IMPACT OF SORBITOL- INDUCED OSMOTIC STRESS ON SOME BIOCHEMICAL TRAITS OF POTATO IN VITRO

2020 ◽  
Vol 51 (4) ◽  
pp. 1038-1047
Author(s):  
Mawia & et al.
Keyword(s):  
Ascorbic Acid ◽  
Osmotic Stress ◽  
Cytoplasmic Membrane ◽  
Genotypic Variation ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Culture Collection ◽  
Nutritive Medium ◽  
Starting Point

This study had as principal objective identification of osmotic-tolerant potato genotypes by using "in vitro" tissue culture and sorbitol as a stimulating agent, to induce water stress, which was added to the  culture nutritive medium in different concentration (0,50, 110, 220, 330 and 440 mM).  The starting point was represented by plantlets culture collection, belonging to eleven potato genotypes: Barcelona, Nectar, Alison, Jelly, Malice, Nazca, Toronto, Farida, Fabulla, Colomba and Spunta. Plantlets were multiplied between two internodes to obtain microcuttings (in sterile condition), which were inoculated on medium. Sorbitol-induced osmotic stress caused a significant reduction in the ascorbic acid, while the concentration of proline, H2O2 and solutes leakage increased compared with the control. Increased the proline content prevented lipid peroxidation, which played a pivotal role in the maintenance of membrane integrity under osmotic stress conditions. The extent of the cytoplasmic membrane damage depends on osmotic stress severity and the genotypic variation in the maintenance of membranes stability was highly associated with the ability of producing more amounts of osmoprotectants (proline) and the non-enzymic antioxidant ascorbic acid in response to osmotic stress level. The results showed that the genotypes Jelly, Nectar, Allison, Toronto, and Colomba are classified as highly osmotic stress tolerant genotypes, while the genotypes Nazca and Farida are classified as osmotic stress susceptible ones.

scholarly journals Role of ascorbic acid in promoting follicle integrity and survival in intact mouse ovarian follicles in vitro

Reproduction ◽  
2001 ◽  
pp. 89-96 ◽  
Author(s):  
AA Murray ◽  
MD Molinek ◽  
SJ Baker ◽  
FN Kojima ◽  
MF Smith ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Basement Membrane ◽  
Growth And Development ◽  
Culture Media ◽  
Membrane Integrity ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Follicular Growth ◽  
Intact Mouse

Ascorbic acid has three known functions: it is necessary for collagen synthesis, promotes steroidogenesis and acts as an antioxidant. Within the ovary, most studies have concentrated on the role of ascorbic acid in luteal formation and regression and little is known about the function of this vitamin in follicular growth and development. Follicular growth and development were investigated in this study using an individual follicle culture system that allows the growth of follicles from the late preantral stage to Graafian morphology. Follicles were isolated from prepubertal mice and cultured for 6 days. Control media contained serum and human recombinant FSH. Further groups of follicles were cultured in the same media but with the addition of ascorbic acid at concentrations of either 28 or 280 micromol l(-1). Addition of ascorbic acid at the higher concentration significantly increased the percentage of follicles that maintained basement membrane integrity throughout culture (P < 0.001). Ascorbic acid had no effect on the growth of the follicles or on oestradiol production. Metalloproteinase 2 activity tended to increase at the higher concentration of ascorbic acid and there was a significant concomitant increase in the activity of tissue inhibitor of metalloproteinase 1 (P < 0.01). Follicles cultured without the addition of serum but with FSH and selenium in the culture media underwent apoptosis. Addition of ascorbic acid to follicles cultured under serum-free conditions significantly reduced apoptosis (P < 0.05). From these data it is concluded that ascorbic acid is necessary for remodelling the basement membrane during follicular growth and that the ability of follicles to uptake ascorbic acid confers an advantage in terms of granulosa cell survival.

