Intestinal Extracts Research Articles

Opioid-induced microbial dysbiosis disrupts irinotecan (CPT-11) metabolism and increases gastrointestinal toxicity in a murine model.

Opioids are commonly used for the management of cancer-associated pain and chemotherapy-induced diarrhoea. The chemotherapeutic irinotecan (CPT-11) causes severe gastrointestinal (GI) toxicity due to deconjugation of inactive metabolite SN-38 glucuronide (SN-38G) by bacterial β-glucuronidases to the active 7-ethyl-10-hydroxycamptothecin (SN-38). Opioids are known to cause gut microbial dysbiosis, this study evaluated whether CPT-11 anti-tumour efficacy and GI toxicity are exacerbated by opioid co-administration. Eight-week-old C57BL/6 male mice were co-administration with CPT-11 ± opioid. 16S rRNA sequencing was used for gut microbiome analysis. LC-MS analyses of plasma and intestinal extracts were performed to investigate the pharmacokinetic profile of CPT-11. Histological analysis and quantitative real-time polymerase chain reaction were used to determine the severity of intestinal tissue damage. Human liver microsome In vitro assay was performed to confirm the effects of opioids on CPT-11 metabolism. Gut microbiome analysis showed that morphine treatment induced enrichment of β-glucuronidase-producing bacteria in the intestines of CPT-11-treated mice, resulting in SN-38 accumulation and exacerbation of GI toxicity in the small intestine. Oral administration of both antibiotics and glucuronidase inhibitor protected mice against GI toxicity induced with CPT-11 and morphine co-administration, implicating a microbiome-dependent mechanism. Additionally, morphine and loperamide decreased the plasma concentration of SN-38 and compromised CPT-11 anti-tumour efficacy, this seemed to be microbiome independent. Gut microbiota play a significant role in opioid and chemotherapeutic agent drug-drug interactions. Inhibition of gut microbial glucuronidase may also prevent adverse GI effects of CPT-11 in patients on opioids.

Intrastriatal injection of Parkinson’s disease intestine and vagus lysates initiates α-synucleinopathy in rat brain

Parkinson’s disease (PD) is characterized by the selective loss of dopaminergic neurons in the midbrain and the pathological accumulation of misfolded α-synuclein (α-syn) in the brain. A growing body of evidence suggests that the formation of misfolded α-syn and aggregation may begin in the peripheral nervous system, specifically the enteric nervous system, and then propagate to the central nervous system via the vagus nerve. However, the PD-like neuropathology induced by the intestine and vagus nerve extracts is rarely investigated. In this work, we injected lysates of the intestine and vagus obtained from a diagnosed PD patient, which contained abnormal α-syn aggregates, into the rat striatum unilaterally. Strikingly, such an injection induced dopaminergic neurodegeneration and α-syn depositions in the striatum, substantia nigra, and other brain regions, including the frontal cortex, somatosensory cortex, hypothalamus, brain stem, and cerebellum. Moreover, significant activation of microglia and the development of astrogliosis were observed in the substantia nigra pars compacta of the injected rats. These findings provide essential information for our understanding of PD pathogenesis, as we established for the first time that the α-syn aggregates in the intestine and vagus of a PD patient were sufficient to induce prion-like propagation of endogenous α-syn pathology in wild-type rats.

In vitro digestibility of oligosaccharides synthesized by dairy propionibacteria β-galactosidase from lactose, lactulose and lactitol

