scholarly journals Antibacterial and Antibiofilm Activity of Methanolic Plant Extracts against Nosocomial Microorganisms

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Eduardo Sánchez ◽  
Catalina Rivas Morales ◽  
Sandra Castillo ◽  
Catalina Leos-Rivas ◽  
Ledy García-Becerra ◽  
...  
Keyword(s):  
Plant Extracts ◽  
Lethal Dose ◽  
Artemia Salina ◽  
Antibiofilm Activity ◽  
Dependent Manner ◽  
Opuntia Ficus Indica ◽  
Abiotic Surfaces ◽  
Before And After ◽  
Dose Concentration ◽  
Well Assay

Biofilm is a complex microbial community highly resistant to antimicrobials. The formation of biofilms in biotic and abiotic surfaces is associated with high rates of morbidity and mortality in hospitalized patients. New alternatives for controlling infections have been proposed focusing on the therapeutic properties of medicinal plants and their antimicrobial effects. In the present study the antimicrobial and antibiofilm activities of 8 methanolic plant extracts were evaluated against clinical isolated microorganisms.Preliminary screening by diffusion well assay showed the antimicrobial activity ofProsopis laevigata,Opuntia ficus-indica, andGutierrezia microcephala. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined ranging from 0.7 to >15 mg/mL. The specific biofilm formation index (SBF) was evaluated before and after the addition of plant extracts (MBC × 0.75).Opuntia ficus-indicacaused the major reduction on SBF in dose-dependent manner. Cytotoxic activity of plant extracts was determined using brine shrimp lethality test (Artemia salinaL.). Lethal Dose concentration (LD50values) of the plant extracts was calculated. LD50values forP. laevigataandG. microcephalawere 141.6 and 323.3 µg/mL, respectively, whileO. ficus-indicashowed a slight lethality with 939.2 µg/mL. Phytochemical analyses reveal the presence of flavonoids, tannins, and coumarines.

The Effect of Active Site-inhibited Factor VIIa on Tissue Factor-initiated Coagulation Using Platelets before and after Aspirin Administration

1997 ◽  
Vol 78 (04) ◽  
pp. 1202-1208 ◽  
Author(s):  
Marianne Kjalke ◽  
Julie A Oliver ◽  
Dougald M Monroe ◽  
Maureane Hoffman ◽  
Mirella Ezban ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Active Site ◽  
Large Scale ◽  
Thrombin Generation ◽  
Factor Viia ◽  
Dependent Manner ◽  
Antithrombotic Agent ◽  
Before And After ◽  
Ic50 Values

SummaryActive site-inactivated factor VIIa has potential as an antithrombotic agent. The effects of D-Phe-L-Phe-L-Arg-chloromethyl ketone-treated factor VIla (FFR-FVIIa) were evaluated in a cell-based system mimicking in vivo initiation of coagulation. FFR-FVIIa inhibited platelet activation (as measured by expression of P-selectin) and subsequent large-scale thrombin generation in a dose-dependent manner with IC50 values of 1.4 ± 0.8 nM (n = 8) and 0.9 ± 0.7 nM (n = 7), respectively. Kd for factor VIIa binding to monocytes ki for FFR-FVIIa competing with factor VIIa were similar (11.4 ± 0.8 pM and 10.6 ± 1.1 pM, respectively), showing that FFR-FVIIa binds to tissue factor in the tenase complex with the same affinity as factor VIIa. Using platelets from volunteers before and after ingestion of aspirin (1.3 g), there were no significant differences in the IC50 values of FFR-FVIIa [after aspirin ingestion, the IC50 values were 1.7 ± 0.9 nM (n = 8) for P-selectin expression, p = 0.37, and 1.4 ± 1.3 nM (n = 7) for thrombin generation, p = 0.38]. This shows that aspirin treatment of platelets does not influence the inhibition of tissue factor-initiated coagulation by FFR-FVIIa, probably because thrombin activation of platelets is not entirely dependent upon expression of thromboxane A2.

scholarly journals Evaluation of Dimer of Epicatechin from an Endophytic Fungus Curvularia australiensis FC2AP on Acute Toxicity Levels, Anti-Inflammatory and Anti-Cervical Cancer Activity in Animal Models

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 654
Author(s):  
Vellingiri Manon Mani ◽  
Arockiam Jeyasundar Parimala Gnana Soundari ◽  
Balamuralikrishnan Balasubramanian ◽  
Sungkwon Park ◽  
Utthapon Issara ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Acute Toxicity ◽  
Endophytic Fungus ◽  
Lethal Dose ◽  
Chemotherapeutic Agents ◽  
Cancer Drug ◽  
Dependent Manner ◽  
Anti Cancer ◽  
Albino Mice ◽  
Anti Inflammatory

