carinii infections.

Urbina, J A; Visbal, G; Contreras, L M; McLaughlin, G; Docampo, R

1997-01-01

260

Effect of commercially available plant-derived essential oil products on arthropod pests.  

PubMed

Plant-derived essential oil products, in general, are considered minimum-risk pesticides and are exempt from Environmental Protection Agency registration under section 25(b) of the Federal Insecticide Fungicide and Rodenticide Act. However, many of the plant-derived essential products available to consumers (homeowners) have not been judiciously evaluated for both efficacy and plant safety. In fact, numerous plant-derived essential oil products labeled for control of arthropod pests have not been subject to rigorous evaluation, and there is minimal scientific information or supporting data associated with efficacy against arthropod pests. We conducted a series of greenhouse experiments to determine the efficacy and phytotoxicity of an array of plant-derived essential oil products available to consumers on arthropod pests including the citrus mealybug, Planococcus citri (Risso); western flower thrips, Frankliniella occidentalis (Pergande); twospotted spider mite, Tetranychus urticae Koch; sweetpotato whitefly B-biotype, Bemisia tabaci (Gennadius); and green peach aphid, Myzus persicae (Sulzer). Although the products Flower Pharm (cottonseed, cinnamon, and rosemary oil) and Indoor Pharm (soybean, rosemary, and lavender oil) provided > 90% mortality of citrus mealybug, they were also the most phytotoxic to the coleus, Solenostemon scutellarioides (L.) Codd, plants. Both GC-Mite (cottonseed, clove, and garlic oil) and Bugzyme (citric acid) were most effective against the twospotted spider mite (> or = 90% mortality). However, SMC (canola, coriander oil, and triethanolamine), neem (clarified hydrophobic extract of neem oil), and Bug Assassin (eugenol, sodium lauryl sulfate, peppermint, and citronella oil) provided > 80% mortality. Monterey Garden Insect Spray, which contained 0.5% spinosad, was most effective against western flower thrips with 100% mortality. All the other products evaluated failed to provide sufficient control of western flower thrips with < 30% mortality. In addition, the products Pest Out (cottonseed, clove, and garlic oil), Bang (Pipereaceae), and Fruit & Vegetable Insect Spray (rosemary, cinnamon, clove oil, and garlic extract) had the highest flower (transvaal daisy, Gerberajamesonii [H. Bolus ex Hook.f]) phytotoxicity ratings (> or = 4.5 of 5) among all the products. None of the plant-derived essential oil products provided sufficient control of sweetpotato whitefly B-biotype or green peach aphid 7, 14, and 21 d after application. Furthermore, the products Bug Assassin (eugenol, sodium lauryl sulfate, peppermint, and citronella oil) and Sharpshooter (sodium lauryl sulfate and clove oil) were phytotoxic to the poinsettia, Euphorbia pulcherrima Willd. ex Klotzsch, plants. This study is one of the first to quantitatively demonstrate that commercially available plant-derived essential oil products vary in their effectiveness against certain arthropod pests stated on the label and are phytotoxic. PMID:19736770

Cloyd, Raymond A; Galle, Cindy L; Keith, Stephen R; Kalscheur, Nanette A; Kemp, Kenneth E

2009-08-01

261

Strategies for engineering plant natural products: the iridoid-derived monoterpene indole alkaloids of Catharanthus roseus.  

PubMed

The manipulation of pathways to make unnatural variants of natural compounds, a process often termed combinatorial biosynthesis, has been robustly successful in prokaryotic systems. The development of approaches to generate new-to-nature compounds from plant-based pathways is, in comparison, much less advanced. Success will depend on the specific chemistry of the pathway, as well as on the suitability of the plant system for transformation and genetic manipulation. As plant pathways are elucidated, and can be heterologously expressed in hosts that are more amenable to genetic manipulation, biosynthetic production of new-to-nature compounds from plant pathways will become more widespread. In this chapter, some of the key strategies that have been developed for metabolic engineering of plant pathways, namely directed biosynthesis, mutasynthesis, and pathway incorporation of engineered enzymes are highlighted. The iridoid-derived monoterpene indole alkaloids from C. roseus, which are the focus of this chapter, provide an excellent system for developing these strategies. PMID:22999175

O'Connor, Sarah E

2012-01-01

262

[Analysis of the transgenic rice plants derived from transformed anther calli].  

PubMed

Rice calli derived from anther culture were used as recipient to transfer a rice blight resistance gene, Xa21, into a japonica rice variety, Taipei 309, via Agrobacterium-mediated transformation. Seven green transgenic plants, including one mixoploid, two haploid, and four diploid plants, were regenerated. PCR, Southern blot, FISH and blight resistance analysis all indicated that Xa21 gene has been integrated into the T0 plant genomes. T1 generations of the four diploid T0 plants were further investigated for resistance segregation. Chi2 test showed that two T1 populations segregated with a ratio of 3:1, indicating that a single copy of Xa21 gene was integrated into the genome, whereas the segregation ratios of the other two T1 populations were non-Mendelian. Therefore, the four diploid transgenic plants should be heterozygous diploids. PMID:15633644

Jiang, Su; Chen, Cai-Yan; Cheng, Zhu-Kuan; Cai, Run; Zhai, Wen-Xue; Zhu, Li-Huang

2004-12-01

263

Simultaneous Effects of Light Intensity and Phosphorus Supply on the Sterol Content of Phytoplankton  

Microsoft Academic Search

Sterol profiles of microalgae and their change with environmental conditions are of great interest in ecological food web research and taxonomic studies alike. Here, we investigated effects of light intensity and phosphorus supply on the sterol content of phytoplankton and assessed potential interactive effects of these important environmental factors on the sterol composition of algae. We identified sterol contents of

Maike Piepho; Dominik Martin-Creuzburg; Alexander Wacker

2010-01-01

264

Expression of human nuclear receptors in plants for the discovery of plant-derived ligands.  

PubMed

Plants have the potential to produce a wide array of secondary metabolites that have utility as drugs to treat human diseases. To tap this potential, functional human nuclear receptors have been expressed in plants to create in planta screening assays as a tool to discover natural product ligands. Assays have been designed and validated using 3 nuclear receptors: the estrogen receptor (ER), the androgen receptor (AR), and the heterodimeric retinoid X receptor-alpha plus thyroid hormone receptor-beta (RXRA/THRB). Nuclear receptor-reporter constructs have been expressed in plants to detect the presence of natural ligands that are produced de novo in several plant species during different stages of development, in various tissues, and in response to different stress elicitors. Screening experiments with ER, AR, and RXRA/THRB have been conducted, leading to the identification of plant sources of natural product ligands of human nuclear receptors. This in planta screen has led to the identification of previously unreported ER ligands, providing evidence of the complementary value of this approach to current in vitro high-throughput screening assays. PMID:17438068

Doukhanina, Elena V; Apuya, Nestor R; Yoo, Hye-Dong; Wu, Chuan-Yin; Davidow, Patricia; Krueger, Shannon; Flavell, Richard B; Hamilton, Richard; Bobzin, Steven C

2007-04-01

265

First European interlaboratory study of the analysis of benzoxazinone derivatives in plants by liquid chromatography  

Microsoft Academic Search

Six laboratories from four different countries participated in the first European interlaboratory comparison exercise within the framework of the “Fate and toxicity of allelochemicals (natural plant toxins) in relation to environment and consumer” (FATEALLCHEM) European Union Project. The study, organized between November 2002 and March 2003, involved the analyses of seven benzoxazinone derivatives in two standard solutions and one purified

E. Eljarrat; M. Guillamón; J. Seuma; B. B. Mogensen; I. S. Fomsgaard; A. Olivero-Bastidas; F. A. Macías; A. Stochmal; W. Oleszek; O. Shakaliene; D. Barceló

2004-01-01

266

Role of Plant-Derived Omega–3 Fatty Acids in Human Nutrition  

Microsoft Academic Search

An international workshop on the role of plant-derived omega–3 fatty acids in human nutrition took place in Milan on February 9, 2000. The meeting was sponsored by the Nutrition Foundation of Italy and was organized by its Scientific Director, Dr. Andrea Poli. It was attended by experts in polyunsaturated fatty acids and human lipid nutrition. This is the first meeting

Michael Crawford; Claudio Galli; Francesco Visioli; Serge Renaud; Artemis P. Simopoulos; Arthur A. Spector

2000-01-01

267

Material derived from hydrothermal carbonization: Effects on plant growth and arbuscular mycorrhiza  

Microsoft Academic Search

Greenhouse gas mitigation options include the production of carbonized materials and their addition to soils for longer term storage. Hydrothermal carbonization (HTC) is a novel way to produce carbonized materials. The goal here was to test if HTC material, in our case derived from beet root chips, has adverse effects on plant growth or that of root associated symbionts such

Matthias C. Rillig; Marcel Wagner; Mohamed Salem; Pedro M. Antunes; Carmen George; Hans-Günter Ramke; Maria-Magdalena Titirici; Markus Antonietti

2010-01-01

268

Plant regeneration from embryogenic cell suspensions derived from anther cultures of barley ( Hordeum vulgare L.)  

Microsoft Academic Search

We have established embryogenic cell suspension cultures of barley (Hordeum vulgare L. cultivars Igri, Gimpel, Princesse, and Baronesse) from anther-derived embryogenic callus. Suspension cultures of cultivars Igri and Gimpel were regenerable. The most successful cultivar was Igri, from which a number of independent cell lines producing plantlets were established. Plants could be transferred to soil; up to now, 50% of

A. Jähne; P. A. Lazzeri; M. Jäger-Gussen; H. Lörz

1991-01-01

269

Free sterols from the holothurians Synapta maculata, Cladolabes bifurcatus and Cucumaria sp.  

PubMed

Free sterol fractions from the holothurians (sea cucumbers) Synapta maculata, Cladolabes bifurcatus and Cucumaria sp. have been isolated and studied by HPLC, GLC, GLC-MS and NMR methods. Forty seven sterols were identified, including several rare ones. In contrast with previously studied holothurians, the presence of a minor amount of Delta7 sterols was indicated in the sterols of S. maculata. This animal contains predominantly Delta(9(11))sterols as well as an abnormally high concentration of Delta5 sterols. In C. bifurcatus and Cucumaria sp., 14alpha-methyl and 4alpha,14alpha-dimethyl-Delta(9(11))sterols were found to be the main sterol constituents. Peculiarities of sterol distribution and the relationship between sterol compositions and taxonomic positions, ecology and toxicity of the corresponding sea cucumbers were discussed. PMID:11163304

Ponomarenko, L P; Kalinovsky, A I; Moiseenko, O P; Stonik, V A

2001-01-01

270

Lipids of a Sterol-Nonrequiring Mycoplasma  

PubMed Central

The lipids of the sterol nonrequiring Mycoplasma strain S743 were found to include both ester glycerophosphatides (phosphatidylglycerol, acylphosphatidylglycerol, and diphosphatidylglycerol) and ceramide glycerophosphate compounds containing N-hydroxyacyl groups. The major phosphosphingolipid was tentatively identified as a hydroxyceramidephosphorylglycerol containing an O-acyl group. These compounds became labeled during growth in the presence of 32P-orthophosphate, 14C-glycerol, or 14C-palmitate. The lipid fraction also contained free long-chain base. 14C-palmitate was converted to labeled sphinganine. The long-chain base composition of the lipids was modified by growing the organisms in media containing different fatty acids, which were converted to bases containing two more C atoms per molecule. Ninety per cent of the long-chain base from cells grown in medium supplemented with elaidate consisted of monounsaturated C20 base. Images

Plackett, P.; Smith, P. F.; Mayberry, W. R.

1970-01-01

271

Oxygen Sensing: Getting Pumped by Sterols  

NSDL National Science Digital Library

Oxygen plays a pivotal role in the maintenance of life for all eukaryotes, with the exception of strict anaerobes. Eukaryotes have developed mechanisms to sense and respond to decreased oxygen levels. How eukaryotes sense oxygen is still not fully understood. What is (or are) the oxygen sensor(s)? This question has vital physiological and pathophysiological implications, because all living aerobic organisms have adaptive mechanisms to maintain oxygen homeostasis. A recent report describes a novel eukaryotic oxygen-sensing mechanism in the fission yeast Schizosaccharomyces pombe, involving the depletion of sterols as a trigger to induce gene expression in response to decreased oxygen levels. It is not yet clear whether this mechanism is involved in the mammalian response to hypoxia, possibly in conjunction with activation of one or both of the hypoxia-inducible factor (HIF-1 or HIF-2) transcription factors.

Brooke M. Emerling (Northwestern University Medical School;Department of Medicine REV); Navdeep S. Chandel (Northwestern University Medical School;Department of Medicine REV)

2005-06-21

272

Lanostane triterpenoids and sterols from Antrodia camphorata.  

PubMed

Four lanostane triterpenes, 3,7,11-trioxo-5?-lanosta-8,24(E)-dien-26-oic acid, methyl 11?-3,7-dioxo-5?-lanosta-8,24(E)-dien-26-oate, methyl 3,7,11,12,15,23-hexaoxo-5?-lanost-8-en-26-oate, and ethyl 3,7,11,12,15,23-hexaoxo-5?-lanost-8-en-26-oate, two sterols, (14?,22E)-14-hydroxyergosta-7,22-diene-3,6-dione and a steroid named as camphosterol A were isolated from a mixture of fruiting bodies and mycelia of solid cultures of Antrodia camphorata. The ąH and ąłC NMR spectra of all compounds were fully assigned using a combination of 2D NMR experiments, including COSY, HMQC, HMBC and NOESY sequences. Six compounds were evaluated for cytotoxicity against several human tumor cell lines, all of which has moderate activity. PMID:22999074

Huang, Hui-Chi; Liaw, Chih-Chuang; Yang, Hsin-Ling; Hseu, You-Cheng; Kuo, Hsiou-Ting; Tsai, Yao-Ching; Chien, Shih-Chang; Amagaya, Sakae; Chen, Yu-Chang; Kuo, Yueh-Hsiung

2012-09-18

273

Plant-derived sweetening agents: saccharide and polyol constituents of some sweet-tasting plants.  

PubMed

Samples of the sweet-tasting species Acanthospermum hispidum DC. (Compositae) (aerial parts), Boscia salicifolia Oliv. (Capparidaceae) (stem bark), Hovenia dulcis Thunb. (Rhamnaceae) (peduncles) and Inga spectabilis Willd. (Leguminosae) (arils) were acquired as part of a continuing search for high-intensity natural sweeteners of plant origin. Following their preliminary safety evaluation, the sweetness of these plants was traced to large amounts of sugars and polyols by taste-guided fractionation, which were identified and quantified using gas chromatography/mass spectrometry. The combined yields of sugars and polyols in the A. hispidum, B. salicifolia, H. dulcis, and I. spectabilis samples investigated were 6.9, 10.1, 18.4 and 12.1% w/w, respectively. These yields are much higher than the total saccharide and polyol content (2.4% w/w) of the sweet dried fruits of Thladiantha grosvenorii (Swingle) C. Jeffrey (Cucurbitaceae), a species which has previously been reported to contain more than 1% w/w of the intensely sweet triterpene, mogroside V. The dried leaves of Symplocos tinctoria (L.) L'Hérit. (Symplocaceae), which were not appreciably sweet, were found to contain only 2.0% w/w of sugars. The results of this investigation, therefore, suggest that unless the saccharide and/or polyol content of a plant part is well over 5% w/w, then it is unlikely to exhibit an overtly sweet taste, unless an intense sweetener is present. PMID:2314108

Hussain, R A; Lin, Y M; Poveda, L J; Bordas, E; Chung, B S; Pezzuto, J M; Soejarto, D D; Kinghorn, A D

1990-02-01

274

Potential of Plant-Derived Natural Products in the Treatment of Leukemia and Lymphoma  

PubMed Central

Hematologic malignancies account for a substantial percentage of cancers worldwide, and the heterogeneity and biological characteristics of leukemias and lymphomas present unique therapeutic challenges. Although treatment options exist for most of these diseases, many types remain incurable and the emergence of drug resistance is pervasive. Thus, novel treatment approaches are essential to improve outcome. Nearly half of the agents used in cancer therapy today are either natural products or derivatives of natural products. The enormous chemical diversity in nature, coupled with millennia of biological selection, has generated a vast and underexplored reservoir of unique chemical structures with biologic activity. This review will describe the investigation and application of natural products derived from higher plants in the treatment of leukemia and lymphoma and the rationale behind these efforts. In addition to the approved vinca alkaloids and the epipodophyllotoxin derivatives, a number of other plant compounds have shown promise in clinical trials and in preclinical investigations. In particular, we will focus on the discovery and biological evaluation of the plant-derived agent silvestrol, which shows potential for additional development as a new therapeutic agent for B-cell malignancies including chronic lymphocytic leukemia.

Lucas, David M.; Still, Patrick C.; Perez, Lynette Bueno; Grever, Michael R.; Kinghorn, A. Douglas

2010-01-01

275

Digitonide precipitable sterols: a reevaluation with special attention to lanosterol  

SciTech Connect

The ability of digitonin to precipitate lanosterol from prepared mixtures and biological sources was evaluated. Commercially available lanosterol was determined to be composed of about 60% lanosterol and 40% dihydrolanosterol. Both sterols were only partially precipitated by digitonin under all conditions examined. The presence of cholesterol increased the precipitation of lanosterol, but never to completion. About 40% of the lanosterols from saponified sheep's-wool fat was not precipitated by digitonin. Also /sup 14/C-labeled lanosterol recovered from rat brain following intracerebral injection of 2-(/sup 14/C)mevalonate was only 70% precipitated by digitonin. Steric hinderance by the methyl groups at carbon -4 is suggesed to explain the poor precipitability of this sterol. In conclusion, lanosterol can not be considered to be a digitonide-precipitable sterol equivalent to cholesterol. Caution should be exercised in situations where digitonin-precipitable sterols are being prepared from sources containing significant concentrations of lanosterol (i.e., mass and/or radiolabel).

Cenedella, R.J.

1982-06-01

276

Inhibition of human polymorphonuclear leukocyte chemotaxis by oxygenated sterol compounds  

SciTech Connect

When preincubated with certain oxygenated sterol compounds in lipoprotein-depleted serum (20% (vol/vol)), human polymorphonuclear leukocytes show inhibition of chemotaxis toward the synthetic dipeptide N-formylmethionylphenylalinine without alteration of random movement or loss of cell viability. These effects can occur at sterol concentrations as low as 6.25 ..mu..M and after as little as 5 min of preincubation, but they are increased at higher concentrations and longer preincubation times. The inhibition can be almost completely reversed by preincubation in lipoprotein-replete serum (human AB serum, 20% (vol/vol)) and may be partially corrected by addition of free cholesterol (0.125 mM) to the medium. These effects are unlikely to be due to inhibition of cellular sterol synthesis, competition for chemotaxin membrane binding sites, or deactivation of the leukocytes but they may be a consequence of insertion of the sterol molecule into the leukocyte plasma membranes.

Gordon, L.I.; Bass, J.; Yachnin, S.

1980-07-01

277

New Cytotoxic Oxygenated Sterols from the Marine Bryozoan Cryptosula pallasiana  

PubMed Central

Six new sterols (1-6), together with seven known sterols (7-13), were isolated from the CCl4 extract of the marine bryozoan Cryptosula pallasiana, four (3-6) of which have already been reported as synthetic sterols. This is the first time that these compounds (3-6) are reported as natural sterols. The structures of the new compounds were determined on the basis of the extensive spectroscopic analysis, including two-dimensional (2D) NMR and HR-ESI-MS data. Compounds 1-4, 7 and 10-13 were evaluated for their cytotoxicity against HL-60 human myeloid leukemia cell line, and all of the evaluated compounds exhibited moderate cytotoxicity to HL-60 cells with a range of IC50 values from 14.73 to 22.11 µg/mL except for compounds 12 and 13.

Tian, Xiang-Rong; Tang, Hai-Feng; Li, Yu-Shan; Lin, Hou-Wen; Chen, Xiao-Li; Ma, Ning; Yao, Min-Na; Zhang, Ping-Hu

2011-01-01

278

Sterol Profile for Natural Juices Authentification by GC-MS  

SciTech Connect

A GC-MS analytical method is described for some natural juices analysis. The fingerprint of sterols was used to characterize the natural juice. A rapid liquid-liquid extraction method was used. The sterols were separated on a Rtx-5MS capillary column, 15mx0.25mm, 0.25{mu}m film thickness, in a temperature program from 50 deg. C for 1 min, then ramped at 15 deg. C/min to 300 deg. C and held for 15 min. Identification of sterols and their patterns were used for juice characterization. The sterol profile is a useful approach for confirming the presence of juices of orange, grapefruit, pineapple and passion fruit in compounded beverages and for detecting of adulteration of fruit juices.

Culea, M. [Faculty of Physics, Babes-Bolyai University of Cluj-Napoca (Romania)

2007-04-23

279

Rapid Analytical Method for the Determination of Aflatoxins in Plant-Derived Dietary Supplement and Cosmetic Oils  

Technology Transfer Automated Retrieval System (TEKTRAN)

Consumption of edible oils derived from conventional crop plants is increasing because they are generally regarded as more healthy alternatives to animal based fats and oils. More recently there has been increased interest in the use of alternative specialty plant-derived oils, including those from...

280

Latitudinal Variation in ?13C derived from Terrestrial Plants during the Cretaceous  

NASA Astrophysics Data System (ADS)

Modern plankton and terrestrial plants exhibit a gradient in ?13C with latitude. Although there are several reasons for ?13C variation in plants, modern latitudinal variation is correlated with environmental and climatic factors such as temperature. We present ?13C values derived from mid-Cretaceous terrestrial plant fossils in Texas at paleolatitude ~30 N and Australia at paleolatitude ~70 S that show an offset in ?13C values, suggesting a latitudinal gradient in ?13C in plants during the Cretaceous. This hypothesis was tested by new data from Antarctica at paleolatitude ~60 S and Alaska at paleolatitude ~70 N, and we compared these data to published carbon isotope records. The latitudinal variation in plant ?13C was on the order of 2‰ more negative at high latitudes, suggesting a shallower Cretaceous latitudinal gradient in plant ?13C than at present. The shallow gradient in plant ?13C during the Cretaceous correlates with a latitudinal temperature gradient that is also less than today.

Strganac, C.; Jacobs, L. L.; Ferguson, K.; Macphee, R. D.; Fiorillo, A. R.; Hooker, J.; Nishida, Y.; Flemming, C.

