scholarly journals Main Allelochemicals from the Rhizosphere Soil of Saussurea lappa (Decne.) Sch. Bip. and Their Effects on Plants’ Antioxidase Systems

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2506 ◽  
Author(s):  
Jingkun Liu ◽  
Min Xie ◽  
Xiuzhuang Li ◽  
Hui Jin ◽  
Xiaoyan Yang ◽  
...  
Keyword(s):  
Rhizosphere Soil ◽  
Membrane Damage ◽  
Significant Inhibition ◽  
Dependent Manner ◽  
Plant Interactions ◽  
Concentration Dependent Manner ◽  
Saussurea Lappa ◽  
Plant Environment ◽  
The Media ◽  
Dehydrocostus Lactone

Allelochemicals are the media of allelopathy and form the chemical bases of plant-environment interactions. To determine true allelochemicals and their autotoxic effects, seven compounds were isolated and identified from in-situ sampled rhizosphere soil of cultivated Saussurea lappa. Of these; costunolide (2), dehydrocostus lactone (3) and scopoletin (4) showed significant inhibition on seedling growth in a concentration-dependent manner. Detection and observation demonstrated that the antioxidase system was found to be affected by these chemicals, resulting in the accumulation of ROS and membrane damage. To investigate their release ways, the compounds were traced back and volumes quantified in rhizosphere soil and plant tissues. This work made clear the chemical bases and their physiological effects on the plants. These chemicals were found to be the secondary metabolites of the plants and included in the rhizosphere soil. The findings identified a potential pathway of plant-plant interactions, which provided theoretical basis to overcoming replanting problems. This research was also useful for exploring ecological effects of allelochemicals in green agriculture.

scholarly journals Inhibition of Cytochrome P450 (CYP450) Isoforms by Isoniazid: Potent Inhibition of CYP2C19 and CYP3A

2001 ◽  
Vol 45 (2) ◽  
pp. 382-392 ◽  
Author(s):  
Zeruesenay Desta ◽  
Nadia V. Soukhova ◽  
David A. Flockhart
Keyword(s):  
Cytochrome P450 ◽  
Liver Microsomes ◽  
Cost Effective ◽  
Competitive Inhibitor ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Specific Substrate ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
The Mean

ABSTRACT Isoniazid (INH) remains the most safe and cost-effective drug for the treatment and prophylaxis of tuberculosis. The use of INH has increased over the past years, largely as a result of the coepidemic of human immunodeficiency virus infection. It is frequently given chronically to critically ill patients who are coprescribed multiple medications. The ability of INH to elevate the concentrations in plasma and/or toxicity of coadministered drugs, including those of narrow therapeutic range (e.g., phenytoin), has been documented in humans, but the mechanisms involved are not well understood. Using human liver microsomes (HLMs), we tested the inhibitory effect of INH on the activity of common drug-metabolizing human cytochrome P450 (CYP450) isoforms using isoform-specific substrate probe reactions. Incubation experiments were performed at a single concentration of each substrate probe at its Km value with a range of INH concentrations. CYP2C19 and CYP3A were inhibited potently by INH in a concentration-dependent manner. At 50 μM INH (∼6.86 μg/ml), the activities of these isoforms decreased by ∼40%. INH did not show significant inhibition (<10% at 50 μM) of other isoforms (CYP2C9, CYP1A2, and CYP2D6). To accurately estimate the inhibition constants (Ki values) for each isoform, four concentrations of INH were incubated across a range of five concentrations of specific substrate probes. The meanKi values (± standard deviation) for the inhibition of CYP2C19 by INH in HLMs and recombinant human CYP2C19 were 25.4 ± 6.2 and 13 ± 2.4 μM, respectively. INH showed potent noncompetitive inhibition of CYP3A (Ki = 51.8 ± 2.5 to 75.9 ± 7.8 μM, depending on the substrate used). INH was a weak noncompetitive inhibitor of CYP2E1 (Ki = 110 ± 33 μM) and a competitive inhibitor of CYP2D6 (Ki = 126 ± 23 μM), but the mean Ki values for the inhibition of CYP2C9 and CYP1A2 were above 500 μM. Inhibition of one or both CYP2C19 and CYP3A isoforms is the likely mechanism by which INH slows the elimination of coadministered drugs, including phenytoin, carbamazepine, diazepam, triazolam, and primidone. Slow acetylators of INH may be at greater risk for adverse drug interactions, as the degree of inhibition was concentration dependent. These data provide a rational basis for understanding drug interaction with INH and predict that other drugs metabolized by these two enzymes may also interact.

