Growth-Inhibiting Properties of Xylem Exudate From Vitis vinifera

1995 ◽  
Vol 22 (1) ◽  
pp. 7 ◽  
Author(s):  
JA Campbell ◽  
BR Loveys ◽  
VWK Lee ◽  
S Strother
Keyword(s):  
Vitis Vinifera ◽  
Inhibitory Activity ◽  
Lemna Minor ◽  
Growth Inhibitor ◽  
Inhibitory Effect ◽  
Vitis Vinifera L ◽  
Inhibitory Effects ◽  
Inhibitor Activity ◽  
Xylem Exudate ◽  
Growth Inhibiting

An inhibitory effect on the growth of Lemna minor L. cultures has been demonstrated in xylem exudate from Vitis vinifera L. var. Waltham Cross bled from canes cut near the time of budburst. Most inhibitory activity was detected up to the time of maximal daily exudation, which corresponded closely with budburst. After this time the inhibitory activity rapidly disappeared. A similar pattern occurred in each of the 3 years of the study, 1988-1990. Using ultrafiltration, it was shown that most of the growth inhibitor activity of the crude exudate was located in the 0.5-10 kDa fraction. This fraction exhibited a seasonal variation in its bioactivity similar to that ofthe crude exudate samples. The 0.5-10 kDa fraction was found to contain abscisic acid but not in a sufficient quantity to account for the inhibitory effects. When chromatographically separated fractions corresponding to oligosaccharides were pooled, biological activity equivalent to that of the crude exudate was retained, which provides evidence that the inhibitor is possibly an oligosaccharide.

Seasonal Variation in pH, Carbohydrate and Nitrogen of Xylem Exudation of Vitis vinifera

1996 ◽  
Vol 23 (1) ◽  
pp. 115 ◽  
Author(s):  
JA Campbell ◽  
S Strother
Keyword(s):  
Seasonal Variation ◽  
Vitis Vinifera ◽  
Growth Inhibitor ◽  
Vitis Vinifera L ◽  
Ph Variation ◽  
Xylem Exudate ◽  
Carbohydrate Concentration ◽  
Plant Growth Inhibitor ◽  
Zero Values ◽  
Xylem Exudation

Over two seasons, 1989 and 1990, pH and carbohydrate concentration of the xylem exudate of Vitis vinifera L. var. Waltham Cross were examined around the time of budburst. During this period in 1990, weekly determinations of NH4+ and NO3- concentrations in xylem exudate were also performed. Over the 2 years, exudate pH varied inversely with daily exudate flow, falling from plateau levels of approximately pH 6.0 to lower than pH 5.5 around the date of greatest daily exudation, then rising again to a plateau of about pH 7.5. Exudate carbohydrate concentration variations were also consistent over the 2 years of the study, falling from plateau values of approximately 120 mg glucose equivalents L-1 (approximately 660 μM) at or immediately prior to the date of maximal exudation flow, to zero values within 4 weeks. These data, as well as reflecting a mobilisation of stored carbohydrates to apical tissues prior to budburst, also concur with previously observed activities of an apparently carbohydrate plant growth inhibitor in grapevine exudate. Exudate NH4+ and NO3- concentrations both increased directly with exudate flow up to the date of maximal daily exudation, then fell again to lower levels. Unlike seasonal pH variation, NH4+ and NO3- concentrations were not significantly correlated to daily exudate volume. The seasonal variations in pH infer a flow-dependent mobilisation from storage tissues, the reasons for which at budburst are discussed.

scholarly journals Melanogenesis Inhibitory Activity of Diterpenoid and Triterpenoid Constituents from the Aerial Part of Isodon trichocarpus

2017 ◽  
Vol 12 (8) ◽  
pp. 1934578X1701200
Author(s):  
Yoshiaki Manse ◽  
Kiyofumi Ninomiya ◽  
Akane Okazaki ◽  
Eriko Okada-Nishida ◽  
Takahiro Imagawa ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Aerial Part ◽  
Methanol Extract ◽  
Inhibitory Effect ◽  
B16 Melanoma ◽  
Related Protein ◽  
Inhibitory Effects

A methanol extract from the aerial part of Isodon trichocarpus (Labiatae) demonstrated inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells (IC50 = 1.6 μg/mL). From the extract, nine diterpenoids (1–9) and four triterpenoids (10–13) were isolated. Among the isolates, enmein (1, IC50 = 0.22 μM), isodocarpin (2, 0.19 μM), nodosin (4, 0.46 μM), and oridonin (6, 0.90 μM) showed an inhibitory effect without notable cytotoxicity at the effective concentrations. These diterpenoids (1, 2, 4, and 6) inhibited the expression of tyrosinase, tyrosine-related protein (TRP)-1, and TRP-2 mRNA, which could be the mechanism of melanogenesis inhibitory activity.