2010-12-01

281

Plant-Derived Small Molecule Inhibitors of Neuronal NO-Synthase  

PubMed Central

Cigarette smoking is known to cause a decrease in NO production in man resulting in a variety of pathological effects, including vascular dysfunction. Aqueous extracts of cigarette and cigarette smoke contain chemical inhibitors to NO-synthases, a heme-containing cytochrome P450 enzymes. More recently, it was shown that freshly harvested leaves from the tobacco plant (Nicotiana tabacum, Solanaceae) also contain chemical inhibitors to neuronal NO-synthase (nNOS). Examination of leaves from 32 other plants representing diverse members of the plant kingdom showed that 17 other plants, besides tobacco, contain these chemical inhibitors. Of all these plants, 16 are members of the core asterids flowering plant group and 6 are members of the Solanaceae family. Although the identity of the chemicals is not known, perhaps the closely related plants contain the same or similar compounds that inhibit nNOS. The inhibitory effects are not attributable to nicotine. The discovery of these chemicals and their further characterization may help to explain the loss of nNOS in smokers. In this addendum, we discuss these results in light of the effect of tobacco-derived chemicals in inhibiting P450 cytochromes, as well as our thoughts on how the inactivation of nNOS leads to its selective downregulation through proteolytic degradation.

Lau, Miranda; Lowe, Ezra R

2007-01-01

282

Lipase-mediated synthesis of water-soluble plant stanol derivatives in tert-butanol.  

PubMed

The effects of solvents with different log P values, and of lipases on the synthesis of water-soluble plant stanol derivatives were investigated. Results showed that conversion in solvents with log P<0.37 was mainly controlled by the hydrophobicity of the solvent and subsequent complete or partial deactivation of the enzyme. The solubility of substrate was the leading factor for the conversion in solvents with log P>0.37. Lipozyme RM IM and tert-butanol was the most suitable biocatalyst and solvent, respectively. The highest yield (>51%) of plant stanyl sorbitol succinate was obtained under the selected conditions: 50 ?mol/mL plant stanyl hemisuccinate, 1:3 molar ratio of plant stanyl hemisuccinate to d-sorbitol, 80 mg/mL 3 Ĺ molecular sieves and 100mg/mL Lipozyme RM IM in tert-butanol, 150 r/min and 55 °C. Fourier transform infrared spectroscopy, mass spectroscopy and nuclear magnetic resonance spectroscopy were adopted to determine the structure of product, suggesting that water-soluble plant stanol derivatives were successfully synthesized. PMID:22464062

He, Wen-Sen; Li, Jing-Jing; Pan, Xiao-Xia; Zhou, Yang; Jia, Cheng-Sheng; Zhang, Xiao-Ming; Feng, Biao

2012-03-03

283

Fatty acids and sterols as source markers of organic matter in sediments of the North Carolina continental slope  

NASA Astrophysics Data System (ADS)

To estimate the source and diagenetic state of organic matter reaching bottom sediments, fatty acids and sterols were measured in unconsolidated surface material (flocs) at 12 sites ranging from 600 to 2000 m across the mid-Atlantic continental slope off Cape Hatteras, North Carolina. Total free and esterefied fatty acids were similar in distribution and concentration to other coastal systems, with values ranging from 0.64 to 46.52 ?g mg -1 organic carbon (1.10-68.85 ?g g -1 dry sediment). Although shallow (600 m) stations contained significantly greater fatty acid concentrations than deep (> 1400m) stations, high variability observed at mid-depth (800 m) collections precluded a consistent relationship between total fatty acid concentration and station depth. At three sites where underlying sediments were also collected, decreases in total fatty acids, reduced amounts of polyenoic acids and significant presence of bacterial fatty acid suggest rapid reworking of labile organic material that reaches the sediment surface. The distribution of sterols was remarkably consistent among all sites even though there were large variations in concentrations (1.8-20.7 ?g mg -1 organic carbon). Sterol composition indicated phytoplankton, principally diatoms and dinoflagellates, as the principal source of labile organic matter to sediments, together with a significant input of cholest-5-en-3?-ol typical of zooplankton and their feeding activity. A minor but widespread terrigenous input was also evident based upon significant concentrations of sterols dominant in vascular plants.

Harvey, H. Rodger

284

Fiber,intestinal sterols, and coloncancer1' 2  

Microsoft Academic Search

It has been postulated that dietary fiber's protective effect against the development of colon cancer, diverticular disease, and atherosclerosis may be due to the adsorption and\\/or dilution of intestinal sterols such as bile acids and neutral sterols and their bacterial metabolites by component(s) of fiber. Dietary fiber is made up of four major components-cellulose, hemicellulose, lignin, and pectin. There is

Charles T. L. Huang; G. S. Gopalakrishna; L. Nichols

285

Sterol Esterification in Yeast: A Two-Gene Process  

Microsoft Academic Search

Unesterified sterol modulates the function of eukaryotic membranes. In human cells, sterol is esterified to a storage form by acyl-coenzyme A (CoA): cholesterol acyl transferase (ACAT). Here, two genes are identified, ARE1 and ARE2, that encode ACAT-related enzymes in yeast. The yeast enzymes are 49 percent identical to each other and exhibit 23 percent identity to human ACAT. Deletion of

Hongyuan Yang; Martin Bard; Debora A. Bruner; Anne Gleeson; Richard J. Deckelbaum; Gordana Aljinovic; Thomas M. Pohl; Rodney Rothstein; Stephen L. Sturley

1996-01-01

286

Authentication of green coffee varieties according to their sterolic profile  

Microsoft Academic Search

Sterols of 31 samples of green coffee beans of the arabica and robusta varieties have been analysed by gas chromatography flame ionization detector. The lipids were Soxhlet extracted from ground coffee beans into hexane. The extract was evaporated and the residue was treated with 0.2% of 5?-cholestane-3?-ol (internal standard). The lipids were saponified and the sterolic fraction of the unsaponifiable

F. Carrera; M. León-Camacho; F. Pablos; A. G. González

1998-01-01

287

Human-derived, plant-produced monoclonal antibody for the treatment of anthrax.  

PubMed

The unpredictable nature of bio-terrorism compels us to develop medical countermeasures that will enable authorities to treat individuals exposed to agents such as anthrax. We report the feasibility of producing a protective, human-derived, monoclonal antibody directed against the protective antigen (PA) of Bacillus anthracis in plants. This was achieved by transient expression using agroinfiltration of Nicotiana benthamiana plants. The resulting antibody was able to neutralize toxin activity in vitro and in vivo at a comparable level to that seen for its hybridoma-produced counterpart. PMID:15755575

Hull, Anna K; Criscuolo, Carolyn J; Mett, Vadim; Groen, Herman; Steeman, Wilma; Westra, Hans; Chapman, Gail; Legutki, Bart; Baillie, Les; Yusibov, Vidadi

2005-03-18

288

Plant-derived natural products exhibiting activity against formosan subterranean termites (Coptotermes formosanus).  

PubMed

The Formosan subterranean termite, Coptotermes formosanus Shiraki, is among the most devastating termite pests. Natural products derived from plant extracts were tested in a discovery programme for effective, environmentally friendly termite control agents. Among the natural products tested, vulgarone B (isolated from Artemisia douglasiana Besser), apiol (isolated from Ligusticum hultenii (Fern.) Calder & Taylor) and cnicin (isolated from Centaurea maculosa Lam.) exhibited significantly higher mortalities than in untreated controls in laboratory bioassay. These compounds are present at high levels in their respective plant sources and also possess other biological activities such as phytotoxic and antifungal properties. PMID:16625680

Meepagala, Kumudini M; Osbrink, Weste; Sturtz, George; Lax, Alan

2006-06-01

289

Food plant derived disease tolerance and resistance in a natural butterfly-plant-parasite interactions.  

PubMed

Organisms can protect themselves against parasite-induced fitness costs through resistance or tolerance. Resistance includes mechanisms that prevent infection or limit parasite growth while tolerance alleviates the fitness costs from parasitism without limiting infection. Although tolerance and resistance affect host-parasite coevolution in fundamentally different ways, tolerance has often been ignored in animal-parasite systems. Where it has been studied, tolerance has been assumed to be a genetic mechanism, unaffected by the host environment. Here we studied the effects of host ecology on tolerance and resistance to infection by rearing monarch butterflies on 12 different species of milkweed food plants and infecting them with a naturally occurring protozoan parasite. Our results show that monarch butterflies experience different levels of tolerance to parasitism depending on the species of milkweed that they feed on, with some species providing over twofold greater tolerance than other milkweed species. Resistance was also affected by milkweed species, but there was no relationship between milkweed-conferred resistance and tolerance. Chemical analysis suggests that infected monarchs obtain highest fitness when reared on milkweeds with an intermediate concentration, diversity, and polarity of toxic secondary plant chemicals known as cardenolides. Our results demonstrate that environmental factors-such as interacting species in ecological food webs-are important drivers of disease tolerance. PMID:23106703

Sternberg, Eleanore D; Lefčvre, Thierry; Li, James; de Castillejo, Carlos Lopez Fernandez; Li, Hui; Hunter, Mark D; de Roode, Jacobus C

2012-06-27

290

Influence of Temperature on Sterol Biosynthesis in Triticum aestivum1  

PubMed Central

Sitosterol, campesterol, stigmasterol, and cholesterol were isolated from green wheat (Triticium aestivum var. Monon) seedlings. Sitosterol was the predominant sterol extracted from the shoot, root, and crown tissue. Cholesterol accounted for less that 1% of sterol in shoot tissue with only trace amounts in the root. A temperature change from 10 to 1 C resulted in a general decrease in sitosterol, stigmasterol, and campesterol in the shoot tissue. The cholesterol level was not altered significantly by the temperature change. The sterols in the root responded in a manner very different from those in the shoots. With the reduction in temperature, sterols first decreased and then recovered over a period of 7 to 14 days to levels that were equal to or exceeded the original levels. From these experiments, it would appear that root tissue can acclimate to the lower temperatures and continue sterol synthesis at the normal rate. The level and response of sterols in the crown tissue were intermediate between the root and shoot tissue. At 10 C the crown response was similar to that of root tissue, whereas, at 1 C the response more closely resembled that of the shoot.

Davis, D. L.; Finkner, V. C.

1973-01-01

291

Inhibition of human lymphocyte transformation of oxygenated sterol compounds  

SciTech Connect

Oxygenated sterol compounds (OSC), potent inhibitors of sterol synthesis in both resting and mitogen-stimulated human lymphocytes, are capable of suppressing the DNA-synthetic response of human peripheral blood lymphocytes to mitogenic lectins, anti-human thymocyte antiserum, and the mixed lymphocyte culture. The most potent OSC are 20..cap alpha..-hydroxycholesterol and 25-hydroxycholesterol, which inhibit DNA synthesis in mitogen stimulated lymphocytes at 7.4 and 3.9 x 10/sup -6/M, respectively. Lymphocytes which have been exposed to OSC for 18 hr and washed free of inhibitor are fully capable of DNA synthesis when subsequentlc challenged with mitogen. Suppression of DNA synthesis by OSC is not apparent during the first 24-40 hr of culture. The inhibition of lymphocyte DNA synthesis by OSC can be partially reversed by the addition of 10/sup -2/M mevalonate to the culture. Sterol synthesis by mitogen-stimulated lymphocytes is enhanced by culturing them in medium supplemented with lipoprotein (and cholesterol-)-depleted serum. In such medium, the 50% inhibitory doses of 25-hydroxycholesterol for suppression of both mitogen-stimulated lymphocyte DNA and sterol synthesis are approximately equal (approx. =3 x 10/sup -7/M). Sterol synthesis is a necessary, but not sufficient, part of the program of lymphocyte proliferative response to mitogens; the evidence presented suggests that lymphocytes can utilize exogenous sterol at least partially for the purpose of cell replication.

Yachnin, S.; Hsu, R.

1980-04-01

292

Regulation of partitioned sterol biosynthesis in Saccharomyces cerevisiae.  

PubMed Central

Using yeast strains with null mutations in structural genes which encode delta-aminolevulinic acid synthetase (HEM1), isozymes of 3-hydroxy-3-methylglutaryl coenzyme A (HMG1 and HMG2), squalene epoxidase (ERG1), and fatty acid delta 9-desaturase (OLE1), we were able to determine the effect of hemes, sterols, and unsaturated fatty acids on both sterol production and the specific activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) in Saccharomyces cerevisiae. We found that the HMGR isozymes direct essentially equal amounts of carbon to the biosynthesis of sterols under heme-competent conditions, despite a huge disparity (57-fold) in the specific activities of the reductases. Our results demonstrate that palmitoleic acid (16:1) acts as a rate-limiting positive regulator and that ergosterol acts as a potent inhibitor of sterol production in strains which possess only the HMGR1 isozyme (HMG1 hmg2). In strains which contain only the HMGR2 isozyme (hmg1 HMG2), sterol production was inhibited by oleic acid (18:1) and to a lesser degree by ergosterol. The specific activities of the two reductases (HMGR1 and HMGR2) were found to be differentially regulated by hemes but not by ergosterol, palmitoleic acid, or oleic acid. The disparate effects of unsaturated fatty acids and sterols on these strains lead us to consider the possibility of separate, compartmentalized isoprenoid pathways in S. cerevisiae.

Casey, W M; Keesler, G A; Parks, L W

1992-01-01

293

50 CFR 23.92 - Are any wildlife or plants, and their parts, products, or derivatives, exempt?  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Are any wildlife or plants, and their parts, products, or derivatives...EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) CONVENTION ON INTERNATIONAL...Species § 23.92 Are any wildlife or plants, and their parts, products, or...

2011-10-01

294

50 CFR 23.92 - Are any wildlife or plants, and their parts, products, or derivatives, exempt?  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Are any wildlife or plants, and their parts, products, or derivatives...EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) CONVENTION ON INTERNATIONAL...Species § 23.92 Are any wildlife or plants, and their parts, products, or...

2012-10-01

295

A set of novel Ti plasmid-derived vectors for the production of transgenic plants  

Microsoft Academic Search

We describe in this paper the construction and use of a set of novel Ti plasmid-derived vectors that can be used to produce transgenic plants. These vectors are based on one of two strategies: 1) double recombination into the wild-type Ti plasmid of genetic information flanked by two T-DNA fragments on a wide-host range plasmid; 2) the binary vector strategy.

A. J. M. Matzke; M. A. Matzke

1986-01-01

296

Dormancy break of celery (Apium graveolens L.) seeds by plant derived smoke extract  

Microsoft Academic Search

Seed dormancy of a highly-dormant cultivar of celery (Apium graveolens L.) was broken by combinations of plant-derived smoke extract or N6-benzyladenine (BA) and gibberellins A4\\/7 (GA4\\/7) in the dark at temperatures between 18 and 26°C. A less dormant cultivar which responded to GA4\\/7 alone showed no additional response to smoke extract or BA. Neither smoke extract nor BA affected either

T. H. Thomas; J. Staden

1995-01-01

297

Development of a plant-derived subunit vaccine candidate against hepatitis C virus  

Microsoft Academic Search

Summary.  ?Hepatitis C virus (HCV) is a major cause of acute and chronic hepatitis with over 180 million cases worldwide. Vaccine development\\u000a for HCV has been difficult. Presently, the virus cannot be grown in tissue culture and there is no vaccine or effective therapy\\u000a against this virus. In this research, we describe the development of an experimental plant-derived subunit vaccine against

L. G. Nemchinov; T. J. Liang; M. M. Rifaat; H. M. Mazyad; A. Hadidi; J. M. Keith

2000-01-01

298

Citrus genus plants contain N-methylated tryptamine derivatives and their 5-hydroxylated forms.  

PubMed

The occurrence and distribution in Citrus genus plants of N-methylated derivatives of tryptamine and their 5-hydroxylated forms are reported. Tryptamine, N-methyltryptamine, N,N-dimethyltryptamine, N,N,N-trimethyltryptamine, 5-hydroxytryptamine (serotonin), 5-hydroxy-N-methyltryptamine, 5-hydroxy-N,N-dimethyltryptamine (bufotenine), and 5-hydroxy-N,N,N-trimethyltryptamine (bufotenidine) were quantitated by LC-ESI-MS/MS. Leaves of all citrus plants examined contained N,N,N-trimethyltryptamine, a compound that we first discovered in the bergamot plant. Interestingly, we also found out that all plants examined contained 5-hydroxy-N,N-dimethyltryptamine and 5-hydroxy-N,N,N-trimethyltryptamine, compounds never described so far in the Citrus genus. As N,N,N-trimethyltryptamine and 5-hydroxy-N,N,N-trimethyltryptamine possess nicotine-like activity by exerting their action on acetylcholine receptors, it is conceivable that both represent the arrival point of a biosynthetic pathway aimed to provide Citrus plants with chemical defense against aggressors. This hypothesis is supported by our finding that leaves and seeds, which are more frequently attacked by biotic agents, are the parts of the plant where the highest levels of those compounds were found. PMID:23682903

Servillo, Luigi; Giovane, Alfonso; Balestrieri, Maria Luisa; Casale, Rosario; Cautela, Domenico; Castaldo, Domenico

2013-05-17

299

Studies on the polyphenol metabolism of tissue cultures derived from the tea plant (Camellia sinensis L.)  

PubMed Central

1. The growth characteristics on various media of solid and liquid suspension cultures derived from the stem of the tea plant are described; chlorophyll and anthocyanin synthesis occurred in the light. 2. Only the simplest catechins and leucoanthocyanins were present in callus tissue, although oligomeric and polymeric leucoanthocyanin fractions were also represented. Light caused an increase in all monomeric components analysed, but inhibited polymerization of the leucoanthocyanins. 3. The polyphenol oxidase activity of cultures was comparable with that of the apical regions of the intact plant, and was inversely correlated with growth rate. 4. Growth was stimulated by hormonal variation, and inhibited by high concentrations of sucrose and by high light-intensity; polyphenol concentrations were generally inversely correlated with growth rate. 5. From the inability of callus tissue and of cultured root apices to synthesize complex catechins, it is inferred that complex catechin formation in intact plants is associated with the process of cell vacuolation.

Forrest, G. I.

1969-01-01

300

A review on plant-derived natural products and their analogs with anti-tumor activity  

PubMed Central

Traditional medicines, including Chinese herbal formulations, can serve as the source of potential new drugs, and initial research focuses on the isolation of bioactive lead compound(s). The development of novel plant-derived natural products and their analogs for anticancer activity details efforts to synthesize new derivatives based on bioactivity- and mechanism of action-directed isolation and characterization coupled with rational drug design - based modification. Also, the anticancer activity of certain natural products and their analogs can be enhanced by synthesizing new derivatives based on active pharmacophore models; drug resistance and solubility and metabolic limitations can be overcome by appropriate molecular modifications; and new biological properties or mechanisms of action can be added by combining other functional groups or molecules. Preclinical screening for in vitro human cell line panels and selected in vivo xenograft testing then identifies the most promising drug development targets.

Dholwani, K.K.; Saluja, A.K.; Gupta, A.R.; Shah, D.R.

2008-01-01

301

Changes in lipids and sterols during composting.  

PubMed

Pyrolysis-gas (Py-GC) chromatography was used to characterize organic [(diethyl ether (DEE) and chloroform (CHCl3)] extracts of raw and composted duck excreta enriched wood shavings from two finishing cycles (C1 and C2). Materials were collected on days 0, 8 and 23. C1 contained 1.7 % total N while C2 contained 0.9 % total N. Py-GC-MS (mass spectrometry) showed that the extracts contained n-alkanes (C12 to C32), alkenes (C12:1 to C33:1), n-fatty acids (C12 to C28), unsaturated fatty acids (C18:1 and C18:2), and sterols (cholestene, cholestadiene, stigmastene, stigmastadiene, stigmastatriene, cholesterol, stigmastanol, stigmastanone, stigmastadienone, 17-methyl dialkylsulfanyl decahydro-1H-cyclopenta [a] phenanthrene, 17-methyl dialkylsulfanyl dodecahydro-1H-cyclopenta [a] phenanthrene, and 17-methyl-17-dialkylsulfanyl decahydro-1H-cyclopenta [a] phenanthrene). Other components identified were prystene, squalene (precursor of cholesterol), phthalic acid, diphenylpropane, diphenylbut-2-ene and 1,3,6 triphenyl hex-4-ene. Our data showed significant changes in the lipid composition of duck excreta enriched wood shavings during composting, which appeared to be related to the total N content of the system. PMID:11599727

Dinel, H; Schnitzer, M; Paré, T; Lemee, L; Ambles, A; Lafond, S

2001-09-01

302

Transferability of retrotransposon primers derived from Persimmon (Diospyros kaki Thunb.) across other plant species.  

PubMed

Retrotransposon-based molecular markers are powerful molecular tools. However, these markers are not readily available due to the difficulty in obtaining species-specific retrotransposon primers. Although recent techniques enabling the rapid isolation of retrotransposon sequences have facilitated primer development, this process nonetheless remains time-consuming and costly. Therefore, research into the transferability of retrotransposon primers developed from one plant species onto others would be of great value. The present study investigated the transferability of retrotransposon primers derived from 'Luotian-tianshi' persimmon (Diospyros kaki Thunb.) across other fruit crops, as well as within the genus using inter-retrotransposon amplified polymorphism molecular marker. Fourteen of the 26 retrotransposon primers tested (53.85%) produced robust and reproducible amplification products across all fruit crops tested, indicating their applicability across plant species. Four of the 13 fruit crops showed the best transferability performances: persimmon, grape, citrus, and peach. Furthermore, similarity coefficients and UPGMA clustering indicated that these primers could further offer a potential tool for germplasm differentiation, parentage identification, genetic diversity assessment, classification, and phylogenetic studies across a variety of plant species. Transferability was further confirmed by examining published primers derived from Rosaceae, Gramineae, and Solanaceae. This study is one of the few currently available studies concerning the transferability of retrotransposon primers across plant species in general, and is the first successful study of the transferability of retrotransposon primers derived from persimmon. The primers presented here will help reduce costs for future retrotransposon primer development and therefore contribute to the popularization of retrotransposon molecular markers. PMID:23913371

Du, X Y; Hu, Q N; Zhang, Q L; Wang, Y B; Luo, Z R

2013-06-06

303

Plant-derived auxin plays an accessory role in symptom development upon Rhodococcus fascians infection.  

PubMed

The biotrophic phytopathogen Rhodococcus fascians has a profound impact on plant development, mainly through its principal virulence factors, a mix of synergistically acting cytokinins that induce shoot formation. Expression profiling of marker genes for several auxin biosynthesis routes and mutant analysis demonstrated that the bacterial cytokinins stimulate the auxin biosynthesis of plants via specific targeting of the indole-3-pyruvic acid (IPA) pathway, resulting in enhanced auxin signaling in infected tissues. The double mutant tryptophan aminotransferase 1-1 tryptophan aminotransferase related 2-1 (taa1-1 tar2-1) of Arabidopsis (Arabidopsis thaliana), in which the IPA pathway is defective, displayed a decreased responsiveness towards R. fascians infection, although bacterial colonization and virulence gene expression were not impaired. These observations implied that plant-derived auxin was employed to reinforce symptom formation. Furthermore, the increased auxin production and, possibly, the accumulating bacterial cytokinins in infected plants modified the polar auxin transport so that new auxin maxima were repetitively established and distributed, a process that is imperative for symptom onset and maintenance. Based on these findings, we extend our model of the mode of action of bacterial and plant signals during the interaction between R. fascians and Arabidopsis. PMID:22181713

Stes, Elisabeth; Prinsen, Els; Holsters, Marcelle; Vereecke, Danny

2012-02-14

304

[Characteristics of the radiation-induced changes in the content of sterols and squalene in the lymphoid system tissues and erythrocyte membranes of rats].  