The Inhibitory Effect of Herbal Medicine -Dai Kenchu To (DKT)- on the Colonic Motility in Rats In Vitro

2001 ◽  
Vol 29 (01) ◽  
pp. 111-118 ◽  
Author(s):  
Mohammad Alhakam Tulimat ◽  
Tadashi Ishiguchi ◽  
Susumu Kurosawa ◽  
Takashi Nakamura ◽  
Toku Takahashi
Keyword(s):  
Herbal Medicine ◽  
Colonic Motility ◽  
Distal Colon ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Ginseng Root ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Beneficial Effects

Dai-Kenchu-To (DKT) is a herbal medicine and is currently used as the treatment of paralytic ileus in Japan. We investigated the mechanism of beneficial effects of DKT in vitro. DKT-extract powder (DKT-EP; 30–300 μg/ml) caused a significant inhibition on carbachol (CCH; 10-6)-induced contraction in a concentration dependent manner of the rat distal colon. DKT-EP (100 μg/ml) consists of 20 μg/ml of Zanthoxylum Fruit, 30 μg/ml of Ginseng Root and 50 μg/ml of Ginger Rhizome. Although each of them had no effect on CCH-induced muscle contraction, the combination of three ingredients caused a significant inhibition on CCH-induced contraction.

scholarly journals Saussurea lappa Clarke extract exhibits potent antioxidant effect and attenuates neuroinflammatory responses in lipopolysaccharide-stimulated microglial cells

2020 ◽  
Vol 19 (9) ◽  
pp. 1911-1917
Author(s):  
Sung-Gyu Lee ◽  
Hyun Kang
Keyword(s):  
Nitric Oxide ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Enzyme Linked Immunosorbent Assay ◽  
No Production ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Saussurea Lappa ◽  
Tnf Α

Purpose: To investigate the antioxidant and anti-neuroinflammatory potential of Saussurea lappa Clarke (SLC-EA) extract in LPS-stimulated BV-2 microglial cells.Methods: Cell viability was measured by using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay while antioxidant activity was evaluated by using the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. Lipopolysaccharide (LPS) was used to stimulate BV-2 microglia. Griess assay was employed to assess nitric oxide (NO) production. iNOS (inducible NO synthase) expression and TNF-α (tumor necrosis factor-alpha) cytokine production were measured by ELISA (enzyme-linked immunosorbent assay) and immuno blot analysis, respectively.Results: Pretreatment of 100 mg/ml of SLC-EA (p < 0.001) was inhibited Nitric Oxide (NO) by 1 ug/ml of LPS-treated murine BV-2 cells. The expression of iNOS and TNF-α were reduced by SLC-EA concentration dependent manner (p < 0.001 at 100 mg/ml). SLC-EA were scavenged 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent manner with an IC50 value of approximately 51.4 μg/ml.Conclusion: The results indicate that SLC-EA extract exhibits strong antioxidant properties and inhibits excessive pro-inflammatory cytokine due probably to the antioxidant phenolic compounds present in SLC-EA extract. Further work in exploring the in-depth mechanisms of SLC-EA extract in regulating inflammatory signaling pathways in treating neuroinflammatory diseases is necessary. Keywords: Saussurea lappa, Antioxidant, Neuroinflammation, Microglia, TNF-α, iNOS

Physico-chemical behaviour and algal toxicity of nanoparticulate CeO2 in freshwater

2010 ◽  
Vol 7 (1) ◽  
pp. 50 ◽  
Author(s):  
Nicola J. Rogers ◽  
Natasha M. Franklin ◽  
Simon C. Apte ◽  
Graeme E. Batley ◽  
Brad M. Angel ◽  
...  
Keyword(s):  
Membrane Damage ◽  
Particle Interaction ◽  
Algal Growth ◽  
Oxidative Activity ◽  
Pseudokirchneriella Subcapitata ◽  
Light Illumination ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
A Cell ◽  
Physical And Chemical

