Everted Gut Sac Model Research Articles

Enhancement in Bioaccessibility and Bioavailability of Phenolic Compounds during Black Glutinous Rice Tape Fermentation

Black glutinous rice (Oryza sativa var. glutinosa) tape fermented with various yeast, mold, and bacteria is often rich in phenolics compounds and can contribute positively to health through its antioxidants activity. Despite the potential, these compounds have limited bioavailability value due to their structure, degree of glycosylation or polymerization, and interactions with other components. Therefore, this study aims to determine the effect of fermentation on bioavailability and bioaccessibility of phenolics compounds in black glutinous rice tape. During the procedures, cooked black glutinous rice was inoculated with ragi tape for 72 hours. Sampling was then performed every 24 hours to analyze bioaccessibility of phenolics compounds, flavonoids, and antioxidants activity. Subsequently, absorption was carried out using an everted gut sac model. The results showed that phenolics compounds were released from the food matrix during gastric and small intestine digestion. Fermentation was shown to increase the content of accessible phenolics compounds from 19.89% to 27.31%, flavonoids from 68.88% to 81.72%, and antioxidants activity from 13.56% to 22.89%. During fermentation, the highest increments were obtained after 72 hours, with 27.31% for total phenolics compounds, 81.72% for flavonoid compounds, and 22.89% for antioxidants activity. The products obtained after 72 hours of fermentation exhibited significantly highest absorption, but no significant differences were observed between the duodenum and ileum segments. The absorption of these compounds in the jejunum from the extract was significantly higher in fermented samples. Therefore, fermentation significantly enhanced bioavailability of phenolics compounds in black glutinous rice tape.

Controlled dual release of phenol compounds from phospholipid complexes of short-chain lipophenols

Ethanol evaporation method was applied to synthesize phospholipid complexes from phosphatidylcholine (PC) and short-chain alkyl gallates (A-GAs, a typical representative of lipophenols) including butyl-, propyl- and ethyl gallates. 1H NMR, UV and FTIR showed that A-GAs were interacted with PC through weak physical interaction. Through the analysis of concentrations of A-GAs and gallic acid (GA) by an everted rat gut sac model coupled with HPLC-UV detection, phospholipid complexes were found to gradually release A-GAs. These liberated A-GAs were further hydrolyzed by intestinal lipases to release GA. Both of GA and A-GAs could cross intestinal membrane. Especially, the transmembrane A-GAs could also be hydrolyzed to produce GA. Undoubtedly, the dual release of phenol compounds from phospholipid complexes of short-chain lipophenols will be effective to extend the in vivo residence period of phenol compounds. More importantly, such behavior is easily adjusted by changing the acyl chain lengths of lipophenols in phospholipid complexes.

Hydrolysis and Transport Characteristics of Phospholipid Complex of Alkyl Gallates: Potential Sustained Release of Alkyl Gallate and Gallic Acid.

Phospholipid complexes of alkyl gallates (A-GAs) including ethyl gallate (EG), propyl gallate (PG), and butyl gallate (BG) were successfully prepared by the thin film dispersion method. HPLC-UV analysis in an everted rat gut sac model indicated that A-GAs can be liberated from phospholipid complexes, which were further hydrolyzed by intestinal lipase to generate free gallic acid (GA). Both A-GAs and GA are able to cross the membrane, and the hydrolysis rate of A-GAs and the transport rate of GA are positively correlated with the alkyl chain length. Especially, compared with the corresponding physical mixtures, the phospholipid complexes exhibit slower sustained-release of A-GAs and GA. Therefore, the formation of phospholipid complexes is an effective approach to prolong the residence time in vivo and additionally enhance the bioactivities of A-GAs and GA. More importantly, through regulating the carbon skeleton lengths, controlled-release of alkyl gallates and gallic acid from phospholipid complexes will be achieved.