PubMed

Ionizing radiation causes considerable changes in the content of sterols and squalene in the lymphoid system tissues and erythrocyte membranes which is in accordance with the concept of high radiosensitivity of haemopoietic tissue. The processes of cholesterol conversion to its oxy-derivatives are increased under the effect of radiation. The content of some lipid components in the lymphoid system tissues and erythrocyte membranes is changed depending on the dose and time after irradiation. There is a relationship between the changes in the sterol composition and in the properties of erythrocyte membranes. PMID:2371389

Palamarchuk, V I

305

A Plant-Derived Morphinan as a Novel Lead Compound Active against Malaria Liver Stages  

PubMed Central

Background The global spread of multidrug–resistant malaria parasites has led to an urgent need for new chemotherapeutic agents. Drug discovery is primarily directed to the asexual blood stages, and few drugs that are effective against the obligatory liver stages, from which the pathogenic blood infection is initiated, have become available since primaquine was deployed in the 1950s. Methods and Findings Using bioassay-guided fractionation based on the parasite's hepatic stage, we have isolated a novel morphinan alkaloid, tazopsine, from a plant traditionally used against malaria in Madagascar. This compound and readily obtained semisynthetic derivatives were tested for inhibitory activity against liver stage development in vitro (P. falciparum and P. yoelii) and in vivo (P. yoelii). Tazopsine fully inhibited the development of P. yoelii (50% inhibitory concentration [IC50] 3.1 ?M, therapeutic index [TI] 14) and P. falciparum (IC50 4.2 ?M, TI 7) hepatic parasites in cultured primary hepatocytes, with inhibition being most pronounced during the early developmental stages. One derivative, N-cyclopentyl-tazopsine (NCP-tazopsine), with similar inhibitory activity was selected for its lower toxicity (IC50 3.3 ?M, TI 46, and IC50 42.4 ?M, TI 60, on P. yoelii and P. falciparum hepatic stages in vitro, respectively). Oral administration of NCP-tazopsine completely protected mice from a sporozoite challenge. Unlike the parent molecule, the derivative was uniquely active against Plasmodium hepatic stages. Conclusions A readily obtained semisynthetic derivative of a plant-derived compound, tazopsine, has been shown to be specifically active against the liver stage, but inactive against the blood forms of the malaria parasite. This unique specificity in an antimalarial drug severely restricts the pressure for the selection of drug resistance to a parasite stage limited both in numbers and duration, thus allowing researchers to envisage the incorporation of a true causal prophylactic in malaria control programs.

Carraz, Maelle; Jossang, Akino; Franetich, Jean-Francois; Siau, Anthony; Ciceron, Liliane; Hannoun, Laurent; Sauerwein, Robert; Frappier, Francois; Rasoanaivo, Philippe; Snounou, Georges; Mazier, Dominique

2006-01-01

306

Effects of sterols on the development and aging of Caenorhabditis elegans.  

PubMed

Although Caenorhabditis elegans lacks several components of the de novo sterol biosynthetic pathway, it requires sterols as essential nutrients. Supplemental cholesterol undergoes extensive enzymatic modification in C. elegans to form certain sterols of unknown function. Since sterol metabolism in C. elegans differs from that in other species, such as mammals and yeast, it is important to examine how sterols regulate worm physiology. To examine the functions of sterols in C. elegans, a sterol-feeding experiment was carried out and several critical parameters, such as brood size, growth rate, and life span, were measured. In addition, the change in lipid distribution in C. elegans can be both qualitatively and quantitatively determined by various methods, including staining and chromatographic techniques. Taken together, the effects of sterols on C. elegans are very prominent and can be easily assessed using the techniques described here. PMID:19160668

Lee, Eun-Young; Jeong, Pan-Young; Kim, Sun-Young; Shim, Yhong-Hee; Chitwood, David J; Paik, Young-Ki

2009-01-01

307

Role of uncondensed 1,2,4-triazine derivatives as biocidal plant protection agents--a review.  

PubMed

The role of uncondensed 1,2,4-triazine derivatives and the related compounds as biocidal plant protection agents such as herbicides, bactericidal, fungicidal, antimicrobial, protozacides, anticoccidal, parasiticides, insecticides, acaricdes and pesticides, is reviewed. PMID:11265582

Abdel-Rahman, R M

2001-03-01

308

40 CFR 180.1179 - Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...  

Code of Federal Regulations, 2013 CFR

...lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria mangle; exemption from the requirement of a tolerance. The biochemical pesticide plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...

2013-07-01

309

Plant regeneration from embryogenic suspension-derived protoplasts of ginger ( Zingiber officinale Rosc.)  

Microsoft Academic Search

A procedure is described to regenerate plants from embryogenic suspension-derived protoplasts of ginger (Zingiber officinale Rosc.). Somatic embryogenic calli were induced from ginger shoot tips on solid MS medium with half the concentration of NH4NO3 and supplemented with 1.0 mg l?1 2,4-Dichloroacetic acid (2, 4-D) and 0.2 mg l?1 Kin. Rapid-growing and well-dispersed suspension cultures were established by subculturing the embryogenic calli in the same

Yinghua Guo; Jinhe Bai; Zhenxian Zhang

2007-01-01

310

Sterol composition of gonad, muscle and digestive gland of Pecten maximus from Málaga (South Spain)  

Microsoft Academic Search

Sterol composition and content and their seasonal variations over 18 months were investigated in adductor muscle, digestive gland and gonads of Pecten maximus. Sterols were isolated by Silicagel 60 thin layer chromatography and identified by gas chromatography\\/mass spectrometry. Eleven sterols were identified, with cholesterol, brassicasterol, 24-methylenecholesterol and 22-trans-dehydrocholesterol being the principal components. The same sterols were found in all three

A. J Pazos; A Silva; V Vázquez; M. L Pérez-Parallé; G Román; J. L Sánchez; M Abad

2003-01-01

311

Yeast oxysterol-binding proteins: sterol transporters or regulators of cell polarization?  

Microsoft Academic Search

Oxysterol-binding protein (OSBP) and OSBP-related proteins (ORPs) are a conserved family of soluble cytoplasmic proteins that\\u000a can bind sterols, translocate between membrane compartments, and affect sterol trafficking. These properties make ORPs attractive\\u000a candidates for lipid transfer proteins (LTPs) that directly mediate nonvesicular sterol transfer to the plasma membrane. To\\u000a test whether yeast ORPs (the Osh proteins) are sterol LTPs, we

Christopher T. Beh; Gabriel Alfaro; Giselle Duamel; David P. Sullivan; Michael C. Kersting; Shubha Dighe; Keith G. Kozminski; Anant K. Menon

2009-01-01

312

Spatiotemporal analysis of endocytosis and membrane distribution of fluorescent sterols in living cells  

Microsoft Academic Search

Distribution and dynamics of cholesterol in the plasma membrane as well as internalization pathways for sterol from the cell\\u000a surface are of great cell biological interest. Here, UV-sensitive wide field microscopy of the intrinsically fluorescent sterols,\\u000a dehydroergosterol (DHE) and cholestatrienol (CTL) combined with advanced image analysis were used to study spatiotemporal\\u000a sterol distribution in living macrophages, adipocytes and fibroblasts. Sterol

Daniel Wüstner; Nils J. Fćrgeman

2008-01-01

313

Targeting Trypanosoma cruzi Sterol 14?-Demethylase (CYP51)  

PubMed Central

There are at least two obvious features that must be considered upon targeting specific metabolic pathways/enzymes for drug development: the pathway must be essential and the enzyme must allow the design of pharmacologically useful inhibitors. Here, we describe Trypanosoma cruzi sterol 14?-demethylase as a promising target for anti-Chagasic chemotherapy. The use of anti-fungal azoles, which block sterol biosynthesis and therefore membrane formation in fungi, against the protozoan parasite has turned out to be highly successful: a broad spectrum anti-fungal drug, the triazole compound posaconazole, is now entering phase II clinical trials for treatment of Chagas disease. This review summarizes comparative information on anti-fungal azoles and novel inhibitory scaffolds selective for Trypanosomatidae sterol 14?-demethylase through the lens of recent structure/functional characterization of the target enzyme. We believe our studies open wide opportunities for rational design of novel, pathogen-specific and therefore more potent and efficient anti-trypanosomal drugs.

Lepesheva, Galina I.; Villalta, Fernando; Waterman, Michael R.

2012-01-01

314

New oxidized sterols from Aspergillus awamori and the endo-boat conformation adopted by the cyclohexene oxide system.  

PubMed

Two new oxidized sterols 1 and 2 were obtained from the active fraction of a mangrove fungus Aspergillus awamori isolated from the soils around the mangrove plant Acrostichum speciosum. Their structures were elucidated using spectroscopic methods as 22E-7alpha-methoxy-5alpha,6alpha-epoxyergosta-8(14),22-dien-3beta-ol (1) and 22E-3beta-hydroxy-5alpha,6alpha,8alpha,14alpha-diepoxyergosta-22-en-7-one (2). The NMR data and complete assignments for both DMSO-d(6) and CDCl(3) were given. Their cytotoxic activity against A549 cell line was evaluated. Furthermore, the detailed conformation analysis for ring B (cyclohexene oxide system) of sterol 1 was given on the basis of NOEs. The endo-boat conformation was considered as the preferred conformation for ring B rather than half-chair conformation. PMID:19877128

Gao, Hao; Hong, Kui; Chen, Guo-Dong; Wang, Chuan-Xi; Tang, Jin-Shan; Yu, Yang; Jiang, Miao-Miao; Li, Man-Mei; Wang, Nai-Li; Yao, Xin-Sheng

2010-01-01

315

Supplementation with sterols improves food quality of a ciliate for Daphnia magna.  

PubMed

Experimental results provide evidence that trophic interactions between ciliates and Daphnia are constrained by the comparatively low food quality of ciliates. The dietary sterol content is a crucial factor in determining food quality for Daphnia. Ciliates, however, presumably do not synthesize sterols de novo. We hypothesized that ciliates are nutritionally inadequate because of their lack of sterols and tested this hypothesis in growth experiments with Daphnia magna and the ciliate Colpidium campylum. The lipid content of the ciliate was altered by allowing them to feed on fluorescently labeled albumin beads supplemented with different sterols. Ciliates that preyed upon a sterol-free diet (bacteria) did not contain any sterols, and growth of D. magna on these ciliates was poor. Supplementation of the ciliates' food source with different sterols led to the incorporation of the supplemented sterols into the ciliates' cells and to enhanced somatic growth of D. magna. Sterol limitation was thereby identified as the major constraint of ciliate food quality for Daphnia. Furthermore, by supplementation of sterols unsuitable for supporting Daphnia growth, we provide evidence that ciliates as intermediary grazers biochemically upgrade unsuitable dietary sterols to sterols appropriate to meet the physiological demands of Daphnia. PMID:16904373

Martin-Creuzburg, Dominik; Bec, Alexandre; von Elert, Eric

2006-08-10

316

Sterol mutants of Neurospora crassa : Their isolation, growth characteristics and resistance to polyene antibiotics  

Microsoft Academic Search

A method is described for isolating sterol mutants of the filamentous fungus, Neurospora crassa. Most of the mutants carry gene mutations affecting the later stages of ergosterol biosynthesis and they accumulate other, as yet unidentified, sterol components but two mutants are blocked earlier in the pathway and respond to exogenous mevalonic acid. Altered sterol metabolism is associated with a reduced

M. Grindle

1973-01-01

317

Neutral sterols of rat epididymis: high concentrations of dehydrocholesterols in rat caput epididymidis  

Microsoft Academic Search

Phospholipids and sterols are known to have multiple functions in reproductive tissue of mammals. High concentrations of the cholesterol precursor desmosterol have been described in testis, epididymis, and spermatozoa of various species. These findings and the recent discovery of some cholesterol precursors as meiosis-activating sterols suggest important functions of cholesterol precursors in fertility. Many sterol intermediates appear from the 19-step

Bernhard Lindenthal; Tayseer A. Aldaghlas; Joanne K. Kelleher; Stephan M. Henkel; René Tolba; Gerhard Haidl; Klaus von Bergmann

318

Cholesterol regulation of genes involved in sterol trafficking in human THP1 macrophages  

Microsoft Academic Search

Modulation of the expression of genes involved in the control of cholesterol homeostasis by sterols in macrophages is crucial to foam cell formation. To characterize this regulation in THP-1 macrophages, we examined the effect of sterol loading and unloading on the expression of a number of genes that participate in lipoprotein uptake and cholesterol efflux. Sterol loading by exposure to

Gemma Llaverias; Diana Lacasa; Manuel Vázquez-Carrera; Rosa M. Sánchez; Juan C. Laguna; Marta Alegret

2005-01-01

319

Sterol Regulatory Element Binding Proteins in Fungi: Hypoxic Transcription Factors Linked to Pathogenesis  

Microsoft Academic Search

Sterol regulatory element binding proteins (SREBPs) are membrane-bound transcription factors whose proteolytic activation is controlled by the cellular sterol concentration. Mammalian SREBPs are activated in cholesterol-depleted cells and serve to regulate cellular lipid homeostasis. Recent work demonstrates that SREBP is functionally conserved in fungi. While the ability to respond to sterols is conserved, fungal SREBPs are hypoxic transcription factors required

Clara M. Bien; Peter J. Espenshade

2010-01-01

320

Annual Variation in the Effect of Red Light on Sterol Biosynthesis in Digitalis purpurea L. 1  

PubMed Central

The effect of varying sequences of red and far red light on sterol biosynthesis in etiolated seedlings of Digitalis purpurea L. was examined. Red light caused a marked increase in the amounts of free and glycosidic sterols and a small decrease in esterified sterols during the first 4 hours after illumination. Far red light elicited the same response but to a lesser degree. Exposure to red followed by far red light or the reverse caused little or no increase in the amounts of free and glycosidic sterols. The magnitude of the increase in the amounts of sterols varied, depending upon the season in which the experiments were performed. The largest increments were obtained during the summer and fall, whereas the smallest were observed during the winter and spring. Correlation of these data with previous observations of an annual cycle in the sterol content of Digitalis seedlings showed that the maximum stimulation in sterol biosynthesis occurs when the endogenous level of sterols is minimal. Sterol monoglycosides, acylmonoglycosides, and an unidentified sterol conjugate from the lipid extracts were quantitated. Changes in conjugated sterol content were related to the particular light conditions of each experiment. The results are discussed in terms of physiological cycles and the possible influence of hormones upon the control of sterol biosynthesis in Digitalis.

Jacobsohn, Myra K.; Orkwiszewski, Joseph A. J.; Jacobsohn, Gert M.

1978-01-01

321

Specific Sterols Required for the Internalization Step of Endocytosis in Yeast  

Microsoft Academic Search

Sterols are major components of the plasma membrane, but their functions in this membrane are not well understood. We isolated a mutant defective in the internalization step of endocytosis in a gene (ERG2) encoding a C-8 sterol isomerase that acts in the late part of the ergosterol biosynthetic pathway. In the absence of Erg2p, yeast cells accumulate sterols structurally different

Alan L. Munn; Antje Heese-Peck; Brian J. Stevenson; Harald Pichler; Howard Riezman

1999-01-01

322

Fly ash-derived Strontium as an index to monitor deposition from coal-fired power plants  

SciTech Connect

The combustion of western US coals releases significant amounts of strontium, which is relatively enriched in the fine particles of fly ash. Fly ash-derived strontium is readily absorbed by agronomic and native plant species when incorporated in soil. The strontium-87 to strontium-86 ratios of fly ash and soils were significantly different, but similar ratios were found in fly ash and plants treated with fly ash. A technique for measuring and monitoring deposition from coal-fired power plants is inferred from the enhanced plant uptake of fly ash strontium and the similarity in the isotopic ratios of fly ash and treated plants.

Straughan, I.R. (California Edison Co., Rosemead); Elseewi, A.A.; Page, A.L.; Kaplan, I.R.; Hurst, R.W.; Davis, T.E.

1981-06-12

323

Protein Mediators of Sterol Transport Across Intestinal Brush Border Membrane  

PubMed Central

Dysregulation of cholesterol balance contributes significantly to atherosclerotic cardiovascular disease (ASCVD), the leading cause of death in the United States. The intestine has the unique capability to act as a gatekeeper for entry of cholesterol into the body, and inhibition of intestinal cholesterol absorption is now widely regarded as an attractive non-statin therapeutic strategy for ASCVD prevention. In this chapter we discuss the current state of knowledge regarding sterol transport across the intestinal brush border membrane. The purpose of this work is to summarize substantial progress made in the last decade in regards to protein-mediated sterol trafficking, and to discuss this in the context of human disease.

Brown, J. Mark; Yu, Liqing

2012-01-01

324

Characterization of Total and Individual Sterols in Canola Sprouts  

Microsoft Academic Search

In this study, the contents of total and individual phytosterols in sprouts made from seeds of seven canola (Brassica\\u000a napus L.) lines (Acropolis, Banjo, Jetton, KS-7740, KSM3-1-124, Mussette and Virginia), grown at three locations in Virginia (Orange,\\u000a Petersburg and Suffolk), were determined. Canola sprouts contained, on an average, 36.3 g sterols in 100 g of unsaponifiable\\u000a matter (UNSAP), 10.7 mg sterols in 1 g

Anwar A. HamamaHarbans; Harbans L. Bhardwaj

2011-01-01

325

Benzothiadiazole (BTH) activates sterol pathway and affects vitamin D3 metabolism in Solanum malacoxylon cell cultures.  

PubMed

Benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), a particularly efficient inducer of systemic acquired resistance (SAR), was developed as an immunizing agent to sensitize various crop species against pathogen infections. Recent works highlighted its activating effect on different metabolic pathways, concerning both primary and secondary metabolites. In this study, we investigated the effect of BTH treatment on sterol levels and vitamin D(3) metabolism in Solanum malacoxylon cultures. Calli of S. malacoxylon were incubated in Gamborg B5 liquid medium alone or added with 50 ?M BTH for different times (one, two or three cycles of light). Histocytochemical investigations performed on our experimental system using 3,3'-diaminobenzidine (DAB) for hydrogen peroxide (H(2)O(2)) detection and phloroglucinol for lignin staining showed that BTH causes H(2)O(2) accumulation and lignin deposition in treated calli. Gas chromatographic analysis of principal cell membrane sterols (?-sitosterol, campesterol, stigmasterol) showed that BTH transiently increases their cellular levels. Callus cultures were found to contain also cholesterol, 7-dehydrocholesterol, the putative precursor of vitamin D(3), and the hydroxylated metabolites 25-hydroxyvitamin D(3) [25(OH)D(3)] and 1?,25-dihydroxyvitamin D(3) [1?,25(OH)(2)D(3)]. BTH treatment enhanced 7-dehydrocholesterol while reduced cholesterol. HPLC analysis of sample extracts showed that BTH does not affect the cell content of vitamin D(3), though results of ELISA tests highlighted that this elicitor moderately enhances the levels of 25(OH)D(3) and 1?,25(OH)(2)D(3) metabolites. In conclusion, BTH treatment not only causes cell wall strengthening, a typical plant defence response, as just described in other experimental models, but in the same time increases the cellular level of the main sterols and 7-dehydrocholesterol. PMID:21779826

Burlini, Nedda; Iriti, Marcello; Daghetti, Anna; Faoro, Franco; Ruggiero, Antonietta; Bernasconi, Silvana

2011-07-16

326

First Report of Plant Regeneration via Somatic Embryogenesis from Shoot Apex-derived Callus of Hedychium muluense  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plants were successfully regenerated via somatic embryogenesis from shoot apex-derived callus of Hedychium muluense R.M. Smith, an important monocotyledonous ornamental ginger plant. Callus was induced on a modified Murashige and Skoog (MS) medium supplemented with 9.05 µM 2-4, D and 4.6µM kinetin. ...

327

DEVELOPING SITE-SPECIFIC DERIVED CONCENTRATION GUIDELINE LEVELS FOR MULTIPLE MEDIA AT THE CONNECTICUT YANKEE HADDAM NECK PLANT  

Microsoft Academic Search

As part of the license termination process, site-specific Derived Concentration Guideline Levels for the Haddam Neck Plant site are developed for soil, groundwater, concrete left standing, and concrete demolished that satisfy the radiological criteria for unrestricted use as defined in 10 CFR 20.1402. Background information on the license termination process and characteristics of the Haddam Neck Plant site are presented.

S. W. Taylor; L. C. Smith; R. K. Carr; A. Carson; E. Darois

2003-01-01

328

Detection of Somaclonal Variations in Tissue Culture-Derived Date Palm Plants Using Isoenzyme Analysis and RAPD Fingerprints  

Microsoft Academic Search

Isoenzyme analysis and activities of peroxidase (PER), polyphenol oxidase (POD) and glutamate oxaloacetate (GOT) and randomly amplified polymorphic DNA (RAPD) fingerprints were used to analyze somaclonal variations in tissue culture-derived date palm plants. The frequency of somaclonal variations was found to be age dependent. Similar isoenzyme patterns for PER and GOT were detected in all analyzed plants. However, variations in

M. M. Saker; S. A. Bekheet; H. S. Taha; A. S. Fahmy; H. A. Moursy

2000-01-01

329

Biochemical and molecular analysis of plants derived from embryogenic tissue cultures of napier grass ( Pennisetum purpureum K. Schum)  

Microsoft Academic Search

We have investigated the extent of biochemical and molecular variation in 63 plants of napier grass (Pennisetum purpureum K. Schum.) regenerated from 3- to 24-week-old embryogenic callus cultures. The calli were derived from cultured basal segments of young leaves and immature inflorescences obtained from a single fieldgrown donor plant. The entire population was analyzed for the activity of 14 isozyme

V. B. Shenoy; I. K. Vasil

1992-01-01

330

Variable Contribution of Soil and Plant Derived Carbon to Dissolved Organic Matter  

NASA Astrophysics Data System (ADS)

The seasonal variation in the amount and sources of dissolved organic matter (DOM) in soil profiles was investigated. In general DOM in soil solution can evolve from the decomposition and mobilization of soil organic matter (SOM), dissolution of dead microbial cells or from the input of plant material such as root exudates or decomposing litter. Here we used vegetation change from C3 to C4 plants to quantify the plant derived carbon in DOM. In 2002 an agricultural field was converted to an experimental grass land. The average carbon isotope value of SOM was -26.5 per mill (sd = 0.2) for the plough horizon. On two independent plots, each 10 x 20 m, we used Amaranthus retroflexus as C4 plant with a carbon isotope label of 13.0 per mill to distinguish unlabeled SOM and plant derived carbon sources. To quantify the contribution of litter input on DOM formation we applied a split plot design. One half had no litter and the other half double amount of above ground litter. Soil water was collected in 10, 20 and 30 cm depth biweekly and DOM concentrations in solution and carbon isotope ratios of the freeze dried and decarbonized material were investigated. During winter uniform concentrations of DOM of about 7 mg/l were measured throughout all depth and treatments. In spring when soil temperatures increase and water availability decreases DOM concentrations increased with similar rates in all depth. Even in the second year of Amaranth growth the carbon isotope ratios of DOM in winter and spring had no C4 signal. The carbon isotope ratios of -26 to -27 per mill suggest SOM as carbon source and contradict a contribution of root exudates to the DOM pool. During summer almost no soil solution was collected. After rewetting in fall DOM concentrations up to 50 mg/l in 10 cm depth and up to 35 mg/l in deeper layers were found. These high concentrations held carbon isotope signals from -25 to -26.5 per mill contradicting carbon input from plant material. With ongoing wetting of the soil the carbon isotope ratios suddenly increased up to -21.7 per mill on the double litter plots and to -24 per mill on no litter plots. However, this signal was not detected in 30 cm depth. Keeling plots proved that the major part of the DOM comes from SOM. In fall and early winter only 36 % and 19 % of plant derived carbon were found in the double litter and no litter plots, respectively. Our results suggest that carbon of the SOM pool is the major source for carbon in DOM. In the spring season root exudates seem to be completely respired by soil organisms suggesting that root and rhizosphere respiration are the same respiratory pool. Only in fall the decomposition of plant litter contributed to carbon in DOM. However, this carbon source is already exhausted in the next spring. In consequence our results may indicate that stored soil carbon is more active than thought and that DOM transport might be a key process to understand carbon sequestration.