Prebiotics synthesized by probiotic genera are of interest due to their specific selectivity. However, modifications of their composition and concentrations by digestion may affect their properties and effects in the host. In the present study we assessed small intestinal digestibility of oligosaccharides synthesized by Acidipropionibacterium acidipropionici LET120-β-gal (β-galactosidase) from lactose (LET120-GOS), lactulose (LET120-OsLu) and lactitol (LET120-LOS) by incubating them with brush border membrane vesicles (BBMV) from pig and a rat small intestinal extract (RSIE) as in vitro models of mammalian mucosa. Both BBMVs and RSIE partially degraded the potential prebiotic oligosaccharides synthesized by dairy propionibacteria and hydrolysis was influenced by the structure and composition of the oligosaccharides. The highest degradation was observed for LET120–GOS, with 46.8% and 58.1% of hydrolysis after 5 h of digestion with BBMV and RSIE, respectively. On the contrary, LET120-OsLu and LET120-LOS showed higher resistance to intestinal degradation. β(1 → 6) linked products showed higher resistance to mammalian digestive enzymes compared to β(1 → 4) and β(1 → 3) linked oligosaccharides. Results emphasize the need of quantifying prebiotics that would reach the colon to anticipate their impact on health and the dose needed to exert that effect.

High-resolution ion mobility spectrometry-mass spectrometry for isomeric separation of prostanoids after Girard's reagent T derivatization.

Isomeric separation of prostanoids is often a challenge and requires chromatography and time-consuming sample preparation. Multiple prostanoid isomers have distinct in vivo functions crucial for understanding the inflammation process, including prostaglandins E2 (PGE2 ) and D2 (PGD2 ). High-resolution ion mobility spectrometry (IMS) based on linear ion transport in low-to-moderate electric fields and nonlinear ion transport in strong electric fields emerges as a broad approach for rapid separations prior to mass spectrometry. Derivatization with Girard's reagent T (GT) was used to overcome inefficient ionization of prostanoids in negative ionization mode due to poor deprotonation of the carboxylic acid group. Three high-resolution IMS techniques, namely linear cyclic IMS, linear trapped IMS, and nonlinear high-field asymmetric waveform IMS, were compared for the isomeric separation and endogenous detection of prostanoids present in intestinal tissue. Direct infusion of GT-derivatized prostanoids proved to increase the ionization efficiency in positive ionization mode by a factor of >10, which enabled detection of these molecules in endogenous concentration levels. The high-resolution IMS comparison revealed its potential for rapid isomeric analysis of biologically relevant prostanoids. Strengths and weaknesses of both linear and nonlinear IMS are discussed. Endogenous prostanoid detection in intestinal tissue extracts demonstrated the applicability of our approach in biomedical research. The applied derivatization strategy offers high sensitivity and improved stereoisomeric separation for screening of complex biological systems. The high-resolution IMS comparison indicated that the best sensitivity and resolution are achieved by linear and nonlinear IMS, respectively.

Development of an Earthworm-Based Intestinal Soft Robot Equipped with a Gripper

An endoscopy is a tool that is used to examine the interior of a hollow organ or cavity of the body by inserting directly into the organ. However, intestinal endoscopy is not friendly to patients due to discomfort, and it can easily cause intestinal damage or even perforation due to the use of the rigid materials of the endoscopy. Here, we provide an earthworm-based intestinal soft robot equipped with a gripper for application on intestinal exams or surgery. The intestinal soft robot is composed of a frontal radial actuator, a central axial actuator, a rear radial actuator and a gripper. The first three actuators drive the robot to move freely in some specific pipes by altering its own deformation, and the gripper, fixed at the end of the frontal radial actuator, is used to pick up “foreign bodies” into and out of the pipes for the purpose of intestinal applications. The different experiments validated that the intestinal soft robot could move forward and backward autonomously in a rigid pipe, a flexible pipe, and a mucus-containing pipe and could extract objects from these pipes. The ultimate weight that the intestinal soft robot extracts is up to 220 g, and the maximum moving speed is 12.0 cm/min in the rigid pipe. This intestinal soft robot is non-destructive to the operating environment, providing a friendly and novel method for the application of intestinal diseases.

OR08-3 Untargeted Nuclear Receptor-Wide Screening reveals Novel Ligands From the Brain and Gut.

