Bioavailability of arsenic, cadmium, lead and mercury as measured by intestinal permeability

AbstractIn this study, the intestinal permeability of metal(loid)s (MLs) such as arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg) was examined, as influenced by gut microbes and chelating agents using an in vitro gastrointestinal/Caco-2 cell intestinal epithelium model. The results showed that in the presence of gut microbes or chelating agents, there was a significant decrease in the permeability of MLs (As-7.5%, Cd-6.3%, Pb-7.9% and Hg-8.2%) as measured by apparent permeability coefficient value (Papp), with differences in ML retention and complexation amongst the chelants and the gut microbes. The decrease in ML permeability varied amongst the MLs. Chelating agents reduce intestinal absorption of MLs by forming complexes thereby making them less permeable. In the case of gut bacteria, the decrease in the intestinal permeability of MLs may be associated to a direct protection of the intestinal barrier against the MLs or indirect intestinal ML sequestration by the gut bacteria through adsorption on bacterial surface. Thus, both gut microbes and chelating agents can be used to decrease the intestinal permeability of MLs, thereby mitigating their toxicity.

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Bicarbonate secretion in rat distal colon in vitro: a measurement technique

AJP Cell Physiology ◽

10.1152/ajpcell.1988.254.3.c383 ◽

1988 ◽

Vol 254 (3) ◽

pp. C383-C390 ◽

Cited By ~ 16

Author(s):

G. M. Feldman ◽

S. F. Berman ◽

R. L. Stephenson

Keyword(s):

Short Circuit ◽

Distal Colon ◽

Apparent Permeability ◽

Chemical Gradients ◽

Acid Generation ◽

Rat Distal Colon ◽

Tissue Surfaces ◽

Apparent Permeability Coefficient ◽

Transepithelial Voltage

To study HCO3- secretion in rat distal colon, we utilized a technique that permits control of electrical and chemical transepithelial gradients. With symmetrical solutions (pH 7.4, [HCO3-] 25 mM, and CO2 tension 40 mmHg) bathing both tissue surfaces and under short-circuit conditions, HCO3- secretion remained stable for greater than 4 h at 1 mueq. h-1.cm-2. As the mucosal solution was alkalinized, the serosal solution was acidified at 3.1 mueq.h-1.cm-2. Ninety-four percent of serosal acidification was accounted for by the rate of metabolic lactic acid generation and transepithelial HCO3- secretion. Clamping transepithelial voltage reversibly affected net HCO3- secretion, and a linear relationship existed between clamped mucosal voltage and net HCO3- flux (r = 0.99); mucosal voltage of -68 mV completely inhibited net secretion. The apparent permeability coefficient of the colon to HCO3- is 2.8 X 10(-6) cm/s. One millimolar ouabain completely inhibited net HCO3- secretion. Acetazolamide (10(-4) M) inhibited secretion by approximately 50%, whereas a 10(-3) M concentration inhibited secretion by 90%. These data demonstrate that net colonic HCO3- secretion can be measured without imposed electrical and chemical gradients and that this flux is voltage sensitive and depends on carbonic anhydrase and Na+-K+-ATPase activities.

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Heterogeneous expression of Pil3 pilus is critical for Streptococcus gallolyticus translocation across polarized colonic epithelial monolayers

10.1101/682278 ◽

2019 ◽

Author(s):

Mariana Martins ◽

Laurence du Merle ◽

Patrick Trieu-Cuot ◽

Shaynoor Dramsi

Keyword(s):