Steinbeiss, S.; Gleixner, G.

2005-12-01

331

Phenotypic variation in plants produced from lateral buds, stem explants and single-cell-derived callus of potato  

Microsoft Academic Search

Summary  Plants regenerated directly from potato stem explants and from callus derived from single potato stem callus cells were compared\\u000a with plants from rooted lateral buds as controls. There was phenotypic variation in explant and cell cultures: grossly abnormal,\\u000a albino and green, shoot-like and root-like structures either failed to root or establish and survive in soil but most surviving\\u000a plants showed

A. C. Cassells; E. M. Goetz; S. Austin

1983-01-01

332

Cytochrome P450 CYP710A Encodes the Sterol C-22 Desaturase in Arabidopsis and Tomato[W][OA  

PubMed Central

?22-Unsaturated sterols, containing a double bond at the C-22 position in the side chain, occur specifically in fungi and plants. Here, we describe the identification and characterization of cytochrome P450s belonging to the CYP710A family as the plant C-22 desaturase. Recombinant proteins of CYP710A1 and CYP710A2 from Arabidopsis thaliana and CYP710A11 from tomato (Lycopersicon esculentum) were expressed using a baculovirus/insect system. The Arabidopsis CYP710A1 and tomato CYP710A11 proteins exhibited C-22 desaturase activity with ?-sitosterol to produce stigmasterol (CYP710A1, Km = 1.0 ?M and kinetic constant [kcat] = 0.53 min?1; CYP710A11, Km = 3.7 ?M and kcat = 10 min?1). In Arabidopsis transgenic lines with CYP710A1 and CYP710A11 overexpression, stigmasterol levels increased by 6- to 32-fold. Arabidopsis CYP710A2 was able to produce brassicasterol and stigmasterol from 24-epi-campesterol and ?-sitosterol, respectively. Sterol profiling analyses for CYP710A2 overexpression and a T-DNA insertion event into CYP710A2 clearly demonstrated in planta that CYP710A2 was responsible for both brassicasterol and stigmasterol production. Semiquantitative PCR analyses and promoter:?-glucuronidase transgenic approaches indicated strict tissue/organ-specific regulation for each CYP710A gene, implicating differential tissue distributions of the ?22-unsaturated sterols in Arabidopsis. Our results support the possibility that the CYP710 family may encode P450s of sterol C-22 desaturases in different organisms.

Morikawa, Tomomi; Mizutani, Masaharu; Aoki, Nozomu; Watanabe, Bunta; Saga, Hirohisa; Saito, Shigeki; Oikawa, Akira; Suzuki, Hideyuki; Sakurai, Nozomu; Shibata, Daisuke; Wadano, Akira; Sakata, Kanzo; Ohta, Daisaku

2006-01-01

333

Microbial production of fatty-acid-derived fuels and chemicals from plant biomass.  

PubMed

Increasing energy costs and environmental concerns have emphasized the need to produce sustainable renewable fuels and chemicals. Major efforts to this end are focused on the microbial production of high-energy fuels by cost-effective 'consolidated bioprocesses'. Fatty acids are composed of long alkyl chains and represent nature's 'petroleum', being a primary metabolite used by cells for both chemical and energy storage functions. These energy-rich molecules are today isolated from plant and animal oils for a diverse set of products ranging from fuels to oleochemicals. A more scalable, controllable and economic route to this important class of chemicals would be through the microbial conversion of renewable feedstocks, such as biomass-derived carbohydrates. Here we demonstrate the engineering of Escherichia coli to produce structurally tailored fatty esters (biodiesel), fatty alcohols, and waxes directly from simple sugars. Furthermore, we show engineering of the biodiesel-producing cells to express hemicellulases, a step towards producing these compounds directly from hemicellulose, a major component of plant-derived biomass. PMID:20111002

Steen, Eric J; Kang, Yisheng; Bokinsky, Gregory; Hu, Zhihao; Schirmer, Andreas; McClure, Amy; Del Cardayre, Stephen B; Keasling, Jay D

2010-01-28

334

Bioefficacy of some plant derivatives that protect grain against the pulse beetle, Callosobruchus maculatus.  

PubMed

Experiments were conducted to study the bioefficacies of different plant/weed derivatives that affect the development of the pulse beetle, Callosobruchus maculates F. (Coleoptera: Bruchidae) fed on black gram, Vigna mungo, seeds. Plant extracts, powder, ash and oil from nishinda (Vitex negundo L.), eucalyptus (Eucalyptus globules Labill.), bankalmi (Ipomoea sepiaria K.), neem (Azadirachta indica L.), safflower (Carthamus tinctorius L.), sesame (Sesamum indicum L.) and bablah (Acacia arabica L.) were evaluated for their oviposition inhibition, surface protectant, residual toxicity and direct toxicity effects on C. maculates. The results showed that plant oils were effective in checking insect infestation. The least number of F(1) adults emerged from black gram seeds treated with neem oil. The nishinda oil extract was the most toxic of three extracts tested (nishinda, eucalyptus and bankalmi). Bablah ash was the most effective compared to the powdered leaves of nishinda, eucalyptus and bankalmi. The powdered leaves and extracts of nishinda, eucalyptus and bankalmi, at a 3% mixture, provided good protection for black gram seeds by reducing insect oviposition, F(1) adult emergence, and grain infestation rates. The oil treatment did not show adverse effects on germination capability of seeds, even after three months of treatment. PMID:19537990

Rahman, A; Talukder, F A

2006-01-01

335

Large-scale Gene Ontology analysis of plant transcriptome-derived sequences retrieved by AFLP technology  

PubMed Central

Background After 10-year-use of AFLP (Amplified Fragment Length Polymorphism) technology for DNA fingerprinting and mRNA profiling, large repertories of genome- and transcriptome-derived sequences are available in public databases for model, crop and tree species. AFLP marker systems have been and are being extensively exploited for genome scanning and gene mapping, as well as cDNA-AFLP for transcriptome profiling and differentially expressed gene cloning. The evaluation, annotation and classification of genomic markers and expressed transcripts would be of great utility for both functional genomics and systems biology research in plants. This may be achieved by means of the Gene Ontology (GO), consisting in three structured vocabularies (i.e. ontologies) describing genes, transcripts and proteins of any organism in terms of their associated cellular component, biological process and molecular function in a species-independent manner. In this paper, the functional annotation of about 8,000 AFLP-derived ESTs retrieved in the NCBI databases was carried out by using GO terminology. Results Descriptive statistics on the type, size and nature of gene sequences obtained by means of AFLP technology were calculated. The gene products associated with mRNA transcripts were then classified according to the three main GO vocabularies. A comparison of the functional content of cDNA-AFLP records was also performed by splitting the sequence dataset into monocots and dicots and by comparing them to all annotated ESTs of Arabidopsis and rice, respectively. On the whole, the statistical parameters adopted for the in silico AFLP-derived transcriptome-anchored sequence analysis proved to be critical for obtaining reliable GO results. Such an exhaustive annotation may offer a suitable platform for functional genomics, particularly useful in non-model species. Conclusion Reliable GO annotations of AFLP-derived sequences can be gathered through the optimization of the experimental steps and the statistical parameters adopted. The Blast2GO software was shown to represent a comprehensive bioinformatics solution for an annotation-based functional analysis. According to the whole set of GO annotations, the AFLP technology generates thorough information for angiosperm gene products and shares common features across angiosperm species and families. The utility of this technology for structural and functional genomics in plants can be implemented by serial annotation analyses of genome-anchored fragments and organ/tissue-specific repertories of transcriptome-derived fragments.

Botton, Alessandro; Galla, Giulio; Conesa, Ana; Bachem, Christian; Ramina, Angelo; Barcaccia, Gianni

2008-01-01

336

Plasma sterol evidence for decreased absorption and increased synthesis of cholesterol in insulin resistance and obesity1234  

PubMed Central

Background: The rise in LDL with egg feeding in lean insulin-sensitive (LIS) participants is 2- and 3-fold greater than in lean insulin-resistant (LIR) and obese insulin-resistant (OIR) participants, respectively. Objective: We determined whether differences in cholesterol absorption, synthesis, or both could be responsible for these differences by measuring plasma sterols as indexes of cholesterol absorption and endogenous synthesis. Design: Plasma sterols were measured by gas chromatography–mass spectrometry in a random subset of 34 LIS, 37 LIR, and 37 OIR participants defined by the insulin sensitivity index (SI) and by BMI criteria selected from a parent group of 197 participants. Cholestanol and plant sterols provide a measure of cholesterol absorption, and lathosterol provides a measure of cholesterol synthesis. Results: The mean (±SD) ratio of plasma total absorption biomarker sterols to cholesterol was 4.48 ± 1.74 in LIS, 3.25 ± 1.06 in LIR, and 2.82 ± 1.08 in OIR participants. After adjustment for age and sex, the relations of the absorption sterol–cholesterol ratios were as follows: LIS > OIR (P < 0.001), LIS > LIR (P < 0.001), and LIR > OIR (P = 0.11). Lathosterol-cholesterol ratios were 0.71 ± 0.32 in the LIS participants, 0.95 ± 0.47 in the LIR participants, and 1.29 ± 0.55 in the OIR participants. After adjustment for age and sex, the relations of lathosterol-cholesterol ratios were as follows: LIS < OIR (P < 0.001), LIS < LIR (P = 0.03), and LIR < OIR (P = 0.002). Total sterol concentrations were positively associated with SI and negatively associated with obesity, whereas lathosterol correlations were the opposite. Conclusions: Cholesterol absorption was highest in the LIS participants, whereas cholesterol synthesis was highest in the LIR and OIR participants. Therapeutic diets for hyperlipidemia should emphasize low-cholesterol diets in LIS persons and weight loss to improve SI and to decrease cholesterol overproduction in LIR and OIR persons.

Knopp, Robert H; Kahn, Steven E; Retzlaff, Barbara M; Fish, Brian; Ma, Lina; Ostlund, Richard E

2011-01-01

337

Modification of the sterol composition of Trypanosoma (Schizotrypanum) cruzi epimastigotes by ? 24(25)-sterol methyl transferase inhibitors and their combinations with ketoconazole  

Microsoft Academic Search

We report a detailed analysis of the sterol composition of Trypanosoma cruzi epimastigotes grown in the absence or presence of two sterol analogs previously reported as inhibitors of ?24(25) sterol methyltransferase (24(25)-SMT, E.C.2.1.1.43) in yeast and fungi, a cholestanol analog with a 6-membered aza ring as side chain (22,26-azasterol) and 24-(R,S),25-epiminolanosterol, as well as combinations of these compounds with the

Julio A. Urbina; Julio Vivas; Gonzalo Visbal; Lellys M. Contreras

1995-01-01

338

Impact of botanical pesticides derived from Melia azedarach and Azadirachta indica plants on the emission of volatiles that attract Parasitoids of the diamondback moth to cabbage plants.  

PubMed

Herbivorous and carnivorous arthropods use chemical information from plants during foraging. Aqueous leaf extracts from the syringa tree Melia azedarach and commercial formulations from the neem tree Azadirachta indica, Neemix 4.5, were investigated for their impact on the flight response of two parasitoids, Cotesia plutellae and Diadromus collaris. Cotesia plutellae was attracted only to Plutella xylostella-infested cabbage plants in a wind tunnel after an oviposition experience. Female C. plutellae did not distinguish between P. xylostella-infested cabbage plants treated with neem and control P. xylostella-infested plants. However, females preferred infested cabbage plants that had been treated with syringa extract to control infested plants. Syringa extract on filter paper did not attract C. plutellae. This suggests that an interaction between the plant and the syringa extract enhances parasitoid attraction. Diadromus collaris was not attracted to cabbage plants in a wind tunnel and did not distinguish between caterpillar-damaged and undamaged cabbage plants. Headspace analysis revealed 49 compounds in both control cabbage plants and cabbage plants that had been treated with the syringa extract. Among these are alcohols, aldehydes, ketones, esters, terpenoids, sulfides, and an isothiocyanate. Cabbage plants that had been treated with the syringa extract emitted larger quantities of volatiles, and these increased quantities were not derived from the syringa extract. Therefore, the syringa extract seemed to induce the emission of cabbage volatiles. To our knowledge, this is the first example of a plant extract inducing the emission of plant volatiles in another plant. This interesting phenomenon likely explains the preference of C. plutellae parasitoids for cabbage plants that have been treated with syringa extracts. PMID:16555134

Charleston, Deidre S; Gols, Rieta; Hordijk, Kees A; Kfir, Rami; Vet, Louise E M; Dicke, Marcel

2006-03-23

339

Inorganic Nitrogen Derived from Foraging Honey Bees Could Have Adaptive Benefits for the Plants They Visit  

PubMed Central

In most terrestrial ecosystems, nitrogen (N) is the most limiting nutrient for plant growth. Honey bees may help alleviate this limitation because their feces (frass) have high concentration of organic nitrogen that may decompose in soil and provide inorganic N to plants. However, information on soil N processes associated with bee frass is not available. The objectives of this work were to 1) estimate the amount of bee frass produced by a honey bee colony and 2) evaluate nitrogen mineralization and ammonia volatilization from bee frass when surface applied or incorporated into soil. Two cage studies were conducted to estimate the amount of frass produced by a 5000-bee colony, and three laboratory studies were carried out in which bee frass, surface-applied or incorporated into soil, was incubated at 25oC for 15 to 45 days. The average rate of bee frass production by a 5,000-bee colony was estimated at 2.27 to 2.69 g N month?1. Nitrogen mineralization from bee frass during 30 days released 20% of the organic N when bee frass was surface applied and 34% when frass was incorporated into the soil. Volatilized NH3 corresponded to 1% or less of total N. The potential amount of inorganic N released to the soil by a typical colony of 20,000 bees foraging in an area similar to that of the experimental cages (3.24 m2) was estimated at 0.62 to 0.74 g N m?2 month?1 which may be significant at a community scale in terms of soil microbial activity and plant growth. Thus, the deposition of available N by foraging bees could have adaptive benefits for the plants they visit, a collateral benefit deriving from the primary activity of pollination.

Mishra, Archana; Afik, Ohad; Cabrera, Miguel L.; Delaplane, Keith S.; Mowrer, Jason E.

2013-01-01

340

Inorganic nitrogen derived from foraging honey bees could have adaptive benefits for the plants they visit.  

PubMed

In most terrestrial ecosystems, nitrogen (N) is the most limiting nutrient for plant growth. Honey bees may help alleviate this limitation because their feces (frass) have high concentration of organic nitrogen that may decompose in soil and provide inorganic N to plants. However, information on soil N processes associated with bee frass is not available. The objectives of this work were to 1) estimate the amount of bee frass produced by a honey bee colony and 2) evaluate nitrogen mineralization and ammonia volatilization from bee frass when surface applied or incorporated into soil. Two cage studies were conducted to estimate the amount of frass produced by a 5000-bee colony, and three laboratory studies were carried out in which bee frass, surface-applied or incorporated into soil, was incubated at 25(o)C for 15 to 45 days. The average rate of bee frass production by a 5,000-bee colony was estimated at 2.27 to 2.69 g N month(-1). Nitrogen mineralization from bee frass during 30 days released 20% of the organic N when bee frass was surface applied and 34% when frass was incorporated into the soil. Volatilized NH3 corresponded to 1% or less of total N. The potential amount of inorganic N released to the soil by a typical colony of 20,000 bees foraging in an area similar to that of the experimental cages (3.24 m(2)) was estimated at 0.62 to 0.74 g N m(-2) month(-1) which may be significant at a community scale in terms of soil microbial activity and plant growth. Thus, the deposition of available N by foraging bees could have adaptive benefits for the plants they visit, a collateral benefit deriving from the primary activity of pollination. PMID:23923006

Mishra, Archana; Afik, Ohad; Cabrera, Miguel L; Delaplane, Keith S; Mowrer, Jason E

2013-07-29

341

Persistence of Sterols other than Cholesterol in Chicken Tissues  

Microsoft Academic Search

RECENT work by Davison and his collaborators1-3 has shown that cholesterol may be incorporated in the nervous tissues of myelinating chickens and rabbits and that this cholesterol will persist in these tissues for considerable lengths of time. Our interests in the metabolism of cholesterol and other sterols prompted us to compare the distributions in chicken tissues of injected sitosterol and

David Kritchevsky; Vittorio Defendi

1961-01-01

342

The Interaction of Dipole Modifiers with Polyene-Sterol Complexes  

PubMed Central

Recently, we showed that the effect of dipole modifiers (flavonoids and styrylpyridinium dyes) on the conductance of single amphotericin B (AmB) channels in sterol-containing lipid bilayers primarily resulted from changes in the membrane dipole potential. The present study examines the effect of dipole modifiers on the AmB multi-channel activity. The addition of phloretin to cholesterol-containing membranes leads to a significant increase in the steady-state AmB-induced transmembrane current. Quercetin significantly decreases and RH 421 increases the current through ergosterol-containing bilayers. Other tested flavonoids and styrylpyridinium dyes do not affect the channel-forming activity of AmB independently on the sterol composition of the bilayers. The effects obtained in these trials may instead be attributed to the direct interaction of dipole modifiers with AmB/sterol complexes and not to the effect of dipole potential changes. The presence of double bonds in the ?7 and ?22 positions of sterol molecules, the number of conjugated double bonds and amino sugar residues in polyene molecules, and the conformation and adsorption plane of dipole modifiers are important factors impacting this interaction.

Ostroumova, Olga S.; Efimova, Svetlana S.; Chulkov, Evgeny G.; Schagina, Ludmila V.

2012-01-01

343

The interaction of dipole modifiers with polyene-sterol complexes.  

PubMed

Recently, we showed that the effect of dipole modifiers (flavonoids and styrylpyridinium dyes) on the conductance of single amphotericin B (AmB) channels in sterol-containing lipid bilayers primarily resulted from changes in the membrane dipole potential. The present study examines the effect of dipole modifiers on the AmB multi-channel activity. The addition of phloretin to cholesterol-containing membranes leads to a significant increase in the steady-state AmB-induced transmembrane current. Quercetin significantly decreases and RH 421 increases the current through ergosterol-containing bilayers. Other tested flavonoids and styrylpyridinium dyes do not affect the channel-forming activity of AmB independently on the sterol composition of the bilayers. The effects obtained in these trials may instead be attributed to the direct interaction of dipole modifiers with AmB/sterol complexes and not to the effect of dipole potential changes. The presence of double bonds in the ?7 and ?22 positions of sterol molecules, the number of conjugated double bonds and amino sugar residues in polyene molecules, and the conformation and adsorption plane of dipole modifiers are important factors impacting this interaction. PMID:23028805

Ostroumova, Olga S; Efimova, Svetlana S; Chulkov, Evgeny G; Schagina, Ludmila V

2012-09-21

344

The use of stable and radioactive sterol tracers as a tool to investigate cholesterol degradation to bile acids in humans in vivo.  

PubMed

Alterations of cholesterol homeostasis represent important risk factors for atherosclerosis and cardiovascular disease. Different clinical-experimental approaches have been devised to study the metabolism of cholesterol and particularly the synthesis of bile acids, its main catabolic products. Most evidence in humans has derived from studies utilizing the administration of labeled sterols; these have several advantages over in vitro assay of enzyme activity and expression, requiring an invasive procedure such as a liver biopsy, or the determination of fecal sterols, which is cumbersome and not commonly available. Pioneering evidence with administration of radioactive sterol derivatives has allowed to characterize the alterations of cholesterol metabolism and degradation in different situations, including spontaneous disease conditions, aging, and drug treatment. Along with the classical isotope dilution methodology, other approaches were proposed, among which isotope release following radioactive substrate administration. More recently, stable isotope studies have allowed to overcome radioactivity exposure. Isotope enrichment studies during tracer infusion has allowed to characterize changes in the degradation of cholesterol via the "classical" and the "alternative" pathways of bile acid synthesis. Evidence brought by tracer studies in vivo, summarized here, provides an exceptional tool for the investigation of sterol metabolism, and integrate the studies in vitro on human tissue. PMID:22343367

Bertolotti, Marco; Crosignani, Andrea; Del Puppo, Marina

2012-02-16

345

Model-derived dose rates per unit concentration of radon in air in a generic plant geometry.  

PubMed

A model for the derivation of dose rates per unit radon concentration in plants was developed in line with the activities of a Task Group of the International Commission on Radiological Protection (ICRP), aimed at developing more realistic dosimetry for non-human biota. The model considers interception of the unattached and attached fractions of the airborne radon daughters by plant stomata, diffusion of radon gas through stomata, permeation through the plant's epidermis and translocation of deposited activity to plant interior. The endpoint of the model is the derivation of dose conversion coefficients relative to radon gas concentration at ground level. The model predicts that the main contributor to dose is deposition of (214)Po ?-activity on the plant surface and that diffusion of radon daughters through the stomata is of relatively minor importance; hence, daily variations have a small effect on total dose. PMID:21739195

Vives i Batlle, J; Smith, A; Vives-Lynch, S; Copplestone, D; Pröhl, G; Strand, T

2011-07-08

346

Depletion of phytosterols from the plant plasma membrane provides evidence for disruption of lipid rafts  

Microsoft Academic Search

Involvement of sterols in membrane structural properties has been extensively studied in model systems but rarely assessed in natural mem- branes and never investigated for the plant plasma membrane (PM). Here, we address the question of the role of phytosterols in the organization of the plant PM. The sterol composition of tobacco BY-2 cell PM was determined by gas chromatography.

