scholarly journals In Vitro and In Vivo Study of the Gastrointestinal Absorption and Metabolisation of Hymenocardine, a Cyclopeptide Alkaloid

Planta Medica ◽  
2017 ◽  
Vol 83 (09) ◽  
pp. 790-796 ◽  
Author(s):  
Emmy Tuenter ◽  
Sebastiaan Bijttebier ◽  
Kenn Foubert ◽  
Annelies Breynaert ◽  
Sandra Apers ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Rat Plasma ◽  
In Vivo Study ◽  
Root Bark ◽  
In Vivo Experiments ◽  
Cyclopeptide Alkaloid ◽  
Blood And Urine Samples ◽  
The Stability

AbstractHymenocardine is a cyclopeptide alkaloid present in the root bark of Hymenocardia acida. In traditional African medicine, the leaves and roots of this plant are used to treat malaria, and moderate in vitro antiplasmodial activity has been reported for hymenocardine. However, in view of its peptide-like nature, potential metabolisation after oral ingestion has to be taken into account when considering in vivo experiments. In this study, the stability and small intestinal absorption of hymenocardine was assessed using an in vitro gastrointestinal dialysis model. In addition, potential liver metabolisation was investigated in vitro by incubation with a human S9 fraction. Moreover, hymenocardine was administered to rats per os, and blood and urine samples were collected until 48 and 24 h after oral administration, respectively. All samples resulting from these three experiments were analyzed by LC-MS. Analysis of the dialysate and retentate, obtained from the gastrointestinal dialysis model, indicated that hymenocardine is absorbed unchanged from the gastrointestinal tract, at least in part. After S9 metabolisation, several metabolites of hymenocardine could be identified, the major ones being formed by the reduction and/or the loss of an N-methyl group. The in vivo study confirmed that hymenocardine is absorbed from the gastrointestinal tract unchanged, since it could be identified in both rat plasma and urine, together with hymenocardinol, its reduction product.

Food supplement “carrageenan” and its effect on the organism

2020 ◽  
Author(s):  
O.E. Luneva ◽  
Keyword(s):  
Gastrointestinal Tract ◽  
Food Additives ◽  
Food Supplement ◽  
The Body ◽  
Laboratory Rats ◽  
Experimental Part ◽  
In Vivo Experiments ◽  
Physiological Processes

Food additives are positioned as harmless, although, their components affectthe physiological processes associated with the permeability of the wall of the gastrointestinal tract (GIT) and intestinal microbiota. This article describes thecarrageenan supplement and its effects on the body in in vitro and in vivo experiments. The experimental part is devoted to analysis of the intestinalmicrobiota of laboratory rats with the consumption of the carrageenan dietary supplement in the amount of about 4,4 % of the standard feed.

Transfer of antibiotic resistance determinants between lactobacilli isolates from the gastrointestinal tract of chicken

2012 ◽  
Vol 3 (2) ◽  
pp. 137-144 ◽  
Author(s):  
F. Vieira de Souza ◽  
R. Roque ◽  
J.L. Silva Moreira ◽  
M. Resende de Souza ◽  
J.R. Nicoli ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gastrointestinal Tract ◽  
Broiler Chickens ◽  
Lactobacillus Reuteri ◽  
Multi Drug Resistance ◽  
Bacterial Strains ◽  
Genetic Traits ◽  
In Vivo Experiments