Abstract The 48-member family of human nuclear receptors (NRs) plays major roles in metabolic homeostasis, immunity, and inflammatory responses, largely under the control of small lipophilic molecule interactions. A critical barrier precluding major breakthroughs in the discovery of new metabolic ligands is a lack of new methods that allow comprehensive mining of the natural metabolome, most of which remains uncharacterized in terms of identity and function. To address this challenge, our group has developed and optimized an NR pulldown and untargeted metabolomics pipeline that can identify novel NR ligands from various complex mixtures, including tissues, fecal samples, microbiotic cultures, environmental waste and compound libraries. In a first proof of concept screen using brain extracts, a novel omega-3 fatty acid ligand was identified using PPARα as bait. 7(S)-HDHA was selectively isolated despite the presence of other more abundant previously published PPARα ligands. Mass spectrometric detection of 7(S)-HDHA in mouse and rat brain, time-resolved FRET analyses, and thermal shift assay results collectively show that 7(S)-HDHA is the strongest activator and highest affinity natural PPARα ligand identified to date. We also show that 7(S)-HDHA activation of PPARα in cortical neurons effectively stimulates neuronal growth and arborization, key measurements of synaptic capacity in neurons. Since many NRs are expressed in or near the gut, and the interplay between NRs and gut-derived metabolites is largely unaddressed, we have since focused the majority of our efforts on intestinal and microbiome extracts. Dozens of new ligands for xenobiotic-sensing receptors have been identified, including fatty acid, phytoestrogen, peptide, and secondary bile acid, with identities soon to be made available in a public database. A subset will be pursued in-house or with collaborators to identify bacterial sources and receptor-based outcomes. Examples of new PPARα, CAR, PXR, and/or RORα ligand-NR interactions and outcomes will be presented. These discoveries will facilitate new directions for drug development, nutritional supplements and probiotic therapies for the prevention and treatment of a wide spectrum of diseases. Presentation: Saturday, June 11, 2022 12:00 p.m. - 12:15 p.m.

Modifications in Abdominal Wall Graft Retrieval: When the Donor Closure Is Not Guaranteed

Twenty percent of intestinal transplant recipients will require a surgical alternative to conventional primary abdominal wall closure. Abdominal wall transplant is adevelopingtechnique that is increasingly performed for this purpose in isolated intestinal or multivisceral recipients; however, adequate closure of the donor is paramount while simultaneously obtaining a large enough graft. The aim of this study is to describe alternative surgical techniques for closure of the donor in cases in which abdominal wall graft extraction hinders subsequent donor abdominal closure. We describe the cases of 2 young donors in whom intestinal extraction was not carried out and in whom wall closure was not feasible, following standard techniques after abdominal wall graft extraction. We performed 2 different procedures to obtain adequate closure. 1. Hemifascia and hemiabdominal wall graft extraction: It is an option when the recipients require an extension of the abdominal aponeurosis yet have enough skin to guarantee skin closure. The perfusion of both epigastric arteries is needed. The remaining cutaneous half is used for closing the donor's abdomen.2. Hemiabdominal wall graft extraction: Full-thickness abdominal wall is harvested from the donor, selecting the most vascularized half. It is an alternative for recipients who need a skin implant in addition to an aponeurosis extension. This option should be used for recipients who do not require a large fascial graft but do require a significant cutaneous graft. The nontransplanted half of full-thickness abdominal wall is used for donor closure. Abdominal wall transplant allows forexpansion of the abdominal cavity in organ recipients and reduces the risk of compartmental syndrome and subsequent ischemia. However, the donor wall defect must be considered. The choice of donation technique was based on the magnitude of the defect in the donor as well as the size of defect to be covered in the recipient while ensuring a tight and complete closure of the donor's abdomen. Abdominal wall graft extraction can be performed using nonconventional techniques that account for the extension and type of coverage needed by the recipient while guaranteeing proper closure of the donor.