Yann Roche; Patricia Gerbeau-Pissot; Blandine Buhot; Dominique Thomas; Laurent Bonneau; Joseph Gresti; Sebastien Mongrand; Jean-Marie Perrier-Cornet; Francoise Simon-Plas

2008-01-01

347

Structure of Dehydroergosterol Monohydrate and Interaction with Sterol Carrier Protein-2  

PubMed Central

Dehydroergosterol [ergosta-5,7,9(11),22-tetraen-3?-ol] is a naturally-occurring, fluorescent sterol utilized extensively to probe membrane cholesterol distribution, cholesterol-protein interactions, and intracellular cholesterol transport both in vitro and in vivo. In aqueous solutions, the low solubility of dehydroergosterol results in the formation of monohydrate crystals similar to cholesterol. Low temperature x-ray diffraction analysis reveals that dehydroergosterol monohydrate crystallizes in the space group P21 with 4 molecules in the unit cell and monoclinic crystal parameters a = 9.975(1)Ĺ, b = 7.4731(9)Ĺ, c = 34.054(4)Ĺ, and ? = 92.970(2)° somewhat similar to ergosterol monohydrate. The molecular arrangement is in a slightly closer packed bilayer structure resembling cholesterol monohydrate. Since dehydroergosterol fluorescence emission undergoes a quantum yield enhancement and red-shift of its maximum wavelength when crystallized, formation or disruption of microcrystals was monitored with high sensitivity using cuvette-based spectroscopy and multi-photon laser scanning imaging microscopy (MPLSM). This manuscript reports on the dynamical effect of sterol carrier protein-2 (SCP-2) interacting between aqueous dispersions of dehydroergosterol monohydrate microcrystal donors and acceptors consisting not only of model membranes but also vesicles derived from plasma membranes isolated by biochemical fractionation and affinity purification from Madin-Darby canine kidney cells. Furthermore, this study provides real-time measurements of the effect of increased SCP-2 levels on the rate of disappearance of dehydroergosterol microcrystals in living cells.

McIntosh, Avery L.; Atshaves, Barbara P.; Gallegos, Adalberto M.; Storey, Stephen M.; Reibenspies, Joseph H.; Kier, Ann B.; Meyer, Edgar; Schroeder, Friedhelm

2008-01-01

348

Sterol composition of Cryptococcus neoformans in the presence and absence of fluconazole.  

PubMed Central

Analysis of the sterol compositions of 13 clinical isolates of the pathogenic yeast Cryptococcus neoformans obtained from five patients with recurring cryptococcal meningitis showed that, unlike Candida albicans, the major sterols synthesized by this yeast were obtusifoliol (range, 21.1 to 68.2%) and ergosterol (range, 0.0 to 46.5%). There was considerable variation in the sterol contents among the 13 isolates, with total sterol contents ranging from 0.31 to 5.9% of dry weight. The isolates from the five patients who had relapses had different total sterol contents and compositions in comparison with those of the pretreatment isolates, indicating either that the sterols had been changed by therapy or that the patients were infected with new isolates with different sterol compositions. Growth of the cryptococcal isolates in the presence of subinhibitory concentrations of fluconazole (0.25x the MIC) significantly altered the sterol content and pattern. The total sterol content decreased in nine isolates and increased in four isolates in response to pretreatment with fluconazole. Fluconazole had no consistent effect on ergosterol levels. In contrast, fluconazole caused a decrease in obtusifoliol levels and an increase in 4,14-dimethylzymosterol levels in all isolates. These results indicate extensive diversity in sterol content, sterol composition, and sterol synthesis in response to subinhibitory concentrations of fluconazole in C. neoformans strains. We propose that fluconazole inhibits the sterol synthesis of C. neoformans by interfering with both 14 alpha-demethylase-dependent and -independent pathways. No correlation between the sterol compositions of C. neoformans isolates and their susceptibilities to fluconazole was found.

Ghannoum, M A; Spellberg, B J; Ibrahim, A S; Ritchie, J A; Currie, B; Spitzer, E D; Edwards, J E; Casadevall, A

1994-01-01

349

Plant-derived extracts in the neuroscience of anxiety on animal models: biases and comments.  

PubMed

Generalized anxiety disorders probably represent one of the world's biggest mental health problems. A large number of studies have also shown that anxiety disorders and depression are often associated with quality of life impairments. As anxiety represents a big concern in public health, a substantial literature supports clinically important associations between psychiatric illness and chronic medical conditions. Actually, most research focuses on depression, finding that depression can adversely affect self-care and increase the risk of incident medical illness, complications, and mortality. Anxiety disorders are less well studied, but robust epidemiological and clinical evidences show that they play an equally important role. Recent reported articles have raised a debate about the effectiveness of some plant-derived extracts in anxiety-like models in mice. Biases about several aspects related with experimental setting, animal selection, environments, operators and investigators, selection and performance of behavioral tests, controls, results managing, and statistics are here discussed. PMID:22050267

Chirumbolo, Salvatore

2011-12-01

350

Inhibitory effects of various oxygenated sterols on the differentiation and function of tumor-specific cytotoxic T lymphocytes  

SciTech Connect

Irradiation of skin with ultraviolet light (UVL) is capable of causing many biological and biochemical changes in this complex organ. One early consequence is the oxidation of epidermal plasma membrane cholesterol, causing the induction of a wide variety of photoproducts. It is well recognized that some oxygenated sterols possess potent biological activity on mammalian cells by their ability to inhibit endogeneous mevalonate and cholesterol biosynthesis. In the few immunological systems that have been studied, there is general agreement that lymphocyte function is altered in the presence of certain oxygenated sterols. Insight into the biochemical basis for altered lymphocyte function is lacking, as both afferent and efferent blockades have been suggested. These studies were undertaken to determine the effect of various oxygenated sterols (representing a number of known cholesterol-derived photoproducts) on the generation (afferent) and function (efferent) of cytotoxic T lymphocytes (CTLs). Cell-mediated immune responses which result in the generation of both alloantigen-specific and syngeneic tumor-specific CTLs were evaluated. (JMT)

Spangrude, G.J.; Sherris, D.; Daynes, R.A.

1982-05-01

351

Targeted Depletion of Hepatic ACAT2-driven Cholesterol Esterification Reveals a Non-biliary Route for Fecal Neutral Sterol Loss*  

PubMed Central

Deletion of acyl-CoA:cholesterol O-acyltransferase 2 (ACAT2) in mice results in resistance to diet-induced hypercholesterolemia and protection against atherosclerosis. Recently, our group has shown that liver-specific inhibition of ACAT2 via antisense oligonucleotide (ASO)-mediated targeting likewise limits atherosclerosis. However, whether this atheroprotective effect was mediated by: 1) prevention of packaging of cholesterol into apoB-containing lipoproteins, 2) augmentation of nascent HDL cholesterol secretion, or 3) increased hepatobiliary sterol secretion was not examined. Therefore, the purpose of these studies was to determine whether hepatic ACAT2 is rate-limiting in all three of these important routes of cholesterol homeostasis. Liver-specific depletion of ACAT2 resulted in reduced packaging of cholesterol into apoB-containing lipoproteins (very low density lipoprotein, intermediate density lipoprotein, and low density lipoprotein), whereas high density lipoprotein cholesterol levels remained unchanged. In the liver of ACAT2 ASO-treated mice, cholesterol ester accumulation was dramatically reduced, yet there was no reciprocal accumulation of unesterified cholesterol. Paradoxically, ASO-mediated depletion of hepatic ACAT2 promoted fecal neutral sterol excretion without altering biliary sterol secretion. Interestingly, during isolated liver perfusion, ACAT2 ASO-treated livers had augmented secretion rates of unesterified cholesterol and phospholipid. Furthermore, we demonstrate that liver-derived cholesterol from ACAT2 ASO-treated mice is preferentially delivered to the proximal small intestine as a precursor to fecal excretion. Collectively, these studies provide the first insight into the hepatic itinerary of cholesterol when cholesterol esterification is inhibited only in the liver, and provide evidence for a novel non-biliary route of fecal sterol loss.

Brown, J. Mark; Bell, Thomas A.; Alger, Heather M.; Sawyer, Janet K.; Smith, Thomas L.; Kelley, Kathryn; Shah, Ramesh; Wilson, Martha D.; Davis, Matthew A.; Lee, Richard G.; Graham, Mark J.; Crooke, Rosanne M.; Rudel, Lawrence L.

2008-01-01

352

Effects of plant-derived phenols on rat liver cytochrome P450 2B1 activity.  

PubMed

Dietary constituents contain a variety of compounds that are known to modulate liver enzyme activity. In this report, the plant-derived phenols catechin, chlorogenic acid, diosmin, epigallo-catechin gallate (EGCG), naringenin, quercetin and resveratrol were studied for their effects on the activity of cytochrome P450 2B1 in liver microsomes from 6- and 20-month male Fisher F344 rats. The compounds at two concentrations (0.1 and 0.25 mM) were incubated with 0.2 mg liver microsomal protein and 50 microM 7-ethoxy-4-trifluoromethyl coumarin (EFC). O-deethylation of EFC to the fluorescence product 7-hydroxy-4-trifluoromethyl coumarin (HFC) is catalyzed by CYP450 2B1. EGCG, naringenin, quercetin and resveratrol inhibited the in vitro O-deethylation of EFC in liver microsomes from both 6- and 20-month rats. Quercetin was the most effective inhibitor. Catechin inhibited the in vitro O-deethylation of EFC only in microsomes from 6-month-old rats whereas diosmin inhibited the reaction only in microsomes from 20-month-old rats. Chlorogenic acid inhibited the in vitro O-deethylation of EFC in microsomes from both age groups at the 0.25 mM concentration only. These results suggest that plant phenols have varied effects on liver microsomal cytochrome P450 2B1 activity that may be influenced by the age of the animal. PMID:12168856

Huynh, H T; Teel, R W

353

Central African biomes and forest succession stages derived from modern pollen data and plant functional types  

NASA Astrophysics Data System (ADS)

New detailed vegetation reconstructions are proposed in Atlantic Central Africa from a modern pollen data set derived from 199 sites (Cameroon, Gabon and Congo) including 131 new sites. In this study, the concept of plant functional classification is improved with new and more detailed plant functional types (PFTs) and new aggregations of pollen taxa. Using the biomisation method, we reconstructed (1) modern potential biomes and (2) potential succession stages of forest regeneration, a new approach in Atlantic Central African vegetation dynamics and ecosystem functioning reconstruction. When compared to local vegetation, potential biomes are correctly reconstructed (97.5% of the sites) and tropical rain forest (TRFO biome) is well identified from tropical seasonal forest (TSFO biome). When the potential biomes are superimposed on the White's vegetation map, only 76.4% of the sites are correctly reconstructed. But using botanical data, correspondence and cluster analyses, the 43 sites from Congo (Mayombe) evidence more affinities with those of central Gabon and so they can also be considered as correctly reconstructed as TRFO biome and White's map should be revised. In terms of potential succession stages of forest regeneration, the mature forest (TMFO) is well differentiated from the secondary forest (TSFE), but inside this latter group, the young and the pioneer stages are not clearly identified due probably to their low sampling representation. Moreover, linked to their progressive and mosaic character, the boundaries between two forest biomes or two forest stages are not clearly detected and need also a more intensive sampling in such transitions.

Lebamba, J.; Ngomanda, A.; Vincens, A.; Jolly, D.; Favier, C.; Elenga, H.; Bentaleb, I.

2009-07-01

354

Plant-Derived Foods For The Attenuation Of Allergic Airway Inflammation.  

PubMed

Asthma is an allergy-mediated inflammatory disease characterised by infiltration of the airway with mast cells, lymphocytes, and eosinophils. The disease is induced by co-ordination of T-helper cell type 2 (Th2) cytokines and inflammatory signal molecules. Fruits and vegetables are a rich source of polyphenolic bioactive compounds, which have been observed to have health-promoting properties when consumed by humans. In particular, fruit-derived proanthocyanins and anthocyanins have been found to attenuate lung inflammation. Epidemiological studies have revealed correlations between fruit consumption and a lower prevalence of respiratory symptoms and lower incidence of non-specific lung diseases. In this review we summarise the current understanding of the pathophysiologic mechanism(s) involved in the development of allergic airway disease. We also review evidence of the beneficial effects of plant-derived foods, their components and metabolites in allergic airway inflammation arising from in vitro and rodent studies, epidemiological studies and human intervention trials. The mechanism, biological relevance and functional benefits, such as immune modulation (e.g. reduction in cytokine and eotaxin production), antioxidant ability, tissue remodelling and tight junction function are also discussed. PMID:23701570

Nyanhanda, Tafadzwa; Gould, Elaine M; Hurst, Roger D

2013-05-17

355

Molecular characterization of geminivirus-derived small RNAs in different plant species  

PubMed Central

DNA geminiviruses are thought to be targets of RNA silencing. Here, we characterize small interfering (si) RNAs—the hallmarks of silencing—associated with Cabbage leaf curl begomovirus in Arabidopsis and African cassava mosaic begomovirus in Nicotiana benthamiana and cassava. We detected 21, 22 and 24 nt siRNAs of both polarities, derived from both the coding and the intergenic regions of these geminiviruses. Genetic evidence showed that all the 24 nt and a substantial fraction of the 22 nt viral siRNAs are generated by the dicer-like proteins DCL3 and DCL2, respectively. The viral siRNAs were 5? end phosphorylated, as shown by phosphatase treatments, and methylated at the 3?-nucleotide, as shown by HEN1 miRNA methylase-dependent resistance to ?-elimination. Similar modifications were found in all types of endogenous and transgene-derived siRNAs tested, but not in a major fraction of siRNAs from a cytoplasmic RNA tobamovirus. We conclude that several distinct silencing pathways are involved in DNA virus-plant interactions.

Akbergenov, Rashid; Si-Ammour, Azeddine; Blevins, Todd; Amin, Imran; Kutter, Claudia; Vanderschuren, Herve; Zhang, Peng; Gruissem, Wilhelm; Meins, Frederick; Hohn, Thomas; Pooggin, Mikhail M.

2006-01-01

356

Model chlorination of plant derived phenolic water contaminants with an assessment of their potential toxicity to Escherichia coli  

SciTech Connect

As a safety measure drinking water is often chemically chlorinated to prevent water-transmittable epidemic diseases. However, great concern about routine water chlorination has been expressed, due to the possible chlorination of unwanted aliphatic and aromatic water contaminants. During the annual litter decay a number of phenolic compounds are released into the environment. Previous studies on water courses have shown that five phenolic acids derived from plants predominate. After water chlorination these compounds are likely to become chlorinated with the production of stable organochlorine derivatives. The objective of the present study was to assess the effects of chlorination on seven plant-derived phenolic compounds. The substitution pattern of the parent (non-chlorinated) compounds was correlated to the number of produced chlorophenolic derivatives (structure versus chemical reactivity). The formed chlorophenolic mixtures were applied to Escherichia coli DSM 613 to examine their potential toxic effects. Escherichia coli DSM 613 was used as an indicator of toxicity for environmental pollution.

Borlakoglu, J.T.; Kickuth, R.

1987-09-01

357

Novel synthetic 2,6-dichloroisonicotinate derivatives as effective elicitors for inducing the biosynthesis of plant secondary metabolites  

Microsoft Academic Search

Two novel 2,6-dichloroisonicotinic acid (INA) derivatives [trifluoroethyl 2,6-dichloroisonicotinate (TFINA) and 2-(2,6-dichloro-pyridine-4-carbonyloxy)-ethyl jasmonate (DPCEJ)] were chemically synthesized and evaluated by bioassay as potential elicitors for inducing the biosynthesis of plant secondary metabolites. A suspension culture of Taxus chinensis, which stably produces a high level of bioactive taxuyunnanine C (Tc), was taken as a model plant cell system. A significant increase in

Zhi-Gang Qian; Zhen-Jiang Zhao; Yufang Xu; Xuhong Qian; Jian-Jiang Zhong

2006-01-01

358

The mechanism of radical-trapping antioxidant activity of plant-derived thiosulfinates.  

PubMed

It has long been recognized that garlic and petiveria, two plants of the Allium genus--which also includes onions, leeks and shallots--possess great medicinal value. In recent times, the biological activities of extracts of these plants have been ascribed to the antioxidant properties of the thiosulfinate secondary metabolites allicin and S-benzyl phenylmethanethiosulfinate (BPT), respectively. Herein we describe our efforts to probe the mechanism of the radical-trapping antioxidant activity of these compounds, as well as S-propyl propanethiosulfinate (PPT), a saturated analog representative of the thiosulfinates that predominate in non-medicinal alliums. Our experimental results, which include thiosulfinate-inhibited autoxidations of the polyunsaturated fatty acid (ester) methyl linoleate, investigations of their decomposition kinetics, and radical clock experiments aimed at obtaining some quantitative insights into their reactions with peroxyl radicals, indicate that the radical-trapping activity of thiosulfinates is paralleled by their propensity to undergo Cope elimination to yield a sulfenic acid. Since sulfenic acids are transient species, we complement our experimental studies with the results of theoretical calculations aimed at understanding the radical-trapping behaviour of the sulfenic acids derived from allicin, BPT and PPT, and contrasting the predicted thermodynamics and kinetics of their reactions with those of the parent thiosulfinates. The calculations reveal that sulfenic acids have among the weakest O-H bonds known (ca. 70 kcal mol(-1)), and that their reactions with peroxyl radicals take place by a near diffusion-controlled proton-coupled electron transfer mechanism. As such, it is proposed that the abundance of a thiosulfinate in a given plant species, and the ease with which it undergoes Cope elimination to form a sulfenic acid, accounts for the differences in antioxidant activity, and perhaps medicinal value, of extracts of these plants. Interestingly, while the Cope elimination of 2-propenesulfenic acid from allicin is essentially irreversible, the analogous reaction of BPT is readily reversible. Thus, in the absence of chain-carrying peroxyl radicals (or other appropriately reactive trapping agent), BPT is reformed. PMID:21445384

Lynett, Philip T; Butts, Krista; Vaidya, Vipraja; Garrett, Graham E; Pratt, Derek A

2011-03-28

359

Fragility of plasma membranes in Saccharomyces cerevisiae enriched with different sterols.  

PubMed Central

Saccharomyces cerevisiae NCYC 366, grown under strictly anaerobic conditions to induce requirements for an unsaturated fatty acid (supplied by Tween 80) and a sterol, contained free sterol fractions enriched to the extent of 67 to 93% with the exogenously supplied sterol (campesterol, cholesterol, 7-dehydrocholesterol, 22, 23-dihydrobrassicasterol, beta-sitosterol, or stigmasterol). Cells enriched in any one of the sterols did not differ in volume, growth rate, contents of free sterol, esters and phospholipids, or phospholipid composition. Cholesterol-enriched cells contained about 2% more lipid than cells enriched in any of the other sterols, which was largely accounted for by increased contents of triacylglycerols and, to a lesser extent, esterified sterols. Phospholipids were enriched to the extent of about 52 to 63% with C18:1 residues. Cells enriched in ergosterol or stigmasterol were slightly less susceptible to the action of a wall-digesting basidiomycete glucanase than cells enriched with any one of the other sterols. The capacity of the plasma membrane to resist stretching, as indicated by the stability and volume of spheroplasts suspended in hypotonic solutions of buffered sorbitol (particularly in the range 0.9 to 0.7 M), was greater with spheroplasts enriched in sterols with an unsaturated side chain at C17 (ergosterol or stigmasterol) than with any of the other sterols. Plasma membranes were obtained from spheroplasts enriched in cholesterol or stigmasterol and had free sterol fractions containing 70 and 71%, respectively, of the sterol supplied exogenously to the cells. The sterol-phospholipid molar ratios in these membranes were, respectively, 1:7 and 1:8.

Hossack, J A; Rose, A H

1976-01-01

360

Differential effects of fenpropimorph and fenhexamid, two sterol biosynthesis inhibitor fungicides, on arbuscular mycorrhizal development and sterol metabolism in carrot roots.  

PubMed

Sterols composition of transformed carrot roots incubated in presence of increasing concentrations of fenpropimorph (0.02; 0.2; 2mgl(-1)) and fenhexamid (0.02; 0.2; 2; 20mgl(-1)), colonized or not by Glomus intraradices was determined. In mycorrhizal roots treated with fenpropimorph, normal Delta(5)-sterols were replaced by unusual compounds such as 9beta,19-cyclopropylsterols (24-methylpollinastanol), Delta(8,14)-sterols (ergosta-8,14-dienol, stigmasta-8,14-dienol), Delta(8)-sterols (Delta(8) sitosterol) and Delta(7)-sterols (ergosta-7,22-dienol). After application of fenpropimorph, a drastic reduction of the mycorrhizal root growth, root colonization and extraradical fungal development was observed. Application of fenhexamid did not modify sterol profiles and the total colonization of roots. But the arbuscule frequency of the fungal partner was significantly affected. Comparison of the effects caused by the tested fungicides indicates that the usual phytosterols may be involved in symbiosis development. Indeed, observed modifications of root sterols composition could explain the high fenpropimorph toxicity to the AM symbiosis. However, the absence of sterolic modifications in the roots treated with fenhexamid could account for its more limited impact on mycorrhization. PMID:19007946

Campagnac, Estelle; Fontaine, Joël; Sahraoui, Anissa Lounčs-Hadj; Laruelle, Frédéric; Durand, Roger; Grandmougin-Ferjani, Anne

2008-11-12

361

Structural complex of sterol 14[alpha]-demethylase (CYP51) with 14[alpha]-methylenecyclopropyl-[delta]7-24, 25-dihydrolanosterol[S  

SciTech Connect

Sterol 14{alpha}-demethylase (CYP51) that catalyzes the removal of the 14{alpha}-methyl group from the sterol nucleus is an essential enzyme in sterol biosynthesis, a primary target for clinical and agricultural antifungal azoles and an emerging target for antitrypanosomal chemotherapy. Here, we present the crystal structure of Trypanosoma (T) brucei CYP51 in complex with the substrate analog 14{alpha}-methylenecyclopropyl-{Delta}7-24,25-dihydrolanosterol (MCP). This sterol binds tightly to all protozoan CYP51s and acts as a competitive inhibitor of F105-containing (plant-like) T. brucei and Leishmania (L) infantum orthologs, but it has a much stronger, mechanism-based inhibitory effect on I105-containing (animal/fungi-like) T. cruzi CYP51. Depicting substrate orientation in the conserved CYP51 binding cavity, the complex specifies the roles of the contact amino acid residues and sheds new light on CYP51 substrate specificity. It also provides an explanation for the effect of MCP on T. cruzi CYP51. Comparison with the ligand-free and azole-bound structures supports the notion of structural rigidity as the characteristic feature of the CYP51 substrate binding cavity, confirming the enzyme as an excellent candidate for structure-directed design of new drugs, including mechanism-based substrate analog inhibitors.