Intestinal absorption components and absorption characteristics of Wuwei Qingzhuo San by everted intestinal sac models

This study investigated the absorption profile of Wuwei Qingzhuo San in different intestinal segments and the absorption characteristics of its alkaloids(piperine, piperanine, piperlonguminine, and dihydropiperlonguminine). The everted gut sac model was established, and the chemical components of Wuwei Qingzhuo San in different intestinal segments were detected by UPLC-Q-TOF-MS. The content of piperine, piperanine, piperlonguminine, and dihydropiperlonguminine in intestinal absorption fluid was determined by UPLC-Q-TRAP-MS and the absorption parameters were calculated. The absorption characteristics in different intestinal segments at different time were analyzed. As a result, 27, 27, 8, and 6 absorbent components from Wuwei Qingzhuo San were detected in the intestinal cyst fluid of jejunum, ileum, duodenum, and colon by UPLC-Q-TOF-MS technology, respectively. It was also found that piperine, piperanine, piperlonguminine, and dihydropiperlonguminine from Wuwei Qingzhuo San showed linear absorption in various intestinal segments, with r values exceeding 0.9. In terms of absorption content, the components were ranked as piperine>piperanine>dihydropiperlonguminine>piperlonguminine in various intestinal segments, but the absorption rate and mechanism of each component varied. The results demonstrate that the absorption of the components of Wuwei Qingzhuo San in different intestinal segments is selective and is not a simple semi-permeable membrane permeation process.

Purification and characterization of a novel zinc chelating peptides from Holothuria scabra and its ex vivo absorption activity in the small intestine

Zinc supplements currently marketed in Indonesia are second-generation zinc supplements, which must be improved for the effectiveness caused by their low absorption rate and side effects on the gastrointestinal tract. Third-generation zinc supplements are currently being investigated to improve the effectiveness of the previous generation of supplements. The present study aimed to discover a new alternative source of zinc-chelating peptide (ZCP) from Holothuria scabra. In addition, the research investigates the ZCP characteristics and absorption abilities in an ex vivo evaluation using the everted gut sac model method. The results obtained were six zinc peptides: Asp-Asp-Ala- Phe-Gln-Ala-Phe-Cys; Thr-Asp-Asn-Leu; Leu-Gly-Cys; Pro-Gly-Thr; Ser-Cys; and Pro-Tyr. The characterization showed that the resulting peptides comprised two to eight amino acids with molecular weights between 208 and 915 Da. The highest zinc binding capacity of the peptides was 92.11 mg/100 g at 30 kDa for molecular weight. Fourier-transform infrared spectra indicate that zinc ions (Zn2+) bind to carboxyl groups and interact with nitrogen atoms in amino acids and amides. The scanning electron microscope-energy dispersion spectroscopy results stated that, topographically and morphologically, ZCP has a different surface with peptides with Zn composition in the sample. Furthermore, we evaluated the peptide fractions for ex vivo absorption in the small intestine using the everted gut sac method. We found that zinc-binding peptides transported and enhanced zinc absorption in the duodenum segment at 60 minutes, resulting in a 40% increase in absorption rate. The potency of ZCPs from H. scabra as an alternative to third-generation zinc supplements with higher absorption than previous-generation supplements.

Exploring the pharmacological mechanisms of Biyan Qingdu Granula in the treatment after nasopharyngeal carcinoma radiotherapy based on UPLC/Q-TOF MS, network pharmacology and molecular docking

