Jejunal Permeability Research Articles

Role of intestinal flora disturbance in perioperative neurocognitive disorders in aged mice

Objective To evaluate the role of intestinal flora disturbance in perioperative neurocognitive disorders in aged mice. Methods Sixty SPF healthy male C57BL/6J mice, aged 18 months, were divided into 4 groups (n=15 each) by a random number table method: control group (group C), operation group (group O), operation plus lactobacillus rhamnosus group (group OL) and operation plus fecal microbiota transplantation group (group OF). Exploratory laparotomy was performed in O, OL and OF groups.In group PL, lactobacillus rhamnosus 200 μl (1×109 CFU/ml, 200 μl/day) was given by gavage once a day for 10 days starting from the end of surgery, and mice received about 0.2×109 CFU probiotics per day.In group OF, broad-spectrum antibiotic mixture (ampicillin and sulbactam 1.5 g/L, vancomycin 500 mg/L, ciprofloxacin 200 mg/L, imipenem cilastatin 250 mg/L and metronidazole 1 g/L) was added to the drinking water at 7 weeks prior to operation and replaced with sterile tap water at 72 h before operation, and fecal filtrates 200 μl was given by gavage once a day for 10 days starting the end of operation.Five mice were sacrificed at day 10 after operation in each group, and Evans blue extravasation test was used to measure the vascular permeability of jejunum and ileum.Five mice were sacrificed at day 10 after operation in each group, and the small intestinal and hippocampal tissues and orbital venous blood samples were obtained for determination of interleukin-6 (IL-6), IL-17, tumor necrosis factor-alpha (TNF-α), interferon gamma (IFN-γ), IL-4 and IL-10 levels by enzyme-linked immunosorbent assay.Five mice were selected at day 10 after operation in each group, and the Morris water maze test was used to assess the cognitive function. Results Compared with group C, the vascular permeability of jejunum and ileum was significantly increased, the levels of IL-6, IL-17, TNF-α and IFN-γ in the small intestine, peripheral blood and hippocampus were increased, the levels of IL-4 and IL-10 were decreased, the swimming distance and escape latency were prolonged, and the time spent in the target quadrant was shortened in group O (P 0.05). Compared with group O, the vascular permeability of jejunum and ileum was significantly decreased, the levels of IL-6, IL-17, TNF-α and IFN-γ in the small intestine, peripheral blood and hippocampus were decreased, the levels of IL-4 and IL-10 were increased, the swimming distance and escape latency were shortened, and the time spent in the target quadrant was prolonged in OL and OF groups (P<0.05). Conclusion Intestinal flora disturbance can mediate inflammatory responses in the hippocampus and cause perioperative neurocognitive disorders in aged mice. Key words: Gastrointestinal microbiome; Neurocognitive disorders; Aged

Fecal Microbiota Transplant From Highly Feed Efficient Donors Affects Cecal Physiology and Microbiota in Low- and High-Feed Efficient Chickens.

Fecal microbiota transplants (FMT) may be used to improve chicken’s feed efficiency (FE) via modulation of the intestinal microbiota and microbe-host signaling. This study investigated the effect of the administration of FMT from highly feed efficient donors early in life on the jejunal and cecal microbiota, visceral organ size, intestinal morphology, permeability, and expression of genes for nutrient transporters, barrier function and innate immune response in chickens of diverging residual feed intake (RFI; a metric for FE). Chicks (n = 110) were inoculated with the FMT or control transplant (CT) on 1, 6, and 9 days posthatch (dph), from which 56 chickens were selected on 30 dph as the extremes in RFI, resulting in 15 low and 13 high RFI chickens receiving the FMT and 14 low and 14 high RFI chickens receiving the CT. RFI rank and FMT only caused tendencies for alterations in the jejunal microbiota and only one unclassified Lachnospiraceae genus in cecal digesta was indicative of high RFI. By contrast, the FMT caused clear differences in the short-chain fatty acid (SCFA) profile in the crop and cecal microbiota composition compared to the CT, which indicated alterations in amylolytic, pullulanolytic and hemicellulolytic bacteria such as Lactobacillus, Dorea, and Ruminococcus. Moreover, the FMT caused alterations in intestinal development as indicated by the longer duodenum and shallower crypts in the ceca. From the observed RFI-associated variation, energy-saving mechanisms and moderation of the mucosal immune response were indicated by higher jejunal permeability, shorter villi in the ileum, and enhanced cecal expression of the anti-inflammatory cytokine IL10 in low RFI chickens. Relationships obtained from supervised multigroup data integration support that certain bacteria, including Ruminococcocaceae-, Lactobacillus-, and unclassified Clostridiales-phylotypes, and SCFA in jejunal and cecal digesta modulated expression levels of cytokines, tight-junction protein OCLN and nutrient transporters for glucose and SCFA uptake. In conclusion, results suggest that the intestine only played a moderate role for the RFI-associated variation of the present low and high RFI phenotypes, whereas modulating the early microbial colonization resulted in long-lasting changes in bacterial taxonomic and metabolite composition as well as in host intestinal development.

