Gastrointestinal Tract Permeability Research Articles

Effects of a multistrain Bacillus-based direct-fed microbial on gastrointestinal permeability and biomarkers of inflammation during and following feed restriction in mid-lactation Holstein cows

Objectives were to evaluate the effects of a multistrain Bacillus-based (Bacillus subtilis and Bacillus pumilus blend) direct-fed microbial (DFM) on production, metabolism, inflammation biomarkers and gastrointestinal tract (GIT) permeability during and following feed restriction (FR) in mid-lactation Holstein cows. Multiparous cows (n = 36; 138 ± 53 DIM) were randomly assigned to 1 of 3 dietary treatments: 1) control (CON; 7.5 g/d rice hulls; n = 12), 2) DFM10 (10 g/d Bacillus DFM, 4.9 × 109 cfu/d; n = 12) or 3) DFM15 (15 g/d Bacillus DFM, 7.4 × 109 cfu/d; n = 12). Before study initiation, cows were fed their respective treatments for 32 d. Cows continued to receive treatments during the trial, which consisted of 3 experimental periods (P): P1 (5 d) served as baseline for P2 (5 d), during which all cows were restricted to 40% of P1 dry matter intake (DMI), and P3 (5 d), a "recovery" where cows were fed ad libitum. On d 4 of P1 and on d 2 and 5 of P2, GIT permeability was evaluated in vivo using the oral paracellular marker chromium (Cr)-EDTA. As anticipated, FR decreased milk production, decreased insulin, glucagon, and BUN but increased nonesterified fatty acids. During recovery, DMI rapidly increased on d 1 then subsequently decreased (4.9 kg) on d 2 before returning to baseline whereas milk yield slowly increased but remained decreased (13%) relative to P1. DFM10-fed cows had increased DMI and milk yield relative to DFM15 during P3 (10%). Overall, milk lactose content was increased in DFM cows relative to CON (0.10 percentage units), and DFM10 cows tended to have increased lactose yield relative to CON and DFM15 during P3 (8 and 10%, respectively). No overall treatment differences were observed for other milk composition variables. Circulating glucose was quadratically increased in DFM10 cows compared with CON and DFM15 during FR and recovery. Plasma Cr area under the curve was increased in all cows on d 2 (9%) and 5 (6%) relative to P1. Circulating lipopolysaccharide binding protein (LBP), serum amyloid A (SAA), and haptoglobin (Hp) increased in all cows during P2 compared with baseline (31%, 100%, and 9.0-fold, respectively). Circulating Hp concentrations continued to increase during P3 (274%). Overall, circulating LBP and Hp tended to be increased in DFM15 cows relative to DFM10 (29 and 81%, respectively), but no treatment differences were observed for SAA. Following feed reintroduction during P3, fecal pH initially decreased (0.62 units), but returned to baseline levels whereas fecal starch markedly increased (2.5-fold) and remained increased (82%). Absolute quantities of a fecal Butyryl-CoA CoA transferase (But) gene associated with butyrate synthesis, collected by fecal swab were increased in DFM10 cows compared with CON and DFM15-fed cows. In summary, FR increased GIT permeability, caused inflammation, and decreased production. Feeding DFM10 increased some key production and metabolism variables and upregulated a molecular biomarker of microbial hindgut butyrate synthesis, while DFM15 appeared to augment immune activation.

Effects of a multispecies direct-fed microbial on gastrointestinal permeability during feed restriction in a growing heifer model

The objectives were to evaluate the effects of a 4-strain direct-fed microbial (DFM) on gastrointestinal tract (GIT) permeability and inflammation during feed restriction (FR) in heifers. Holstein heifers (n = 32; mean ± standard deviation; 295 ± 25 kg body weight; 287 ± 17 d of age) were used in an experiment conducted in 2 replicates (16/replicate). Heifers were randomly assigned to 1 of 2 top-dressed dietary treatments: (1) control (CON; 10 g/d dried lactose; n = 16) or (2) DFM containing a commercial blend of Lactobacillus animalis, Propionibacterium freudenreichii, Bacillus licheniformis, and Bacillus subtilis at 11.8 × 109 cfu/d (PRO; 10 g/d 4-strain DFM; n = 16). The trial consisted of 2 experimental periods (P): P1 (14 d) served as baseline for P2 (5 d), when all heifers were restricted to 40% of their P1 dry matter intake (DMI). On P1 d 12 and P2 d 2 and 5, GIT permeability was evaluated using oral chromium (Cr)-EDTA. By design, FR decreased DMI (60%) and body weight (∼18 kg) in all heifers. Regardless of treatment, during FR, all heifers had decreased circulating glucose, β-hydroxybutyrate, insulin, and l-lactate (4, 14, 45, and 19%, respectively), but increased nonesterified fatty acids, serum amyloid A, and haptoglobin (3.0-, 1.7-, and 5.0-fold, respectively). Circulating white blood cells, neutrophils, lymphocytes, and basophils decreased (4, 7, 5, and 6%, respectively), whereas eosinophils increased (41%) during P2 irrespective of dietary treatment. Circulating IFN-γ inducible protein-10 increased (23%) during FR compared with P1 regardless of treatment. Plasma Cr area under the curve increased in all heifers on d 2 and 5 (10 and 14%, respectively) of P2 relative to P1, but this was unaltered by dietary treatment. In summary, FR compromised GIT barrier function and stimulated an inflammatory response, but this did not appear to be ameliorated by PRO.