Cervical cancer, as the most frequent cancer in women globally and accounts almost 14% in India. It can be prevented or treated with vaccines, radiation, chemotherapy, and brachytherapy. The chemotherapeutic agents cause adverse post effects by the destruction of the neighboring normal cells or altering the properties of the cells. In order to reduce the severity of the side effects caused by the chemically synthesized therapeutic agents, the current research developed an anti-cancer agent dimer of epicatechin (DoE), a natural bioactive secondary metabolite (BSM) mediated from an endophytic fungus Curvularia australiensis FC2AP. The investigation has initiated with the evaluation of inhibiting the angiogenesis which is a main activity in metastasis, and it was assessed through Hen’s Egg Test on Chorio Allantoic Membrane (HET-CAM) test; the BSM inhibited the growth of blood vessels in the developing chick embryo. Further the DoE was evaluated for its acute toxicity levels in albino mice, whereas the survival dose was found to be 1250 mg/kg and the lethal dose was 1500 mg/kg body weight of albino mice; hematological, biochemical, and histopathological analyses were assessed. The anti-inflammatory responses of the DoE were evaluated in carrageenan induced Wistar rats and the reduction of inflammation occurred in a dose-dependent manner. By fixing the effective dose for anti-inflammation analysis, the DoE was taken for the anti-cervical cancer analysis in benzo (a) pyrene induced female Sprague-Dawley rats for 60 days trial. After the stipulated days, the rats were taken for hematological antioxidants, lipid peroxidation (LPO), member bound enzymes, cervical histopathological and carcinogenic markers analyses. The results specified that the DoE has the capability of reducing the tumor in an efficient way. This is the first report of flavonoid-DoE production from an endophytic fungus C. australiensis has the anticancer potentiality and it can be stated as anti-cancer drug.

scholarly journals Antimicrobial Peptide Modifications against Clinically Isolated Antibiotic-Resistant Salmonella

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4654
Author(s):  
Suthee Mangmee ◽  
Onrapak Reamtong ◽  
Thareerat Kalambaheti ◽  
Sittiruk Roytrakul ◽  
Piengchan Sonthayanon
Keyword(s):  
Antibacterial Activity ◽  
Hemolytic Activity ◽  
Multidrug Resistant ◽  
Terminal Group ◽  
Scorpion Venom ◽  
Antibiofilm Activity ◽  
Peptide Antibiotic ◽  
Dependent Manner ◽  
C Terminus ◽  
Relationship Of

Antimicrobial peptides are promising molecules to address the global antibiotic resistance problem, however, optimization to achieve favorable potency and safety is required. Here, a peptide-template modification approach was employed to design physicochemical variants based on net charge, hydrophobicity, enantiomer, and terminal group. All variants of the scorpion venom peptide BmKn-2 with amphipathic α-helical cationic structure exhibited an increased antibacterial potency when evaluated against multidrug-resistant Salmonella isolates at a MIC range of 4–8 µM. They revealed antibiofilm activity in a dose-dependent manner. Sheep red blood cells were used to evaluate hemolytic and cell selectivity properties. Peptide Kn2-5R-NH2, dKn2-5R-NH2, and 2F-Kn2-5R-NH2 (variants with +6 charges carrying amidated C-terminus) showed stronger antibacterial activity than Kn2-5R (a variant with +5 charges bearing free-carboxyl group at C-terminus). Peptide dKn2-5R-NH2 (d-enantiomer) exhibited slightly weaker antibacterial activity with much less hemolytic activity (higher hemolytic concentration 50) than Kn2-5R-NH2 (l-enantiomer). Furthermore, peptide Kn2-5R with the least hydrophobicity had the lowest hemolytic activity and showed the highest specificity to Salmonella (the highest selectivity index). This study also explained the relationship of peptide physicochemical properties and bioactivities that would fulfill and accelerate progress in peptide antibiotic research and development.

scholarly journals Identification of Wild-Derived Inbred Mouse Strains Highly Susceptible to Monkeypox Virus Infection for Use as Small Animal Models