The antibacterial activity of BF-30 in vitro and in infected burned rats is through interference with cytoplasmic membrane integrity

Peptides ◽  
2011 ◽  
Vol 32 (6) ◽  
pp. 1131-1138 ◽  
Author(s):  
Huimin Zhou ◽  
Jie Dou ◽  
Jing Wang ◽  
Lili Chen ◽  
Hui Wang ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Cytoplasmic Membrane ◽  
Membrane Integrity

scholarly journals Potential Antioxidant Activity of New Tetracyclic and Pentacyclic Nonlinear Phenothiazine Derivatives

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Godwill Azeh Engwa ◽  
Eugene Lekem Ayuk ◽  
Benardeth Ujunwa Igbojekwe ◽  
Marcellus Unaegbu
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Membrane Damage ◽  
The Body ◽  
Phenothiazine Derivatives ◽  
Antioxidant Agents ◽  
Group 3

The global increase in oxidative stress related diseases such as cancer, cardiovascular, and inflammatory diseases caused by overwhelming level of free radicals in the body has encouraged the search for new antioxidant agents. Based on the ability of newly synthesized phenothiazine derivatives (6-chloro-11-azabenzo[a]phenothiazine-5-one and 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one) to oxidize H2O2, a known free radical to sulfoxide, this study assessed the in vitro and in vivo antioxidant activity. The synthesized phenothiazine derivatives exhibited reducing power potential to convert Fe3+to Fe2+and high ability to scavenge H2O2free radical in vitro. These activities were comparable to ascorbic acid, a standard antioxidant. The catalase activity significantly increased (p<0.05) in groups 1 and 2 animals that received the phenothiazine derivatives compared to the controls (groups 3 and 4) suggesting the ability of the phenothiazine derivatives to scavenge H2O2in vivo. The malondialdehyde level in groups 1 and 2 animals was lower than that in group 3 that received the reference compound (ascorbic acid) and group 4 that received the solvent suggesting the ability of the phenothiazine derivatives to prevent lipid membrane damage. AST and bilirubin levels were higher in group 2 animals which received 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one compared to group 3, the positive control. The results suggest that phenothiazine derivatives, especially 6-chloro-11-azabenzo[a]phenothiazine-5-one, possess antioxidant activity though 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one was slightly toxic. This activity may be due to the presence of electron donors such as sulfur as well as the richness of hydrogen in the additional benzene rings for substitution. Further study is needed to identify tolerable doses for possible therapeutic purposes.

scholarly journals Strategies to Investigate Membrane Damage, Nucleoid Condensation, and RNase Activity of Bacterial Toxin–Antitoxin Systems

2021 ◽  
Vol 4 (4) ◽  
pp. 71
Author(s):  
Stefano Maggi ◽  
Alberto Ferrari ◽  
Korotoum Yabre ◽  
Aleksandra Anna Bonini ◽  
Claudio Rivetti ◽  
...  
Keyword(s):  
Cell Transformation ◽  
Expression System ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Host Cells ◽  
Rnase Activity ◽  
Bacterial Toxin ◽  
Type I

A large number of bacterial toxin–antitoxin (TA) systems have been identified so far and different experimental approaches have been explored to investigate their activity and regulation both in vivo and in vitro. Nonetheless, a common feature of these methods is represented by the difficulty in cell transformation, culturing, and stability of the transformants, due to the expression of highly toxic proteins. Recently, in dealing with the type I Lpt/RNAII and the type II YafQ/DinJ TA systems, we encountered several of these problems that urged us to optimize methodological strategies to study the phenotype of recombinant Escherichia coli host cells. In particular, we have found conditions to tightly repress toxin expression by combining the pET expression system with the E. coli C41(DE3) pLysS strain. To monitor the RNase activity of the YafQ toxin, we developed a fluorescence approach based on Thioflavin-T which fluoresces brightly when complexed with bacterial RNA. Fluorescence microscopy was also applied to reveal loss of membrane integrity associated with the activity of the type I toxin Lpt, by using DAPI and ethidium bromide to selectively stain cells with impaired membrane permeability. We further found that atomic force microscopy can readily be employed to characterize toxin-induced membrane damages.