Nutraceutical and bioactive potential of high-quality date fruit varieties (Phoenix dactylifera L.) as a function of in-vitro simulated gastrointestinal digestion

The present study aims to investigate the digestive process (gastric and intestinal phases) effects on the survivability of total and individual phenolic compounds, and the in vitro health-related bioactive properties of four high-quality and commonly consumed dates (Phoenix dactylifera) varieties (Safawi, Khalas, Khudri, and Booman). Phenolic compounds were analyzed by HPLC-UV (at 275 nm) and a higher amount of phenolics were identified in Khalas and Booman intestinal digested extracts, compared to the other date varieties-based extracts, which corroborates with the total phenolic contents in those samples, with respective values of 186.5 and 358.14 mg GAE/100 g. Considering their bioactive potentialities, the highest DPPH radical scavenging activities, of around 320 TEAC µg/mL, were observed with Khalas and Khudri gastric extracts. In contrast, Khalas intestinal extract displayed the highest ABTS radical scavenging potential of 969 TEAC µg/mL. Moreover, the Safawi intestinal extract, along with Khalas and Booman gastric extracts, showed the highest increase in the α-glucosidase inhibition activity, compared to the other date varieties-based extracts. Safawi and Khalas intestinal extracts displayed the highest DPP-IV inhibition activities (IC50 of 2.85 µg/mL). Additionally, regarding the pancreatic lipase and cholesterol esterase inhibition, Khudri and Khalas varieties after intestinal digestion demonstrated the highest activities. These results suggested that the Khalas variety showed more potent bioactive properties than other date varieties, mainly related to the variations in the phenolic content between date varieties. Overall, this study provides additional insight into investigating these dates varieties upon their simulated gastro-intestinal digestion and exhibition of multifunctional bioactive properties.

Synthesis of salicylic acid phenylethyl ester (SAPE) and its implication in immunomodulatory and anticancer roles

Salicylic acid phenylethyl ester (SAPE) was synthesized by Zn(OTf)2-catalyzed selective esterification of salicylic acid and phenylethyl alcohol and studied for its role as an immunomodulatory and anticancer agent. Low toxicity and favorable physical, Lipinski-type, and solubility properties were elucidated by ADME-tox studies. Molecular docking of SAPE against COX-2 revealed favorable MolDockscore, rerank score, interaction energy, internal pose energy, and hydrogen bonding as compared to ibuprofen and indomethacin. An average RMSD of ~ 0.13 nm for the docked complex with stable dynamic equilibrium condition was noted during the 20 ns MD simulation. A low band gap predicting a strong binding affinity at the enzyme’s active site was further predicted by DFT analysis. The ester caused a reduction in the percentage of erythrocyte hemolysis and was shown to be non-cytotoxic against human lymphocytes, CaCo-2, and HepG-2 cells by the MTT assay. Moreover, it’s in vitro efficacy in inhibiting COX-2 enzyme under both LPS stimulated intestinal cells and direct sequestration assays was found to be higher than salicylic acid and indomethacin. The anticancer activity of SAPE was tested on the breast cancer cell line MCF-7, and potential efficacy was exhibited in terms of decreased cell viability. Flow cytometry analysis exhibited the arrest of the cell cycle at G1/G0 and S phases, during which induction of autophagic vesicle formation and decrease in mitochondrial membrane potential was observed owing to increased ROS production. Furthermore, at these phases, the onset of apoptosis along with DNA damage was also observed. Pre-treatment with SAPE in colitis-induced Wistar rats displayed low disease activity index and reduction in the extent of intestinal tissue disruption and lipid peroxidation. A marked increase of anti-oxidative enzymes viz., catalase, GGT, and GST, and a decrease of pro-inflammatory cytokines IL-6 and TNF-α in the intestinal tissue extracts of the treated groups was noted. The results of this study have sufficient credence to support that the synthesised ester (SAPE) be considered as an anti-oxidative and anti-inflammatory compound with therapeutic potential for the effective management of cancer.

Regional Splanchnic Oxygenation during Continuous versus Bolus Feeding among Stable Preterm Infants.