Inhibitory effect of phenolic compounds from grape seeds (Vitis vinifera L.) on the activity of angiotensin I converting enzyme

LWT ◽  
2013 ◽  
Vol 54 (1) ◽  
pp. 265-270 ◽  
Author(s):  
Joana Afonso ◽  
Cláudia P. Passos ◽  
Manuel A. Coimbra ◽  
Carlos M. Silva ◽  
Patrício Soares-da-Silva
Keyword(s):  
Phenolic Compounds ◽  
Vitis Vinifera ◽  
Inhibitory Effect ◽  
Vitis Vinifera L ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Grape Seeds ◽  
Angiotensin I Converting Enzyme

scholarly journals The inhibition of glucosylceramide β-glucosidase and other acid hydrolases by nucleic acids

1988 ◽  
Vol 254 (1) ◽  
pp. 297-300 ◽  
Author(s):  
A Sano ◽  
N S Radin
Keyword(s):  
Absorption Spectrum ◽  
Nucleic Acids ◽  
Protein Content ◽  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
Acid Hydrolases ◽  
Activator Protein ◽  
Excess Amount ◽  
Beta Glucosidase

During the isolation of the activator protein for glucosylceramide beta-glucosidase, we found that certain column fractions contained an inhibitor of the enzyme. After separation from the activator protein by a DEAE-Sephacel column, the inhibitor was purified further with a Spehadex G-75 column. The u.v. absorption spectrum of the purified material was similar to that of nucleic acids and the protein content of the purified material was negligible. Furthermore the purified inhibitor reacted with orcinol but not with diphenylamine, and its inhibitory activity was completely destroyed by treatment with RNAases. It seems likely that the purified inhibitor was tRNA. Authentic RNA, tRNA and DNA had similar inhibitory effects on beta-glucosidase (Ki 17 micrograms/ml for tRNA, noncompetitive toward the substrate). The inhibitory effect of nucleic acids was not fully overcome by an excess amount of the activator protein, but phosphatidylserine could restore the activity to normal. Tests with several other hydrolases revealed that the inhibitory effect of nucleic acids was fairly general.

Effect of Azadirachta indica A. Juss var indica, Nicotiana tabacum L., and Derris elliptica (Roxb.) on Growth of Duckweed

2014 ◽  
Vol 1060 ◽  
pp. 211-214
Author(s):  
Patamawan Phuagphong ◽  
Srisombat Nawanopparatsakul ◽  
Nudchanart Kitcharoen
Keyword(s):  
Nicotiana Tabacum ◽  
Azadirachta Indica ◽  
Lemna Minor ◽  
Cost Effective ◽  
Inhibitory Effect ◽  
Test Method ◽  
Biological Weed Control ◽  
Inhibitory Effects ◽  
Natural Herbicides ◽  
Extraction Solvents

The study was designed to evaluate the inhibitory effects of selected herbs on plant growth. Three insecticides containing plants (leaf of Azadirachta indica A. Juss var indica (AI), Nicotiana tabacum L. (NT), and root of Derris elliptica (Roxb.) (DE) were selected for various solvent extractions. Five extraction solvents: methanol, hexane, dichloromethane, butanol and aqueous were used in this study. The test method was lemna phytotoxicity assay which measured the inhibitory effect on duckweed, Lemna minor growth. This toxicity test proved to be a practical bioassay method because this method is simple, sensitive and cost effective. Butanol extracts of AI were shown to have more inhibition activity on duckweed growth than NT (% inhibition growth rate is 66.08, 27.08 respectively). Butanol extracts of AI had inhibitory effect (EC10) of 40.87 μg/ ml while dichloromethane extracts had EC10 of 131.72 μg/ ml. It could therefore be concluded that butanol extracts of AI showed the greatest inhibitory effects. The results from this study suggest that butanol extracts of AI were the most promising candidates for biological weed control and might be used as potential natural herbicides or as alternatives for the reduction of chemical herbicides. The study is worthy of further investigation since this could provide potential bioherbicide and may lead to the discovery of new effective and applicable bioherbicide.

Enhanced Inhibition of Escherichia coli O157:H7 by Lysozyme and Chelators

2003 ◽  
Vol 66 (10) ◽  
pp. 1783-1789 ◽  
Author(s):  
J. S. BOLAND ◽  
P. M. DAVIDSON ◽  
J. WEISS
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Activity ◽  
Chelating Agents ◽  
Inhibitory Effect ◽  
Escherichia Coli O157 ◽  
Inhibitory Effects ◽  
Antimicrobial Spectrum ◽  
E Coli ◽  
Dilution Assay ◽  
Microbroth Dilution