Evaluation of drug permeability calculation based on luminal disappearance and plasma appearance in the rat single-pass intestinal perfusion model

The rat single-pass intestinal perfusion (SPIP) model is commonly used to investigate gastrointestinal physiology and membrane drug transport. The SPIP model can be used with the intestinal segment inside or outside the abdomen. The rats can also be treated with parecoxib, a selective cycloxygenase-2 inhibitor that has been shown to affect some intestinal functions following abdominal surgery, such as motility, epithelial permeability, fluid flux and ion transport. However, the impact of extra-abdominal placement of the intestinal segment in combination with parecoxib on intestinal drug transport has not been investigated. There is also uncertainty how well intestinal permeability determinations based on luminal drug disappearance and plasma appearance correlate in the rat SPIP model. The main objective of this rat in vivo study was to investigate the effect of intra- vs. extra-abdominal SPIP, with and without, pretreatment with parecoxib. The effect was evaluated by determining the difference in blood-to-lumen 51Cr-EDTA clearance, lumen-to-blood permeability of a cassette-dose of four model compounds (atenolol, enalaprilat, ketoprofen, and metoprolol), and water flux. The second objective was to compare the jejunal permeability values of the model drugs when determined based on luminal disappearance or plasma appearance. The study showed that the placement of the perfused jejunal segment, or the treatment with parecoxib, had minimal effects on membrane permeability and water flux. It was also shown that intestinal permeability of low permeability compounds should be determined on the basis of data from plasma appearance rather than luminal disappearance. If permeability is calculated on the basis of luminal disappearance, it should preferably include negative values to increase the accuracy in the determinations.

Oral administration of Lactobacillus rhamnosus GG to newborn piglets augments gut barrier function in pre-weaning piglets.

To understand the effects of Lactobacillus rhamnosus GG (ATCC 53103) on intestinal barrier function in pre-weaning piglets under normal conditions, twenty-four newborn littermate piglets were randomly divided into two groups. Piglets in the control group were orally administered with 2 mL 0.1 g/mL sterilized skim milk while the treatment group was administered the same volume of sterilized skim milk with the addition of viable L. rhamnosus at the 1st, 3rd, and 5th days after birth. The feeding trial was conducted for 25 d. Results showed that piglets in the L. rhamnosus group exhibited increased weaning weight and average daily weight gain, whereas diarrhea incidence was decreased. The bacterial abundance and composition of cecal contents, especially Firmicutes, Bacteroidetes, and Fusobacteria, were altered by probiotic treatment. In addition, L. rhamnosus increased the jejunal permeability and promoted the immunologic barrier through regulating antimicrobial peptides, cytokines, and chemokines via Toll-like receptors. Our findings indicate that oral administration of L. rhamnosus GG to newborn piglets is beneficial for intestinal health of pre-weaning piglets by improving the biological, physical, and immunologic barriers of intestinal mucosa.