Effects of Bacillus subtilis PB6 supplementation on production, metabolism, inflammatory biomarkers, and gastrointestinal tract permeability in transition dairy cows

Objectives were to evaluate the effects of Bacillus subtilis PB6 (BSP) on gastrointestinal tract permeability, metabolism, inflammation, and production parameters in periparturient Holstein cows. Multiparous cows (n = 48) were stratified by previous 305-d mature equivalent milk yield and parity and assigned to 1 of 2 top-dressed dietary treatments 21 d before expected calving through 63 DIM: (1) control (CON; 13 g/d calcium carbonate; n = 24) or (2) BSP (13 g/d BSP; CLOSTAT, Kemin Industries, Des Moines, IA; n = 24). Gastrointestinal tract permeability was evaluated in vivo using the oral paracellular marker chromium (Cr)-EDTA. Effects of treatment, time, and treatment × time were assessed using PROC MIXED of SAS version 9.4 (SAS Institute Inc.). Prepartum dry matter intake (DMI) was unaffected by treatment; however, BSP supplementation decreased postpartum DMI relative to CON (0.7 kg). Milk yield, energy-corrected milk (ECM), fat-corrected milk (FCM), and solids-corrected milk (SCM) increased in BSP cows compared with CON (1.6, 1.8, 1.6, and 1.5 kg, respectively). Decreased DMI and increased production collectively improved feed efficiency of milk yield, ECM, FCM, and SCM for BSP cows (6, 5, 5, and 5%, respectively). No treatment differences were observed for concentrations of milk fat, protein, total solids, somatic cell count, somatic cell score, body weight, or body condition score. Milk urea nitrogen concentrations decreased (5%), whereas milk protein and lactose yield increased (5 and 2%, respectively) with BSP supplementation. Prepartum fecal pH did not differ among treatments; conversely, postpartum fecal pH was increased with BSP supplementation (0.09 pH units). Prepartum fecal dry matter percentage, starch, acetic acid, propionic acid, butyric acid, and ethanol did not differ among treatments. Postpartum concentrations of the aforementioned fecal parameters were also unaffected by treatment, but fecal propionic acid concentration was decreased (24%) in BSP cows relative to CON. Circulating glucose, nonesterified fatty acids, l-lactate, and insulin were similar between treatments both pre- and postpartum. Prepartum β-hydroxybutyrate (BHB) did not differ between treatments, but postpartum BSP supplementation decreased (21%) circulating BHB relative to CON. Regardless of treatment, inflammatory markers (serum amyloid A and haptoglobin) peaked immediately following parturition and progressively decreased with time, but this pattern was not influenced by treatment. Postpartum lipopolysaccharide binding protein tended to be decreased on d 3 in BSP relative to CON cows (19%). Neither treatment nor time affected Cr-EDTA area under the curve. In summary, supplementing BSP had no detectable effects prepartum, but increased key postpartum production parameters. Bacillus subtilis PB6 consistently increased postpartum fecal pH and decreased fecal propionate concentrations but did not appear to have an effect on gastrointestinal tract permeability.

Effects of microencapsulated blend of organic acids and botanicals on growth performance, intestinal barrier function, inflammatory cytokines, and endocannabinoid system gene expression in broiler chickens