Abstract 8: GTPase-Activating Protein for Rho Associated with FAK (GRAF) Regulates Cardiomyocyte Membrane Integrity

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Thomas J O'Neill ◽  
Kaitlin Lenhart ◽  
Jason Doherty ◽  
Mauricio Rojas ◽  
Mack P Christopher ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Muscle Pathology ◽  
Blue Dye ◽  
Membrane Repair ◽  
Cell Membrane Damage ◽  
Deficient Mice

Cardiac myocytes are unique in their requirement to sustain continuous repetitive contraction in the setting of intense mechanical stress while simultaneously maintaining high membrane integrity for an appropriate electrical gradient. The consequence of failure of the membrane repair response has been highlighted in recent reports linking cardiomyocyte membrane fragility with cardiac degeneration in patients as well as in their analogous mouse models. Herein, we describe a novel role for GTPase activator for Rho associated with Focal Adhesion Kinase (GRAF) in regulating cardiomyocyte membrane integrity. We previously published that disruption of GRAF in Xenopus laevis resulted in progressive skeletal muscle degeneration. We now show that GRAF-depleted tadpoles exhibit defective cardiac formation and function. Interestingly, damage of muscle cells in vivo and in vitro led to a translocation of GRAF to the sarcolemma, suggesting that GRAF may be an important component of the cardiac membrane repair machinery. To further explore this possibility, we generated GRAF hypomorphic mice that exhibit greater than 99% reduction of endogenous GRAF expression. While GRAF deficient mice show normal Mendelian birth distribution and are viable, they exhibit a modest skeletal muscle pathology. Although baseline cardiac integrity was not compromised in GRAF deficient mice, treatment either with cardiotoxin or intraperitoneal injection of isoproterenol led to elevated cardiomyocyte membrane damage (assessed by Evan’s blue dye uptake) in GRAF deficient compared to control mice (19% vs 2% of myocytes within afflicted ventricular area for cardiotoxin, 18% vs 8% for isoproterenol respectively). Moreover, cultured GRAF null myocytes exhibited a significantly attenuated membrane resealing response following laser-mediated disruption compared to GRAF-containing control cells as assessed by accumulation of the membrane impermeable dye, FM-143. As well, the survival rate after injury of GRAF-deficient cells was markedly attenuated (20% vs 85% in control cells). While cardiac cell membrane damage is likely a frequent and important event, the repair process is currently understudied, and this is the first report to implicate a Rho regulator in this response.

scholarly journals Carvacrol exhibits rapid bactericidal activity against Streptococcus pyogenes through cell membrane damage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Niluni M. Wijesundara ◽  
Song F. Lee ◽  
Zhenyu Cheng ◽  
Ross Davidson ◽  
H. P. Vasantha Rupasinghe
Keyword(s):  
Cell Membrane ◽  
Streptococcus Pyogenes ◽  
Bactericidal Activity ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Streptococcal Pharyngitis ◽  
Cell Membrane Integrity ◽  
Cell Membrane Damage ◽  
Antibiotic Development

AbstractStreptococcus pyogenes is an important human pathogen worldwide. The identification of natural antibacterial phytochemicals has renewed interest due to the current scarcity of antibiotic development. Carvacrol is a monoterpenoid found in herbs. We evaluated carvacrol alone and combined with selected antibiotics against four strains of S. pyogenes in vitro. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of carvacrol against S. pyogenes were 125 µg/mL (0.53 mM) and 250 µg/mL (1.05 mM), respectively. Kill curve results showed that carvacrol exhibits instantaneous bactericidal activity against S. pyogenes. We also demonstrated the potential mechanism of action of carvacrol through compromising the cell membrane integrity. Carvacrol induced membrane integrity changes leading to leakage of cytoplasmic content such as lactate dehydrogenase enzymes and nucleic acids. We further confirmed dose-dependent rupturing of cells and cell deaths using transmission electron microscopy. The chequerboard assay results showed that carvacrol possesses an additive-synergistic effect with clindamycin or penicillin. Carvacrol alone, combined with clindamycin or penicillin, can be used as a safe and efficacious natural health product for managing streptococcal pharyngitis.

scholarly journals Nanoceria and bulk cerium oxide effects on the germination of asplenium adiantum-nigrum spores