Impact of a dietary challenge with peroxidized oil on the glutathione redox status and integrity of the small intestine in weaned piglets

Glutathione (GSH) is considered to play an important role in maintaining the integrity of the small intestine. In piglets, altered mucosal GSH levels might therefore be involved in weaning-induced changes of the small intestinal morphology and barrier function. To test this hypothesis, we aimed to challenge the mucosal GSH redox status during the first 28 days after weaning, by feeding diets containing 5% fresh linseed oil (CON), or 2.5% (OF1) or 5% (OF2) peroxidized linseed oil (peroxide value 225 mEq O2/kg oil) and exploring the effects on gut integrity. Piglets were pair-fed and had a total daily feed allowance of 32 g/kg BW. A fourth treatment included animals that were fed the control diet ad libitum (ACON). Animals were sampled at days 5 and 28 post-weaning. The malondialdehyde (MDA) concentration and GSH redox status (GSH/GSSG Eh) were determined in blood, liver and small intestinal mucosa. Histomorphology of the duodenal and jejunal mucosa was determined, and Ussing chambers were used to assess fluorescein isothiocyanate dextran (FD4) and horseradish peroxidase (HRP) fluxes across the mucosa. Results show that peroxidized linseed oil imposed an oxidative challenge at day 28, but not at day 5 post-weaning. At day 28, increasing levels of dietary peroxides to pair-fed pigs linearly increased MDA levels in duodenal and jejunal mucosa. Moreover, FD4 fluxes were significantly increased in OF1 (+75%) and OF2 (+64%) in the duodenum, and HRP fluxes tended (P=0.099) to show similar differences, as compared to CON. This co-occurred with a significant 11 mV increase of the hepatic GSH/GSSG Eh, potentiated by a significantly increased GSH peroxidase activity for treatments OF1 (+47%) and OF2 (+63%) in liver as compared to CON. Furthermore; duodenal HRP flux significantly correlated with the hepatic glutathione disulphide (GSSG) level (r=0.650), as also observed in the jejunum for hepatic GSSG (r=0.627) and GSH/GSSG Eh (r=0.547). The jejunal permeability was not affected, but FD4 and HRP fluxes significantly correlated with the local GSH (r=0.619; r=0.733) and GSSG (r=0.635; r=0586) levels. Small intestinal histomorphology was not affected by dietary lipid peroxides, nor were there any correlations found with the GSH redox system. To conclude, under oxidative stress conditions, jejunal barrier function is related to the local and hepatic GSH redox system. It is suggested that the hepatic GSH system participates in the elimination of luminal peroxides, and thereby impacts on duodenal barrier function.

Betaine and Antioxidants Improve Growth Performance, Breast Muscle Development and Ameliorate Thermoregulatory Responses to Cyclic Heat Exposure in Broiler Chickens.

Simple SummaryThe physiological and metabolic responses of broiler chickens to control thermoregulation during heat stress divert energy from efficient production in addition to increasing morbidity and mortality. Therefore, heat stress amelioration strategies may improve the productivity of poultry meat production over the summer months and in tropical regions. Increasingly, low-cost feed additives are being investigated as potential amelioration strategies against heat stress. Scholars have investigated the effects of betaine alone on growth performance and gut physiology, while a small number of studies have been made regarding the impacts of the combination of betaine and antioxidants. Therefore, this study was conducted to investigate the effects of the osmolyte betaine and selenium and vitamin E supplementation on growth performance, physiological responses, and gut physiology in broiler chickens exposed to cyclic heat stress.Heat stress (HS) is an environmental stressor challenging poultry production and requires a strategy to cope with it. A total of 288-day-old male broiler chicks were fed with one of the following diets: basal diet, basal with betaine (BET), or with selenium and vitamin E (AOX), or with a combination of BET and AOX, under thermoneutral and cyclic HS. Results showed that HS reduced average daily feed intake (ADFI) (p = 0.01) and average daily gain (ADG) (p < 0.001), and impaired feed conversion ratio (FCR) (p = 0.03) during rearing period (0–42 day). BET increased ADG (p = 0.001) and decreased FCR (p = 0.02), whereas AOX had no effects. Breast muscle weight was decreased by HS (p < 0.001) and increased by BET (p < 0.001). Rectal temperature was increased by HS (p < 0.001) and improved by BET overall. Respiration rate was increased by HS (p < 0.001), but BET decreased it during HS (p = 0.04). Jejunum transepithelial resistance was reduced by HS and had no effect on permeability whereas BET increased jejunum permeability (p = 0.013). Overall, the reductions in ADG of broiler chickens during HS were ameliorated by supplementation with BET, with much of the increase in ADG being breast muscle.

Increased jejunal permeability in human obesity is revealed by a lipid challenge and is linked to inflammation and type 2 diabetes.