Environmental context. It cannot be assumed that nanomaterials entering aquatic environments will have the same impacts on aquatic biota as their macroscopic particle equivalents. If their toxicities are different, this will have implications for the way in which nanomaterial usage is regulated. Algae, at the bottom of the food chain, are likely to be a sensitive indicator of toxic effects. Understanding the physical and chemical factors controlling nanoparticle toxicity to algae will assist in evaluating their ecological risk. Abstract. In assessing the risks posed by nanomaterials in the environment, the overriding research challenges are to determine if nanomaterials are more toxic than the bulk forms of the same material, and the extent to which toxicity is governed by particle size and reactivity. In this study, the toxicity of nanoparticulate CeO2 (nominally 10–20 nm) to the freshwater alga Pseudokirchneriella subcapitata was compared to the same material at the micron size (nominally <5 μm). Growth inhibition experiments revealed inhibitory concentration values, giving 50% reduction in algal growth rate after 72 h (IC50), of 10.3 ± 1.7 and 66 ± 22 mg L–1 for the nanoparticles and bulk materials respectively. Cells exposed to CeO2 particles were permeable to the DNA-binding dye SYTOX® Green in a concentration-dependent manner indicating damage to the cell membrane. Screening assays to assess the oxidative activity of the particles showed that the light illumination conditions used during standard algal bioassays are sufficient to stimulate photocatalytic activity of CeO2 particles, causing the generation of hydroxyl radicals and peroxidation of a model plant fatty acid. No oxidative activity or lipid peroxidation was observed in the dark. These findings indicate that inhibitory mode of action of CeO2 to P. subcapitata is mediated by a cell-particle interaction causing membrane damage. The effect is most likely photochemically induced and is enhanced for the nanoparticulate form of the CeO2.

Inhibition of amyloid fibrillation of HEWL by 4-methylcoumarin and 4- methylthiocoumarin derivatives

2020 ◽  
Vol 21 ◽  
Author(s):  
Shivani Kumar ◽  
Manoj Kumar ◽  
Yogesh Kumar Tyagi ◽  
Suresh Kumar
Keyword(s):  
Molecular Dynamics ◽  
Protein Aggregation ◽  
Fibril Formation ◽  
Significant Inhibition ◽  
Fluorescence Assay ◽  
Intrinsic Fluorescence ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Amyloid Fibrillation

Background: Several human diseases like Parkinson’s, Alzheimer’s disease, and systemic amyloidosis are associated with the misfolding and aggregation of protein molecules. Objective: The present study demonstrated the comparison of 4-methyl coumarin and 4methylthiocoumarin derivative for their anti-amyloidogenic and disaggregation activity. The hen egg-white lysozyme is used as a model system to study protein aggregation and disaggregation under in vitro conditions. Methods: Techniques used in the study were Thioflavin T fluorescence assay, intrinsic fluorescence assay, circular dichroism, transmission electron microscopy, and molecular dynamics. Results: Fifteen compounds were screened for their anti-amyloidogenic and disaggregation potential. Six compounds significantly inhibited the fibril formation, whereas ten compounds showed disaggregation property of pre-formed fibrils. Under in vitro conditions, the compound C3 and C7 showed significant inhibition of fibril formation in a concentration-dependent manner as compared to control. C3 and C7 demonstrated 93% and 76% inhibition of fibril formation, respectively. Discussion: Furthermore, C3 and C7 exhibited 83% and 76% disaggregation activity, respectively, of pre-formed HEWL fibrils at their highest concentration. These anti-amyloidogenic and disaggregation potential of C3 and C7 were validated by intrinsic fluorescence, CD, molecular dynamics, and TEM study. Conclusion: C3 and C7 are novel 4-methylthiocoumarin derivatives that can be used as a lead for alleviation and symptoms associated with protein aggregation disorders.

scholarly journals Cytotoxic Effect of Resveratrol on Colorectal Cancer Cell Line