2010 ◽  
Vol 84 (16) ◽  
pp. 8172-8180 ◽  
Author(s):  
Jeffrey L. Americo ◽  
Bernard Moss ◽  
Patricia L. Earl
Keyword(s):  
Animal Models ◽  
B Lymphocyte ◽  
Inbred Mouse ◽  
Lethal Dose ◽  
Small Animal ◽  
Congo Basin ◽  
Mouse Strains ◽  
Dependent Manner ◽  
Inbred Mouse Strains ◽  
Monkeypox Virus

ABSTRACT Infection with monkeypox virus (MPXV) causes disease manifestations in humans that are similar, although usually less severe, than those of smallpox. Since routine vaccination for smallpox ceased more than 30 years ago, there is concern that MPXV could be used for bioterrorism. Thus, there is a need to develop animal models to study MPXV infection. Accordingly, we screened 38 inbred mouse strains for susceptibility to MPXV. Three highly susceptible wild-derived inbred strains were identified, of which CAST/EiJ was further developed as a model. Using an intranasal route of infection with an isolate of the Congo Basin clade of MPXV, CAST/EiJ mice exhibited weight loss, morbidity, and death in a dose-dependent manner with a calculated 50% lethal dose (LD50) of 680 PFU, whereas there were no deaths of BALB/c mice at a 10,000-fold higher dose. CAST/EiJ mice exhibited greater MPXV sensitivity when infected via the intraperitoneal route, with an LD50 of 14 PFU. Both routes resulted in MPXV replication in the lung, spleen, and liver. Intranasal infection with an isolate of the less-pathogenic West African clade yielded an LD50 of 7,600 PFU. The immune competence of CAST/EiJ mice was established by immunization with vaccinia virus, which induced antigen-specific T- and B-lymphocyte responses and fully protected mice from lethal doses of MPXV. The new mouse model has the following advantages for studying pathogenesis of MPXV, as well as for evaluation of potential vaccines and therapeutics: relative sensitivity to MPXV through multiple routes, genetic homogeneity, available immunological reagents, and commercial production.

Strain-specific transgene methylation occurs early in mouse development and can be recapitulated in embryonic stem cells

Development ◽  
1995 ◽  
Vol 121 (9) ◽  
pp. 2853-2859 ◽  
Author(s):  
A. Weng ◽  
T. Magnuson ◽  
U. Storb
Keyword(s):  
De Novo ◽  
Es Cells ◽  
Embryonic Stem ◽  
Dependent Manner ◽  
Mouse Development ◽  
Partial Methylation ◽  
Distal Chromosome ◽  
Before And After ◽  
Endogenous Genes ◽  
De Novo Methylation

A murine transgene, HRD, is methylated only when carried in certain inbred strain backgrounds. A locus on distal chromosome 4, Ssm1 (strain-specific modifier), controls this phenomenon. In order to characterize the activity of Ssm1, we have investigated developmental acquisition of methylation over the transgene. Analysis of postimplantation embryos revealed that strain-specific methylation is initiated prior to embryonic day (E) 6.5. Strain-specific transgene methylation is all-or-none in pattern and occurs exclusively in the primitive ectoderm lineage. A strain-independent pattern of partial methylation occurs in the primitive endoderm and trophectoderm lineages. To examine earlier stages, embryonic stem (ES) cells were derived from E3.5 blastocysts and examined for transgene methylation before and after differentiation. Though the transgene had already acquired some methylation in undifferentiated ES cells, differentiation induced further, de novo methylation in a strain-dependent manner. Analysis of methylation in ES cultures suggests that the transgene and endogenous genes (such as immunoglobulin genes) are synchronously methylated during early development. These results are interpreted in the context of a model in which Ssm1-like modifier genes produce alterations in chromatin structure during and/or shortly after implantation, thereby marking target loci for de novo methylation with the rest of the genome during gastrulation.

scholarly journals Human Recombinant Fab Fragment Neutralizes Shiga Toxin Type 2 Cytotoxic Effects in vitro and in vivo

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 508 ◽  
Author(s):  
Daniela Luz ◽  
Maria Amaral ◽  
Flavia Sacerdoti ◽  
Alan Bernal ◽  
Wagner Quintilio ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
Lethal Dose ◽  
Dependent Manner ◽  
Fab Fragment ◽  
Cell Viability Assay ◽  
Cytotoxic Effects ◽  
Morphological Alterations ◽  
Viability Assay