2016 ◽  
Vol 25 (3) ◽  
pp. e067 ◽  
Author(s):  
Aranzazu Gomez-Garay ◽  
Beatriz Pintos ◽  
José Antonio Manzanera ◽  
Carmen Prada ◽  
Luisa Martin ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Cerium Oxide ◽  
Spore Germination ◽  
Germination Rate ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Engineered Nanoparticles ◽  
Cellular Damage ◽  
Effect Concentration

Aim of study: The effect of cerium oxide engineered nanoparticles on the spore germination of the fern. Asplenium adiantum-nigrum.Area of study: France, Britanny Region, Finistére Department, Plougonvelin, in rocks near the sea.Material and methods: Asplenium spores were cultured in vitro on agar medium with Nano-CeO2 (less than 25 nm particle size) and bulk-CeO2. The addition of each nano- and bulk particles ranged from 0 to 3000 mg L-1. Observations on rhizoidal and prothallial cells during first stages of gametophyte development were made. The No-Observed-Adverse-Effect concentration (NOAEC) and Lowest-Observed-Adverse-Effect-Concentration (LOEC) values for spore germination rate data were analyzed. Main results: Germination was speeded up by 100 to 2000 mg L-1 nanoceria, while bulk cerium oxide had the same effect for 500 to 200 mg L-1 concentrations. Present results showed cellular damage in the protonema while rhizoid cells seemed not to be affected, as growth and membrane integrity remained.Research highlights: Both nanosized and bulk cerium oxide are toxic for the fern Asplenium adiantum-nigrum, although diverse toxicity patterns were shown for both materials. Diverse toxic effects have been observed: chloroplast membrane damage and lysis, cell wall and membrane disruption which leads to cell lysis; and alterations in morphology and development.Keywords: Nanoparticles; rhizoid; prothallus; chloroplast; fern.

scholarly journals Clinically Relevant Concentrations of Polymyxin B and Meropenem Synergistically Kill Multidrug-Resistant Pseudomonas aeruginosa and Minimize Biofilm Formation

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 405
Author(s):  
Hasini Wickremasinghe ◽  
Heidi H. Yu ◽  
Mohammad A. K. Azad ◽  
Jinxin Zhao ◽  
Phillip J. Bergen ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Respiratory Infections ◽  
Population Analysis ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Bacterial Killing

The emergence of antibiotic resistance has severely impaired the treatment of chronic respiratory infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa. Since the reintroduction of polymyxins as a last-line therapy against MDR Gram-negative bacteria, resistance to its monotherapy and recurrent infections continue to be reported and synergistic antibiotic combinations have been investigated. In this study, comprehensive in vitro microbiological evaluations including synergy panel screening, population analysis profiling, time-kill kinetics, anti-biofilm formation and membrane damage analysis studies were conducted to evaluate the combination of polymyxin B and meropenem against biofilm-producing, polymyxin-resistant MDR P. aeruginosa. Two phylogenetically unrelated MDR P. aeruginosa strains, FADDI-PA060 (MIC of polymyxin B [MICpolymyxin B], 64 mg/L; MICmeropenem, 64 mg/L) and FADDI-PA107 (MICpolymyxin B, 32 mg/L; MICmeropenem, 4 mg/L) were investigated. Genome sequencing identified 57 (FADDI-PA060) and 50 (FADDI-PA107) genes predicted to confer resistance to a variety of antimicrobials, as well as multiple virulence factors in each strain. The presence of resistance genes to a particular antibiotic class generally aligned with MIC results. For both strains, all monotherapies of polymyxin B failed with substantial regrowth and biofilm formation. The combination of polymyxin B (16 mg/L)/meropenem (16 mg/L) was most effective, enhancing initial bacterial killing of FADDI-PA060 by ~3 log10 CFU/mL, followed by a prolonged inhibition of regrowth for up to 24 h with a significant reduction in biofilm formation (* p < 0.05). Membrane integrity studies revealed a substantial increase in membrane depolarization and membrane permeability in the surviving cells. Against FADDI-PA107, planktonic and biofilm bacteria were completely eradicated. In summary, the combination of polymyxin B and meropenem demonstrated synergistic bacterial killing while reinstating the efficacy of two previously ineffective antibiotics against difficult-to-treat polymyxin-resistant MDR P. aeruginosa.