BackgroundBiyan Qingdu Granula (BYQD) is a traditional Chinese medicine (TCM) formula commonly used for post-radiotherapy treatment of nasopharyngeal carcinoma (NPC). Despite its extensive use, the underlying pharmacological mechanisms have yet to be fully elucidated. MethodsUPLC/Q-TOF MS was used to comprehensively analyze the chemical composition of BYQD. Additionally, an everted gut sac model, coupled with UPLC/Q-TOF MS, was used to screen and identify the active ingredients. Subsequently, we conducted a network pharmacological analysis to delve into the potential mechanisms of these active ingredients. Molecular docking experiments were also performed to assess the interactions between active ingredients and potential core targets. ResultsThe findings revealed the identification of 62 identical ingredients upon comparing the sample solution and intestinal absorbed solution of BYQD. We constructed a protein-protein interaction (PPI) network, which led to the identification of five core targets, namely, TP53, STAT3, MAPK1, SRC and AKT1. Through the construction of a drug-active ingredient-intersection target network, we identified Quercetin, Luteolin, Eupatilin, Magnoflorine, Acacetin and other compound as potential active ingredients. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis suggested that pathways in cancer, PI3K-Akt signaling pathway, lipid and atherosclerosis, proteoglycans in cancer, and the MAPK signaling pathway might play the key roles in the treatment of NPC after radiotherapy using BYQD. Molecular docking results corroborated strong binding activity between the putative core targets and the corresponding key active ingredients. ConclusionThis study provides a preliminary revelation of the active ingredients and potential pharmacological mechanisms of BYQD in the post-radiotherapy treatment of NPC. These findings establish a vital theoretical basis and serve as a scientific reference for the future investigating the pharmacological mechanisms and clinical application of BYQD.

Molecular Insights into the Mechanism of Modulatory Effects of Proton Pump Inhibitors on P-glycoprotein Mediated Drug Transport of Palbociclib and Ribociclib.

Palbociclib and ribociclib are substrates of efflux transporter, P-glycoprotein plays a key role in absorption and transport of these drugs. Proton pump inhibitors, when co-administered with them are known to show inhibitory effect on P-glycoprotein. Therefore, this study aims to investigate the role of proton pump inhibitors in inhibition of P-glycoprotein mediated efflux of palbociclib and ribociclib. A combined approach of molecular docking and ex vivo everted gut sac model was implemented to predict the potential of proton pump inhibitors i.e., omeprazole, esomeprazole, lansoprazole, pantoprazole and rabeprazole to inhibit the P-glycoprotein mediated intestinal transport of palbociclib and ribociclib and study the molecular basis of interaction taking place. Molecular docking studies revealed that omeprazole, rabeprazole and pantoprazole bound to the ATP site of nucleotide binding domain with binding energies of -27.53, -29.56 and -38.44 Kcal/mol respectively. In ex-vivo studies, rabeprazole and omeprazole, affected the absorptive permeability of palbociclib by 3.04 and 1.26 and ribociclib by 1.76 and 2.54 folds, respectively. Results of molecular docking studies and ex vivo studies highlighted that proton pump inhibitors bound to the ATP binding site to block its hydrolysis thereby inhibiting the P-glycoprotein mediated efflux of palbociclib and ribociclib. The experimental evidence presented highlights the fact that proton pump inhibitors have potential to inhibit P-glycoprotein, giving rise to drug interactions with palbociclib and ribociclib. Hence, monitoring is required while proton pump inhibitors and cyclin-dependent kinase inhibitors are being co-administered to avoid adverse events.

Quality-by-design based fabrication of febuxostat-loaded nanoemulsion: Statistical optimization, characterizations, permeability, and bioavailability studies

The present work deals with QbD-based development of FEB-loaded nanoemulsion (FEB-NE) in order to enhance bioavailability and permeability. In the beginning, the risk assessment was performed on different experimental variables using the Ishikawa diagram followed by FMEA study in order to find critical process parameter (CPP) and critical material attributes (CMAs). To build quality in nanoemulsion, the quality target product profiles (QTPP) and critical quality attributes (CQAs) were determined. The different batches of FEB-NE were produced by the microemulsification-probe sonication method. Effect of varying levels of independent variables such as oil concentration (X1), Smix concentration (X3), and amplitude (X3) on responses such as globule size (Y1), zeta potential (Y2), and entrapment efficiency (Y3) were studied using Box-Behnken design (BDD). FEB-NE formulation was optimized using a graphical and numerical method. The optimized formulation concentrations and their responses (CQAs) were located as design space in an overlay plot. The spherical shapes of globules were visualized by surface morphology using AFM and TEM. In vitro dissolution study showed 93.32% drug release from the optimized FEB-NE formulation. The drug release mechanism followed by the formulation was the Higuchi-matrix kinetics with a regression coefficient of 0.9236 (R2). FEB-NE showed enhanced permeability using PAMPA (artificial non-cell membrane) and everted gut sac model method. The developed optimized FEB-NE exhibited the enhancement of bioavailability by 2.48 fold as compared to FEB-suspension using Wistar rats suggesting improvement of solubility of a lipophilic drug. The optimized batch remained stable for 90 days at 4 °C and 25 °C. Thus, QbD-based development of FEB-NE can be useful for a better perspective on a commercial scale.