Obesity and its metabolic complications are characterized by subclinical systemic and tissue inflammation. In rodent models of obesity, inflammation and metabolic impairments are linked with intestinal barrier damage. However, whether intestinal permeability is altered in human obesity remains to be investigated. In a cohort of 122 severely obese and non-obese patients, we analyzed intestinal barrier function combining in vivo and ex vivo investigations. We found tight junction impairments in the jejunal epithelium of obese patients, evidenced by a reduction of occludin and tricellulin. Serum levels of zonulin and LPS binding protein, two markers usually associated with intestinal barrier alterations, were also increased in obese patients. Intestinal permeability per se was assessed in vivo by quantification of urinary lactitol/mannitol (L/M) and measured directly ex vivo on jejunal samples in Ussing chambers. In the fasting condition, L/M ratio and jejunal permeability were not significantly different between obese and non-obese patients, but high jejunal permeability to small molecules (0.4 kDa) was associated with systemic inflammation within the obese cohort. Altogether, these results suggest that intestinal barrier function is subtly compromised in obese patients. We thus tested whether this barrier impairment could be exacerbated by dietary lipids. To this end, we challenged jejunal samples with lipid micelles and showed that a single exposure increased permeability to macromolecules (4 kDa). Jejunal permeability after the lipid load was two-fold higher in obese patients compared to non-obese controls and correlated with systemic and intestinal inflammation. Moreover, lipid-induced permeability was an explicative variable of type 2 diabetes. In conclusion, intestinal barrier defects are present in human severe obesity and exacerbated by a lipid challenge. This paves the way to the development of novel therapeutic approaches to modulate intestinal barrier function or personalize nutrition therapy to decrease lipid-induced jejunal leakage in metabolic diseases. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Effect of biphenyl hydrolase-like (BPHL) gene disruption on the intestinal stability, permeability and absorption of valacyclovir in wildtype and Bphl knockout mice

Biphenyl hydrolase-like protein (BPHL) is a novel human serine hydrolase that was originally cloned from a breast carcinoma cDNA library and shown to convert valacyclovir to acyclovir and valganciclovir to ganciclovir. However, the exclusivity of this process has not been determined and, indeed, it is possible that a number of esterases/proteases may mediate the hydrolysis of valacyclovir and similar prodrugs. The objectives of the present study were to evaluate the in situ intestinal permeability and stability of valacyclovir in wildtype (WT) and Bphl knockout (KO) mice, as well as the in vivo oral absorption and intravenous disposition of valacyclovir and acyclovir in the two mouse genotypes. We found that Bphl knockout mice had no obvious phenotype and that Bphl ablation did not alter the jejunal permeability of valacyclovir during in situ perfusions (i.e., 0.54 × 10−4 in WT vs. 0.53 × 10−4 cm/s in KO). Whereas no meaningful changes occurred between genotypes in the gene expression of proton-coupled oligopeptide transporters (i.e., PepT1, PepT2, PhT1, PhT2), enzymatic upregulation of Cyp3a11, Cyp3a16, Abhd14a and Abhd14b was observed in some tissues of Bphl knockout mice. Most importantly, we found that valacyclovir was rapidly and efficiently hydrolyzed to acyclovir in the absence of BPHL, and that hydrolysis was more extensive after the oral vs. intravenous route of administration (for both genotypes). Taken as a whole, BPHL is not obligatory for the conversion of valacyclovir to acyclovir either presystemically or systemically.

A Refined Developability Classification System

In 2010, the Developability Classification System (DCS) was proposed. The DCS was designed to close the gap between the biopharmaceutics classification system, which is aimed at guiding regulatory decisions about well-characterized drugs, and the need for early evaluation of drug candidates with respect to their suitability for oral delivery. The DCS applied solubility in fasted state simulated intestinal fluid to estimate intestinal solubility, assessed the compensatory nature of permeability and solubility during oral absorption and provided a way of estimating the critical the particle size at which dissolution becomes rate-limiting to absorption. Building on this framework, a refined developability classification system (rDCS) is now proposed. The rDCS is stratified into standard investigations applied to all candidates, and customized investigations. Standard investigation of solubility and permeability can be performed according to in-house methods, and the results compared with standard data sets of fasted state human intestinal fluid solubility and human effective jejunal permeability, which have been generated specifically for rDCS. Customized investigations are triggered when there is potential for supersaturation/precipitation (weak bases; salts of weak acids) and to assess dissolution versus permeation limited absorption. In addition, the rDCS offers facile visualization of the results, enabling pragmatic comparison of drug candidates and formulation approaches.