Hargrove, Tatiana Y.; Wawrzak, Zdzislaw; Liu, Jialin; Waterman, Michael R.; Nes, W. David; Lepesheva, Galina I. (Vanderbilt); (TTU); (NWU)

2012-06-28

362

Expression of a fungal sterol desaturase improves tomato drought tolerance, pathogen resistance and nutritional quality  

PubMed Central

Crop genetic engineering mostly aims at improving environmental stress (biotic and abiotic) tolerance as well as nutritional quality. Empowering a single crop with multiple traits is highly demanding and requires manipulation of more than one gene. However, we report improved drought tolerance and fungal resistance along with the increased iron and polyunsaturated fatty acid content in tomato by expressing a single gene encoding C-5 sterol desaturase (FvC5SD) from an edible fungus Flammulina velutipes. FvC5SD is an iron binding protein involved in ergosterol biosynthesis. Morphological and biochemical analyses indicated ?23% more epicuticular wax deposition in leaves of transgenic plants that provides an effective waterproof barrier resulting in improved protection from drought and infection by phytopathogenic fungus Sclerotinia sclerotiorum. Furthermore, the transgenic fruits have improved nutritional value attributed to enhanced level of beneficial PUFA and 2-3 fold increase in total iron content. This strategy can be extended to other economically important crops.

Kamthan, Ayushi; Kamthan, Mohan; Azam, Mohammad; Chakraborty, Niranjan; Chakraborty, Subhra; Datta, Asis

2012-01-01

363

Homology modeling, molecular docking and spectra assay studies of sterol 14?-demethylase from Penicillium digitatum.  

PubMed

Sterol 14?-demethylase from Penicillium digitatum (PdCYP51) is a prime target of antifungal drugs for citrus disease in plants. To design novel antifungal compounds, a homology model of PdCYP51 was constructed using the recently reported crystal structure of human CYP51 as the template. Molecular docking was performed to investigate the interaction of four commercial fungicides with the modeled enzyme. The side chain of these compounds interplayed with PdCYP51 mainly through hydrophobic and van der Waals interactions. Biochemical spectra analysis of inhibitors combined with PdCYP51 are also compatible with the docking results. This is the first molecular modeling for PdCYP51 based on the eukaryotic crystal structure of CYP51. The structural information and binding site mapping of PdCYP51 for different inhibitors obtained from this study could aid in screening and designing new antifungal compounds targeting this enzyme. PMID:21660575

Li, Shuxiang; Zhang, Jianhua; Cao, Shufen; Han, Rui; Yuan, Yongze; Yang, Jiangke; Yan, Yunjun; Liu, Deli

2011-06-10

364

A promoter derived from taro bacilliform badnavirus drives strong expression in transgenic banana and tobacco plants.  

PubMed

Taro bacilliform virus (TaBV) is a pararetrovirus of the genus Badnavirus which infects the monocotyledonous plant, taro ( Colocasia esculenta). A region of the TaBV genome spanning nucleotides 6,281 to 12 (T1200), including the 3' end of open reading frame 3 (ORF 3) and the intergenic region to the end of the tRNA(met)-binding site, was tested for promoter activity along with four different 5' deletion fragments (T600, T500, T250 and T100). In transient assays, only the T1200, T600, T500 fragments were shown to have promoter activity in taro leaf, banana suspension cells and tobacco callus. When these three promoters were evaluated in stably transformed, in vitro-grown transgenic banana and tobacco plants, all were found to drive near-constitutive expression of either the green fluorescent protein or beta-glucuronidase (GUS) reporter gene in the stem (or pseudostem), leaves and roots, with strongest expression observed in the vascular tissue. In transgenic banana leaves, the T600 promoter directed four-fold greater GUS activity than that of the T1200, T500 and the maize polyubiquitin-1 promoters. In transgenic tobacco leaves, the levels of GUS expression directed by the three promoters was between four- and ten-fold lower than that of the double Cauliflower mosaic virus 35S promoter. These results indicate that the TaBV-derived promoters may be useful for the high-level constitutive expression of transgenes in either monocotyledonous or dicotyledonous species. PMID:12910370

Yang, I C; Iommarini, J P; Becker, D K; Hafner, G J; Dale, J L; Harding, R M

2003-05-15

365

Quantification of bisphenol A, 353-nonylphenol and their chlorinated derivatives in drinking water treatment plants.  

PubMed

Bisphenol A (BPA) and nonylphenols (NP) are of major concern to public health due to their high potential for human exposure and to their demonstrated toxicity (endocrine disruptor effect). A limited number of studies have shown that BPA and NP are present in drinking water. The chlorinated derivatives that may be formed during the chlorination step in drinking water treatment plants (DWTP) exhibit a higher level of estrogenic activity than their parent compounds. The aim of this study was to investigate BPA, 353NP, and their chlorinated derivative concentrations using an accurate and reproducible method of quantification. This method was applied to both surface and treated water samples from eight French DWTPs producing from surface water. Solid-phase extraction followed by liquid chromatography-tandem mass spectrometry was developed in order to quantify target compounds from water samples. The limits of detection ranged from 0.3 to 2.3 ng/L for BPA and chlorinated BPA and from 1.4 to 63.0 ng/L for 353NP and chlorinated 353NP. BPA and 353NP were found in most analyzed water samples, at a level ranging from 2.0 to 29.7 ng/L and from 0 to 124.9 ng/L, respectively. In most of DWTPs a decrease of BPA and 353NP was observed between surface water and treated water (36.6 to 78.9 % and 2.2 to 100.0 % for BPA and 353NP, respectively). Neither chlorinated BPA nor chlorinated 353NP was detected. Even though BPA and 353NP have been largely removed in the DWTPs studied, they have not been completely eliminated, and drinking water may consequently remain a source of human exposure. PMID:22648348

Dupuis, Antoine; Migeot, Virginie; Cariot, Axelle; Albouy-Llaty, Marion; Legube, Bernard; Rabouan, Sylvie

2012-05-31

366

Two novel C29-5beta-sterols from the stems of Opuntia dillenii.  

PubMed

Two novel C29-5beta-sterols, opuntisterol [(24R)-24-ethyl-5beta-cholest-9-ene-6beta,12alpha-diol] (1) and opuntisteroside [(24R)-24-ethyl-6beta-[(beta-d-glucopyranosyl)oxy]-5beta-cholest-9-ene-12alpha-ol] (2), together with nine known compounds, beta-sitosterol (3), taraxerol (4), friedelin (5), methyl linoleate (6), 7-oxositosterol (7), 6beta-hydroxystigmast-4-ene-3-one (8), daucosterol (9), methyl eucomate (10) and eucomic acid (11), were isolated from the stems of Opuntia dillenii collected in Guizhou Province, China. Their structures were elucidated mainly by spectroscopic analysis. The absolute configuration of 1 were deduced from comparative 1H NMR data of the (S)- and (R)-methoxyphenyl acetate derivatives. Compounds 6-8, 10 and 11 were isolated from O. dillenii for the first time. PMID:17112557

Jiang, Jianqin; Li, Yanfang; Chen, Zhen; Min, Zhida; Lou, Fengchang

2006-11-16

367

Maintaining cholesterol homeostasis: Sterol regulatory element-binding proteins  

Microsoft Academic Search

The molecular mechanism of how hepatocytes maintain cholesterol homeostasis has become much more transparent with the discovery of sterol regulatory element binding proteins (SREBPs) in recent years. These membrane proteins are members of the basic helix-loop-helix-leucine zipper (bHLH- Zip) family of transcription factors. They activate the expression of at least 30 genes involved in the synthesis of cholesterol and lipids.

Lutz W. Weber; Meinrad Boll; Andreas Stampfl

2004-01-01

368

Maintaining cholesterol homeostasis: sterol regulatory element-binding proteins.  

PubMed

The molecular mechanism of how hepatocytes maintain cholesterol homeostasis has become much more transparent with the discovery of sterol regulatory element binding proteins (SREBPs) in recent years. These membrane proteins are members of the basic helix-loop-helix-leucine zipper (bHLH-Zip) family of transcription factors. They activate the expression of at least 30 genes involved in the synthesis of cholesterol and lipids. SREBPs are synthesized as precursor proteins in the endoplasmic reticulum (ER), where they form a complex with another protein, SREBP cleavage activating protein (SCAP). The SCAP molecule contains a sterol sensory domain. In the presence of high cellular sterol concentrations SCAP confines SREBP to the ER. With low cellular concentrations, SCAP escorts SREBP to activation in the Golgi. There, SREBP undergoes two proteolytic cleavage steps to release the mature, biologically active transcription factor, nuclear SREBP (nSREBP). nSREBP translocates to the nucleus and binds to sterol response elements (SRE) in the promoter/enhancer regions of target genes. Additional transcription factors are required to activate transcription of these genes. Three different SREBPs are known, SREBPs-1a, -1c and -2. SREBP-1a and -1c are isoforms produced from a single gene by alternate splicing. SREBP-2 is encoded by a different gene and does not display any isoforms. It appears that SREBPs alone, in the sequence described above, can exert complete control over cholesterol synthesis, whereas many additional factors (hormones, cytokines, etc.) are required for complete control of lipid metabolism. Medicinal manipulation of the SREBP/SCAP system is expected to prove highly beneficial in the management of cholesterol-related disease. PMID:15457548

Weber, Lutz-W; Boll, Meinrad; Stampfl, Andreas

2004-11-01

369

Attenuation of Leishmania infantum chagasi metacyclic promastigotes by sterol depletion.  

PubMed

The infectious metacyclic promastigotes of Leishmania protozoa establish infection in a mammalian host after they are deposited into the dermis by a sand fly vector. Several Leishmania virulence factors promote infection, including the glycosylphosphatidylinositol membrane-anchored major surface protease (MSP). Metacyclic Leishmania infantum chagasi promastigotes were treated with methyl-beta-cyclodextrin (M?CD), a sterol-chelating reagent, causing a 3-fold reduction in total cellular sterols as well as enhancing MSP release without affecting parasite viability in vitro. M?CD-treated promastigotes were more susceptible to complement-mediated lysis than untreated controls and reduced the parasite load 3-fold when inoculated into BALB/c mice. Paradoxically, M?CD-treated promastigotes caused a higher initial in vitro infection rate in human or murine macrophages than untreated controls, although their intracellular multiplication was hindered upon infection establishment. There was a corresponding larger amount of covalently bound C3b than iC3b on the parasite surfaces of M?CD-treated promastigotes exposed to healthy human serum in vitro, as well as loss of MSP, a protease that enhances C3b cleavage to iC3b. Mass spectrometry showed that M?CD promotes the release of proteins into the extracellular medium, including both MSP and MSP-like protein (MLP), from virulent metacyclic promastigotes. These data support the hypothesis that plasma membrane sterols are important for the virulence of Leishmania protozoa at least in part through retention of membrane virulence proteins. PMID:23630964

Yao, Chaoqun; Gaur Dixit, Upasna; Barker, Jason H; Teesch, Lynn M; Love-Homan, Laurie; Donelson, John E; Wilson, Mary E

2013-04-29

370

Dietary Phosphilipids and Sterols Protective against Peptic Ulceration.  

PubMed

The prevalence of duodenal ulceration in regions of developing countries with a stable diet is related to the staple food(s) in that diet. A higher prevalence occurs in areas where the diet is principally milled rice, refined wheat or maize, yams, cassava, sweet potato or green bananas, and a lower prevalence in areas where the staple diet is based on unrefined wheat or maize, soya, certain millets or certain pulses. Experiments using animal peptic ulcer models showed that the lipid fraction in foods from the staple diets of low prevalence areas gave protection against both gastric and duodenal ulceration, including ulceration due to non-steroidal anti-inflammatory drugs (NSAIDs), and also promoted healing of ulceration. The protective activity was found to lie in the phospholipid, sterol and sterol ester fractions of the lipid. Amongst individual phospholipids present in the phospholipid fraction, phosphatidyl ethanolamine (cephalin) and phosphatidyl choline (Lecithin) predominated. The sterol fraction showing activity contained ?-sitosterol, stigmasterol and an unidentified isomer of ?-sitosterol. The evidence shows that dietary phytosterols and phospholipids, both individually and in combination, have a protective effect on gastroduodenal mucosa. These findings may prove to be important in the prevention and management of duodenal and gastric ulceration including ulceration due to NSAIDs. Copyright © 2012 John Wiley & Sons, Ltd. PMID:23097339

Tovey, F I; Bardhan, K D; Hobsley, M

2012-10-24

371

Novel composition of mitochondrial genomes in Petunia somatic hybrids derived from cytoplasmic male sterile and fertile plants  

Microsoft Academic Search

The mitochondrial genomes of petunia somatic hybrid plants, which were derived from the fusion of male fertile P. hybrida protoplasts with cytoplasmic male sterile P. parodii protoplasts, were analyzed by endonuclease restriction and Southern blot hybridization analyses. We studied sterile and fertile somatic hybrids to address two main questions. First, is there any correlation between the mitochondrial DNA restriction banding

Maury L. Boeshore; Irit Lifshitz; Maureen R. Hanson; Shamay Izhar

1983-01-01

372

High frequency plant regeneration from microspore-derived embryos of ornamental kale ( Brassica oleracea L. var. acephala)  

Microsoft Academic Search

The aim of this work was to study the effect of solid medium, developmental stage, embryonic age, cold treatment and additives to the medium on plant regeneration from microspore-derived embryos in four F1 hybrids of ornamental kale (Brassica oleracea L. var. acephala). The results showed that all of the cultivars responded best when the embryos were cultured in solidified B5

Yushu Wang; Yan Tong; Yuefei Li; Yun Zhang; Jun Zhang; Jianyun Feng; Hui Feng

2011-01-01

373

The promotive effect of smoke derived from burnt native vegetation on seed germination of Western Australian plants  

Microsoft Academic Search

Exposure of dormant seed to cold smoke derived from burnt native vegetation had a positive influence on germination in one or more seed provenances in 45 out of 94 species of native Western Australian plants that are normally hard to germinate. When tested under controlled conditions some species showed earlier germination in smoke treatments than controls; in others smoke-treated seeds

Kingsley W. Dixon; Shauna Roche; John S. Pate

1995-01-01

374

Somatic embryogenesis and fertile green plant regeneration from suspension cell-derived protoplasts of rye ( Secale cereale L.)  

Microsoft Academic Search

A method for somatic embryogenesis and fertile green plant regeneration from suspension cell-derived protoplasts of rye ( Secale cereale L. cv. Auvinen) was developed. Fast-growing and friable embryogenic calli with a high regeneration capacity were induced from immature rye inflorescences using modified MS medium. These friable embryogenic calli were used for suspension culture initiation in liquid AA medium. A high

R. Ma; Y.-D. Guo; S. Pulli

2003-01-01

375

The use of antimicrotubule herbicides for the production of doubled haploid plants from anther-derived maize callus  

Microsoft Academic Search

Four antimicrotubule herbicides, amiprophosmethyl (APM), pronamide, oryzalin, and trifluralin, were evaluated for their ability to induce chromosome doubling in anther-derived, haploid maize callus. Effects of various herbicide treatments on the growth and regenerative capacity of callus along with the ploidy and seed set of regenerated plants were determined. Flow cytometric analysis was also used to measure changes in ploidy levels

Y. Wan; D. R. Duncan; A. L. Rayburn; J. F. Petolino; J. M. Widholm

1991-01-01

376

The role of Niemann-Pick C1 - Like 1 (NPC1L1) in intestinal sterol absorption  

PubMed Central

The absorption of cholesterol by the proximal small intestine represents a major pathway for the entry of cholesterol into the body pools. This cholesterol is derived primarily from the bile and the diet. In adult humans, typically several hundred milligrams of cholesterol reach the liver from the intestine daily, with the potential to impact the plasma low density lipoprotein-cholesterol (LDL-C) concentration. There are three main phases involved in cholesterol absorption. The first occurs intraluminally and culminates in micellar solubilization of unesterified cholesterol which facilitates its movement up to the brush border membrane (BBM) of the enterocyte. The second phase involves the transport of cholesterol across the BBM by Niemann-Pick C1 Like-1 (NPC1L1), while the third phase entails a series of steps within the enterocyte involving the esterification of cholesterol and its incorporation, along with other lipids and apolipoprotein B48 (apo B48), into nascent chylomicrons (CM). The discovery of the role of NPC1L1 in intestinal sterol transport occurred directly as a consequence of efforts to identify the molecular target of ezetimibe, a novel, potent, and specific inhibitor of sterol absorption that is now widely used in combination therapy with statins for the management of hypercholesterolemia in the general population. Some aspects of the role of NPC1L1 in cholesterol absorption nevertheless remain controversial and are the subject of ongoing research. For example, one report suggests that NPC1L1 is located not in the plasma membrane but intracellularly where it is thought to be involved in cytosolic trafficking of cholesterol, while another concludes that a protein other than NPC1L1 is responsible for the high affinity binding of cholesterol on intestinal BBM. However, other new studies which show that the in vivo responsiveness of different species to ezetimibe correlates with NPC1L1 binding affinity further support the widely held belief that NPC1L1 does facilitate sterol uptake by the enterocyte and is the target of ezetimibe. Added to this is the unequivocal finding that deletion of the gene for NPC1L1 in mice results in a near complete prevention of cholesterol absorption and an accelerated rate of fecal neutral sterol excretion. In summary, the development of ezetimibe and the identification of NPC1L1 as a key player in sterol absorption have taken research on the molecular control of this pathway to an exciting new level. From this it is hoped that we will now be able to determine more precisely what effect, if any, other classes of lipid lowering agents, particularly the statins, might exert on the amount of intestinal cholesterol reaching the liver.

Turley, Stephen D.

2008-01-01

377

Inhibition of Nox-4 activity by plumbagin, a plant-derived bioactive naphthoquinone.  

PubMed

NAD(P)H oxidase contributes to the pathogenesis of cancer and cardiovascular diseases such as hypertension, atherosclerosis, restenosis, cardiac hypertrophy and heart failure. Plumbagin, a plant-derived naphthoquinone, has been shown to exert anticarcinogenic and anti-atherosclerosis effects in animals. However, the molecular mechanisms underlying these effects remain unknown. It is possible that the beneficial effect of plumbagin is due to the inhibition of NAD(P)H oxidase. Human embryonic kidney 293 (HEK293) and brain tumour LN229 cells express mainly Nox-4, a renal NAD(P)H oxidase. We have examined the effect of plumbagin on Nox-4 activity in HEK293 and LN229 cells using lucigenin-dependent chemiluminescence assay. Plumbagin inhibited the activity of Nox-4 in a time- and dose-dependent manner in HEK293 and LN229 cells. Production of superoxide in HEK293 cells was inhibited by diphenyleneiodonium (DPI), a NAD(P)H oxidase inhibitor. The superoxide production in HEK293 cells was NADPH- and NADH-dependent indicating that the superoxide was generated by a NAD(P)H oxidase in HEK293 cells, but not by the redox-cycling of lucigenin. Furthermore, plumbagin inhibited the superoxide production in Nox-4 transfected COS-7 cells. These results indicated that plumbagin directly interacted with Nox-4 and inhibited its activity. PMID:15638999

Ding, Yaxian; Chen, Zi-Jiang; Liu, Shiguo; Che, Danian; Vetter, Michael; Chang, Chung-Ho

2005-01-01

378

Cytotoxic tetramic acid derivative produced by a plant type-III polyketide synthase.  

PubMed

The tetramic acid (2,4-pyrrolidinedione) scaffold has been recognized as an important structural feature because of its mycotoxic, antibacterial, antiviral, and antioxidant activities. This important class of natural products is reportedly produced by the type-I polyketide synthase/nonribosomal peptide synthetase (PKS/NRPS) hybrid megaenzyme systems. In contrast, the benzalacetone synthase (BAS) from Rheum palmatum is a structurally simple, plant-specific type-III PKS that catalyzes the one-step decarboxylative condensation of malonyl-CoA with 4-coumaroyl-CoA. The type-III PKS exhibits unusually broad substrate specificity and notable catalytic versatility. Here we report that R. palmatum BAS efficiently produces a series of unnatural, novel tetramic acid derivatives by the condensation of malonyl-CoA with aminoacyl-CoA thioesters chemically synthesized from L- and D-amino acids. Remarkably, the novel tetramic acid dimer D-5 formed from D-phenylalanoyl-CoA showed moderate antiproliferative activity against murine leukemia P388 cells. PMID:21391603

Wakimoto, Toshiyuki; Mori, Takahiro; Morita, Hiroyuki; Abe, Ikuro

2011-03-10

379

Pharmacokinetics, metabolism and toxicity of the plant-derived photoxin alpha-terthienyl.  

PubMed

The plant-derived insecticide, alpha-terthienyl was prepared by synthesis as 3',4'-di[14C]-alpha-terthienyl for pharmacokinetic and metabolism studies. When administered orally to rats at a single dose of 50 mg/kg, excretion of the labelled material was maximal one day after administration and declined to no measurable quantities by day 4. Two metabolites [1,4-di(2'-thienyl)1,4-butadione and 2-2'-bithiophene-5-carboxylic acid] and trace quantities of the parent material were isolated from the urine and chemically identified. These represent the first metabolites of alpha-terthienyl identified. In pilot acute and subacute trials, unlabelled alpha-terthienyl was non-toxic when administered orally to rats as the "ready to use" formulation (0.1% active ingredient). The pure compound had an LD50 of 110 mg/kg when administered intraperitoneally to rats. The results suggest that there is considerable separation with respect to mosquito larvae and non-target mammal sensitivity. PMID:8884878

Marles, R; Durst, T; Kobaisy, M; Soucy-Breau, C; Abou-Zaid, M; Arnason, J T; Kacew, S; Kanjanapothi, D; Rujjanawate, C; Meckes, M

1995-09-01

380

The Endocannabinoid System and Plant-Derived Cannabinoids in Diabetes and Diabetic Complications  

PubMed Central

Oxidative stress and inflammation play critical roles in the development of diabetes and its complications. Recent studies provided compelling evidence that the newly discovered lipid signaling system (ie, the endocannabinoid system) may significantly influence reactive oxygen species production, inflammation, and subsequent tissue injury, in addition to its well-known metabolic effects and functions. The modulation of the activity of this system holds tremendous therapeutic potential in a wide range of diseases, ranging from cancer, pain, neurodegenerative, and cardiovascular diseases to obesity and metabolic syndrome, diabetes, and diabetic complications. This review focuses on the role of the endocannabinoid system in primary diabetes and its effects on various diabetic complications, such as diabetic cardiovascular dysfunction, nephropathy, retinopathy, and neuropathy, particularly highlighting the mechanisms beyond the metabolic consequences of the activation of the endocannabinoid system. The therapeutic potential of targeting the endocannabinoid system and certain plant-derived cannabinoids, such as cannabidiol and ?9-tetrahydrocannabivarin, which are devoid of psychotropic effects and possess potent anti-inflammatory and/or antioxidant properties, in diabetes and diabetic complications is also discussed.