With restricted usage of growth-promoting antibiotics, identifying alternative feed additives that both improve intestinal barrier function and reduce inflammation is the center to improve chickens' health. This study examined the effects of a microencapsulated feed additive containing citric acid, sorbic acids, thymol, and vanillin on intestinal barrier function and inflammation status. A total of 240 birds were assigned to either a commercial control diet or control diet supplemented with 500 g/MT of the microencapsulated additive product. Birds were raised by feeding a 2-phase diet (starter, d 1 to d 21; and grower, d 15 to d 42). Growth performance was recorded weekly. At d 21 and d 42, total gastrointestinal tract permeability was evaluated by FITC-dextran (FD4) oral gavage. Jejunum-specific barrier functions were evaluated by Ussing chamber. Intestinal gene expression of selected epithelial cell markers, tight junction (TJ) proteins, inflammatory cytokines, and endocannabinoid system (ECS) markers were determined by RT-PCR. Statistical analysis was performed using Student t test. Results showed significant improvement of feed efficiency in the birds supplemented with the blend of organic acids and botanicals. At d 21, both oral and jejunal FD4 permeability were lower in the supplemented group. Jejunal transepithelial resistance was higher in the supplemented birds. At d 21, expression of TJs mRNA (CLDN1 and ZO2) was both upregulated in the jejunum and ileum of supplemented birds, while CLDN2 was downregulated in cecum. Proliferating cell marker SOX9 was higher expressed in jejunum and ceca. Goblet cell marker (MUC2) was upregulated, while Paneth cell marker (LYZ) was downregulated in the ileum. Proinflammatory cytokine expressions of IL1B, TNFA, and IFNG were downregulated in jejunum, while anti-inflammatory IL10 expression was higher in jejunum, ileum, cecum, and cecal tonsil. The ECS markers expressions were upregulated in most intestinal regions. Together, these results demonstrated that the blend of organic acids and botanical supplementation reduced inflammation, improved the TJs expression and intestinal barrier function, and thus improved chicken feed efficiency. The activated ECS may play a role in reducing intestinal tissue inflammation.

In Vivo Toxicity, Redox-Modulating Capacity and Intestinal Permeability of Novel Aroylhydrazone Derivatives as Anti-Tuberculosis Agents

The emergence and spread of Mycobacterium tuberculosis strains resistant to many or all anti-tuberculosis (TB) drugs require the development of new compounds both efficient and with minimal side effects. Structure-activity-toxicity relationships of such novel, structurally diverse compounds must be thoroughly elucidated before further development. Here, we present the aroylhydrazone compounds (3a and 3b) regarding their: (i) acute and subacute toxicity in mice; (ii) redox-modulating in vivo and in vitro capacity; (iii) pathomorphology in the liver, kidney, and small intestine tissue specimens; and (iv) intestinal permeability. The acute toxicity test showed that the two investigated compounds exhibited low toxicity by oral and intraperitoneal administration. Changes in behavior, food amount, and water intake were not observed during 14 days of the oral administration at two doses of 1/10 and 1/20 of the LD50. The histological examination of the different tissue specimens did not show toxic changes. The in vitro antioxidant assays confirmed the ex vivo results. High gastrointestinal tract permeability at all tested pH values were demonstrated for both compounds. To conclude, both compounds 3a and 3b are highly permeable with low toxicity and can be considered for further evaluation and/or lead optimization.

140 Redefining gut Barrier Function for Beef and Dairy Cattle

Abstract Of the many roles that the gastrointestinal tract (GIT) must facilitate, coordinated regulation of molecule movement across the gastrointestinal is key. This coordinated regulation allows for nutrient absorption while limiting permeation of non-desired molecules and is referred to as barrier function. Barrier function of the GIT includes intrinsic, extrinsic, and immunological factors, but generally permeability assessments are conducted to evaluate the whole-animal response and most studies focus on the extrinsic components of GIT barrier function. Common approaches to evaluate GIT permeability include the use of inert external markers varying in size and their measurement in blood or urine. Methodology exists for ex vivo, in vitro, and in vivo assessment; however, only in ex vivo and in vitro methods currently allow regionally specific information. Moreover, ex vivo studies have been essential to further elucidate factors that affect permeability such as osmolality, pH, and bioactive components such as histamine and lipopolysaccharides. For ruminants, extensive microbial degradation challenges the use of fermentable substrates as markers when assessing permeability and there is interest to compartmentalize permeability by region of the GIT. Recent research using dual markers to allow for total GIT and post-ruminal permeability have highlighted that regional permeability responses may be affected by production system, environmental conditions, and dietary characteristics. Future research is needed to improve the understanding of factors that affect GIT permeability, the regions involved, and strategies to support regulation of permeability.