The aim of this study was to assess the potential horizontal transfer of genetic traits for antibiotic resistance between lactobacilli isolated from the chicken gut, both in vitro and in vivo. Thirty-seven Lactobacillus spp. strains isolated from the gizzard, small and large intestines and caeca of free-range broiler chickens showed multi-drug resistance as assessed by disc diffusion assays. The minimum inhibitory concentration (MIC) for vancomycin, tetracycline, erythromycin and chloramphenicol was determined in De Man, Rogosa and Sharpe broth in a microplate assay. Almost all the lactobacilli isolates were resistant to vancomycin (except strains belonging to the Lactobacillus acidophilus group) and to tetracycline (MIC≥128 μg/ml). Only five strains were resistant to erythromycin, and six to chloramphenicol. The transfer rate in filter mating experiments performed using L. acidophilus strain 4M14E (EmR), Lactobacillus vaginalis strain 5M14E (CmR), Lactobacillus salivarius strain 5C14C (EmR), and the 4G14L and 3C14C strains of Lactobacillus reuteri (CmR) showed a frequency of approximately 1×104 cfu/ml of double-resistant transconjugants for the different combinations. The exception was the L. salivarius 5C14C (EmR) and L. vaginalis 5M14E (CmR) mating combination, which produced no transconjugants. In vivo experiments performed in gnotobiotic mice by mating L. acidophilus 4M14E (EmR) with L. reuteri 3C14C (CmR), L. reuteri 4G14L (CmR) or L. vaginalis 5M14E (CmR) resulted in transconjugants at 3.95±0.29, 3.16±0.33, and 4.55±1.52 log10 cfu/g of faeces, respectively. Taken together, these data suggest that genetic exchange may occur between native bacterial strains within the gastrointestinal tract of chickens, which might maintain a dynamic gene pool conferring antibiotic resistance upon indigenous microbiota components, even in the absence of the pathogens. This possibility must be taken into account as a complementary criterion when lactobacilli are screened for probiotic use.

scholarly journals Short artificial hairpins sequester splicing signals and inhibit yeast pre-mRNA splicing.

1993 ◽  
Vol 13 (11) ◽  
pp. 6841-6848 ◽  
Author(s):  
V Goguel ◽  
Y Wang ◽  
M Rosbash
Keyword(s):  
Splice Site ◽  
Major Effect ◽  
Yeast Saccharomyces Cerevisiae ◽  
Spliceosome Assembly ◽  
In Vivo Experiments ◽  
Small Nuclear Ribonucleoprotein ◽  
Sequence Elements ◽  
The Stability

To examine the stability of yeast (Saccharomyces cerevisiae) pre-mRNA structures, we inserted a series of small sequence elements that generated potential RNA hairpins at the 5' splice site and branch point regions. We analyzed spliceosome assembly and splicing in vitro as well as splicing and nuclear pre-mRNA retention in vivo. Surprisingly, the inhibition of in vivo splicing approximately paralleled that of in vitro splicing. Even a 6-nucleotide hairpin could be shown to inhibit splicing, and a 15-nucleotide hairpin gave rise to almost complete inhibition. The in vitro results indicate that hairpins that sequester the 5' splice site have a major effect on the early steps of spliceosome assembly, including U1 small nuclear ribonucleoprotein binding. The in vivo experiments lead to comparable conclusions as the sequestering hairpins apparently result in the transport of pre-mRNA to the cytoplasm. The observations are compared with previous data from both yeast and mammalian systems and suggest an important effect of pre-mRNA structure on in vivo splicing.

Bioavailability and Speciation of Mineral Micronutrients: The Enzymolysis Approach

1997 ◽  
Vol 80 (4) ◽  
pp. 920-927 ◽  
Author(s):  
Pierre Hocquellet ◽  
Marie-Dominique L'Hotellier
Keyword(s):  
Gastrointestinal Tract ◽  
Absorption Spectrometry ◽  
Insoluble Residue ◽  
In Vivo Experiments ◽  
Treatment Data ◽  
Dietary Components ◽  
Vitro Model ◽  
Good Agreement

Abstract Speciation analyses are essential to investigate the effects of dietary components on bioavailability of mineral micronutrients. Enzymolysis was used. An in vitro model simulating enzymatic activity in the gastrointestinal tract of monogastric species was developed and used to assess availability of Fe, Cu, Mn, and Zn in some foodstuffs. The solubility of each element in samples was measured by atomic absorption spectrometry after enzymatic treatment. Data are in good agreement with information obtained from earlier, more expensive nutritional surveys or in vivo experiments and, therefore, allow prediction of the tendency of a particular food to induce mineral deficiency. In addition, ligands responsible for inhibiting intestinal absorption were identified by determining the amount of metal released after treatment of the insoluble residue with an appropriate enzyme such as cellulase and phytase, used respectively to study fiber and phytate interactions. Enzymolysis may be useful for optimizing mineral supplementations though its nutritional significance is somewhat limited by the fact that it does not take into account the dynamic changes in the gastrointestinal tract. Enzymolysis is a prerequisite for further speciation studies of complex systems and in some instances is the only way for specifying physicochemical forms of elements.