This study examined the effects of three chelating agents (EDTA, disodium pyrophosphate [DSPP], and pentasodium tripolyphosphate [PSTPP]) on the inhibition of the growth of Escherichia coli O157:H7 by lysozyme. The objective of this study was to identify replacement chelators that exhibit synergistic properties similar to those of EDTA. The inhibitory effects of EDTA at 300 to 1,500 μg/ml and of DSPP and PSTPP at 3,000 to 15,000 μg/ml in combination with lysozyme at 200 to 600 μg/ml for up to 48 h at pHs of 6.0, 7.0, and 8.0 on four strains of E. coli O157:H7 was studied with the use of a microbroth dilution assay. The addition of EDTA enhanced lysozyme's inhibitory effect on strains of E. coli O157:H7. EDTA at ≥300 μg/ml combined with lysozyme at 200 to 600 μg/ml was sufficient to inhibit the growth of the strains at pHs of 6.0 and 8.0. At pH 7.0, lysozyme at 200 to 600 μg/ml and EDTA concentrations of ≥1,000 μg/ml were effective in inhibiting three of the four strains. DSPP at pH 6.0 was inhibitory at ≥10,000 μg/ml when combined with lysozyme at 200 to 300 μg/ml. In contrast, PSTPP increased the inhibitory activity of lysozyme more effectively at pH 8.0. Lysozyme at 200 to 600 μg/ml was effective against two strains of E. coli O157:H7 when used in conjunction with PSTPP at ≥5,000 μg/ml. The remaining strains were inhibited by PSTPP at ≥10,000 μg/ml. Our results indicate that inhibition occurred with each lysozyme-chelator combination, but the concentrations of phosphates required to increase the antimicrobial spectrum of lysozyme against E. coli O157:H7 were higher than the EDTA concentrations required to achieve the same effect.

Evaluation of some plants for potential dipeptidyl peptidase IV inhibitory effects in vitro

2015 ◽  
Vol 40 (3) ◽  
Author(s):  
Ali Zeytünlüoğlu ◽  
Figen Zihnioğlu
Keyword(s):  
Inhibitory Activity ◽  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Vitis Vinifera L ◽  
Aqueous Extracts ◽  
Inhibitory Effects ◽  
Dpp Iv ◽  
Ic50 Values ◽  
Glucagon Like Peptide 1

AbstractObjective: Dipeptidyl peptidase IV (DPP IV) is a serine amino (exo) peptidase which regulates various processes most notably plasma glucose homeostasis by cleaving incretin peptide hormones as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulin releasing polypeptide (GIP). Realization of the inhibition of this enzyme in controlling diabetes is one of the strategies adopted in recent years. The present study was designed to investigate the DPP IV inhibitory effects of sixteen plant having antidiabetic property in aqueous extracts in correlation with their protein content.Methods: In vitro DPP IV inhibition was evaluated by the specific inhibitory activity of plant aqueous extracts prepared without and with heat (60°C) treatment.Results: Among the tested plants Vitis vinifera L., Artemisia dracunculus L., Prunus laurocerasus L., Rubus caesius L. and Olea europaea L. extracts showed DPP IV inhibitory activity with respect to IC50 values of 0.04-0.09 mg protein/ml. Kinetic analysis indicated that the inhibitor potency of A. dracunculus extract was stronger than the other extracts.Conclusion: The present study is the first report on screening and preliminary characterization of DPP IV inhibitory activity in aqueous extracts of selected antidiabetic medicinal food. This study could provide a new insight into DPP IV inhibitors from plants that could be useful for treatment of Type 2 diabetes.

scholarly journals New Insights into the Exploitation of Vitis vinifera L. cv. Aglianico Leaf Extracts for Nutraceutical Purposes

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 708 ◽  
Author(s):  
Fabiana Labanca ◽  
Immacolata Faraone ◽  
Maria Rosaria Nolè ◽  
Ruth Hornedo-Ortega ◽  
Daniela Russo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vitis Vinifera ◽  
Inhibitory Activity ◽  
Vitis Vinifera L ◽  
Ultrasound Assisted Extraction ◽  
Leaf Extracts ◽  
Assisted Extraction ◽  
Long Time ◽  
Bioactive Potential ◽  
First Time