99 Why Should the Beef Industry be Concerned About gut Health?

Abstract The gastrointestinal tract (GIT) uses a disproportionate amount of energy relative to its weight to facilitate digestion and movement of dig, nutrient absorption, and barrier function. Through these roles, the GIT acts as the first barrier for the immune system. As such, it is clear that understanding factors that affect these functions, particular absorptive and barrier function, can help improve nutrient utilization and limit immune activation. Cattle fed highly fermentable diets provide a unique opportunity to explore functions of the GIT and improve our understanding of the connection between digestive and metabolic disorders, and infectious disease. Consistent feed intake is a major challenge facing epithelia lining the GIT as feed-deprivation: induces behavioral stress that may alter epithelial cell function increasing risk for inflammation; induces rapid reductions in absorptive surface area; reduces rates of short-chain fatty acid absorption, and results in a transient increase in GIT permeability. Upon re-feeding, cattle previously experiencing off-feed events are at high risk for ruminal acidosis. Reasons for depressed feed intake are numerous and the off-feed event imposed by many diseases may provide a theorized linkage between respiratory disease, ruminal acidosis, and liver abscesses. Recent research has highlighted that increased GIT permeability may decrease gain and alter carcass composition supportive of inflammatory-mediated responses. In addition, there is growing evidence that highly fermentable diets may alter the regional permeability; however, future research is needed to confirm these findings.

Technical Note: A procedure to place urinary catheters in 1- and 6-week-old preweaned Holstein heifer calves for the in vivo evaluation of intestinal permeability.

Oral administration of indigestible markers and subsequent urine collection is a useful method to determine in vivo gastrointestinal tract (GIT) permeability in cattle for research purposes. However, urine sampling techniques often rely on total waste collection, which reduces the ability to perform more frequent sampling and obtain accurate volumes and sterile samples. An alternative is urethral catheterization, though the feasibility of this technique has not been thoroughly tested in preweaned Holstein heifer calves. The study objective was to develop a urethral catheter placement procedure in preweaned Holstein heifer calves for continuous and accurate urine collection to evaluate GIT permeability using an indigestible marker. Fifteen Holstein heifer calves had catheters placed at approximately 1 wk (8.0 ± 1.5 d) and 6 wk (40.0 ± 1.5 d) of age. During the procedure, calves were individually housed and restrained. The vulva was sterilized and then a sterile, lubricated speculum was inserted into the vagina. A sterile 0.09 cm diameter guidewire was guided into a lubricated, sterile 10 French Foley catheter. The catheter was inserted at approximately 5 through 7 cm into the urethral opening, guided into the bladder, and the catheter balloon was filled with 10 mL of water. The guidewire was removed, and urine flow confirmed correct placement before a 4-L urinary drainage bag was attached to the catheter. After catheterization (24 h), 1 L of chromium (Cr)-ethylenediaminetetraacetic acid was orally dosed to the calves. Calf health observations were made six times over a 48-h period, and any occurrence of vaginal discharge, tissue discharge in catheter, bleeding, inflammation, or abnormal urine was considered a localized reaction. The proportion of localized reactions for each age group was determined using Microsoft Excel, and the total Cr output was analyzed using PROC GLIMMIX. Localized reactions occurred for 20.0% of the 1-wk-old calves and 13.3% of the 6-wk-old calves. In the first 4 h, urine was collected every 15 min, and there were no overall Cr output differences (P = 0.38; 10.28 ± 3.21 mg Cr) when comparing 1- and 6-wk-old calves. However, 1-wk-old calves tended (P = 0.08) to have greater overall Cr output at 480 min (19.2%) and 1,440 min (41.9%) when compared with 6-wk-old calves. In summary, urinary catheterization is a viable urinary collection method for the determination of in vivo GIT permeability in preweaned Holstein heifer calves.

Preterm Delivery: Microbial Dysbiosis, Gut Inflammation and Hyperpermeability

Preterm birth is one of the main health problems encountered in the neonatal period, especially because it is also the first cause of death in the critical 1st month of life and the second in children under 5 years of age. Not only preterm birth entails short term health risks due to low weight and underdeveloped organs, but also increases the risk of suffering from non-transmissible diseases in the long term. To date, it is known that medical conditions and lifestyle factors could increase the risk of preterm birth, but the molecular mechanisms that control this process remain unclear. Luteolysis, increased inflammation or oxidative stress have been described as possible triggers for preterm birth and, in some cases, the cause of dysbiosis in preterm neonates. Several murine models have been developed to shed light into the mechanistic of preterm birth but, for the most part, are inflammation-based labor induction models and the offspring health readouts are mainly limited to survival and weight. Using a set of SWISS-CD1 mice born prematurely we analyzed inflammation and gut permeability parameters compared with term pups at weaning age. Overall, preterm mice presented higher systemic inflammation and gastrointestinal tract permeability. In this perspective article, we discuss the recent discoveries on preterm birth and the necessity of non-inflammatory murine models to really understand these phenotypes and be able to design strategies to prevent the sequels of this traumatic event in neonates.