scholarly journals Short artificial hairpins sequester splicing signals and inhibit yeast pre-mRNA splicing

1993 ◽  
Vol 13 (11) ◽  
pp. 6841-6848
Author(s):  
V Goguel ◽  
Y Wang ◽  
M Rosbash
Keyword(s):  
Splice Site ◽  
Major Effect ◽  
Yeast Saccharomyces Cerevisiae ◽  
Spliceosome Assembly ◽  
In Vivo Experiments ◽  
Small Nuclear Ribonucleoprotein ◽  
Sequence Elements ◽  
The Stability

To examine the stability of yeast (Saccharomyces cerevisiae) pre-mRNA structures, we inserted a series of small sequence elements that generated potential RNA hairpins at the 5' splice site and branch point regions. We analyzed spliceosome assembly and splicing in vitro as well as splicing and nuclear pre-mRNA retention in vivo. Surprisingly, the inhibition of in vivo splicing approximately paralleled that of in vitro splicing. Even a 6-nucleotide hairpin could be shown to inhibit splicing, and a 15-nucleotide hairpin gave rise to almost complete inhibition. The in vitro results indicate that hairpins that sequester the 5' splice site have a major effect on the early steps of spliceosome assembly, including U1 small nuclear ribonucleoprotein binding. The in vivo experiments lead to comparable conclusions as the sequestering hairpins apparently result in the transport of pre-mRNA to the cytoplasm. The observations are compared with previous data from both yeast and mammalian systems and suggest an important effect of pre-mRNA structure on in vivo splicing.

Formation and Structure of Casein Micelles in Lactating Mammary Tissue

1970 ◽  
Vol 28 ◽  
pp. 150-151
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell
Keyword(s):  
Size Distribution ◽  
G Protein ◽  
Milk Proteins ◽  
Mammary Tissue ◽  
Colloidal System ◽  
Casein Micelles ◽  
The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

Anti-thrombotic Effect of a PAI-1 Inhibitor in Rats Given Endotoxin

1996 ◽  
Vol 75 (01) ◽  
pp. 118-126 ◽  
Author(s):  
T Abrahamsson ◽  
V Nerme ◽  
M Strömqvist ◽  
B Åkerblom ◽  
A Legnehed ◽  
...  
Keyword(s):  
Plasminogen Activator Inhibitor ◽  
Rat Plasma ◽  
Clot Lysis ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Fab Fragment ◽  
Dose Dependent Decrease ◽  
Pai 1

SummaryThe aim of this study was to investigate the anti-thrombotic effects of an inhibitor of the plasminogen activator inhibitor-1 (PAI-1) in rats given endotoxin. In studies in vitro, PRAP-1, a Fab-fragment of a polyclonal antibody against human PAI-1, was shown to inhibit PAI-1 activity in rat plasma as well as to stimulate clot-lysis of the euglobulin fraction derived from rat plasma. Endotoxin administered to anaesthetised rats produced a marked increase in plasma PAI-1 activity. To study fibrin formation and lysis in vivo after intravenous (i. v.) injection of the coagulant enzyme batroxobin, 125I-fibrinogen was administered to the animals. The thrombi formed by batroxobin were rapidly lysed in control animals, while the rate of lysis was markedly attenuated in rats given endotoxin. PRAP-1 was administered i.v. (bolus + infusion) to rats given endotoxin and batroxobin and the PAI-1 inhibitor caused a dose-dependent decrease in the 125I-fibrin deposition in the lungs. An immunohistochemical technique was used to confirm this decrease in density of fibrin clots in the tissue. Furthermore, PRAP-1 decreased plasma PAI-1 activity in the rats and this reduction was correlated to the decrease in lung 125I-fibrin deposition at the corresponding time point. It is concluded that in this experimental model the PAI-1 antibody PRAP-1 may indeed inhibit thrombosis in animals exposed to endotoxin.

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