Intestinal Barrier ◽

Opportunistic Pathogen ◽

Oral Route ◽

Elderly Persons ◽

Dependent Manner ◽

Bacterial Surface ◽

Streptococcus Gallolyticus ◽

Heterogeneous Expression ◽

Colonic Cells

ABSTRACTStreptococcus gallolyticus subspecies gallolyticus (Sgg) is an opportunistic pathogen responsible for septicaemia and endocarditis in elderly persons. Sgg is also a commensal of the human gastrointestinal tract. Here we demonstrate that Sgg strain UCN34 translocates across tight intestinal barriers in vitro in a Pil3-dependent manner. Confocal images of UCN34 passage across human colonic cells reveals that Sgg utilizes a paracellular pathway. Pil3 was previously shown to be expressed heterogeneously and WT UCN34 consists of about 90% of Pil3low and 10% of Pil3high cells. We found that both the Δpil3 mutant and the Pil3+ overexpressing variant could not translocate across Caco-2 and T84 barriers. Interestingly, combining live Δpil3 mutant cells with fixed Pil3+ variants in a 10:1 ratio (mimicking UCN34 WT population) allowed efficient translocation of the Δpil3 mutant. These experiments demonstrate that heterogeneous expression of Pil3 plays a key role in optimal translocation of Sgg across the intestinal barrier.ABSTRACT IMPORTANCEStreptococcus gallolyticus subsp. gallolyticus (Sgg) is an opportunistic pathogen responsible for septicemia and infective endocarditis in elderly persons. Sgg is a commensal of the rumen of herbivores and transmission to humans most probably occurs through the oral route. In this work, we have studied how this bacterium crosses the intestinal barrier using well-known in vitro models. Confocal microscopy images revealed that Sgg UCN34 can traverse the epithelial monolayer in between adjacent cells. We next showed that passage of Sgg from the apical to the basolateral compartment is dependent on the heterogenous expression of the Pil3 pilus at the bacterial surface. We hypothesize that Pil3high cocci adhere firmly to epithelial cells to activate transient opening of tight junctions thereby allowing the traversal of Pil3low bacteria.

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Development and In Vitro Evaluation of a Mucoadhesive Oral Deliverv System for Antisense Oliaonucleotides

Scientia Pharmaceutica ◽

10.3797/scipharm.aut-03-17 ◽

2003 ◽

Vol 71 (3) ◽

pp. 165-177 ◽

Cited By ~ 2

Author(s):

Andreas Bernkop-Schnürch ◽

Julia Telsnig ◽

Margit Hornof

Keyword(s):

Delivery System ◽

Permeability Coefficient ◽

Enzymatic Degradation ◽

Phosphorothioate Oligonucleotide ◽

Apparent Permeability ◽

Release Studies ◽

Apparent Permeability Coefficient ◽

Permeation Studies ◽

Membrane Bound

It was the aim of this study to develop an oral phosphorothioate oligodeoxynucleotide (PS-ODN) drug delivery system and to evaluate its properties in vitro. Results demonstrated that the 16-mer phosphorothioate oligonucleotide used was completely stable towards enzymatic degradation by secreted and membrane bound intestinal enzymes. Permeation studies with freshly excised intestinal mucosa showed a comparatively high uptake of the PS-ODN with an apparent permeability coefficient (Papp) of 8.35 ± 1.24 x 10-6 cm/sec. The PS-ODN was incorporated in a poly(acrylic acid)-cysteine carrier matrix system exhibiting high cohesive and mucoadhesive properties. Release studies demonstrated that a controlled and sustained PS-ODN release out of this delivery system could be achieved. Because of these features, the dosage form developed within this study seems to represent a promising novel tool for oral PS-ODN delivery.

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Functional and structural alterations of epithelial barrier properties of rat ileum following X-irradiation

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y03-129 ◽

2004 ◽

Vol 82 (2) ◽

pp. 84-93 ◽

Cited By ~ 17

Author(s):

I Dublineau ◽

F Lebrun ◽

S Grison ◽

N M Griffiths

Keyword(s):