The Systems of Naringenin with Solubilizers Expand Its Capability to Prevent Neurodegenerative Diseases.

Background: Naringenin (NAR) is a flavonoid with excellent antioxidant and neuroprotective potential that is limited by its low solubility. Thus, solid dispersions with β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), hydroxypropylmethylcellulose (HPMC), and microenvironmental pH modifiers were prepared. Methods: The systems formation analysis was performed by X-Ray Powder Diffraction (XRPD) and Fourier-transform infrared spectroscopy (FT-IR). Water solubility and dissolution rates were studied with a pH of 1.2 and 6.8. In vitro permeability through the gastrointestinal tract (GIT) and the blood-brain barrier (BBB) was assessed with the parallel artificial membrane permeability assay (PAMPA) assay. The antioxidant activity was studied with the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and cupric ion reducing antioxidant capacity (CUPRAC) assays, while in vitro enzymes studies involved the inhibition of acetylcholinesterase, butyrylcholinesterase, and tyrosinase. For the most promising system, in silico studies were conducted. Results: NAR solubility was increased 458-fold by the solid dispersion NAR:HP-β-CD:NaHCO3 in a mass ratio of 1:3:1. The dissolution rate was elevated from 8.216% to 88.712% in a pH of 1.2 and from 11.644% to 88.843% in a pH of 6.8 (within 3 h). NAR GIT permeability, described as the apparent permeability coefficient, was increased from 2.789 × 10−6 cm s−1 to 2.909 × 10−5 cm s−1 in an acidic pH and from 1.197 × 10−6 cm s−1 to 2.145 × 10−5 cm s−1 in a basic pH. NAR BBB permeability was established as 4.275 × 10−6 cm s−1. The antioxidant activity and enzyme inhibition were also increased. Computational studies confirmed NAR:HP-β-CD inclusion complex formation. Conclusions: A significant improvement in NAR solubility was associated with an increase in its biological activity.

PSX-B-10 Effect of undigested neutral detergent fiber concentration and forage inclusion rate on ruminal pH, reticular motility, and total tract permeability for finishing beef heifers

Abstract This study evaluated the effects of undigested neutral detergent fiber (uNDF) concentration and forage inclusion (FI) rate on dry matter (DM) intake, ruminal pH, reticular contractions, and gastrointestinal permeability for finishing beef cattle. Five ruminally cannulated Hereford′Simmental heifers (699±69.1 kg) were used in an incomplete 6×6 Latin square (26-d periods) with a 2×3 factorial treatment arrangement. Barley grain-based diets were formulated using barley silage or wheat straw to provide low or high uNDF (7.1 vs. 8.5% DM) with forage proportions of 5, 10, or 15% of dietary DM. Dry matter intake (P ≥ 0.10) and eating time (P ≥ 0.13) were not affected by uNDF, FI, or uNDF′FI. With low uNDF diets, increasing FI numerically (P = 0.02) increased rumination time (min/d); while, with high uNDF diets, rumination time increased with 5 to 10% FI, but not thereafter (P = 0.03). Mean ruminal pH was not affected by uNDF (6.17 vs. 6.19; P = 0.08), but increased with increasing FI (6.04b, 6.23a, and 6.28a; P = 0.02). Duration of ruminal pH < 5.5 was not affected by uNDF but tended (P = 0.07) to be reduced with increasing FI. High uNDF diet tended to increase the frequency of reticular contractions (1.43 vs. 1.51 contractions/min; P = 0.07) but decreased the contraction duration (13.2 vs. 14.1 sec; P = 0.04). Increasing FI increased contraction frequency (1.39b, 1.50a, and 1.53a contractions/min; P = 0.03) and tended to reduce contraction duration as forage increased from 5 to 10 and 15% (14.3, 13.1, and 13.6 sec; P = 0.07). Feeding high uNDF decreased (P = 0.05) permeability of the gastrointestinal tract based on the appearance of Cr-EDTA in urine following an intra-ruminal dose. Increasing FI tended to reduce gastrointestinal tract permeability (P = 0.06). Limited interactions indicate that uNDF and FI act independently suggesting that increasing dietary uNDF, without increasing FI rate, can stimulate frequency of reticulo-ruminal contractions and reduce gastrointestinal permeability for finishing cattle.