Investigation of the potential of Glycyrrhiza glabra as a bioavailability enhancer of Vitamin B12.

Vitamin B12 deficiency is prevalent among individuals globally. Inadequate consumption of B12 rich diet and low bioavailability (due to diet based/physiological factors) are linked to the deficiency of Vitamin B12 inside the body. Bioavailability enhancers augment the bioavailability of an ingested substance (drug/nutrient) thus increasing their concentration inside the body and maximizing their therapeutic benefits. In traditional medicine, Licorice (Glycyrrhiza glabra) finds utility in the treatment of various health conditions. Thus, the present study aimed to examine the potential of ethanolic extract obtained from G. glabra roots to enhance the bioavailability of Vitamin B12. The effect of ethanolic extract of G. glabra (GgEtOH) on intestinal absorption enhancement of B12 was assessed in vitro on Caco-2 and ex-vivo everted gut sac models. The influence of extract on the pharmacokinetics of Vitamin B12 was determined in vivo in Swiss albino mice. GgEtOH significantly enhanced the permeation (Papp) of B12 by 2-5 fold in vitro (25, 50, and 100 μg/ml concentrations) and ex-vivo (250 and 500 μg/ml concentrations). The pharmacokinetic parameters of B12 such as Cmax, AUC, Tmax, etc. were also significantly elevated in vivo upon oral administration of B12 (1 mg/kg dose) in combination with GgEtOH (100 and 1,000 mg/kg dose). These preliminary findings indicate that the ethanolic extract of G. glabra is capable of enhancing the bioavailability of Vitamin B12. To the best of our knowledge, this is the first report to demonstrate herbal extract-mediated enhancement of Vitamin B12 bioavailability through in vitro, ex vivo, and in vivo assays.

P17-17 Assessment of the intestinal absorption of higher olefins by the everted gut sac model in combination with in silicon newapproach methodologies

P17-17 Assessment of the intestinal absorption of higher olefins by the everted gut sac model in combination with in silicon newapproach methodologies

Assessment of the Intestinal Absorption of Higher Olefins by the Everted Gut Sac Model in Combination with In Silico New Approach Methodologies.

To reduce the number of animals and studies needed to fulfill the information requirements as required by Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) (EC no. 1907/2006), a read-across approach was used to support approximately 30 higher olefins. This study aimed to assess the absorption potential of higher olefins through the gut wall as the experimentally determined bioavailability which would strengthen the read-across hypothesis and justification, reducing the need for toxicity studies on all of the higher olefins. The absorption potential of a series of higher olefins (carbon range from 6 to 28, with five configurations of the double bond) was determined in the in vitro everted rat small intestinal sac model and subsequently ranked. In addition, in silico approaches were applied to predict the reactivity, lipophilicity, and permeability of higher olefins. In the in vitro model, everted sacs were incubated in “fed-state simulated small intestinal fluid” saturated with individual higher olefins. The sac contents were then collected, extracted, and analyzed for olefin content using gas chromatography with a flame ionization detector. The C6 to C10 molecules were readily absorbed into the intestinal sacs. Marked inter-compound differences were observed, with the amount of absorption generally decreasing with the increase in carbon number. Higher olefins with ≥C14 carbons were either not absorbed or very poorly absorbed. In the reactivity simulation study, the reactivity is well described by the position of the double bond rather than the number of carbon atoms. In the lipophilicity and permeability analysis, both parameter descriptors depend mainly on the number of carbon atoms and less on the position of the double bond. In conclusion, these new approach methodologies provide supporting information on any trends or breakpoints in intestinal uptake and a hazard matrix based on carbon number and position of the double bond. This matrix will further assist in the selection of substances for inclusion in the mammalian toxicity testing programme.