Differences in intestinal size, structure, and function contributing to feed efficiency in broiler chickens reared at geographically distant locations

The contribution of the intestinal tract to differences in residual feed intake (RFI) has been inconclusively studied in chickens so far. It is also not clear if RFI-related differences in intestinal function are similar in chickens raised in different environments. The objective was to investigate differences in nutrient retention, visceral organ size, intestinal morphology, jejunal permeability and expression of genes related to barrier function, and innate immune response in chickens of diverging RFI raised at 2 locations (L1: Austria; L2: UK). The experimental protocol was similar, and the same dietary formulation was fed at the 2 locations. Individual BW and feed intake (FI) of chickens (Cobb 500FF) were recorded from d 7 of life. At 5 wk of life, chickens (L1, n = 157; L2 = 192) were ranked according to their RFI, and low, medium, and high RFI chickens were selected (n = 9/RFI group, sex, and location). RFI values were similar between locations within the same RFI group and increased by 446 and 464 g from low to high RFI in females and males, respectively. Location, but not RFI rank, affected growth, nutrient retention, size of the intestine, and jejunal disaccharidase activity. Chickens from L2 had lower total body weight gain and mucosal enzyme activity but higher nutrient retention and longer intestines than chickens at L1. Parameters determined only at L1 showed increased crypt depth in the duodenum and jejunum and enhanced paracellular permeability in low vs. high RFI females. Jejunal expression of IL1B was lower in low vs. high RFI females at L2, whereas that of TLR4 at L1 and MCT1 at both locations was higher in low vs. high RFI males. Correlation analysis between intestinal parameters and feed efficiency metrics indicated that feed conversion ratio was more correlated to intestinal size and function than was RFI. In conclusion, the rearing environment greatly affected intestinal size and function, thereby contributing to the variation in chicken RFI observed across locations.

Pharmaceutical Characterization of MyoNovin, a Novel Skeletal Muscle Regenerator: in silico, in vitro and in vivo Studies.

MyoNovin is a novel skeletal muscle-regenerating compound developed through synthesis of two nitro groups onto a guaifenesin backbone to deliver nitric oxide to skeletal muscle with a potential to treat muscle atrophy. The purpose of this study was to utilize in silico, in vitro, and in vivo approaches to characterize MyoNovin and examine its safety, biodistribution, and feasibility for drug delivery. In silico software packages were used to predict the physicochemical and biopharmaceutical properties of MyoNovin. In vitro cardiotoxicity was assessed using human cardiomyocytes (RL-14) while effects on CYP3A4 metabolic enzyme and antioxidant activity were examined using commercial kits. A novel HPLC assay was developed to measure MyoNovin concentration in serum, and delineate initial pharmacokinetic and acute toxicity after intravenous administration (20 mg/kg) to male Sprague-Dawley rats. MyoNovin showed relatively high lipophilicity with a LogP value of 3.49, a 20-fold higher skin permeability (19.89 cm/s*107) compared to guaifenesin (0.66 cm/s*107), and ~10-fold higher effective jejunal permeability (2.24 cm/s*104) compared to guaifenesin (0.26 cm/s*104). In vitro, MyoNovinwas not cytotoxic to cardiomyocytes at concentrations below 8 μM and did not inhibit CYP3A4 or show antioxidant activity. In vivo, MyoNovin had a short half-life (t1/2) of 0.16 h, and a volume of distribution Vss of 0.62 L/kg. Biomarkers of MyoNovincardiac and renal toxicity did not differ significantly from baseline control levels. The predicted high lipophilicity and skin permeability of MyoNovin render it a potential candidate for transdermal administration while its favourable intestinal permeation suggests it may be suitable for oral administration. Pharmacokinetics following IV administration of MyoNovin were delineated for the first time in a rat model. Preliminary single 20 mg/kg dose assessment of MyoNovin suggest no influenceon cardiac troponin or β-N-Acetylglucosaminidase.This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Surgical Anatomy Does Not Affect the Progression of Intestinal Failure-Associated Liver Disease in Neonatal Piglets.