scholarly journals Combinations of Trolox and ascorbic acid have a beneficial effect on in vitro maturation of pig oocytes

2021 ◽  
Author(s):  
Ileana Miclea ◽  
Marius Zahan
Keyword(s):  
Ascorbic Acid ◽  
Embryo Development ◽  
In Vitro Maturation ◽  
Polar Body ◽  
Membrane Damage ◽  
High Concentration ◽  
First Polar Body ◽  
Morula Stage ◽  
Vitro Development

Abstract: The poor in vitro development of pig oocytes and embryos has been blamed on oxidative stress. We sought to find out if combinations of Trolox (T), a synthetic and cell-permeable derivative of vitamin E, and ascorbic acid (AA) could improve the maturation rates of in vitro cultured pig oocytes. Pig oocytes underwent maturation for 44–45 h in medium M 199 supplemented with 0 μM T + 0 μM AA, 100 μM T + 250 μM AA, 300 μM T + 250 μM AA, 100 μM T + 750 μM AA or 300 μM T + 750 μM AA. These combinations were chosen based on previous research conducted in our laboratory and on the available literature. After maturation, several parameters were assessed: cumulus oophorus expansion, oocyte viability (based on the presence of metabolic activity versus membrane damage), extrusion of the first polar body, mitochondrial membrane potential (MMP), pronucleus formation, and embryo development after fertilization. All antioxidant combinations significantly improved cumulus expansion and formation of the first polar body. The best was 300 μM T + 250 μM AA for the first characteristic and 300 μM T + 750 μM AA for the second. Antioxidant presence in the maturation media increased the percentages of viable oocytes but not significantly. MMP was not significantly modified by the addition of antioxidant combinations. We also found that a low concentration of T (100 µM) mixed with a high concentration of AA (750 µM) in the oocyte maturation media led to significantly higher rates of both female and male pronuclei formation and also enhanced embryo development to the morula stage. Therefore, we recommend this combination to improve the in vitro maturation media of pig oocytes.  

scholarly journals Trichomonas vaginalisWeakens Human Amniochorion in an In Vitro Model of Premature Membrane Rupture

1995 ◽  
Vol 2 (6) ◽  
pp. 267-274 ◽  
Author(s):  
Deborah Draper ◽  
Ward Jones ◽  
R. Phillip Heine ◽  
Michelle Beutz ◽  
Janice I. French ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Fetal Membrane ◽  
Fetal Membranes ◽  
Ph Effects ◽  
Induced Membrane ◽  
Membrane Rupture ◽  
Membrane Strength

Objective: Trichomonas vaginalis (TV)infection is associated with preterm rupture of membranes (PROM) and preterm birth. We evaluated the effects ofTVgrowth and metabolism on preparations of human amniochorion to understand and characterize howTVmay impair fetal-membrane integrity and predispose to PROM and preterm birth.Methods:Term fetal membranes were evaluated using an established in vitro fetal-membrane model. FreshTVclinical isolates were obtained from pregnant women. The protozoa (5.0×105to1.5×106/ml) were incubated with fetal membranes in modified Diamond's medium for 20 h at 37°C in 5%CO2.The effects of fetal-membrane strength (bursting tension, work to rupture, and elasticity) were measured using a calibrated Wheatstone-bridge dynamometer. Tests were also performed to evaluate the effects of 1) inoculum size; 2) metronidazole (50 μg/ml); and 3) cell-free filtrate.Results:TheTV-induced membrane effects were 1) isolate variable; 2) inoculum dependent; 3) incompletely protected by metronidazole; and 4) mediated by both live organisms as well as protozoan-free culture filtrates. Six of 9 isolates significantly reduced the calculated work to rupture (P≤ 0.02); 7 of 9 reduced bursting tension; and 1 of 9 reduced elasticity. One isolate significantly increased the work to rupture and bursting tension (P≤ 0.002).Conclusions:In vitro incubation of fetal membranes withTVcan significantly impair the measures of fetal-membrane strength. This model may be used to delineate the mechanisms ofTV-induced membrane damage. This study suggests that there are enzyme-specific effects as well as pH effects.

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