Shiga toxin (Stx) producing Escherichia coli (STEC) is responsible for causing hemolytic uremic syndrome (HUS), a life-threatening thrombotic microangiopathy characterized by thrombocytopenia, hemolytic anemia, and acute renal failure after bacterially induced hemorrhagic diarrhea. Until now, there has been neither an effective treatment nor method of prevention for the deleterious effects caused by Stx intoxication. Antibodies are well recognized as affinity components of therapeutic drugs; thus, a previously obtained recombinant human FabC11:Stx2 fragment was used to neutralize Stx2 in vitro in a Vero cell viability assay. Herein, we demonstrated that this fragment neutralized, in a dose-dependent manner, the cytotoxic effects of Stx2 on human glomerular endothelial cells, on human proximal tubular epithelial cells, and prevented the morphological alterations induced by Stx2. FabC11:Stx2 protected mice from a lethal dose of Stx2 by toxin-antibody pre-incubation. Altogether, our results show the ability of a new encouraging molecule to prevent Stx-intoxication symptoms during STEC infection.

Synthesis of 70K stress protein by human leukocytes: effect of exercise in the heat

1991 ◽  
Vol 70 (1) ◽  
pp. 466-471 ◽  
Author(s):  
A. J. Ryan ◽  
C. V. Gisolfi ◽  
P. L. Moseley
Keyword(s):  
Protein Synthesis ◽  
Relative Humidity ◽  
Treadmill Exercise ◽  
Stress Protein ◽  
Exercise Bout ◽  
Time Dependent ◽  
Dependent Manner ◽  
Human Leukocytes ◽  
Before And After

To determine whether reinduction of 70,000-Da (70K) stress protein synthesis could be used as an assay for thermal history and/or cellular levels of 70K stress protein in hyperthermic humans, leukocytes were obtained before and after 2 h of exercise and then incubated at 37 or 41 degrees C. Five healthy males completed 2 h of treadmill exercise consisting of running at 4–6 km/h for 30–45 min followed by 75–90 min of walking up a 2–10% grade. This exercise bout was performed by two subjects in hot (46 degrees C, 15% relative humidity) and by five subjects in cooler (30 degrees C, 40% relative humidity) environmental conditions. Exercise resulting in rectal temperature (Tre) less than 40 degrees C did not alter the amount of 70K stress protein synthesized by leukocytes incubated at 41 degrees C. In contrast, exercise resulting in Tre greater than 40 degrees C reduced the amount of 70K stress protein synthesized by leukocytes incubated at 41 degrees C. A protein immunoblot, probed with an antibody specific for the inducible 72K stress protein, showed that the reduction of 35S-labeled 70K stress protein in these postexercise leukocyte samples occurred without marked elevations of this protein. In vitro incubation of human leukocytes at 40 degrees C for 15–120 min reduced, in a time-dependent manner, the amount of 70K stress protein synthesized during a subsequent 41 degrees C heat stress. This reduction of 70K stress protein synthesis in 41 degrees C-treated leukocytes was abolished when cycloheximide was present during the 40 degrees C preincubation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals ASSESSMENT OF SNAKE ANTIVENOM ACTIVITY OF TAMARINDUS INDICA SEED COAT EXTRACT

2021 ◽  
Vol 9 (09) ◽  
pp. 489-497
Author(s):  
Priyanka D. Mundhe ◽  
◽  
Balasaheb S. Pawade ◽  
Indrasen G. Waykar ◽  
Innus K. Shaikh ◽  
...  
Keyword(s):  
Snake Venom ◽  
Seed Coat ◽  
Rural Areas ◽  
Proteolytic Enzymes ◽  
Lethal Dose ◽  
Medical Emergency ◽  
Dependent Manner ◽  
Tamarindus Indica

Snakebite is a life-threatening medical emergency, and globally responsible for millions of deaths. In snakebites accidents only deaths are not a concern, it leads to more morbidities. Due to scanty healthcare facilities in rural areas of India, many people seek alternative treatment available in ethnic practices. Tamarindus Indica (TI) plant is rich in medicinal value and used to treat many diseases including snakebite treatment traditionally. In view of this TI seed coat extract (TISCE) was evaluated for antivenom activity. The phytochemical screening of TISCE was performed to understand its chemical composition. TISCE was evaluated for antivenom activity against Indian cobra venom (ICV), common krait venom (CKV), Russells viper venom (RVV), and saw-scaled viper venom (SCV) for phospholipase A2 (PLA-2), haemorrhagic in vitro and in vivo, procoagulant, proteolytic activity, and lethality studies. TISCE majorly contains saponins, glycosides, alkaloids, and phenolic compounds. Minimum indirect haemorrhagic dose (MIHD) observed for ICV (12.5 µg), CKV (5.0 µg),RVV (10.0 µg), and SVV (12.5 µg). TISCE inhibits the procoagulant activity of all venoms at a concentration of 18.0 µg. It also shows the neutralization of proteolytic enzymes of venom in a dose-dependent manner. A pre-incubated mixture containing five lethal dose 50 (LD50) of venom and TISCE was injected intravenously, all mice survived as venom neutralized by TISCE. The present study demonstrates the ability of TISCE to neutralize snake venom using suitable in vivo and in vitro methods. Further studies required to unravelling the specific active chemical constituent of TISCE that may used as novel alternative snakebite treatment. TISCE was able to prolong the deaths during the simulation study and may be used in the topical pharmaceutical formulation that will reduce local venom reactions causing much morbidity, which will collectively with Anti-snake venom (ASV), used to treat envenomed patients more effectively.