The leaves of Vitis vinifera L. have been used for a long time in traditional medicine for the treatment of many ailments. Grape polyphenols, indeed, have been demonstrated to be able to defend against oxidative stress, responsible for various disorders such as cancer, diabetes and neurodegenerative diseases. The effects of different extraction techniques, Soxhlet (SOX), Accelerated Solvent (ASE 40, ASE 50) and Ultrasound Assisted Extraction (UAE) were studied in this work to evaluate their impact on the chemical profile and bioactive potential of Vitis vinifera L. (cv. Aglianico) leaf extracts. The phytochemical profile was investigated by HPLC-DAD and 9 phenolic compounds were identified and quantified in the extract. Moreover, the antioxidant, anticholinesterase and antityrosinase activities were evaluated. In detail, the total polyphenol content and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl, Oxygen Radical Absorbance Capacities and β-Carotene Bleaching assays) were evaluated and compared to assess the Relative Antioxidant Capacity Index (RACI). To test the inhibitory activity of extracts towards cholinesterases, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition assays were performed. SOX and ASE 50 have shown the highest value of RACI, 0.76 and 0.65, respectively. Regarding enzymatic inhibitory activity, ASE 50 (IC50 = 107.16 ± 8.12 μg/mL) and SOX (IC50 = 171.34 ± 12.12 μg/mL) extracts exhibited the highest AChE and BChE inhibitory activity, respectively, while UAE (IC50 = 293.2 ± 25.6 μg/mL, followed by SOX (IC50 = 302.5 ± 38.3 μg/mL) showed the highest tyrosinase inhibition value. Our results demonstrated for the first time that Aglianico leaves are important sources of phenols that could be used to prevent oxidative stress and be potentially helpful in diseases treatable with tyrosinase and cholinesterase inhibitors, like myasthenia gravis or Alzheimer’s.

The Mode of Action of Endosidin20 Differs from That of Other Cellulose Biosynthesis Inhibitors

2020 ◽  
Author(s):  
Lei Huang ◽  
Chunhua Zhang
Keyword(s):  
Plant Growth ◽  
Broad Spectrum ◽  
Mode Of Action ◽  
Catalytic Domain ◽  
Growth Inhibitor ◽  
Inhibitory Effect ◽  
Missense Mutations ◽  
Cellulose Biosynthesis ◽  
Inhibitory Effects ◽  
Synergistic Inhibitory Effect

Abstract Endosidin20 (ES20) was recently identified as a cellulose biosynthesis inhibitor (CBI) that targets the catalytic domain of CELLULOSE SYNTHASE 6 (CESA6) and thus inhibits the growth of Arabidopsis thaliana. Here, we characterized the effects of ES20 on the growth of other plant species and found that ES20 is a broad-spectrum plant growth inhibitor. We tested the inhibitory effects of previously characterized CBIs (isoxaben, indaziflam and C17) on the growth of Arabidopsis cesa6 mutants that have reduced sensitivity to ES20. We found that most of these mutants are sensitive to isoxaben, indaziflam and C17, indicating that these tested CBIs have a different mode of action than ES20. ES20 also has a synergistic inhibitory effect on plant growth when jointly applied with other CBIs, further confirming that ES20 has a different mode of action than isoxaben, indaziflam and C17. We demonstrated that plants carrying two missense mutations conferring resistance to ES20 and isoxaben can tolerate the dual inhibitory effects of these CBIs when combined. ES20 inhibits Arabidopsis growth in growth medium and in soil following direct spraying. Therefore, our results pave the way for using ES20 as a broad-spectrum herbicide, and for the use of gene-editing technologies to produce ES20-resistant crop plants.

scholarly journals Cholinesterase and microbial inhibitory activities of Tetrapleura tetraptera

2012 ◽  
Vol 4 (2) ◽  
pp. 156-163
Author(s):  
N. E. Okoronkwo ◽  
J. O. Echeme
Keyword(s):  
Inhibitory Activity ◽  
Water Extract ◽  
Antimicrobial Activities ◽  
Inhibitory Effect ◽  
Klebsiella Pneumonia ◽  
Inhibitory Effects ◽  
Continuous Increase ◽  
Water Extracts ◽  
Tetrapleura Tetraptera ◽  
Inhibitory Activities

The cholinesterase and microbial inhibitory activities of different parts of Tetrapleura tetraptera plant were evaluated due to their local applications. The cholinesterase results revealed that the extracts showed some levels of inhibitory effects depending on the solvents used. Tetrapleura tetraptera leaves had better inhibitory effects with maximum inhibitory activity of 70.0% at a concentration of 1.00mg/l for the water extract. Tetrapleura tetraptera bark showed highest inhibitory effect of 71.05% and (84.34%) for the ethanol and chloroform extracts at concentrations of 0.5mg/l and 1.0 mg/l respectively. While for petroleum ether, T. tetraptera bark recorded 74.34% inhibitory effect at concentration of 2.0 mg/l and also showed continuous increase in inhibitory activity as the concentration increases for aqueous methanol. The results of the antimicrobial activities showed that among all the test organisms, theethanol and water extracts of the leaves, stem, bark and root of the plants had promising activity against Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa and Klebsiella pneumonia bacteria and Aspergillus fumigatus and Rhizopus species fungi. There was no activity shown by the ethanol and water extracts ofthe parts of the plants with Fugarium oxysporum, Penicillium chrysogenum and Mucor species fungi. The bacteria strains were more sensitive to the tested extracts than the fungi strains.

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