Predictive medicinal metabolites from Momordica dioica against comorbidity related proteins of SARS-CoV-2 infections

Momordica dioica have proven medicinal potential of antidiabetic, antiviral and immune stimulating properties. Flavonoids and triterpenoids from M. dioica were more extensively investigated for antiviral, antidiabetic and immunomodulatory activities. In this present study, we have predicted the reported bioactive flavonoids and triterpenoids of the plant against the SARS-CoV-2 main protease, RNA-dependent RNA polymerase (RdRp), spike protein, angiotensin converting enzyme (ACE-2) receptor and dipeptidyl peptidase (DPP4) receptor through molecular docking and in silico ADME predictions methods. According to the binding affinities, the two triterpenoids, hederagenin and oleanolic acid exhibited the best docking scores with these proteins than the catechin and quercetin with compared to standard remdesivir, favipiravir and hydroxychloroquine. The in vitro protein-drug studies have also showed significant interaction of catechin and quercetin compounds than standard drugs. The in silico binding studies correlated with the in silico binding studies. Further, M. dioica being used as antidiabetic and its metabolite had significant interaction with DDP4, a comorbidity protein involved in aiding the viral entry. Out of all the natural ligands, quercetin was reported relatively good and safe for humans with high gastrointestinal tract permeability and poor blood brain barrier crossing abilities. Hence, M. dioica phytocompounds reflects promising therapeutic properties against SARS-CoV-2 infections under comorbid conditions such as diabetes, cardiovascular disease and kidney disorders. Communicated by Ramaswamy H. Sarma

Use of aspirin to intentionally induce gastrointestinal tract barrier dysfunction in feedlot cattle.

Stress negatively affects the gastrointestinal tract (GIT) barrier function, resulting in compromised animal health. A deeper understanding of how diet and stress impacts the GIT barrier function in feedlot cattle is needed. Aspirin decreases mucus production and mucosal repair in the GIT and could be used as a model for GIT barrier dysfunction research. The objective of this study was to evaluate the effectiveness of aspirin to induce GIT barrier dysfunction in beef cattle. In experiment 1, sixteen crossbred heifers (425.0 ± 8.6 kg) were allotted to 0, 50, 100, or 200 mg/kg body weight (BW) aspirin doses based on BW. Experiment 1 consisted of two periods separated by 4 wk where four heifers per treatment received the same aspirin dose during each period. Heifers were fed a 49.4% corn silage and 50.6% concentrate diet. The 200 mg/kg BW aspirin treatment was dosed as a 100 mg/kg BW aspirin oral bolus 36 and 24 h prior to Cr-ethylenediaminetetraacetic acid (EDTA) dosing (1 liter; 180 mM). The 50 and 100 mg/kg BW aspirin treatments were dosed as an oral bolus 24 h prior to Cr-EDTA dosing. Urine was collected every 3 h for 48 h and analyzed for Cr. Serum was collected at 0 and 48 h and analyzed for lipopolysaccharide-binding protein (LBP), interleukin-6, serum amyloid A (SAA), haptoglobin, and aspartate aminotransferase. In experiment 2, sixteen crossbred steers (576.0 ± 14.2 kg) fed a similar diet were allotted by BW to the 0 and 200 mg/kg BW aspirin treatments (eight steers/treatment) and were slaughtered 24 h after the last dose. Jejunal tissues were collected, and claudin (CLDN) 1, 2, and 3, occludin, and zonula occludens tight junction messenger ribonucleic acid (mRNA) expression was determined. Data were analyzed using the MIXED procedure of SAS. Urinary Cr excretion increased linearly at hours 3, 6, 9, and 12 (P ≤ 0.04) as aspirin dose increased from 0 to 200 mg/kg. Aspirin linearly increased Cr absorption (P = 0.02) and elimination (P = 0.04) rates and linearly decreased mean retention time of Cr (P = 0.02). Aspirin increased SAA (P = 0.04) and tended to increase LBP (P = 0.09) in serum but did not affect any other serum inflammatory marker (P ≥ 0.19). Aspirin tended to increase jejunal CLDN-1 mRNA expression (P = 0.10) but did not affect the mRNA expression of other genes regulating tight junction function (P ≥ 0.20). Results from this study indicate that aspirin disrupts the GIT barrier function in beef cattle and has a potential as a model in GIT permeability research.

Development Of Saquinavir Mesylate Nanoemulsion-Loaded Transdermal Films: Two-Step Optimization Of Permeation Parameters, Characterization, And Ex Vivo And In Vivo Evaluation.