Introduction: There is no agreement regarding the best method for tube-feeding preterm infants. Few studies, to date, have evaluated the influence of different methods of enteral feeding on intestinal oxygenation. The use of near-infrared spectroscopy (NIRS) has permitted the noninvasive measurement of splanchnic regional oxygenation (rSO2S) in different clinical conditions. The aim of this prospective, single-center study was to compare rSO2S during continuous versus bolus feeding among stable preterm infants. Methods: Twenty-one preterm infants, less than 32 weeks gestation and appropriate for gestational age, were enrolled. All infants were clinically stable and on full tube feedings. Each infant received a bolus feeding initially (20 min duration), and after 3 h, a continuous feeding (5 h duration). Infants were evaluated 30 min before and 30 min after the bolus and continuous feedings. The regional splanchnic saturation (rSO2S) was measured using near-infrared spectroscopy (NIRS) technology and systemic saturation was measured with pulse oximetry. From these measurements, we calculated the splanchnic fractional oxygen extraction ratio (FOES) for each of the four intervals. Results: rSO2S decreased after continuous vs. bolus feeding (p = 0.025), while there was a trend toward decreased SaO2 after bolus feeding (p = 0.055). The FOES, which reflects intestinal oxygen extraction, was not affected by the feeding mode (p = 0.129). Discussion/Conclusion: Continuous vs. bolus feeding decreases rSO2S but does not affect oxygen extraction by intestinal tissue; after bolus feeding there was a trend towards decreased systemic saturation.

Pharmacokinetics of DA-6886, A New 5-HT4 Receptor Agonist, in Rats.

DA-6886 is a novel serotonin (5-hydroxytrypamine [5-HT]) receptor 4 agonist for the potential treatment of constipation-predominant irritable bowel syndrome. The purpose of this study was to validate the quantitative assay of DA-6886 in rat plasma and to evaluate the pharmacokinetics and tissue distribution of DA-6886 in rats. The liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the robust quantification of DA-6886 in rat plasma was successfully validated and applied to the pharmacokinetic studies in rats. The pharmacokinetic parameters of DA-6886 in rats were evaluated following single intravenous or oral administration at three dose levels (2, 10, and 20 mg/kg). DA-6886 exhibited a smaller dose-normalized area under the plasma concentration–time curve (AUC) values and faster clearances in the low-dose group than in the high-dose group following both intravenous and oral administration. The steady-state volume of distribution (Vss) of DA-6886 was relatively large (4.91–7.84 L/kg), which was consistent with its high distribution to the liver, kidney, lung, and digestive tract, and was dose-independent. After oral administration, the extent of absolute bioavailability (F) tended to increase (18.9–55.0%) with an increasing dose. The slope of the log-transformed AUC and/or Cmax values versus log dose was greater than unity and greater for oral administration (~1.9) than for intravenous administration (~1.1). Because the nonlinear pharmacokinetics of DA-6886 was more obviously observed after oral administration, it appears that the saturation of pre-systemic intestinal and/or hepatic first-pass extraction of DA-6886 at high doses occurred.

Engineered Nanoparticles inside a Microparticle Oral System for Enhanced Mucosal and Systemic Immunity.

Antigen delivery through an oral route requires overcoming multiple challenges, including gastrointestinal enzymes, mucus, and epithelial tight junctions. Although each barrier has a crucial role in determining the final efficiency of the oral vaccination, transcytosis of antigens through follicle-associated epithelium (FAE) represents a major challenge. Most of the research is focused on delivering an antigen to the M-cell for FAE transcytosis because M-cells can easily transport the antigen from the luminal site. However, the fact is that the M-cell population is less than 1% of the total gastrointestinal cells, and most of the oral vaccines have failed to show any effect in clinical trials. To challenge the current dogma of M-cell targeting, in this study, we designed a novel tandem peptide with a FAE-targeting peptide at the front position and a cell-penetrating peptide at the back position. The tandem peptide was attached to a smart delivery system, which overcomes the enzymatic barrier and the mucosal barrier. The result showed that the engineered system could target the FAE (enterocytes and M-cells) and successfully penetrate the enterocytes to reach the dendritic cells located at the subepithelium dome. There was successful maturation and activation of dendritic cells in vitro confirmed by a significant increase in maturation markers such as CD40, CD86, presentation marker MHC I, and proinflammatory cytokines (TNF-α, IL-6, and IL-10). The in vivo results showed a high production of CD4+ T-lymphocytes (helper T-cell) and a significantly higher production of CD8+ T-lymphocytes (killer T-cell). Finally, the production of mucosal immunity (IgA) in the trachea, intestine, and fecal extracts and systemic immunity (IgG, IgG1, and IgG2a) was successfully confirmed. To the best of our knowledge, this is the first study that designed a novel tandem peptide to target the FAE, which includes M-cells and enterocytes rather than M-cell targeting and showed that a significant induction of both the mucosal and systemic immune response was achieved compared to M-cell targeting.