2020 ◽  
Vol 44 (1) ◽  
pp. 68-74
Author(s):  
Hussein A. Khayoon
Keyword(s):  
Colorectal Cancer ◽  
Cell Line ◽  
Cytotoxic Effect ◽  
Driving Forces ◽  
Cancer Cell Line ◽  
Negative Control ◽  
Significant Inhibition ◽  
Colorectal Cancer Cell Line ◽  
Dependent Manner ◽  
Concentration Dependent Manner

This study aimed to examine the cytotoxic effect of resveratrol as an anticancer in human colorectal cancer (HRT) cell line by assessment of its half-maximal inhibitory concentration (IC50) and its ability to inhibit the growth of these cancerous cells. Resveratrol inhibited the proliferation of HRT cell lines when used at different increased concentrations in this study (25, 50, 100, 200, 300) μmol respectively. These increased concentrations of resveratrol caused a corresponding significant inhibition in the growth percentage of the tested cancerous cell line (13%, 31.33%, 53.66%, 63.66 %, and 76.33%) respectively when compared with DMSO0.1% as negative control, in a concentration-dependent manner. Resveratrol at 300 μmol concentration showed the highest significant increase in the growth inhibitory percentage (76.33%). Moreover, resveratrol IC50 against (HRT) cell line was determined as 75.63 μmol. The study suggested a promising anticancer activity of resveratrol which can interfere with many dysregulated signaling pathways in transformed cells which are proposed to be driving forces for its anticancer effect.

scholarly journals Protein-lipid interaction at low pH induces oligomerisation of the MakA cytotoxin from Vibrio cholerae

2021 ◽  
Author(s):  
Aftab Nadeem ◽  
Alexandra Berg ◽  
Hudson Pace ◽  
Athar Alam ◽  
Eric Toh ◽  
...  
Keyword(s):  
Host Cell ◽  
Vibrio Cholerae ◽  
Pore Formation ◽  
Pathogenic Bacteria ◽  
Membrane Damage ◽  
Bacterial Toxin ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Membrane Pore

AbstractMany pathogenic bacteria produce protein toxins that target and perturb host cell membranes. The secreted α-pore-forming toxins (α-PFTs) cause membrane damage via pore formation. This study demonstrates a remarkable, hitherto unknown mechanism by an α-PFT protein from Vibrio cholerae. As part of the MakA/B/E tripartite toxin, MakA is involved in membrane pore formation similar to other α-PFTs. In contrast, MakA protein alone induces tube-like structures in the acidic lysosomal host cell compartment. In vitro studies unravel the dynamics of tubular growth, which occur in a pH-, lipid- and concentration-dependent manner. A 3.7-Å cryo-electron microscopy structure of MakA filaments reveals a unique protein-lipid superstructure. In its active α-PFT conformation, MakA embeds its transmembrane helices into a thin annular lipid bilayer and spirals around a central cavity. Our study provides molecular insights into a novel tubulation mechanism of an α-PFT protein, revealing a new mode of action by a secreted bacterial toxin.

scholarly journals Cytotoxic activity of the aqueous extract of Micromeria fruticosa (L.) Druce subsp. serpyllifolia on human U-87 MG cell lines

2017 ◽  
Vol 69 (3) ◽  
pp. 449-453 ◽  
Author(s):  
Kubra Koc ◽  
Ozlem Ozdemir ◽  
Faruk Kizilkaya ◽  
Meryem Sengul ◽  
Hasan Turkez
Keyword(s):  
Aqueous Extract ◽  
Membrane Damage ◽  
Folk Medicine ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cell Membrane Damage ◽  
Human Glioblastoma Multiforme ◽  
Total Antioxidant ◽  
High Concentrations ◽  
Micromeria Fruticosa

Micromeria fruticosa (L.) Druce subsp. serpyllifolia, which is widely used in folk medicine as a medicinal herbal tea, is grown in different areas of Turkey and the Mediterranean region. The present study was conducted to evaluate the aqueous extract of Micromeria fruticosa subsp. serpyllifolia for its antioxidant and antiproliferative activity on a human glioblastoma multiforme cell line (U-87 MG), which has not been reported before. Here, the extract was added to cultures at 8 different concentrations (0-200 ?g/mL). Cell viability and cell membrane damage was determined using the MTT and LDH assays for 48 h, respectively. To examine the oxidative effects, total antioxidant capacity (TAC) and total oxidant status (TOS) levels were measured. The extract displayed considerable antiproliferative activities at the high concentrations of 175 and 200 ?g/mL. Furthermore, the extract caused a significant increase in the release of the lactate dehydrogenase (LDH) enzyme in a concentration-dependent manner; 200 ?g/mL of extract enhanced the release of LDH. Treatments with extract at higher doses increased TOS levels and decreased TAC levels in human U-87 MG cells. Our study suggests that the aqueous extract of Micromeria fruticosa ssp. serpyllifolia was capable of inducing growth inhibition of cancer cells. These results encourage further research to assess the value of the extract in modern phytotherapy.