BackgroundSaquinavir mesylate (SQR) tablets are widely used against human immunodeficiency virus. SQR has bioavailability issues owing to its poor aqueous solubility, extensive first-pass metabolism, and even low gastrointestinal tract permeability and absorption.ObjectiveAn in-depth optimization process was carried out using factorial design to improve the permeation parameters and thereby the bioavailability of SQR by formulating self-nanoemulsifying drug delivery system (SNEDDS)-loaded polymeric transdermal films.MethodsThe solubility of SQR in different nanoemulsion components was examined. Various combinations of selected components were prepared in an extreme vertices mixture design to identify the useful nanoemulsion zone and to develop SNEDDS with minimum globule size. The optimized SQR-SNEDDS was loaded in polyvinyl alcohol (PVA)-based transdermal films. The Box-Behnken design was used to optimize and evaluate SQR permeability. The prepared films were characterized for thickness, tensile strength, elongation, folding endurance, and accelerated stability studies. The optimized film was examined for ex vivo skin permeation and in vivo pharmacokinetic parameters.ResultsThe optimized SQR-SNEDDS was prepared in proportions of 0.1, 0.55, and 0.35 of clove oil, labrasol, and Transcutol, respectively. The implemented Box-Behnken design indicated the optimized film consisted of 1.0% PVA, 0.25% propylene glycol, and clove oil as the oil phase. The tensile strength, thickness, percent elongation, and folding endurance of the optimized SQR-SNEDDS film were 0.93 ± 0.013 kg/cm2, 0.22 ± 0.006 mm, 43.1 ± 0.022%, and >200 times, respectively. A higher Cmax and double the AUC were observed for SQR-SNEDDS–loaded film in comparison to pure SQR-loaded films.ConclusionImplementation of a two-step design to optimize and control experimental factors in the preparation of SQR-SNEDDS and its loading onto PVA-based transdermal films was achieved. The films indicated improved ex vivo skin permeation, enhanced bioavailability, and overcame the limitations of the oral dosage form.

72 Use of aspirin to intentionally induce gastrointestinal tract barrier dysfunction in feedlot cattle

Abstract Stress negatively effects gastrointestinal tract (GIT) barrier function, resulting in compromised animal health. The objective of this study was to evaluate the effectiveness of aspirin to intentionally induce GIT barrier dysfunction in beef cattle. In experiment 1, sixteen crossbred heifers (425 ± 8.6 kg) were enrolled in 2 experimental periods and allotted by BW to 0, 50, 100, or 200 mg/kg BW aspirin. Four heifers per treatment received the same aspirin dose during each period, which were separated by 4 wks. Heifers were fed a 49.4% corn silage, 50.6% concentrate diet. Aspirin was delivered to animals as an oral bolus. The 200 aspirin treatment was dosed as 100 mg/kg BW aspirin 36 and 24 h prior to Cr-EDTA dosing (1 L; 180 mM). The 50 and 100 aspirin treatments were dosed 24 h prior to Cr-EDTA dosing. Urine was collected every 3 h for 48 h and analyzed for Cr using atomic absorption spectrometry. Serum was collected at 0, 24, and 48 h and analyzed for lipopolysaccharide binding protein (LBP) and interleukin-6 (IL-6) using ELISA. In experiment 2, sixteen crossbred steers (576 ± 14.2 kg) fed the same diet were allotted by BW to the 0 and 200 mg/kg BW aspirin treatments (8 steers/treatment) and were slaughtered 24 h after the last dose. Jejunal tissues were collected and tight junction mRNA expression was determined. Data were analyzed using the MIXED procedure of SAS. Aspirin linearly increased Cr absorption (P = 0.02) and elimination (P = 0.04) rate and linearly decreased mean retention time of Cr (P = 0.02). Aspirin tended to increase jejunal claudin-1 mRNA expression (P = 0.10) but did not affect serum IL-6 or LBP or expression of other jejunal tight junction mRNA (P ≥ 0.20). This study indicates that aspirin disrupts GIT barrier function in beef cattle and has potential as a model in GIT permeability research.

Potential Role of Structural Variants of Circulating Lipopolysaccharide in Exercise‐Induced Heat Illness

Previous investigations at the Falmouth Road Race (FRR; Falmouth, MA) indicated that combined exercise, heat, and dehydration stress increased gastrointestinal tract permeability. This subsequently exposed the circulatory system to components of the microbiome usually found only in the gut. Lipopolysaccharide (LPS), a component of Gram‐negative bacterial membranes, is one such element released into circulation, especially post‐exercise. LPS in circulation activates host immune cell signaling cascades that can lead to inflammatory responses (e.g. cell pyroptosis, exertional heat stroke, and sepsis) and upregulated proinflammtory gene expression (e.g. TNF‐α and IL‐1β). While subjects of the 2015 FRR (N=30) had elevated core temperature post race compared to pre (pre 36.87°C vs. post 39.87°C, p<0.05), there is unexplained variation in the relationship among the level of circulating LPS (2.90EU/ml pre vs. 3.48EU/ml post, p<0.05; Hycult Biotech, ELISA), core temperature, and subsequent heat stroke presentation. Since some strains of bacteria induce a strong immune response while others do not, it is of interest to determine if structural variations in LPS contribute to varying immune system activation during exercise‐heat stress. Diet influences the composition of the microbiome and different microbiome species have varying LPS structures. Because of this, even short‐term alterations in macronutrient consumption can alter the composition and gene expression of the microbiome. Ongoing research will utilize extraction of LPS from pre‐race and post‐race plasma and HPLC/MS to characterize structural variations in LPS in individuals of the 2015, 2016, and 2017 FRR.Support or Funding InformationNew investigator start‐up, McNair Scholar Program, FRRThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Human immunodeficiency virus infection and the liver