Horvath, Bela; Mukhopadhyay, Partha; Hasko, Gyorgy; Pacher, Pal

2012-01-01

381

A review of plant-derived and herbal approaches to the treatment of sexual dysfunctions.  

PubMed

Despite the increasing availability of effective conventional medical treatments, plant-derived and herbal remedies continue to provide a popular alternative for men and women seeking to improve their sex life. Nevertheless, the efficacy of most herbal agents in treating sexual problems remains uncertain. Therapists and consumers alike would benefit from an increased understanding of commonly used herbal agents on the market, their purported or supported effects, and their potential side effects. To this end, we cataloged the major prosexual herbal agents currently sold in several representative health food stores. We also specify the sexual problem purportedly ameliorated by each herbal agent. Finally, we evaluate eight herbal agents commonly promoted for the treatment of sexual problems. This evaluation includes a review of the research supporting the use, efficacy, dose, adverse effects, contraindications, and possible mechanism of action of each. We conclude by commenting on the quality of current research, pointing out gaps in our knowledge, and noting the need for rigorous research and product control to adequately address questions regarding the efficacy of these agents. PMID:12851124

Rowland, David L; Tai, Wendi

382

Life history consequences of sterol availability in the aquatic keystone species Daphnia.  

PubMed

The absence of essential biochemical nutrients, such as polyunsaturated fatty acids or sterols, has been considered as a mechanism determining trophic interactions between the herbivore Daphnia and its phytoplankton food source. Here, we experimentally quantify the sensitivity of two Daphnia species to decreasing amounts of dietary sterols by measuring variations in life history traits. The two species Daphnia magna and D. galeata were fed different mixtures of the sterol-containing green alga Scenedesmus obliquus and the sterol-free cyanobacterium Synechococcus elongatus; a higher proportion of Synechococcus in the food is equivalent to a decrease in dietary sterols. To address the significance of sterol limitation, the Daphnia species were also fed Synechococcus supplemented with cholesterol. In both species, somatic and population growth rates, maternal dry mass, the number of viable offspring, and the probability of survival were significantly reduced with the lower availability of sterols. A high correlation between the sterol content of the mixed diet and the somatic and population growth rates was found, and growth on cholesterol-supplemented Synechococcus fitted well into this correlation. Somatic growth of first-clutch neonates grown on 100% Synechococcus exhibited a pattern similar to that of somatic growth of their mothers grown on the different food regimes, which demonstrated the significance of maternal effects for sterol-limited population growth. Daphnia galeata had a twofold higher incipient limiting sterol level than D. magna, which indicated interspecific differences in sterol requirements between the two Daphnia species. The results suggest a strong impact of dietary sterols on life history traits and therefore, population dynamics of the keystone species Daphnia. PMID:15891820

Martin-Creuzburg, Dominik; Wacker, Alexander; von Elert, Eric

2005-09-16

383

Evidence for facilitated transport in the absorption of sterols by Saccharomyces cerevisiae  

Microsoft Academic Search

Saccharomyces cerevisiae is known to absorb sterols readily in the absence of air. As shown in this paper yeast cells also will absorb sterols with\\u000a and without various double bonds or an alkyl group at C-24 in the presence of air at a concentration (ca. 10% of the gas phase)\\u000a which is growth-limiting due to limited sterol synthesis. However, if

William R. Nes; Inder C. Dhanuka; William J. Pinto

1986-01-01

384

Sterol regulation of scavenger receptor class B type I in macrophages  

Microsoft Academic Search

Scavenger receptor class B type I (SR-BI) is ex- pressed in macrophages, but its role in sterol trafficking in these cells remains controversial. We examined the effect of sterol loading on SR-BI expression in human monocytes\\/ macrophages, mouse peritoneal macrophages, and a cul- tured mouse macrophage cell line (J774 cells). Sterol load- ing using either acetylated LDL or 25-hydroxycholesterol re-

Liqing Yu; Guoqing Cao; Joyce Repa; Herbert Stangl

2004-01-01

385

Stability of Rice Bran Oil in Terms of Oryzanol, Tocopherols, Tocotrienols and Sterols  

Microsoft Academic Search

The effect of oryzanol, tocopherols and tocotrienols (tocols) and sterols individually and as combinations of two were analyzed\\u000a for DPPH radical scavenging activity and antioxidant activity. Oryzanol, tocols and sterols were isolated by using column\\u000a chromatography and then added at known concentrations in stripped RBO. The results showed that tocol added samples are more\\u000a stable than with oryzanol and sterol

L. S. Afinisha Deepam; A. Sundaresan; C. Arumughan

2011-01-01

386

Lymphatic absorption of shellfish sterols and their effects on cholesterol absorption13  

Microsoft Academic Search

Studies have been conducted on the absorbabihity of individual sterols from a mixture ofoystersterolswhen administered intragastrically to ratswith indwellingcathetersinthe left thoracic duct. In addition, the effect of oyster sterols on cholesterol absorption has been assessed using (4-'4C)cholesterolin the mixture,and comparison againstabsorption of cholesterolalone. The order of absorbabiity (percentage absorption) of individual sterols from the mixture of oyster sterohs was: cholesterol

George V. Vahouny; William E. Connor; Timothy Roy

387

Heritable somaclonal variation in gliadin proteins of wheat plants derived from immature embryo callus culture  

Microsoft Academic Search

Fertile r0 plants of the winter wheat line ND7532 (Triticum aestivum L.) were regenerated from callus tissue after 60–190 days in culture. Seeds produced from these self-pollinated plants were planted in the field. Of the 5586 R1 plants, 32 differed for one or more agronomic traits from plants not passed through tissue culture process. Gliadin electrophoregrams were prepared from bulk

D. B. Cooper; R. G. Sears; G. L. Lookhart; B. L. Jones

1986-01-01

388

Sterol Biosynthesis Inhibitors: Potential for Transition State Analogs and Mechanism-Based Inactivators Targeted at Sterol Methyltransferase  

Microsoft Academic Search

Sterol biosynthesis inhibitors (SBIs), discovered in the late 1960s and subsequently used commercially to treat ergosterol-dependent\\u000a fungal diseases, represent a unique drug class targeted at an enzyme in a biosynthetic pathway. To date, few drugs have been\\u000a commercialized as enzyme inhibitors; yet, prescription of SBIs has emerged as the gold standard for some cases of non-life-threatening\\u000a antifungal chemotherapy and in

Zhihong Song; W. David Nes

2007-01-01

389

Differences in sterol composition between male and female gonads of dominant limpet species.  

PubMed

The present study demonstrated here for the first time that there are statistically significant differences in sterol composition between male and female gonads of the dominant limpets Cellana grata and Cellana toreuma, which are intertidal gastropods. Among 11 different sterols identified in this study, unusually high levels (11.2-19.8% of total sterols) of the Delta8-sterols 5alpha-cholest-8-en-3beta-ol (zymostenol) and 5alpha-cholesta-8,24-dien-3beta-ol (zymosterol), which have never been reported in aquatic invertebrate gonads, were present in only the male gonads. PMID:19452182

Kawashima, Hideki; Ohnishi, Masao; Ogawa, Satoshi

2009-05-19

390

[Micromycetes metabolites--inhibitors of growth and sterol biosynthesis in yeasts].  

PubMed

Antifungal activity of micelial fungus metabolites (of genera Aspergillus, Penicillium, Fusarium, Stachybotris, Cladosporium, Alternaria, Gliocladium, Paecilomyces, Trichoderma etc.) was determined. It was shown that antifungal activity of some micromycetes is due to the formation of substances inhibiting sterols biosynthesis in eucaryote cells. Inhibitors of enzymes of sterols biosynthesis were isolated and their activity was investigated. It was shown, that isolated fungus inhibitors of sterols biosynthesis inhibited the growth of test-organism Rhodotorula rubra and decreased ergosterin level in yeast cells. The qualitative content of yeast cell sterols was not changed in the presence of fungus inhibitors. PMID:12077938

Baranova, N A; Kre?er, V G; Landau, N S; Egorov, N S

2002-01-01

391

Glucose induces de novo lipogenesis in rat muscle satellite cells through a sterol-regulatory-element-binding-protein-1c-dependent pathway  

Microsoft Academic Search

We previously reported that sterol-regulatory-element- binding-protein-1c (SREBP-1c) mediates insulin upregulation of genes encoding glycolytic and lipogenic enzymes in rat skeletal muscle. Here, we assessed whether glucose could regulate gene expression in contracting myotubes deriving from cultured muscle satellite cells. Glucose uptake increased twofold after a 30 minute treatment with a high glucose concentration, suggesting an acute glucose-stimulated glucose uptake. Time-course

Isabelle Guillet-Deniau; Anne-Lise Pichard; Aminata Koné; Catherine Esnous; Myriam Nieruchalski; Jean Girard; Carina Prip-Buus

2004-01-01

392

Reliance on prey-derived nitrogen by the carnivorous plant Drosera rotundifolia decreases with increasing nitrogen deposition.  

PubMed

• Carnivory in plants is presumed to be an adaptation to a low-nutrient environment. Nitrogen (N) from carnivory is expected to become a less important component of the N budget as root N availability increases. • Here, we investigated the uptake of N via roots versus prey of the carnivorous plant Drosera rotundifolia growing in ombrotrophic bogs along a latitudinal N deposition gradient through Sweden, using a natural abundance stable isotope mass balance technique. • Drosera rotundifolia plants receiving the lowest level of N deposition obtained a greater proportion of N from prey (57%) than did plants on bogs with higher N deposition (22% at intermediate and 33% at the highest deposition). When adjusted for differences in plant mass, this pattern was also present when considering total prey N uptake (66, 26 and 26 ?g prey N per plant at the low, intermediate and high N deposition sites, respectively). The pattern of mass-adjusted root N uptake was opposite to this (47, 75 and 86 ?g N per plant). • Drosera rotundifolia plants in this study switched from reliance on prey N to reliance on root-derived N as a result of increasing N availability from atmospheric N deposition. PMID:22506640

Millett, J; Svensson, B M; Newton, J; Rydin, H

2012-04-16

393

Scavenger receptor BI and ABCG5/G8 differentially impact biliary sterol secretion and reverse cholesterol transport in mice.  

PubMed

Biliary lipid secretion plays an important role in gallstone disease and reverse cholesterol transport (RCT). Using Sr-bI/Abcg5 double knockout mice (dko), the present study investigated the differential contribution of two of the most relevant transporters: adenosine triphosphate (ATP)-binding cassette subfamily G member 5 and 8 (ABCG5/G8) and scavenger receptor class B type I (SR-BI) to sterol metabolism and RCT. Plasma cholesterol levels increased in the following order, mainly due to differences in high density lipoprotein (HDL): Abcg5 ko < wild type < Sr-bI/Abcg5 dko < Sr-bI ko. Liver cholesterol content was elevated in Sr-bI ko only (P < 0.05). In Sr-bI/Abcg5 dko plasma plant sterols were highest, while hepatic plant sterols were lower compared with Abcg5 ko (P < 0.05). Under baseline conditions, biliary cholesterol secretion rates decreased in the following order: wild type > Sr-bI ko (-16%) > Abcg5 ko (-75%) > Sr-bI/Abcg5 dko (-94%), all at least P < 0.05, while biliary bile acid secretion did not differ between groups. However, under supraphysiological conditions, upon infusion with increasing amounts of the bile salt tauroursodeoxycholic acid, Abcg5 became fully rate-limiting for biliary cholesterol secretion. Additional in vivo macrophage-to-feces RCT studies demonstrated an almost 50% decrease in overall RCT in Sr-bI/Abcg5 dko compared with Abcg5 ko mice (P < 0.01). Conclusion: These data demonstrate that (1) SR-BI contributes to ABCG5/G8-independent biliary cholesterol secretion under basal conditions; (2) biliary cholesterol mass secretion under maximal bile salt-stimulated conditions is fully dependent on ABCG5/G8; and (3) Sr-bI contributes to macrophage-to-feces RCT independent of Abcg5/g8. PMID:23401258

Dikkers, Arne; Freak de Boer, Jan; Annema, Wijtske; Groen, Albert K; Tietge, Uwe J F

2013-05-14

394

Sterol-mediated regulation of mevalonic acid synthesis. Accumulation of 4-carboxysterols as the predominant sterols synthesized in a Chinese hamster ovary cell cholesterol auxotroph (mutant 215)  

SciTech Connect

Chinese hamster ovary-215 (CHO-215) mutant cells are auxotrophic for cholesterol. Berry and Chang (Berry, D. J., and Chang, T. Y. (1982) Biochemistry 21, 573-580) suggested that the metabolic lesion was at the level of 4-methyl sterol oxidation. However, the observed cellular accumulation of lanosterol was not consistent with a defect at this metabolic site. With the use of a novel Silica Sep Pak sterol separation procedure, we demonstrated that 60-80% of the acetonesoluble lipid radioactivity in (5-3H)mevalonate-labeled CHO-215 cells was incorporated into acidic sterols. 7(8),Cholesten-4 beta-methyl,4 alpha-carboxy,3 beta-ol was the dominant end product. In addition to this acidic sterol, 7(8),24-cholestadien,4 beta-methyl,4 alpha-carboxy,3 beta-ol and 7(8),24-cholestadien,4 alpha-carboxy,3 beta-ol were also isolated. Incubation of cell-free extracts with (3H)7(8)-cholesten-4 beta-methyl, 4 alpha-carboxy,3 beta-ol and pyridine nucleotides confirmed that CHO-215 4-carboxysterol decarboxylase activity was less than 1% of that for wild type cells. Thus, a correspondence between decreased 4-carboxysterol decarboxylase activity and the spectrum of accumulated sterol products by intact CHO-215 cells was demonstrated. No detectable cholesterol was synthesized by CHO-215 cells. 3H-Product accumulation studies demonstrated that 7(8),24-cholestadien, 4 beta-methyl,4 alpha-carboxy,3 beta-ol increased prior to its subsequent saturation at the delta 24 carbon. Furthermore, the steady state ratio for delta 24-saturated acidic sterols/unsaturated acidic sterols was dependent on media cholesterol source and amount. Finally, the accumulated acidic sterol(s) were not regulatory signal molecules for the modulation of 3-hydroxy-3-methyl-glutaryl coenzyme. A reductase activity in response to cholesterol availability.

Plemenitas, A.; Havel, C.M.; Watson, J.A. (Univ. of California, San Francisco (USA))

1990-10-05

395

Deriving the optimal scale for relating topographic attributes and cover crop plant biomass  

NASA Astrophysics Data System (ADS)

The use of cover crops generates a number of agro-ecological benefits for sustainable row-crop agriculture. However, their performance across agricultural fields is often highly spatially variable and there is insufficient information on factors affecting this variability and on tools to manage it. Topography is one of the main factors affecting spatial patterns of plant growth in the American Midwest. Digital elevation models are readily available for deriving topographic attributes; also sensor digital data can be used to indirectly assess cover crop biomass. However, processing procedures for identifying the proper scale of topographic and biomass representations are not well defined. The objectives of this study are to examine how relationships between cover crop biomass, assessed using the normalized difference vegetation index (NDVI), and topography depend on the neighborhood size used for deriving topographic attributes and creating NDVI maps; and identify the optimal neighborhood size for correlation and regression analyses. Slope, relative elevation and the potential solar radiation index were the variables that contributed the most to explaining variability in NDVI for raw data. However, other topographic attributes became significant predictors of NDVI at larger neighborhood sizes. We demonstrated that neighborhood size greatly affects some topographic attributes, i.e. curvature, flow accumulation, flow length and the wetness index; and changing the neighborhood size in both topography and NDVI considerably changes the strength of the prediction performance in multiple regression models. We studied six neighborhood sizes from 1 to 40 m and the original raw data. On average, across all studied fields the best performance of multiple regression, as determined by the adjusted-R2, was obtained at neighborhood sizes 20 and 40 m. Parameters of semivariogram models for terrain slope, such as the spatial autocorrelation range and the nugget/sill ratio, were found to be good indicators of prediction performance and optimum neighborhood size for filtering the raw data. The results demonstrate that topographic effects on growth and biomass production of cover crops are most pronounced at certain spatial scales, and topographic model predictions will be most accurate when used at the optimal scales.

Muńoz, Juan D.; Kravchenko, Alexandra

2012-12-01

396

Marine sterols. III--The sterol compositions of oceanic jellyfish. The use of gas chromatographic mass spectrometric techniques to identify unresolved components.  

PubMed

The sterol compositions of three oceanic jellyfish have been determined using gas chromatographic mass spectrometric techniques involving the use of two separate gas chromatographic column systems. The components in overlapping peaks have been identified by comparison of the mass spectra of peaks in the two column systems using subtractive techniques. A mid-water animal, Periphylla periphylla, was found to contain a very complex and unusual sterol profile including rare 5alpha-stanols, whereas two other oceanic jellyfish Pelagia noctiluca and Atolla wyvillei contained similar mixtures of delta5 sterols to those previously isolated from coastal species. PMID:4172

Ballantine, J A; Roberts, J C; Morris, R J

1976-02-01

397

Carotenoid Biosynthesis in Photo-Synthetic Bacteria and Higher Plants.  

National Technical Information Service (NTIS)

Investigation on the biosynthesis of plant sterols are described. A number of possible phytosterol precursors were identified in peas and larch and include squalene, cycloartenol, 24-methylene cycloartenol, 24-methylene lophenol. The incorporation of (2-1...

T. W. Goodwin L. J. Goad

1966-01-01

398

Bioactive natural products derived from polygonum species of plants: their structures and mechanisms of action  

Microsoft Academic Search

This review encompasses the natural products literature (with the exception of the patent literature or conference abstracts) of some of the different species of plants in the Polygonum species. Some of the plants in this genus originated in Japan and were later introduced to other parts of the world. These plants are commonly used in Chinese and Japanese folk medicine

Nwaka Ogwuru; Madeline Adamczeski

2000-01-01

399

Apigenin, a plant-derived flavone, activates transient receptor potential vanilloid 4 cation channel  

PubMed Central

BACKGROUND AND PURPOSE Transient receptor potential vanilloid 4 (TRPV4) is a Ca2+-permeable channel with multiple modes of activation. Apigenin is a plant-derived flavone, which has potential preventive effects on the development of cardiovascular disease. We set out to explore the effects of apigenin on TRPV4 channel activity and its role in vasodilatation. EXPERIMENTAL APPROACH The effects of apigenin (0.01–30 µM) on TPRV4 channels were investigated in HEK293 cells over-expressing TRPV4, rat primary cultured mesenteric artery endothelial cells (MAECs) and isolated small mesenteric arterial segments using whole-cell patch clamp, fluorescent Ca2+ imaging, intracellular recording and pressure myography. KEY RESULTS Whole-cell patch clamp and fluorescent Ca2+ imaging in HEK cells over-expressing TRPV4 showed that apigenin concentration-dependently stimulated the TRPV4-mediated cation current and Ca2+ influx. In MAECs, apigenin stimulated Ca2+ influx in a concentration-dependent manner. These increases in cation current and Ca2+ influx were markedly inhibited by TRPV4-specific blockers and siRNAs. Furthermore, pressure myography and intracellular recording in small third-order mesenteric arteries showed that apigenin dose-dependently evoked smooth muscle cell membrane hyperpolarization and subsequent vascular dilatation, which were significantly inhibited by TRPV4-specific blockers. TRPV4 blocker or charybdotoxin (200 nM) plus apamin (100 nM) diminished the apigenin-induced dilatation. CONCLUSION AND IMPLICATIONS This is the first study to demonstrate the selective stimulation of TRPV4 by apigenin. Apigenin was found to activate TRPV4 channels in a dose-dependent manner in HEK cells over-expressing TRPV4 and in native endothelial cells. In rat small mesenteric arteries, apigenin acts on TRPV4 in endothelial cells to induce EDHF-mediated vascular dilatation.

Ma, Xin; He, Dongxu; Ru, Xiaochen; Chen, Yun; Cai, Yanfei; Bruce, Iain C; Xia, Qiang; Yao, Xiaoqiang; Jin, Jian

2012-01-01

400

CHROMOPHORIC DISSOLVED ORGANIC MATTER (CDOM) DERIVED FROM DECOMPOSITION OF VARIOUS VASCULAR PLANT AND ALGAL SOURCES  

EPA Science Inventory

Chromophoric dissolved organic (CDOM) in aquatic environments is derived from the microbial decomposition of terrestrial and microbial organic matter. Here we present results of studies of the spectral properties and photoreactivity of the CDOM derived from several organic matter...

401

Effects of phytoestrogens and other plant-derived compounds on mesenchymal stem cells, bone maintenance and regeneration.  

PubMed

Phytoestrogens and other plant-derived compounds and extracts have been developed for the treatment of menopause-related complaints and disorders, e.g. hot flushes and osteoporosis. Since estrogens have been discussed to enhance the risk for hormone-sensitive cancers, research activities try to find alternatives. Phytoestrogens like genistein and resveratrol as well as other plant-derived compounds are capable of substituting for estrogens to some extent. Their effects on mesenchymal stem cells and the tissues derived therefrom have been investigated in vitro and in preclinical settings. Besides their well-known estrogenic, i.e. mainly antiresorptive effects on bone via estrogen receptor (ER) signalling, they also directly or indirectly affect osteogenic and adipogenic pathways. As a novel mechanism, phytoestrogens and plant-derived saponins and flavonoids like kaempferol and xanthohumol have been described to reciprocally affect the osteogenic versus the adipogenic differentiation pathway. Both, ER-mediated and other pathways mediate a shift towards osteogenesis by inhibiting PPAR? and C/EBP?, the key adipogenic transcription factors (TFs), while stimulating the key osteogenic TFs Runx2 and Sp7. Besides ER signalling, the broad spectrum of molecular mechanisms supporting osteogenesis comprises the modulation of PPAR?, Wnt/?-catenin, and Sirt1 signalling, which inversely influence the transcription or transactivation of osteogenic versus adipogenic TFs. Preventing the age- and hormone deficiency-related shift towards adipogenesis without provoking adverse estrogenic effects represents a very promising strategy for treating bone loss and other metabolic diseases beyond bone. Research on plant-derived compounds will have to be pursued in vitro as well as in preclinical studies and controlled clinical trials in humans are urgently needed. This article is part of a Special Issue entitled 'Phytoestrogens'. PMID:23262262

Schilling, Tatjana; Ebert, Regina; Raaijmakers, Nadja; Schütze, Norbert; Jakob, Franz

2012-12-20

402

Sterols as bio-markers for waste impact and source characterization in stream sediment.  