Feeding-Induced Changes of Bacteriolytic Activity and the Pattern of Bacteriolytic Compounds in the Stomach and Small Intestine of the Haematophagous Bug Triatoma infestans (Klug, 1834) (Reduviidae, Triatominae)

Intestinal homeostasis mechanisms of the haematophagous triatomines regulate the development of mutualistic symbionts and other gut bacteria. Investigating antimicrobial compounds of these insects, we have determined spectrophotometrically that the bacteriolytic activity is between pH 3 and pH 9 using homogenates of fifth instar Triatoma infestans stomachs and small intestines from unfed bugs and up to 50 days after feeding. The activity against Gram-positive Micrococcus luteus was strongest at pH 4 and pH 7 and was higher in the stomach than in the small intestine. Symbiotic Rhodococcus triatomae were not lysed. Lysis of Gram-negative Escherichia coli showed a maximum at pH 7 in the stomach and at pH 5 in the small intestine. Bacteriolytic activity against both M. luteus and E. coli was reduced 24 h after feeding, then increased, and at 50 days after feeding was strongly reduced. In zymographs, the activity against M. luteus was mainly correlated to proteins of about 16 kDa. At different periods of time after feeding, seven bands of lysis appeared between 15 and 40 kDa and more bands using extracts of the small intestine than those of the stomach. This is the first proof for the synthesis of antibacterial proteins of 22–40 kDa in triatomines.

Bioaccessibility Study of Aflatoxin B1 and Ochratoxin A in Bread Enriched with Fermented Milk Whey and/or Pumpkin.

The presence of mycotoxins in cereals and cereal products remains a significant issue. The use of natural ingredients such as pumpkin and whey, which contain bioactive compounds, could be a strategy to reduce the use of conventional chemical preservatives. The aim of the present work was to study the bioaccessibility of aflatoxin B1 (AFB1) and ochratoxin (OTA) in bread, as well as to evaluate the effect of milk whey (with and without lactic acid bacteria fermentation) and pumpkin on reducing mycotoxins bioaccessibility. Different bread typologies were prepared and subjected to an in vitro digestion model. Gastric and intestinal extracts were analyzed by HPLC–MS/qTOF and mycotoxins bioaccessibility was calculated. All the tested ingredients but one significantly reduced mycotoxin intestinal bioaccessibility. Pumpkin powder demonstrated to be the most effective ingredient showing significant reductions of AFB1 and OTA bioaccessibility up to 74% and 34%, respectively. Whey, fermented whey, and the combination of pumpkin-fermented whey showed intestinal bioaccessibility reductions between 57–68% for AFB1, and between 11–20% for OTA. These results pointed to pumpkin and milk whey as potential bioactive ingredients that may have promising applications in the bakery industry.

Gut microbiota-based vaccination engages innate immunity to improve blood glucose control in obese mice