Intestinal Permeability ◽

Intestinal Barrier ◽

Barrier Properties ◽

Epithelial Tissue ◽

Barrier Integrity ◽

Rat Ileum ◽

Ussing Chambers ◽

Junctional Proteins ◽

X Irradiation

Irradiation of the digestive system leads to alterations of the small intestine. We have characterized the disruption of the barrier integrity in rat ileum from 1 to 14 days following irradiation ranging from 6 to 12 Gy. The intestinal permeability to 14C-mannitol and 3H-dextran 70 000 was measured in vitro in Ussing chambers. In parallel to these functional studies, immunohistochemical analyses of junctional proteins (ZO-1 and β-catenin) of ileal epithelium were performed by confocal microscopy. Irradiation with 10 Gy induced a marked decrease in epithelial tissue resistance at three days and a fivefold increase in mannitol permeability, without modifications of dextran permeability. A disorganization of the localization for ZO-1 and β-catenin was also observed. At 7 days after irradiation, we observed a recovery of the organization of junctional proteins in parallel to a return of intestinal permeability to control value. In addition to these time-dependent effects, a gradual effect on epithelial integrity of the radiation doses was observed 3 days after irradiation. This study shows a disruption of the integrity of the intestinal barrier in rat ileum following abdominal X-irradiation, depending on the time postirradiation and on the delivered dose. The loss of barrier integrity was characterized by a disorganization of proteins of tight and adherent junctions, leading to increased intestinal permeability to mannitol.Key words: intestinal permeability, ZO-1, β-catenin, tight and adherent junctions.

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Transport of Corilagin, Gallic Acid, and Ellagic Acid from Fructus Phyllanthi Tannin Fraction in Caco-2 Cell Monolayers

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2016/9205379 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 12

Author(s):

Xin Mao ◽

Ling-Fang Wu ◽

Hai-juan Zhao ◽

Wen-Yi Liang ◽

Wen-Jing Chen ◽

...

Keyword(s):

Tight Junction ◽

Gallic Acid ◽

Ellagic Acid ◽

Organic Anion ◽

Multidrug Resistance Proteins ◽

Apparent Permeability ◽

Glycoprotein P ◽

Sodium Glucose Cotransporter ◽

Apparent Permeability Coefficient

Objective. To investigate the absorption property of the representative hydrolyzable tannin, namely corilagin, and its hydrolysates gallic acid (GA) and ellagic acid (EA) from the Fructus Phyllanthi tannin fraction (PTF)in vitro.Methods. Caco-2 cells monolayer model was established. Influences of PTF on Caco-2 cells viability were detected with MTT assay. The transport across monolayers was examined for different time points, concentrations, and secretory directions. The inhibitors of P-glycoprotein (P-gp), multidrug resistance proteins (MRPs), organic anion transporting polypeptide (OATP) and sodium/glucose cotransporter 1 (SGLT1), and tight junction modulators were used to study the transport mechanism. LC-MS method was employed to quantify the absorption concentration.Results. The apparent permeability coefficient(Papp)values of the three compounds were below 1.0 × 10−6 cm/s. The absorption of corilagin and GA were much lower than their efflux, and the uptake of both compounds was increased in the presence of inhibitors of P-gp and MRPs. The absorption of EA was decreased in the company of OATP and SGLT1 inhibitors. Moreover, the transport of corilagin, GA, and EA was enhanced by tight junction modulators.Conclusion. These observations indicated that the three compounds in PTF were transported via passive diffusion combined with protein mediated transport. P-gp and MRPs might get involved in the transport of corilagin and GA. The absorption of EA could be attributed to OATP and SGLT1 protein.

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Gut Microbiota of Ostrinia Nubilalis Larvae Degrade Maize Cellulose

10.21203/rs.3.rs-589374/v1 ◽

2021 ◽

Author(s):

Junfeng Li ◽

Sifan Chen ◽

Xuxiong Tao ◽

Tao Shao

Keyword(s):