Angiography significantly decreased serum levels of IL-8 independent of artery stenosis

2020 ◽  
Author(s):  
Lida Zare ◽  
Akram Eidi ◽  
Mohammad Safarian ◽  
Mohammad Kazemi Arababadi
Keyword(s):  
Protective Factor ◽  
Serum Levels ◽  
Artery Stenosis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Before And After ◽  
Elisa Technique ◽  
Factor Alpha

Abstract Background Angiography is a safe cardiovascular technique for the diagnosis and treatment of the cardiovascular disorders. The potential effects of angiography on the cytokines are yet to be clarified completely. Interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) are the important pro-inflammatory cytokines that participate in the pathogenesis of artery stenosis. The aim of his project was to study the angiography effects on the serum levels of IL-8 and TNF-α. Methods Fifty-five participants in three groups, without, with one and with more than one artery stenosis, were explored in this project. Serum levels of IL-8 and TNF-α were measured in the participants before and after angiography using enzyme linked immunosorbent assay (ELISA) technique. Results Serum levels of IL-8, but not TNF-α, were significantly decreased following angiography. X-ray doses had moderate positive correlation with serum levels of TNF-α in the patients with more than one artery stenosis. Serum levels of IL-8 and TNF-α were not different among male and female participants in all groups. Discussion Angiography may be a protective factor for inflammation in IL-8 dependent manner. Using angiography in the patients with more than one artery stenosis needs to be executed cautiously.

Calcium dependence of the thrombin-induced increase in endothelial albumin permeability

1989 ◽  
Vol 66 (3) ◽  
pp. 1471-1476 ◽  
Author(s):  
H. Lum ◽  
P. J. Del Vecchio ◽  
A. S. Schneider ◽  
M. S. Goligorsky ◽  
A. B. Malik
Keyword(s):  
Endothelial Cells ◽  
Endothelial Permeability ◽  
Base Line ◽  
Dependent Manner ◽  
Extracellular Medium ◽  
Influx Rate ◽  
Before And After ◽  
Dependent Inhibition ◽  
Permeability Increase ◽  
Dose Dependent

We examined whether the increase in endothelial albumin permeability induced by alpha-thrombin is dependent on extracellular Ca2+ influx. Permeability of 125I-albumin across confluent monolayers of cultured bovine pulmonary artery endothelial cells was measured before and after the addition of 0.1 microM alpha-thrombin. In the presence of normal extracellular Ca2+ concentration ([Ca2+]o, 1000 microM), alpha-thrombin produced a 175 +/- 10% increase in 125I-albumin permeability. At lower [Ca2+]o (100, 10, 1, or less than 1 microM), alpha-thrombin caused a 140% increase in permeability (P less than 0.005). LaCl3 (1 mM), which competes for Ca2+ entry, blunted 38% of the increase in permeability. Preloading endothelial monolayers with quin2 to buffer cytosolic Ca2+ (Cai2+) produced a dose-dependent inhibition of the increase in 125I-albumin permeability. Preincubation with nifedipine or verapamil was ineffective in reducing the thrombin-induced permeability increase. A 60 mM K+ isosmotic solution did not alter base-line endothelial permeability. alpha-Thrombin increased [Ca2+]i in a dose-dependent manner and the 45Ca2+ influx rate. Extracellular medium containing 60 mM K+ did not increase 45Ca2+ influx, and nifedipine did not block the rise in 45Ca2+ influx caused by alpha-thrombin. Ca2+ flux into endothelial cells induced by alpha-thrombin does not occur through voltage-sensitive channels but may involve receptor-operated channels. In conclusion, the increase in endothelial albumin permeability caused by alpha-thrombin is dependent on Ca2+ influx and intracellular Ca2+ mobilization.

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