Intestinal failure-associated liver disease (IFALD) causes significant morbidity in neonates with short bowel syndrome (SBS) dependent on parenteral nutrition (PN). Resected ileum, with loss of the ileocecal valve (ICV), is the most common anatomy in SBS, yet its impact on IFALD has not been adequately studied. Neonatal piglets were randomized to 75% intestinal resection with jejunocolic anastomosis (JC, n=12), 75% resection with jejunoileal anastomosis and intact ICV (JI, n=13), PN-fed sham (sham, n=14), or sow-fed control (SF, n=8). Surgical and sham piglets received 100% PN for 14 days before bile flow was measured and blood chemistry, liver pathology, jejunal permeability, and bacterial translocation were assessed. Bile flow was lower for PN-fed compared with SF (P=.002) but not different between the PN-fed groups. Total bilirubin (P=.03) and liver pathology (P < .001) were greater in PN-fed than SF groups but not different between PN-fed groups. Serum bile acids were increased in sham (P=.01) but not different between SBS groups. PN-fed piglets with sepsis had lower bile flow (P=.001) and increased bilirubin (P=.04). Neither jejunal permeability nor bacterial translocation were different between JC, JI, or sham groups. Contrary to our hypothesis, the remnant anatomy does not appear to worsen the progression of IFALD. However, the role of sepsis in IFALD should be further explored, in addition to other mechanisms, including PN factors, host immune responses, and intestinal bacterial dysbiosis.

Kinetics of lipid bilayer permeation of a series of ionisable drugs and their correlation with human transporter-independent intestinal permeability

For low molecular weight drugs, lipid bilayer permeation is considered the major route for in vivo cell barrier passage. We recently introduced a fluorescence assay with liposomes to determine permeation kinetics of ionisable compounds across the lipid bilayer by monitoring drug-induced pH changes inside the liposomes. Here, we determined the permeability coefficients (PFLipP, FLipP for “Fluorescence Liposomal Permeability”) across 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayers of 35 ionisable drugs at pH6.0 and compared them to available in vivo human jejunal permeability (Peff) data. PFLipP values were furthermore compared with published Caco-2 cell permeability coefficients (PCaco-2), permeability coefficients determined with the parallel artificial membrane permeability assay (PAMPA) and with log D (pH6.0). The log PFLipP, corrected for predicted para-cellular diffusion, and log PCaco-2 correlated best with log Peff, with similar adjusted R2 (0.75 and 0.74, n=12). Our results suggest that transporter-independent intestinal drug absorption is predictable from liposomal permeability.

Variants of β-casofensin, a bioactive milk peptide, differently modulate the intestinal barrier: In vivo and ex vivo studies in rats

β-Casofensin is a bioactive milk peptide that modulates the intestinal barrier, particularly through its action on goblet cells. β-Casofensin corresponds to fragment (f) 94-123 of the bovine β-casein (β-CN) A2 variant. Fifteen genetic variants of bovine β-CN (A1-3, B-G, H1-2, I-L) are known, of which the A2, A1, and B forms are the most common. These variants differ from each other by the substitution of one or more amino acids, some of which are localized in f94 to 123. The aim of our study was to compare the intestinal effects of β-casofensin A2 and its 3 main variants: A1, A3, and B. For this purpose, a solution (0.1 µM; 10 μL/g of body weight, postnatal d 10-20) containing β-casofensin A2, one of its variants (A1, A3, or B), or drinking water (control; CT) was administered to rat pups orally. After euthanasia (postnatal d 20), intestinal segments were collected for biochemical and histochemical analysis and also used to determine paracellular permeability to fluorescein isothiocyanate-labeled 4-kDa dextran in an Ussing chamber. We also studied the direct effects of β-casofensin A2 and its A1 variant on the paracellular permeability of jejunum segments of adult rats. β-Casofensin A2 and its B variant significantly increased the population of goblet cells compared with the CT, A1, and A3 groups. The mucin 2 mRNA level was significantly higher in the β-casofensin A2 group than in the CT, A3, and B groups. Our results also revealed that the protein expression of zonula occludens-1 and occludin was reduced in the jejunum of rats in the A1, A3, and B groups compared with the CT group. However, the A1 variant was the only peptide to decrease jejunal permeability compared with the CT group. This variant, tested directly in the apical compartment of an Ussing chamber at a concentration of 0.1 nM, also reduced jejunal permeability. In conclusion, the substitution of a single amino acid alters the effect of β-CN sequence f94 to 123 on goblet cells and on intestinal permeability. A genetic polymorphism of β-CN can affect the biological activity of peptides derived from this protein. These data should be taken into account in the production of bioactive foods.