ObjectiveObesity and diabetes increase circulating levels of microbial components derived from the gut microbiota. Individual bacterial factors (i.e., postbiotics) can have opposing effects on blood glucose. MethodsWe tested the net effect of gut bacterial extracts on blood glucose in mice using a microbiota-based vaccination strategy. ResultsMale and female mice had improved glucose and insulin tolerance five weeks after a single subcutaneous injection of a specific dose of a bacterial extract obtained from the luminal contents of the upper small intestine (SI), lower SI, or cecum. Injection of mice with intestinal extracts from germ-free mice revealed that bacteria were required for a microbiota-based vaccination to improve blood glucose control. Vaccination of Nod1−/−, Nod2−/−, and Ripk2−/− mice showed that each of these innate immune proteins was required for bacterial extract injection to improve blood glucose control. A microbiota-based vaccination promoted an immunoglobulin-G (IgG) response directed against bacterial extract antigens, where subcutaneous injection of mice with the luminal contents of the lower SI elicited a bacterial extract-specific IgG response that is compartmentalized to the lower SI of vaccinated mice. A microbiota-based vaccination was associated with an altered microbiota composition in the lower SI and colon of mice. Lean mice only required a single injection of small intestinal-derived bacterial extract, but high fat diet (HFD)-fed, obese mice required prime-boost bacterial extract injections for improvements in blood glucose control. ConclusionsSubversion of the gut barrier by vaccination with a microbiota-based extract engages innate immunity to promote long-lasting improvements in blood glucose control in a dose-dependent manner.

Tissue‐specific differences in detection of Yersinia ruckeri carrier status in rainbow trout (Oncorhynchus mykiss)

Effective monitoring for subclinical infections is a cornerstone of proactive disease management in aquaculture. Salmonid fish that survive enteric redmouth disease (ERM) can carry Yersinia ruckeri as a latent infection for several months, potentially facilitating cryptic spread between facilities that exchange fish. In this study, fingerling rainbow trout (Oncorhynchus mykiss) were infected by immersion and sampled for up to 14weeks post-infection. Yersinia ruckeri was cultured from the posterior kidney of more than 89% of fish up to 4weeks post-infection, but from 2% or fewer of fish sampled at later time points. In contrast, qPCR-based detection of the Y.ruckeri 16s rRNA gene in intestine and spleen extracts revealed a much higher rate of infection: at 14weeks post-infection Y.ruckeri was detected in nearly 50% of spleens and 15% of intestines. The difference between spleen and intestine is likely due at least in part to technical limitations of qPCR on intestinal DNA extracts; accordingly, we propose that qPCR of spleen DNA ought to be considered the preferred standard for detection of carriers of Y.ruckeri.

PHYTOCHEMICAL SCREENING AND EVALUATION OF ANTIDIARRHOEAL ACTIVITY OF BUNIUM BULBOCASTANUM SEEDS EXTRACT IN EXPERIMENTAL WISTAR RATS

Objective: The main objective of this study was to evaluate the antidiarrheal activity of Bunim bulbocastanum seeds extracts, to exploit the medicinal use of plant in the traditional system of medicine scientifically.
 Methods: The adult Wistar albino rats were divided in four groups, i.e. Group M1 (control group) receiving normal saline, group M2 (test group 1) receiving the 250 mg/kg Bunium bulbocastanum extract, group M2 (test group 2) receiving the 500 mg/kg Bunium bulbocastanum extract and group M4 (reference) receiving 3 mg/kg P. O Loperamide. Each group of mice with a bodyweight of 1 ml/100 g received castor oil. Mice were sacrificed and the distance traveled by the charcoal meal and the total length of the intestine was then measured. The peristaltic index and percentage of inhibition were calculated by using the formula.
 Results: It was found that in the castor oil-induced intestinal transit method extract produced a significant (p<0.0001) dose-dependent reduction in the distance traveled by charcoal meal comparable to the control peak effect was at the dose of 500 mg/kg (PI=12.06±3.38). Likewise, in the diarrheal dropping test, Bunium bulbocastanum extract causes a significant (p<0.05) dose-dependent reduction in the number of wet feces i.e. the mean wet of feces was decreased from 2.3±0.44 gm to 1.28±0.36 gm i.e. significantly different from that elicited by control (0.80±0.17 gm) (p=0.0081). However, there were no significant differences in inhibition at a dose of 250 mg/kg of extract.
 Conclusion: This study demonstrated that the crude methanol extract from B. bulbocastanum seeds possesses significant antidiarrheal property and the presence of various secondary metabolites. This justified the antidiarrheal use of plant in the traditional system of medicine.