Gut Microbiota ◽

Ostrinia Nubilalis ◽

European Corn Borer ◽

Gut Bacteria ◽

Cellulose Content ◽

Bacterial Isolates ◽

Corn Borer ◽

Gut Microbes ◽

Maize Plants

Abstract BackgroundWhile most insects rely on gut bacteria to digest cellulose and produce sugars or fatty acids that are then available to the host, this has been disputed in Lepidopteran larvae due to their simple gut morphology and rapid digestive throughput. The European corn borer (ECB), Ostrinia nubilalis (Hübner), is a devastating pest that feeds the lignocellulose-rich tissues of maize plants. However, the potential role of ECB gut microbes in degrading maize cellulose remains unexplored. Here, we investigate the gut microbiota of ECB fed with different diets and the potential function of their gut bacteria in maize lignocellulose degradation.ResultsThe diversity and composition of gut bacterial communities varied dramatically between the ECB larva fed with artificial diets (ECB-D) and maize plants (ECB-M). Draft genomes of the bacterial isolates from ECB-D and ECB-M show that the principal degraders of cellulose mainly belonged to Firmicutes or Proteobacteria and were primarily found in the midgut. The bacterial isolates contained genes encoding various carbohydrate-active enzymes (CAZyme). Furthermore, scanning electron microscopy (SEM) revealed significant breakdown of lignocellulose in maize treated by the two bacterial isolates for nine days in vitro. Cellulose content in maize particles treated with BI-M were significantly lower than those treated with BI-D or the control (Kruskal–Wallis test: Χ2 = 6.72, df = 2; P = 0.0259). Metabolomic analyses reveal that maize particles treated by two bacterial isolates generate distinctive metabolomic profiles, with enrichment for different monosaccharides and amino acids.ConclusionThe results indicated that the diet of the host impacts the composition and the function of its gut microbiota, and that ECB exploits specific gut microbes to digest maize lignocellulose with distinctive products. Our study provides valuable microbiota resources for lignocellulose bioconversion.

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Effect of two surfactants on in vitro permeation of butorphanol through horse nasal mucosa

Uniciencia ◽

10.15359/ru.35-2.1 ◽

2021 ◽

Vol 35 (2) ◽

pp. 1-10

Author(s):

María Inés Velloso ◽

Héctor Alfredo Andreeta ◽

María Fabiana Landoni

Keyword(s):

Nasal Mucosa ◽

Tween 80 ◽

Ionic Surfactant ◽

Apparent Permeability ◽

In Vitro Permeation ◽

Apparent Permeability Coefficient ◽

Dose Control ◽

Franz Diffusion Cells ◽

Cetrimonium Bromide

The aim of the present study was to evaluate the effect of two surfactants on in vitro permeation of butorphanol through equine nasal mucosa. Franz diffusion cells and equine nasal mucosa were used. Three formulations were developed based on citric acid, sodium citrate, sodium chloride, and butorphanol tartrate and administered at a 24.4 g cm-3 dose. Control formulation lacked any penetration enhancer. Formulation 1 (F1) had a cationic surfactant (cetrimonium bromide) and formulation 2 (F2) had a non-ionic surfactant (Tween 80). Statistically comparing flux values at the steady state (Jss), apparent permeability coefficient (Kp), and lag-time from control, F1 and F2 for the respiratory region does not show statistically significant differences (α= 0.05). However, statistically significant differences were found on the Jss and Kp, values from control, F1, and F2 in olfactory mucosa. A statistical analysis on the latter showed significant differences between the Jss values of F1 and F2 and between control and F2. Based on this, Tween 80 proved to be a promising excipient in developing intranasal butorphanol formulations in equines since it increases its passage through the nasal mucosa. These results are very promising to continue with the development of intranasal butorphanol formulation in equines.

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Partial Least Square Model (PLS) as a Tool to Predict the Diffusion of Steroids Across Artificial Membranes

Molecules ◽

10.3390/molecules25061387 ◽

2020 ◽

Vol 25 (6) ◽

pp. 1387

Author(s):

Eleni Tsanaktsidou ◽

Christina Karavasili ◽

Constantinos K. Zacharis ◽

Dimitrios G. Fatouros ◽

Catherine K. Markopoulou

Keyword(s):

Animal Experiments ◽

Pharmaceutical Research ◽

Partial Least Square ◽

Least Square ◽

Predictive Tool ◽

Apparent Permeability ◽

Internal Validation ◽

Candidate Drug ◽

Apparent Permeability Coefficient

One of the most challenging goals in modern pharmaceutical research is to develop models that can predict drugs’ behavior, particularly permeability in human tissues. Since the permeability is closely related to the molecular properties, numerous characteristics are necessary in order to develop a reliable predictive tool. The present study attempts to decode the permeability by correlating the apparent permeability coefficient (Papp) of 33 steroids with their properties (physicochemical and structural). The Papp of the molecules was determined by in vitro experiments and the results were plotted as Y variable on a Partial Least Squares (PLS) model, while 37 pharmacokinetic and structural properties were used as X descriptors. The developed model was subjected to internal validation and it tends to be robust with good predictive potential (R2Y = 0.902, RMSEE = 0.00265379, Q2Y = 0.722, RMSEP = 0.0077). Based on the results specific properties (logS, logP, logD, PSA and VDss) were proved to be more important than others in terms of drugs Papp. The models can be utilized to predict the permeability of a new candidate drug avoiding needless animal experiments, as well as time and material consuming experiments.

