Search results for "Vivo"
showing 10 items of 1905 documents
Synthetic Polyclonal-Derived CDR Peptides as an Innovative Strategy in Glaucoma Therapy
2019
The pathogenesis of glaucoma is strongly associated with the occurrence of autoimmune-mediated loss of retinal ganglion cells (RGCs) and additionally, recent evidence shows that specific antibody-derived signature peptides are significantly differentially expressed in sera of primary-open angle glaucoma patients (POAG) compared to healthy controls. Synthetically antibody-derived peptides can modulate various effector functions of the immune system and act as antimicrobial or antiviral molecules. In an ex vivo adolescent glaucoma model, this study, for the first time, demonstrates that polyclonal-derived complementarity-determining regions (CDRs) can significantly increase the survival rate …
Nanoincorporation of curcumin in polymer-glycerosomes and evaluation of their in vitro–in vivo suitability as pulmonary delivery systems
2015
The aim of this work was to deliver curcumin into the lungs by incorporating it into innovative vesicles obtained using phospholipids and high concentrations of glycerol (50%, v/v), so called glycerosomes, which were then combined with two polymers: sodium hyaluronate and trimethyl chitosan to form polymer-glycerosomes. These systems were prepared without the use of organic solvents or acidic solutions and their physico-chemical properties were fully characterized. Cryogenic transmission electron microscopy and small-angle X-ray scattering showed that both glycerosomes and polymer-glycerosomes were spherical, mainly unilamellar and of nanometric size (65–112 nm). The vesicles were readily n…
Polyoxypregnanes as safe, potent, and specific ABCB1-inhibitory pro-drugs to overcome multidrug resistance in cancer chemotherapy in vitro and in vivo
2021
Multidrug resistance (MDR) mediated by ATP binding cassette subfamily B member 1 (ABCB1) is significantly hindering effective cancer chemotherapy. However, currently, no ABCB1-inhibitory drugs have been approved to treat MDR cancer clinically, mainly due to the inhibitor specificity, toxicity, and drug interactions. Here, we reported that three polyoxypregnanes (POPs) as the most abundant constituents of Marsdenia tenacissima (M. tenacissima) were novel ABCB1-modulatory pro-drugs, which underwent intestinal microbiota-mediated biotransformation in vivo to generate active metabolites. The metabolites at non-toxic concentrations restored chemosensitivity in ABCB1-overexpressing cancer cells v…
Effect of a dominant-negative form of ADAM10 in a mouse model of Alzheimer's disease.
2009
The alpha-secretase cleaves in the non-amyloidogenic pathway the amyloid-beta protein precursor (AbetaPP) within the region of the amyloid-beta peptides to prevent their formation and aggregation in the brain. Members of the ADAM family (a disintegrin and metalloprotease) are the main candidates for physiologically relevant alpha-secretases. We recently demonstrated that overexpression of ADAM10 in mice transgenic for human AbetaPP (ADAM10 x APP[V717I]) alleviated functional deficits related to Alzheimer's disease. To further demonstrate that this is due to the specific activity of alpha-secretase, we characterized mice overexpressing an inactive form of ADAM10 (ADAM10[E384A]; ADAM10-dn). T…
Differential effects of CB1 neutral antagonists and inverse agonists on gastrointestinal motility in mice
2010
Background Cannabinoid type 1 (CB1) receptors are involved in the regulation of gastrointestinal (GI) motility and secretion. Our aim was to characterize the roles of the CB1 receptor on GI motility and secretion in vitro and in vivo by using different classes of CB1 receptor antagonists. Methods Immunohistochemistry was used to examine the localization of CB1 receptor in the mouse ileum and colon. Organ bath experiments on mouse ileum and in vivo motility testing comprising upper GI transit, colonic expulsion, and whole gut transit were performed to characterize the effects of the inverse agonist/antagonist AM251 and the neutral antagonist AM4113. As a marker of secretory function we mea…
Interactions between artemisinin derivatives and P-glycoprotein
2019
Abstract Background Artemisinin was isolated and identified in 1972, which was the starting point for a new era in antimalarial drug therapy. Furthermore, numerous studies have demonstrated that artemisinin and its derivatives exhibit considerable anticancer activity both in vitro, in vivo, and even in clinical Phase I/II trials. P-glycoprotein (P-gp) mediated multi-drug resistance (MDR) is one of the most serious causes of chemotherapy failure in cancer treatment. Interestingly, many artemisinin derivatives exhibit excellent ability to overcome P-gp mediated MDR and even show collateral sensitivity against MDR cancer cells. Furthermore, some artemisinin derivatives show P-gp-mediated MDR r…
Microbiological characterization and effect of resin composites in cervical lesions
2017
Background Non carious cervical lesions associated to muscle hyperfunctions are increasing. Microhybrid resin composites are used to restore cervical abfractions. The purpose of this study was to investigate if resin composites modify tooth plaque, inducing an increment of cariogenic microflora and evaluate their effect, in vivo and in vitro, against S. mutans. Material and Methods Eight abfractions were restored with two microhybrid resin composites (Venus, Heraeus-Kulzer® and Esthet-X, Dentsply®), after gnatological therapy, in three patients with muscle hyperfunctions. For each abfraction three samples of plaque were taken from the cervical perimeter: before the restoration, one week and…
New prospective in treatment of Parkinson's disease: Studies on permeation of ropinirole through buccal mucosa
2012
The aptitude of ropinirole to permeate the buccal tissue was tested using porcine mucosa mounted on Franz-type diffusion cells as ex vivo model. Drug permeation was also evaluated in presence of various penetration enhancers and in iontophoretic conditions. Ropinirole, widely used in treatment of motor fluctuations of Parkinson's disease, passes the buccal mucosa. Flux and permeability coefficient values suggested that the membrane does not appear a limiting step to the drug absorption. Nevertheless, an initial lag time is observed but the input rate can be modulated by permeation enhancement using limonene or by application of electric fields. Absorption improvement was accompanied by the …
Intestinal absorption pathway of gamma-aminobutyric acid in rat small intestine.
1994
Intestinal absorption of gamma-aminobutyric acid (GABA), as a model compound for gamma-aminoacids, has not been extensively studied from the kinetic viewpoint. Since data from our laboratory suggested that some competition arises between intestinal absorption of beta-alanine and GABA and since our intent was to maintain the aqueous stagnant diffusion layer in order to approach absorption tests to in vivo physiological conditions, a rat jejunum in situ study was undertaken in order to gain an insight into the mechanism of GABA absorption. In the present paper, results from assays using isotonic perfusion solutions with starting GABA concentrations ranging from 1 to 50 mM are reported. They s…
Optimized In Silico Modeling of Drug Absorption after Gastric Bypass: The Case of Metformin
2021
Bariatric surgery is an effective treatment for severe obesity and related comorbidities, such as type II diabetes. Gastric bypass surgery shortens the length of the intestine, possibly leading to altered drug absorption. Metformin, a first-line treatment for type II diabetes, has permeability-dependent drug absorption, which may be sensitive to intestinal anatomic changes during bypass surgery, including Roux-en-Y gastric bypass (RYGB). Previous computer simulation data indicate increased metformin absorption after RYGB. In this study, we experimentally determined the region-dependent permeability of metformin, using the rat single-pass intestinal perfusion method (SPIP), which we then imp…