Inhibition of α-glucosidases by tea polyphenols in rat intestinal extract and Caco-2 cells grown on Transwell

Inhibition of maltase, sucrase, isomaltase and glucoamylase activity by acarbose, epigallocatechin gallate, epicatechin gallate and four polyphenol-rich tea extract from white, green, oolong, black tea, were investigated by using rat intestinal enzymes and human Caco-2 cells. Regarding rat intestinal enzyme mixture, all four tea extracts were very effective in inhibiting maltase and glucoamylase activity, but only white tea extract inhibited sucrase and isomaltase activity and the inhibition was limited. Mixed-type inhibition on rat maltase activity was observed. Tea extracts in combination with acarbose, produced a synergistic inhibitory effect on rat maltase activity. Caco-2 cells experiments were conducted in Transwells. Green tea extract and epigallocatechin gallate show dose-dependent inhibition on human sucrase activity, but no inhibition on rat sucrase activity. The opposite was observed on maltase activity. The results highlighted the different response in the two investigated model systems and show that tea polyphenols are good inhibitors for α-glucosidase activity.

Prediction of Oral Pharmacokinetics Using a Combination of In Silico Descriptors and In Vitro ADME Properties.

Accurate prediction of oral pharmacokinetics remains challenging. This study investigated quantitative approaches for the prediction of the area under the plasma concentration-time curve after oral administration (AUCp,oral) to rats using the in vitro-in vivo extrapolation (IVIVE), in silico model using machine learning approaches and the combination of the in silico model and in vitro data. A set of 595 structurally diverse compounds with determined AUCp,oral at 1 mg/kg, in vitro intrinsic clearance (CLint), an unbound fraction in plasma (fu,p) in rats, and kinetic solubility at pH 6.8 was used for this assessment. Prediction models developed by two different types of machine learning techniques (i.e., random forest regression and Gaussian processes) were evaluated using three validation methods implementing the time and cluster-split training and test set and fivefold cross-validation. The developed machine learning models have a square of correlation coefficient (R2) in the range of 0.381-0.685 with 33-45% of the compounds being predicted within 2-fold of the observed AUCp,oral value. The predictivity was improved by incorporating CLint, fu,p, and solubility as explanatory variables with R2 = 0.554-0.743. In cases where extraction by the liver is the main elimination pathway and intestinal extraction is negligible, AUCp,oral can be expressed by dose, CLint, and fu,p based on a well-stirred model. By using this conventional IVIVE approach, only 1.7-5.0% of compounds were predicted within the 2-fold error with R2 = 0.354-0.487. Two empirical scaling factors (ESFs) determined by linear regression analysis and machine learning approaches improved the predictivity of AUCp,oral with 33-44% predicted within twofold variability. The IVIVE using ESF predicted by random forest regression showed better predictivity of AUCp,oral with R2 = 0.471-0.618, while it still showed lower predictivity than machine learning approaches applied directly to AUCp,oral prediction. This study demonstrated that the combination of in silico and in vitro parameters is useful to improve the predictivity of the machine learning model for rat AUCp,oral and supports consideration for predicting AUCp,oral for human and other non-clinical species in a similar manner.

In vitro digestion of polysaccharides: InfoGest protocol and use of small intestinal extract from rat

Starch, dextran, pectin and modified citrus pectin were subjected to intestinal digestion following InfoGest protocol and a rat small intestine extract (RSIE) treatment. Gastric stage did not show any modification in the structure of the carbohydrates, except for modified pectin. Regarding intestinal phases, starch was hydrolyzed by different ways, resulting in a complementary behavior between InfoGest and RSIE. Contrarily, digestion of dextran was only observed using RSIE. Similar situation occurred in the case of pectins with RSIE, obtaining a partial hydrolysis, especially in the modified citrus pectin. However, citrus pectin was the less prone to hydrolysis by enzymes. The results demonstrated that InfoGest method underestimates the significance of the carbohydrates hydrolysis at the small intestine, thus indicating that RSIE is a very reliable and useful method for a more realistic study of polysaccharides digestion.