Preliminary screening of the potential active ingredients in traditional Chinese medicines using the Ussing chamber model combined with HPLC-PDA-MS

An in vitro intestinal absorption model combined with high-performance liquid chromatography-photo diode array-tandem mass spectrometry (HPLC-PDA-MS) was used for preliminary screening of potential active ingredients from complex multi-component traditional Chinese medicine (TCM) system. Oral administration is one of the main administration methods for TCMs. Only the ingredients that could be absorbed have the opportunity to play a role. Thus, these were defined as potential active ingredients. Studying of intestinal absorption can provide a theoretical basis for the mechanism of TCMs. The Caco-2 cell model, the everted rat gut sac model, and the Ussing chamber model were established for TCMs. The degree of anastomosis between the in vitro intestinal model and the actual intestinal absorption of TCMs were evaluated by the gavage method in rats. The Ussing chamber model was best fit for oral experiments in rats and was selected as the research means to preliminarily screen potential active ingredients from eight TCMs, including Salvia miltiorrhiza Bunge, Astragalus propinquus Schischkin, Plantago asiatica L, Fallopia multiflora (Thunb.) Harald, Epimedium brevicornu Maxim, Moutan Cortex, Citrus reticulata Blanco, and Panax notoginseng (Burkill) F. H. Chen ex C. H. Chow. A total of 44 components were absorbed and screened as the potential active ingredients from the 80 components identified in eight TCMs by HPLC-PDA-MS.

Development of ritonavir-loaded nanostructured lipid carriers employing quality by design (QbD) as a tool: characterizations, permeability, and bioavailability studies.

The objective of the present work was to optimize ritonavir (RTV)-loaded nanostructured lipid carriers (NLCs) to improve bioavailability using a quality by design (QbD)-based technique. Risk assessment was studied using "cause and effect" diagram followed by failure mode effect analysis (FMEA) to identify the effective high-risk variables for the formulation development. Quality target product profile (QTPP) and critical quality attributes (CQAs) were initially assigned for the proposed product. Central composite rotatable design (CCRD) was used to identify the individual and combined interactions of formulation variables. RTV-loaded NLC (RTV-NLC) was prepared using emulsification-ultrasonication method. The effect of formulation variables like ultrasound amplitude, lipid concentration, surfactant concentration on their responses like particle size, polydispersity index (PDI), and entrapment efficiency (EE) were studied by CCRD. The optimized formulation was subjected to lyophilization to obtain dry NLCs for solid-state analysis. DSC and PXRD investigations showed that RTV was molecularly dispersed in lipid matrix indicating amorphous form present in the formulation. FESEM and AFM depicted the spherical and uniform particles. The increase in solubility and dissolution rate is expected to be related to the molecular dispersion, amorphous state, of the drug in the nanoparticle. The optimized NLCs showed good physical stability during storage for 6months. RTV-NLC was further subjected to in vitro studies and found a successful sustained release rate of 92.37 ± 1.03%. The parallel artificial membrane permeability assay (PAMPA) and everted gut sac model have demonstrated the permeation enhancement of RTV. In vivo study observed the enhanced bioavailability with 2.86-fold suggesting optimized NLC successfully overcome the issue of solubility.

Effect of Short-Term Exposure to Titanium Dioxide Nanoparticles on Intestinal Absorption of Glucose by Ex Vivo Everted Rat Gut Sac Model.

Titanium dioxide nanoparticles (TiO₂ NPs) as food additives were widely found in various foodrelated products, especially in high-sugar foods. The daily intake of TiO₂ NPs in the diet may therefore expose the small intestine to TiO₂ NPs and affect its physiological functions, including the absorption of nutrients. It is speculated that TiO₂ may cause serious health hazards by increasing sugar uptake. To explore this possibility, transport of glucose from small intestine was studied using an everted gut sac model prepared from small intestine of young healthy male SD rats. The translocation of TiO₂ NPs and the morphological changes of small intestine were also observed after exposure of intestinal lumen to TiO₂ NPs for 2 h. The results showed that TiO₂ NPs can enter into enterocyte but hardly cross the intestinal epithelium. No change on microstructure of gut epithelia and expression of glucose transporter was found, and there is no obvious impact on intestinal absorption and metabolism of glucose. These results suggest that short-term exposure to TiO₂ NPs has little influence on intestinal absorption of glucose. More attention should be paid to the chronic effect of dietary consumption of TiO₂ NPs on nutrient absorption.