Synergy of glucagon-like peptide-2 and epidermal growth factor coadministration on intestinal adaptation in neonatal piglets with short bowel syndrome.

Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) treatment enhance intestinal adaptation. To determine whether these growth factors exert synergistic effects on intestinal growth and function, GLP-2 and EGF-containing media (EGF-cm) were administered, alone and in combination, in neonatal piglet models of short bowel syndrome (SBS). Neonatal Landrace-Large White piglets were block randomized to 75% midintestinal [jejunoileal (JI) group] or distal intestinal [jejunocolic (JC) group] resection or sham control, with 7-day infusion of saline (control), intravenous human GLP-2 (11 nmol·kg-1·day-1) alone, enteral EGF-cm (80 μg·kg-1·day-1) alone, or GLP-2 and EGF-cm in combination. Adaptation was assessed by intestinal length, histopathology, Üssing chamber analysis, and real-time quantitative PCR of intestinal growth factors. Combined EGF-cm and GLP-2 treatment increased intestinal length in all three surgical models (P < 0.01). EGF-cm alone selectively increased bowel weight per length and jejunal villus height in the JI group only. The JC group demonstrated increased intestinal weight and villus height (P < 0.01) when given either GLP-2 alone or in combination with EGF-cm, with no effect of EGF-cm alone. Jejunal permeability of mannitol and polyethylene glycol decreased with combination therapy in both SBS groups (P < 0.05). No difference was observed in fat absorption or body weight gain. IGF-1 mRNA was differentially expressed in JI vs. JC piglets with treatment. Combined treatment with GLP-2 and EGF-cm induced intestinal lengthening and decreased permeability, in addition to the trophic effects of GLP-2 alone. Our findings demonstrate the benefits of novel combination GLP-2 and EGF treatment for neonatal SBS, especially in the JC model representing most human infants with SBS.NEW & NOTEWORTHY Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) are intestinotrophic, with demonstrated benefit in both animal models and human studies of short bowel syndrome (SBS). The current research shows that over and above known trophic effects, the combination of GLP-2 and EGF synergistically lengthens the bowel in neonatal piglet models of SBS. Most notable benefit occurred with resection of the terminal ileum, the common clinical anatomy seen in neonatal SBS and associated with least de novo lengthening postsurgery.

Predicting Passive Permeability of Drug-like Molecules from Chemical Structure: Where Are We?

Intestinal absorption in human is routinely predicted in drug discovery using in vitro assays such as permeability in the Madin-Darby canine kidney cell line. In silico models trained on these data are used in drug discovery efforts to prioritize novel chemical targets for synthesis; however, their proprietary nature and the limited validation available, which is usually restricted to predicting in vitro permeability, are barriers to widespread adoption. Because of the categorical nature of the in vitro permeability assay, intrinsic assay variability, and the challenges often encountered when translating in vitro data to an in vivo drug property, validation based solely on in vitro data might not be a good characterization of the usefulness of the in silico tool. In this work, we analyze the performance of three different in silico models in predicting the in vitro and in vivo permeability of 300 marketed drugs and 86 discovery compounds. The models differ in their approach (mechanistic vs quantitative structure-activity relationship) and the degree of complexity; one of them is a linear equation based on seven simple physicochemical descriptors and is presented for the first time in this work. Results show that in silico models can be successfully used to complement the discovery toolbox for characterizing in vivo intestinal permeability, defined using fraction of dose absorbed in human (Fa) and human jejunal permeability (Peff). While the in vitro permeability models outperformed the in silico approach at predicting each of the in vivo end points explored, the gap in predictivity between the in vitro and the in vivo data was generally comparable to the gap between in silico and in vitro data. The in vitro and in silico approaches shared many of the same outliers, which can often be explained by the route of drug absorption (paracellular vs transcellular, active vs passive). Data suggest that the discovery process can greatly benefit from an early adoption of in silico models for predicting permeability as well as from a careful analysis of the in silico to in vivo disconnects.