PubMed

Sterols are involved in life processes in organisms and are therefore potential biomarkers for assessment of environmental ecosystems. Current data indicate that sterols are persistent in stream sediments, since sterols are not sufficiently soluble in water to be readily detected in water samples. Stream sediment therefore can act as an integrating exposure index of pollution for animal or human waste in streams. The study reported here was conducted in two phases. Phase 1 involved development and validation of a simplified method for the determination of sterols, and Phase 2 involved application of that method to evaluate actual environmental samples. Stream sediment samples from agricultural settings, wastewater-treatment-facility outfalls, and recreational state parks in Iowa and Pennsylvania were analyzed for sterol compounds. Sterol profiles differ considerably among animals, and the study distinguished sterol profiles within stream sediments. Feces from different animal species were also analyzed to provide reference sterol profiles. Individual-sterol and total-sterol concentrations were determined. Sterols were observed in 73.4 percent of environmental sediment samples tested (n = 124) and at 100 percent of the sites (n = 18). Coprostanol, a key indicator of fecal pollution, was observed in 38.7 percent of the environmental sediment samples tested and at 72.2 percent of the sites. Samples were collected from multiple points at selected sites, and duplicate samples were analyzed at a frequency of 16.1 percent. One to five months later, additional samples were collected from the duplicate locations and were analyzed. Data generated by the study provide a basis for stream sediment monitoring that enables the chronological recording of waste impact; this method may be coupled with other measurements to determine the extent and possible source of stream contaminants. PMID:16780001

Ayebo, Amadu; Breuer, George M; Cain, Terry G; Wichman, Michael D; Subramanian, Periyasamy; Reynolds, Stephen J

2006-06-01

403

A Rapid Analytical Method for Determination of Aflatoxins in Plant-Derived Dietary Supplement and Cosmetic Oils  

PubMed Central

Consumption of edible oils derived from conventional crop plants is increasing because they are generally regarded as more healthy alternatives to animal based fats and oils. More recently there has been increased interest in the use of alternative specialty plant-derived oils, including those from tree nuts (almonds, pistachios and walnuts) and botanicals (borage, evening primrose and perilla) both for direct human consumption (e.g. as salad dressings) but also for preparation of cosmetics, soaps, and fragrance oils. This has raised the issue as to whether or not exposure to aflatoxins can result from such oils. Although most crops are subject to analysis and control, it has generally been assumed that plant oils do not retain aflatoxins due to their high polarity and lipophobicity of these compounds. There is virtually no scientific evidence to support this supposition and available information is conflicting. To improve the safety and consistency of botanicals and dietary supplements, research is needed to establish whether or not oils used directly, or in the formulation of products, contain aflatoxins. A validated analytical method for the analysis of aflatoxins in plant-derived oils is essential, in order to establish the safety of dietary supplements for consumption or cosmetic use that contain such oils. The aim of this research was therefore to develop an HPLC method applicable to a wide variety of oils from different plant sources spiked with aflatoxins, thereby providing a basis for a comprehensive project to establish an intra- and inter-laboratory validated analytical method for analysis of aflatoxins in dietary supplements and cosmetics formulated with plant oils.

Mahoney, Noreen; Molyneux, Russell J.

2010-01-01

404

Derivatives of diterpen labdane-8?,15-diol as photosynthetic inhibitors in spinach chloroplasts and growth plant inhibitors.  

PubMed

In a search of new efficient herbicides of natural origin, four derivatives were prepared from labdane-8?,15-diol (1) and 15-O-acetyl-8?-hydroxy labdane (2) isolated from Croton ciliatoglanduliferus. Their inhibitory activity on photosynthetic electron transport on fresh, broken spinach chloroplasts and on the growth of plants were determined. Derivative 15-O-benzoyl-8?-hydroxy labdane (5) was seven times more active than 2 as reaction Hill inhibitor. Complex of 5 with the adjuvant 2-hydroxypropyl-?-cyclodextrin (5:HPB) (200 ?M) was sprayed on Physalys ixocarpa (green tomato) plants; 48 h later the complex inhibited PS II by transforming the active reaction centers to silent reaction centers or "heat sinks". After 72 h this effect disappeared, probably 5:HPB was metabolized by the plant. Chlorophyll a fluorescence of Trifolium alexandrinum (clover) leaves was affected with 5:HPB at the level of PQ pool reduction. 5:HPB decreases the tomato and clover dry-biomass, without affecting Lolium perenne (grass) plants, suggesting that complex 5 acts as selective herbicide for dicotyledonous plants. PMID:23733160

Morales-Flores, Félix; Aguilar, María Isabel; King-Díaz, Beatriz; Lotina-Hennsen, Blas

2013-05-15

405

Triterpenes, A sterol and A monocyclic alcohol from Momordica charantia  

Microsoft Academic Search

Five new compounds have been isolated from the fresh fruits of Momordica charantia and their structures elucidated through spectroscopic studies. These include three pentacyclic triterpenes 13-hydroxy-28-methoxy-urs-11-en-3-one (momordicin), 13?,28-epoxy-urs-11-en-3-one (momordicinin), 24-[1?-hydroxy,1?-methyl-2?-pentenyloxyl]-ursan-3-one (momordicilin), a sterol 3?-hydroxy-stigmasta-5,14-dien-16-one (momordenol) and a monocyclic alcohol 1-hydroxy-1,2-dimethyl-2-[8?,10?-dihydroxy-4?,7?-dimethyl-11?-hydroxy methyl-trideca]-3-ethyl-cyclohex-5-en-4-one (momordol).

Sabira Begum; Mansoor Ahmed; Bina S. Siddiqui; Abdullah Khan; Zafar S. Saify; Mohammed Arif

1997-01-01

406

Antitumor sterols from the mycelia of Cordyceps sinensis  

Microsoft Academic Search

Activity guided fractionations led to the isolation of two antitumor compounds 5?,8?-epidioxy-24(R)-methylcholesta-6,22-dien-3?-d-glucopyranoside and 5,6-epoxy-24(R)-methylcholesta-7,22-dien-3?-ol from the methanol extract of Cordyceps sinensis. Two previously known compounds, ergosteryl-3-O-?-d-glucopyranoside and 22-dihydroergosteryl-3-O-?-d-glucopyranoside were also isolated. The structures of hitherto unknown sterols were established by 1D and 2D NMR spectroscopic techniques with the former synthesized in order to confirm the identity of the sugar moiety

Jin Woo Bok; Leonard Lermer; Jeff Chilton; Hans G Klingeman; G. H. Neil Towers

1999-01-01

407

Antitumor sterols from the mycelia of Cordyceps sinensis  

Microsoft Academic Search

Activity guided fractionations led to the isolation of two antitumor compounds 5a,8a-epidioxy-24(R)-methylcholesta-6,22- dien-3b-D-glucopyranoside and 5,6-epoxy-24(R)-methylcholesta-7,22-dien-3b-ol from the methanol extract of Cordyceps sinensis. Two previously known compounds, ergosteryl-3-O-b-D-glucopyranoside and 22-dihydroergosteryl-3-O-b-D-glucopyranoside were also isolated. The structures of hitherto unknown sterols were established by 1D and 2D NMR spectroscopic techniques with the former synthesized in order to confirm the identity of the sugar

Jin Woo Boka; Hans G. Klingeman; G. H. Neil Towers

408

Fusion and Fission, the Evolution of Sterol Carrier Protein2  

Microsoft Academic Search

Sterol carrier protein-2 (SCP-2) is an intracellular, small, basic protein domain that in vitro enhances the transfer of lipids between membranes. It is expressed in bacteria, archaea, and eukaryotes. There are five human\\u000a genes, HSD17B4, SCPX, HSDL2 STOML1, and C20orf79, which encode SCP-2. HSD17B4, SCPX, HSDL2, and STOML1 encode fusion proteins with SCP-2 downstream of another protein domain, whereas C20orf79

Johan Edqvist; Kristina Blomqvist

2006-01-01

409

A potential biochemical mechanism underlying the influence of sterol deprivation stress on Caenorhabditis elegans longevity  

Technology Transfer Automated Retrieval System (TEKTRAN)

To investigate the biochemical mechanism for sterol-mediated alteration in aging in Caenorhabditis elegans, we established sterol depletion conditions by treating worms with azacoprostane, which reduced mean lifespan of adult C. elegans by 35%. Proteomic analyses of egg proteins from treated and un...

410

Life history consequences of sterol availability in the aquatic keystone species Daphnia  

Microsoft Academic Search

The absence of essential biochemical nutrients, such as polyunsaturated fatty acids or sterols, has been considered as a mechanism\\u000a determining trophic interactions between the herbivore Daphnia and its phytoplankton food source. Here, we experimentally quantify the sensitivity of two Daphnia species to decreasing amounts of dietary sterols by measuring variations in life history traits. The two species Daphnia magna and

Dominik Martin-Creuzburg; Alexander Wacker; Eric von Elert

2005-01-01

411

Functional Interactions between Sphingolipids and Sterols in Biological Membranes Regulating Cell Physiology  

Microsoft Academic Search

Abstract Sterols and sphingolipids are limited to eukaryotic cells and their interaction has been proposed to favor formation of lipid microdomains. While there is abundant biophysical evidence demonstrating their interaction in simple systems, convincing evidence is lacking to show that they function together in cells. Using lipid analysis by mass spectrometry and a genetic approach on mutants in sterol metabolism,we

Xueli Guan; Cleiton M. Souza; Harald Pichler; Gisčle Dewhurst; Olivier Schaad; Kentaro Kajiwara; Hirotomo Wakabayashi; Tanya Ivanova; Guillaume A. Castillon; Manuele Piccolis; Fumiyoshi Abe; Robbie Loewith; Kouichi Funato; Markus R. Wenk; Howard Riezman

2009-01-01

412

The sterols isolated from Evening Primrose oil modulate the release of proinflammatory mediators.  

PubMed

Evening Primrose oil is a natural product extracted by cold-pressed from Oenothera biennis L. seeds. The unsaponifiable matter of this oil is an important source of interesting minor compounds, like long-chain fatty alcohols, sterols and tocopherols. In the present study, sterols were isolated from the unsaponifiable matter of Evening Primrose oil, and the composition was identified and quantified by GC and GC-MS. The major components of sterols fraction were ?-Sitosterol and campesterol. We investigated the ability of sterols from Evening Primrose oil to inhibit the release of different proinflammatory mediators in vitro by murine peritoneal macrophages stimulated with lipopolysaccharide. Sterols significantly and dose-dependently decreased nitric oxide production. Western blot analysis showed that nitric oxide reduction was a consequence of the inhibition of inducible nitric oxide synthetase expression. Sterols also reduced tumor necrosis factor-?, interleukine 1? and tromboxane B?. However, sterols did not reduce prostaglandin E?. The reduction of eicosanoid release was related to the inhibition of cyclooxygenase-2 expression. These results showed that sterols may have a protective effect on some mediators involved in inflammatory damage development, suggesting its potential value as a putative functional component of Evening Primrose oil. PMID:22819447

Montserrat-de la Paz, Sergio; Fernández-Arche, Angeles; Angel-Martín, María; García-Giménez, María Dolores

2012-07-21

413

Subinhibitory Concentration of Octenidine and Pirtenidine: Influence on the Lipid and Sterol Contents of Candida albicans  

Microsoft Academic Search

The effect of subinhibitory concentrations of octenidine and pirtenidine on the lipid and sterol composition of Candida albicans was investigated. The total lipid and sterol contents of C. albicans grown in the presence of either octenidine or pirtenidine were reduced compared with control-grown cells. The major differences in the lipid composition of drug-grown and control cells were phosphatidylglycerol, phosphatidylcholine and

Mahmud A. Ghannoum; Naguib M. Moussa; Peter Whittaker; Iman Swairjo; Khalid H. Abu-Elteen

1992-01-01

414

Effect of Sterol Structure on Chain Ordering of an Unsaturated Phospholipid: A 2H-NMR Study of POPC/Sterol Membranes  

NASA Astrophysics Data System (ADS)

The physical properties of biological membranes are considerably altered by the presence of sterols. In particular, sterols help to maintain the integrity of the cell by adjusting the fluidity of the plasma membrane. Cholesterol is in addition an important component of lipid rafts which are hypothesized to compartmentalize the cell membrane surface thereby making it possible for certain proteins to function. Using 2H-NMR spectroscopy, we studied the effect of a series of different sterols on the chain ordering of POPC, an unsaturated phospholipid present in eukaryotic cell membranes. We were able to assigned specific roles to the structural differences between the sterols by comparing the manner in which they affect the average lipid chain conformation of POPC.

Shaghaghi, Mehran; Thewalt, Jenifer; Zuckermann, Martin

2012-10-01

415

Development of high-temperature subsystem technology to a technology readiness state: Phase I. Topical report, overall plant design description for operation with coal-derived gaseous fuel  

Microsoft Academic Search

Under Task 1 of Phase 1 of the High-Temperature Turbine Technology Program a conceptual definition was made of an advanced plant design for operation of coal-derived gaseous fuel. This conceptual design takes into full consideration both mechanical and functional operational aspects of the different plant systems, in addition to the method of process control and maintenance. In establishing the plant

1977-01-01

416

Influence of host plant-derived and abiotic environmental parameters on the composition of the diazotroph assemblage associated with roots of Juncus roemerianus  

Microsoft Academic Search

Environmental factors governing the distributions of plant root-associated bacteria are poorly understood. Most plant species occurring in salt marsh estuaries are restricted to very specific habitats within the marsh and plant-derived and abiotic environmental features covary. We examined diazotrophic bacteria inhabiting the rhizoplanes of different populations of the black needlerush, Juncus roemerianus, growing in two different habitats, in order to

Jeannine R. LaRocque; Peter W. Bergholz; Christopher E. Bagwell; Charles R. Lovell

2004-01-01

417

Plant Regeneration from Immature Zygotic Embryo-Derived Embryogenic Calluses and Cell Suspension Cultures of Catharanthus roseus  

Microsoft Academic Search

Culture conditions for plant regeneration in immature zygotic embryo-derived embryogenic cell suspension cultures of Catharanthus roseus (Madagascar periwinkle) ‘Little Bright Eye’ are described. Immature zygotic embryos formed off-white, friable calluses at a frequency of 20% on Murashige and Skoog (MS) medium supplemented with 4.52 µM 2,4-dichlorophenoxyacetic acid (2,4-D) after 8 weeks of culture. After a second subculture using MS basal

Suk Weon Kim; Dong Su In; Pil Son Choi; Jang R. Liu

2004-01-01

418

Identification of the aph IV gene from protoplast-derived maize plants by a simple nonradioactive DNA hybridization method  

Microsoft Academic Search

Summary  Protoplast-derived, transformed maize plants were evaluated by Southern analysis for the presence of the aph IV gene which codes for resistance to the antibiotic, hygromycin B. This gene was used as a selectable marker for the transformation\\u000a of maize protoplasts. Southern analysis was performed with fluorescein-labeled probe DNA. A new method for labeling molecular\\u000a weight markers with fluorescein-N6 is presented.

Martha Hill; Denise Melanson; Martha Wright

1999-01-01

419

High-sensitivity measurement of diverse vascular plant-derived biomarkers in high-altitude ice cores  

Microsoft Academic Search

Semi-volatile organic compounds derived from burned and fresh vascular plant sources and preserved in high-altitude ice fields were detected and identified through use of recently developed analytical tools. Specifically, stir bar sorptive extraction and thermal desorption coupled with gas chromatography\\/time-of-flight mass spectrometry allowed measurement of multiple biomarkers in small sample volumes (?30 ml). Among other compounds of interest, several diterpenoids,

Matthew C. Makou; Lonnie G. Thompson; Daniel B. Montluçon; Timothy I. Eglinton

2009-01-01

420

Interaction between a plant-derived smoke extract, light and phytohormones on the germination of light-sensitive lettuce seeds  

Microsoft Academic Search

Plant-derived smoke extracts mimics the effect of red light on germination in light-sensitive lettuce seeds and partially overcomes the inhibitory effect of far-red light. Interaction between a smoke extract and gibberellins, cytokinins, abscisic acid and ethephon was investigated. Smoke acted synergistically with GA3 and increased the sensitivity of the lettuce seeds to ABA. It seems likely that smoke affects membrane

J. Staden; A. K. Jäger; A. Strydom

1995-01-01

421

Production of doubled haploids through anther culture of M 1 rice plants derived from mutagenized fertilized egg cells  

Microsoft Academic Search

To produce stable mutants from Mankeumbyeo, a japonica rice ( Oryza sativa L.) variety, we estimated the mutation efficiency of ethyl methane sulfonate (EMS) and N-methyl- N-nitrosourea (MNU) on fertilized egg cells using doubled haploids (DHs) derived from anther culture of M 1 plants. M 1seed production and germination were higher in 1 m M MNU than in 94.2 m M EMS.

S. Y. Lee; J. I. Cheong; T. S. Kim

2003-01-01

422

High frequency production of rapeseed transgenic plants via combination of microprojectile bombardment and secondary embryogenesis of microspore-derived embryos  

Microsoft Academic Search

Transgenic doubled haploid rapeseed (Brassica napus L. cvs. Global and PF704) plants were obtained from microspore-derived embryo (MDE) hypocotyls using the microprojectile bombardment. The binary vector\\u000a pCAMBIA3301 containing the gus and bar genes under control of CaMV 35S promoter was used for bombardment experiments. Transformed plantlets were selected and continuously\\u000a maintained on selective medium containing 10 mg l?1 phosphinothricin (PPT) and transgenic

M. R. Abdollahi; A. Moieni; A. Mousavi; A. H. Salmanian

2011-01-01

423

Antibiotic properties of extracts derived from medicinal plants with liquid carbon dioxide  

Microsoft Academic Search

UDC 615.779 We have studied the antimicrobial properties of substances extracted from spice-aromatic and medicinal plants. For evaluation of the antimicrobial activity of preparations isolated from plants, essential and extractive oils, alcohol-water extracts, freshly prepared slurry, and also tissue juices of the original raw material are used in general practice [1-3]. Substances isolated from plants that possess antimicrobial characteristics are

M. L. Khanin; A. I. Korotyaev; A. F. Prokopchuk; T. V. Perova; O. F. Vyazemskii

1968-01-01

424

Host Defense against Viral Infection Involves Interferon Mediated Down-Regulation of Sterol Biosynthesis  

PubMed Central

Little is known about the protective role of inflammatory processes in modulating lipid metabolism in infection. Here we report an intimate link between the innate immune response to infection and regulation of the sterol metabolic network characterized by down-regulation of sterol biosynthesis by an interferon regulatory loop mechanism. In time-series experiments profiling genome-wide lipid-associated gene expression of macrophages, we show a selective and coordinated negative regulation of the complete sterol pathway upon viral infection or cytokine treatment with IFN? or ? but not TNF, IL1?, or IL6. Quantitative analysis at the protein level of selected sterol metabolic enzymes upon infection shows a similar level of suppression. Experimental testing of sterol metabolite levels using lipidomic-based measurements shows a reduction in metabolic output. On the basis of pharmacologic and RNAi inhibition of the sterol pathway we show augmented protection against viral infection, and in combination with metabolite rescue experiments, we identify the requirement of the mevalonate-isoprenoid branch of the sterol metabolic network in the protective response upon statin or IFN? treatment. Conditioned media experiments from infected cells support an involvement of secreted type 1 interferon(s) to be sufficient for reducing the sterol pathway upon infection. Moreover, we show that infection of primary macrophages containing a genetic knockout of the major type I interferon, IFN?, leads to only a partial suppression of the sterol pathway, while genetic knockout of the receptor for all type I interferon family members, ifnar1, or associated signaling component, tyk2, completely abolishes the reduction of the sterol biosynthetic activity upon infection. Levels of the proteolytically cleaved nuclear forms of SREBP2, a key transcriptional regulator of sterol biosynthesis, are reduced upon infection and IFN? treatment at both the protein and de novo transcription level. The reduction in srebf2 gene transcription upon infection and IFN treatment is also found to be strictly dependent on ifnar1. Altogether these results show that type 1 IFN signaling is both necessary and sufficient for reducing the sterol metabolic network activity upon infection, thereby linking the regulation of the sterol pathway with interferon anti-viral defense responses. These findings bring a new link between sterol metabolism and interferon antiviral response and support the idea of using host metabolic modifiers of innate immunity as a potential antiviral strategy.

Blanc, Mathieu; Hsieh, Wei Yuan; Robertson, Kevin A.; Watterson, Steven; Shui, Guanghou; Lacaze, Paul; Khondoker, Mizanur; Dickinson, Paul; Sing, Garwin; Rodriguez-Martin, Sara; Phelan, Peter; Forster, Thorsten; Strobl, Birgit; Muller, Matthias; Riemersma, Rudolph; Osborne, Timothy; Wenk, Markus R.; Angulo, Ana; Ghazal, Peter

2011-01-01

425

Tritium Suicide Selection Identifies Proteins Involved in the Uptake and Intracellular Transport of Sterols in Saccharomyces cerevisiae  

Microsoft Academic Search

Sterol transport between the plasma membrane (PM) and the endoplasmic reticulum (ER) occurs by a nonve- sicular mechanism that is poorly understood. To identify proteins required for this process, we isolated Saccharo- myces cerevisiae mutants with defects in sterol transport. We used Upc2-1 cells that have the ability to take up sterols under aerobic conditions and exploited the observation that

David P. Sullivan; Alexander Georgiev; Anant K. Menon

2009-01-01

426

Stimulation of hepatic biogenesis of sterols on administration of adenosine compounds.  

PubMed Central

1. Re-feeding starved rats increased the biogenesis of sterols in livers, with highest activity at 6h after the start of food intake. 2. Complete deficiency of protein or fat and partial deficiency of carbohydrate in the diet had no effect on sterol biogenesis. 3. Glucose, citrate or pyruvate, when administered intraperitoneally to starved rats, stimulated the biogenesis of sterols only at high concentrations. 4. ATP given intraperitoneally at low concentrations (10mg/rat) stimulated biogenesis of sterols, but not of fatty acids, from [1-14C]acetate. This effect was also obtained with other adenosine compounds, but not with adenine or guanosine. 5. Administration of adenosine compounds to starved rats also increased the incorporation of [1-14C]acetate into sterols in liver slices and also the activity of microsomal 3-hydroxy-3-methylglutaryl-CoA reductase. The results suggest a regulatory role for adenosine compounds in the hepatic biogenesis of isoprenoid compounds.

Rao, G S; George, R; Ramasarma, T

1976-01-01

427

The Identification of CVP1 Reveals a Role for Sterols in Vascular Patterning  

PubMed Central

Vascular cell axialization refers to the uniform alignment of vascular strands. In the Arabidopsis cotyledon vascular pattern1 (cvp1) mutant, vascular cells are not arranged in parallel files and are misshapen, suggesting that CVP1 has a role in promoting vascular cell polarity and alignment. Characterization of an allelic series of cvp1 mutations revealed additional functions of CVP1 in organ expansion and elongation. We identified CVP1 and found that it encode