Development of a BCS Class II Drug Microemulsion for Oral Delivery: Design, Optimization, and Evaluation

Our work is aimed at exploring the composition and the properties of microemulsion (ME), as a drug delivery system, to enhance the permeability across the gastrointestinal (GI) barrier of fenofibrate, a BCS class II drug. It is a prodrug that is converted rapidly after oral administration into a major active metabolite which is the fenofibric acid. It undergoes a nearly complete presystemic metabolism. Its main drawback is the low bioavailability of the metabolite. A quick selection of excipients was made based on the capacity of solubilization and the value of hydrophilic-lipophilic balance. The classical method of ME development was coupled with the factorial design in order to minimize the droplet size using a low concentration of surfactant. The optimized ME showed a droplet size of 48.5 nm and physical stability. The passive permeability evaluated using Sartorius was 1.6 times higher than that of the free drug. The ex vivo technique, performed using the everted gut sac model, showed a 2.5-fold higher permeability. This suggests that the carrier-mediated uptake/efflux may present the dominant transport mechanism of fenofibrate. The use of the excipients that inhibit GI P-glycoprotein may be a new perspective. Thus, this paper shows that the composition and the characteristics of ME may be explored to increase the permeability of fenofibrate across the GI membrane.

Comparative study on the stability/intestinal absorption kinetics of 2,3,5,4′-tetrahydroxy-stilbene-2-O-β-D-glucoside derived from Polygoni Multiflori Radix and its herb pairs

The 2,3,5,4’-tetrahydroxy-stilbene-2-O-β-D-glucoside (THSG) is a main active ingredient of Polygoni Multiflori Radix (PMR). In this study, THSG was found to be a differential chemical composition between PMR and its compatible herb pairs through chemometrics techniques. The effects of the herb pairs Codonopsis Radix-PMR, Astragali Radix-PMR, and Ophiopogonis Radix (OR)-PMR on the stability and absorption behavior of THSG were investigated by simulating the digestive environment in vitro and using an everted gut sac model. The results indicated that the compatible pairs were able to significantly increase the stability of THSG in the gastrointestinal tract and delay the absorption of THSG in the small intestine. OR had the most obvious influence on THSG as the t0.9 values of THSG increased by 14.74- and 6.68-fold in simulated gastric juice and small intestinal fluid, and the apparent permeability coefficient of THSG were 2.07- and 1.97-fold lower for OR-PMR in the ileum and duodenum, respectively. Thus, the compatibility could potentially be used to change the biopharmaceutical properties of THSG. Moreover, the present study established a research method for describing the compatibilities of traditional Chinese medicine based on stability-intestinal absorption, which may provide important reference values for the compatibilities of traditional Chinese medicine.

Uncovering the pharmacological mechanisms of Xijiao Dihuang decoction combined with Yinqiao powder in treating influenza viral pneumonia by an integrative pharmacology strategy