Inhibitory Activity of Extract, Fractions, and Compounds from Zingiber montanum Rhizomes on the Migration of Breast Cancer Cells

Planta Medica ◽  
2020 ◽  
Vol 86 (06) ◽  
pp. 387-394
Author(s):  
Mohammad Al-Amin ◽  
Nagla Mustafa Eltayeb ◽  
Chowdhury Faiz Hossain ◽  
Melati Khairuddean ◽  
Siti Sarah Fazalul Rahiman ◽  
...  
Keyword(s):  
Cell Migration ◽  
Inhibitory Activity ◽  
Gelatin Zymography ◽  
Significant Inhibition ◽  
Dependent Manner ◽  
Cell Viability Assay ◽  
Traditional Use ◽  
Concentration Dependent Manner ◽  
Scratch Assay ◽  
Migration Assay

Abstract Zingiber montanum rhizomes are traditionally used for the treatment of numerous human ailments. The present study was carried out to investigate the inhibitory activity of the crude extract, chromatographic fractions, and purified compounds from Z. montanum rhizomes on the migration of MDA-MB-231 cells. The effect of the extract on cell migration was investigated by a scratch assay, which showed significant inhibition in a concentration-dependent manner. Vacuum liquid chromatography on silica gel afforded four fractions (Frs. 1 – 4), which were tested on cell migration in the scratch assay. Frs. 1 and 2 showed the most significant inhibition of MDA-MB-231 cell migration. The effect of the most potent fraction (Fr. 2) was further confirmed in a transwell migration assay. The study of Frs. 1 and 2 by gelatin zymography showed significant inhibition of MMP-9 enzyme activity. Chromatographic separation of Frs. 1 and 2 afforded buddledone A (1), zerumbone (2), (2E,9E)-6-methoxy-2,9-humuradien-8-one (3), zerumbone epoxide (4), stigmasterol (5), and daucosterol (6). In a cell viability assay, compounds 1 – 4 inhibited the viability of MDA-MB-231 cells in a concentration-dependent manner. The study of buddledone A (1) and zerumbone epoxide (4) on cell migration revealed that 4 significantly inhibited the migration of MDA-MB-231 cells in both scratch and transwell migration assays. The results of the present study may lead to further molecular studies behind the inhibitory activity of zerumbone epoxide (4) on cell migration and support the traditional use of Z. montanum rhizomes for the treatment of cancer.

Diaryl-substituted carboranes as inhibitors of hypoxia inducible factor-1 transcriptional activity

2015 ◽  
Vol 87 (2) ◽  
pp. 143-154 ◽  
Author(s):  
Hiroyuki Nakamura ◽  
Lisa Tazaki ◽  
Daisuke Kanoh ◽  
Shinichi Sato
Keyword(s):  
Mrna Expression ◽  
Transcriptional Activity ◽  
Hypoxia Inducible Factor ◽  
Significant Inhibition ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
New Class ◽  
Hypoxia Inducible Factor 1 ◽  
High Yields

AbstractDiaryl-substituted carboranes, as a new class of HIF-1α inhibitors, were synthesized from the corresponding diaryl-substituted alkynes by decaborane coupling. The microwave-irradiated conditions with a combination of N,N-dimethylaniline and chlorobenzene were effective to obtain the diaryl-substituted carboranes in good to high yields. Among the compounds synthesized, compounds 1a and 1d showed significant inhibition of HIF-1 mediated transcriptional activity under hypoxia. Both compounds similarly suppressed hypoxia-induced HIF-1α accumulation in a concentration-dependent manner without affecting HIF-1α mRNA expression.

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