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Validation of an Ex Vivo Permeation Method for the Intestinal Permeability of Different BCS Drugs and Its Correlation with Caco-2 In Vitro Experiments

Pharmaceutics ◽

10.3390/pharmaceutics11120638 ◽

2019 ◽

Vol 11 (12) ◽

pp. 638 ◽

Cited By ~ 3

Author(s):

Aroha B. Sánchez ◽

Ana C. Calpena ◽

Mireia Mallandrich ◽

Beatriz Clares

Keyword(s):

Ex Vivo ◽

Colon Adenocarcinoma ◽

Apparent Permeability ◽

Pharmaceutical Dosage Forms ◽

Diffusion Cells ◽

Intestinal Membrane ◽

Ex Vivo Permeation ◽

Apparent Permeability Coefficient ◽

Franz Diffusion Cells

The absorption study of drugs through different biological membranes constitutes an essential step in the development of new pharmaceutical dosage forms. Concerning orally administered forms, methods based on monolayer cell culture of Caco-2 (Caucasian colon adenocarcinoma) have been developed to emulate intestinal mucosa in permeability studies. Although it is widely accepted, it has disadvantages, such as high costs or high technical complexity, and limitations related to the simplified structure of the monolayer or the class of molecules that can be permeated according to the transport mechanisms. The aim of this work was to develop a new ex vivo methodology which allows the evaluation of the intestinal apparent permeability coefficient (Papp) while using fewer resources and to assess the correlation with Caco-2. To this end, pig (Sus scrofa) duodenum segments were mounted in Franz diffusion cells and used to permeate four different drugs: ketorolac tromethamine (Kt), melatonin (Mel), hydrochlorothiazide (Htz), and furosemide (Fur). No statistically significant differences (p > 0.05) were observed corelating Papp values from Franz diffusion cells and Caco-2 cell experiments for Kt, Htz, and Fur. However, there were statistically significant differences (p < 0.05) correlating Papp values and Mel. The difference is explained by the role of Mel in the duodenal epithelial paracellular permeability reduction. Ex vivo permeation may be an equivalent method to Caco-2 for drugs that do not produce intestinal membrane phenomena that could affect absorption.

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The Intestinal Barrier and Current Techniques for the Assessment of Gut Permeability

Cells ◽

10.3390/cells9081909 ◽

2020 ◽

Vol 9 (8) ◽

pp. 1909 ◽

Cited By ~ 2

Author(s):

Ida Schoultz ◽

Åsa V. Keita

Keyword(s):

Intestinal Permeability ◽

Barrier Function ◽

Ex Vivo ◽

Intestinal Barrier ◽

The Body ◽

Functional Studies ◽

Gut Barrier Function ◽

Diverse Backgrounds

The intestinal barrier is essential in human health and constitutes the interface between the outside and the internal milieu of the body. A functional intestinal barrier allows absorption of nutrients and fluids but simultaneously prevents harmful substances like toxins and bacteria from crossing the intestinal epithelium and reaching the body. An altered intestinal permeability, a sign of a perturbed barrier function, has during the last decade been associated with several chronic conditions, including diseases originating in the gastrointestinal tract but also diseases such as Alzheimer and Parkinson disease. This has led to an intensified interest from researchers with diverse backgrounds to perform functional studies of the intestinal barrier in different conditions. Intestinal permeability is defined as the passage of a solute through a simple membrane and can be measured by recording the passage of permeability markers over the epithelium via the paracellular or the transcellular route. The methodological tools to investigate the gut barrier function are rapidly expanding and new methodological approaches are being developed. Here we outline and discuss, in vivo, in vitro and ex vivo techniques and how these methods can be utilized for thorough investigation of the intestinal barrier.

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