Xijiao Dihuang decoction combined with Yinqiao powder (XDD-YQP) is a classical combination formula; however, its therapeutic effects in treating influenza viral pneumonia and the pharmacological mechanisms remain unclear. The therapeutic effect of XDD-YQP in influenza viral pneumonia was evaluated in mice. Subsequently, an everted gut sac model coupled with UPLC/Q-TOF MS were used to screen and identify the active compounds of XDD-YQP. Furthermore, network pharmacological analysis was adopted to probe the mechanisms of the active compounds. Lastly, we verified the targets predicted from network pharmacological analysis by differential bioinformatics analysis. Animal experiments showed that XDD-YQP has a therapeutic effect on influenza viral pneumonia. Moreover, 113 active compounds were identified from intestinal absorbed solutions of XDD-YQP. Using network pharmacological analysis, 90 major targets were selected as critical in the treatment of influenza viral pneumonia through 12 relevant pathways. Importantly, the MAPK signaling pathway was found to be closely associated with the other 11 pathways. Moreover, seven key targets, EGFR, FOS, MAPK1, MAP2K1, HRAS, NRAS, and RELA, which are common targets in the MAPK signaling pathway, were investigated. These seven key targets were identified as differentially expressed genes (DEGs) between influenza virus-infected and uninfected individuals. Hence, the seven key targets in the MAPK signaling pathway may play a vital role in the treatment of influenza viral pneumonia with XDD-YQP. This research may offer an integrative pharmacology strategy to clarify the pharmacological mechanisms of traditional Chinese medicines. The results provide a theoretical basis for a broader clinical application of XDD-YQP.

Promoting effect of the Maillard reaction products produced during the stir-frying process of Hordei Fructus Germinatus on the intestinal absorption of active ingredients in Hordei Fructus Germinatus.

This study was designed to evaluate the absorption promoting capacity of Maillard Reaction Products (MRPs) produced during the stir-frying process of Hordei Fructus Germinatus on catechin, ferulic acid, quercetin and kaempferol by the ex vivo rat everted gut sac model, in situ single-pass intestinal perfusion model and the whole animal model. Moreover, verapamil, EDTA and mannitol were used for determining the transport mechanism of catechin, ferulic acid, quercetin and kaempferol. The tight junction (TJ) proteins including zonula occudens-1(ZO-1) and claudin-1 were chosen to investigate the promoting mechanism of MRPs by quantitative real-time PCR (qRT-PCR) and western blot analyses. The results showed that the MRPs produced during the stir-frying process of Hordei Fructus Germinatus could improve the intestinal absorption of catechin, ferulic acid, quercetin and kaempferol. And the absorption-promoting effect of MRPs was related to chelating effect and the reduced expression of claudin-1 and ZO-1. Our results suggested that MRPs could be promising oral absorption promoters, which might be another processing mechanism of Hordei Fructus Germinatus.

Measurement of Intestinal Permeability During Sepsis.

Gut barrier function has been hypothesized to play a critical role in the pathophysiology of sepsis. Measuring intestinal permeability allows for a determination of barrier dysfunction under conditions of health and disease. Fluorescence-conjugated dyes such as fluorescein isothiocyanate-4kDa dextran (FD4) have been commonly used for evaluating hyperpermeability. Here we describe a common method to measure gut permeability in vivo, following gavage with different sized dyes. In addition, we describe an ex vivo everted gut sac model that allows for discrimination of permeability by segmental geographic location along the intestine.

A dynamic and integrated in vitro/ex vivo gastrointestinal model for the evaluation of the probability and severity of infection in humans by Salmonella spp. vehiculated in different matrices

The lack of proper gastrointestinal models assessing the inter-strain virulence variability of foodborne pathogens and the effect of the vehicle (food matrix) affects the risk estimation. This research aimed to propose a dynamic and integrated in vitro/ex vivo gastrointestinal model to evaluate the probability and severity of infection of foodborne pathogens at different matrices. An everted gut sac was used to determine the adhesion and invasion of Salmonella enterica and tissue damage. S. Typhimurium ATCC 14028 was used as a representative bacterium, and two matrices (water and cheese) were used as vehicles. No differences (p > 0.05) in the probability of infection (Pinf) were found for intra-experimental repeatability. However, the Pinf of cheese-vehiculated S. Typhimurium was different compared to water- vehiculated S. Typhimurium, 7.2-fold higher. The histological analysis revealed Salmonella-induced tissue damage, compared with the control (p < 0.05). In silico proposed interactions between two major Salmonella outer membrane proteins (OmpA and Rck) and digested peptides from cheese casein showed high binding affinity and stability, suggesting a potential protective function from the food matrix. The results showed that the everted gut sac model is suitable to evaluate the inter-strain virulence variability, considering both physiological conditions and the effect of the food matrix.