English

The in silico simulations and predictions approach in evaluation of pharmacokinetic properties of new chemical entities (NCEs) is fast becoming an acceptable trend in natural products research and drug discovery. This paper focuses on the properties of trolline with respect to its anti-inflammatory and MCF-7 breast cancer cell line growth inhibition effects and an attempt to predict physico-chemical drug-like properties in silico. The compound was isolated for the first time from aerial parts of Mirabilis jalapa and the structure was elucidated by 1D and 2D NMR, FTIR and mass spectroscopic analyses. The compound was screened for anti-inflammatory and anti-MCF-7 cell lines proliferation using chemoluminiscence oxidative burst and MTT assays respectively. Predictions on physico-chemical properties central to oral route drug administration were done using commercial software Admet predictor. Results show anti-inflammatory effects at IC50 concentration of 53.8 &micro;g/ml and 48% mortality of breast cancer cell lines at 50 &micro;M concentration. Predictions suggest moderate solubility of 1.72 to 2.92 mg/ml across pH range of 1.6 to 6.8 in simulated solvent systems and effective jejunal permeability of 5.61 x 10-4 cm/s. The compound was also predicted to be 60% unbound to plasma proteins and an LD50 of 950 mg/kg in rats. The compound, trolline had clinically important bioactive effects, probably possess promising drug-like properties suitable for further high throughput screening. Key words: ADMET, anti-inflammatory, in silico prediction, Mirabilis jalapa, NMR, trolline.

Effects of aqueous extracts from Ceratonia siliqua L. pods on small intestinal motility in rats and jejunal permeability in mice

The current study was performed to assess the effects of carob pod aqueous extracts (CPAE, pulp, seeds or mixture) on gastrointestinal transit (GIT) and intestinal epithelium permeability.

Chromatographic and Computational Assessment of Potential Biological Activity of N-(Substituted Phenyl)- 2-Chloroacetamides Applying Multivariate Methods

The lipophilicity of the newly synthesized N-(substituted phenyl)-2-chloroacetamides, as the most commonly used molecular descriptor of a potential biological activity was the subject of research. The lipophilicity of the tested derivatives was determined by applying the reversed-phase thin-layer chromatography (RPTLC18F254s) in mixtures of water and one protic (n-propanol) and one aprotic (acetonitrile) solvent, as well as mathematically. The effects of the substituent on the lipophilicity of chloroacetamides were discussed. The obtained chromatographic retention constant, , of examined chloroacetamides was correlated with the standard measure of lipophilicity, log P, and with pharmacokinetic predictors such as human effective permeability in jejunum, Peff, plasma protein binding, PPB, and distribution through blood-brain barrier, log BBB, using linear regression analysis and two multivariate methods, cluster analysis and principal component analysis. All the applied methods gave very similar results, and all the procedures also confirmed the fact that determined by RPTLC could be used as a descriptor to estimate the potential biological activity of N-(substituted phenyl)-2-chloroacetamides.

The biopharmaceutics of successful controlled release drug product: Segmental-dependent permeability of glipizide vs. metoprolol throughout the intestinal tract

The purpose of this work was to study the challenges and prospects of regional-dependent absorption in a controlled-release scenario, through the oral biopharmaceutics of the sulfonylurea antidiabetic drug glipizide. The BCS solubility class of glipizide was determined, and its physicochemical properties and intestinal permeability were thoroughly investigated, both in-vitro (PAMPA and Caco-2) and in-vivo in rats. Metoprolol was used as the low/high permeability class boundary marker. Glipizide was found to be a low-solubility compound. All intestinal permeability experimental methods revealed similar trend; a mirror image small intestinal permeability with opposite regional/pH-dependency was obtained, a downward trend for glipizide, and an upward trend for metoprolol. Yet the lowest permeability of glipizide (terminal Ileum) was comparable to the lowest permeability of metoprolol (proximal jejunum). At the colon, similar permeability was evident for glipizide and metoprolol, that was higher than metoprolol’s jejunal permeability. We present an analysis that identifies metoprolol’s jejunal permeability as the low/high permeability class benchmark anywhere throughout the intestinal tract; we show that the permeability of both glipizide and metoprolol matches/exceeds this threshold throughout the entire intestinal tract, accounting for their success as controlled-release dosage form. This represents a key biopharmaceutical characteristic for a successful controlled-release dosage form.