Liver disease in human immunodeficiency virus (HIV)-infected individuals encompasses the spectrum from abnormal liver function tests, liver decompensation, with and without evidence of cirrhosis on biopsy, to non-alcoholic liver disease and its more severe form, non-alcoholic steatohepatitis and hepatocellular cancer. HIV can infect multiple cells in the liver, leading to enhanced intrahepatic apoptosis, activation and fibrosis. HIV can also alter gastro-intestinal tract permeability, leading to increased levels of circulating lipopolysaccharide that may have an impact on liver function. This review focuses on recent changes in the epidemiology, pathogenesis and clinical presentation of liver disease in HIV-infected patients, in the absence of co-infection with hepatitis B virus or hepatitis C virus, with a specific focus on issues relevant to low and middle income countries.

The effect of a single dose of tumor necrosis factor alpha inhibitor on gut permeability in rats during exposure to a heat stress

Heat stroke is a life threatening illness characterized by a core body temperature of >40°C, delirium and convulsions, and often results in multi-organ dysfunction, due to the release of endotoxin through the intestinal wall into the circulation. While playing a major role in the gastrointestinal tract permeability changes seen in Crohn's disease, it is not clear whether tumor necrosis factor alpha (TNF-α) mediates the increase in intestinal permeability and the release of endotoxin into the circulation in heat stroke. The aim of the present study was to determine the acute effects of a single dose of TNF-α antibody on gut permeability in rats during heat stress. Fifty-five Sprague-Dawley rats (28 male and 27 female) were treated with either saline or infliximab (a monoclonal antibody to TNF-α), anesthetized with pentobarbitone (50mgkg−1) and then exposed to either normothermic conditions or an ambient temperature of between 41 and 42°C for 70min. Fluorescent isothiocyanate labeled dextrans (FITC-dextrans) were administered intragastrically as a marker of intestinal permeability. Liver enzymes, endotoxin and TNF-α were analyzed in the blood. Exposure to a heat stress significantly increased intestinal permeability to FITC-dextrans compared to the controls (P<0.05). Infliximab did not have an effect on the intestinal permeability to the FITC-dextrans. Heat stress had no significant effect on liver enzymes or endotoxin concentration versus controls (P>0.05). TNF-α was not detectable in any of the samples. TNF-α did not mediate the release of endotoxin into the circulation after an acute bout of heat stroke.

Toxicological mechanisms and potential health effects of deoxynivalenol and nivalenol

Produced by the mould genus Fusarium, the type B trichothecenes include deoxynivalenol (DON), nivalenol (NIV) and their acetylated precursors. These mycotoxins often contaminate cereal staples, posing a potential threat to public health that is still incompletely understood. Understanding the mechanistic basis by which these toxins cause toxicity in experimental animal models will improve our ability to predict the specific thresholds for adverse human effects as well as the persistence and reversibility of these effects. Acute exposure to DON and NIV causes emesis in susceptible species such as pigs in a manner similar to that observed for certain bacterial enterotoxins. Chronic exposure to these mycotoxins at low doses causes growth retardation and immunotoxicity whereas much higher doses can interfere with reproduction and development. Pathophysiological events that precede these toxicities include altered neuroendocrine responses, upregulation of proinflammatory gene expression, interference with growth hormone signalling and disruption of gastrointestinal tract permeability. The underlying molecular mechanisms involve deregulation of protein synthesis, aberrant intracellular cell signalling, gene transactivation, mRNA stabilisation and programmed cell death. A fusion of basic and translational research is now needed to validate or refine existing risk assessments and regulatory standards for DON and NIV. From the perspective of human health translation, biomarkers have been identified that potentially make it possible to conduct epidemiological studies relating DON consumption to potential adverse human health effects. Of particular interest will be linkages to growth retardation, gastrointestinal illness and chronic autoimmune diseases. Ultimately, such knowledge can facilitate more precise science-based risk assessment and management strategies that protect consumers without reducing availability of critical food sources.