Rat Intestinal Tract Research Articles

Integrating multi-spectral imaging and Raman spectroscopy for in vivo endoscopic assessment of rat intestinal tract

An integrated system for in vivo multi-spectral imaging (MSI) and Raman spectroscopy was developed to understand the external morphology and internal molecular information of biological tissues. The achieved MSI images were reconstructed by eighteen separated images from 400 nm to 760 nm, whose illumination bands were selected with six tri-channel band filters. Based on the spectral analysis algorithms, the spatial distribution patterns of blood volume, blood oxygen content and tissue scatterer volume fraction were visualized. In vivo Raman spectral measurements were executed by inserting specially designed optical probe into instrumental channel of endoscope. By this way, the molecular composition at selected sampling points could be identified with its fingerprint spectral information under the guidance of molecular imaging modality. Therefore, both structural and compositional features of intestinal membrane could be addressed without labeling and continuously. The achieved results testified that our presented methodology reveals insights not easily extracted from either MSI or Raman spectroscopy individually, which brings the enrichment of biological and chemical meanings for future in vivo studies.

Exploring the role of Yuxuebi tablet in neuropathic pain with the method of similarity research of drug pharmacological effects based on unsupervised machine learning.

Having multiple pharmacological effects is a characteristic of Traditional Chinese Medicine (TCM). Currently, there is a lack of suitable methods to explore and discover modern diseases suitable for TCM treatment using this characteristic. Unsupervised machine learning technology is an efficient strategy to predict the pharmacological activity of drugs. This study takes Yuxuebi Tablet (YXB) as the research object. Using the unsupervised machine learning technology of drug cell functional fingerprint similarity research, the potential pharmacological effects of YXB were discovered and verified. LC-MS combined with the in vitro intestinal absorption method was used to identify components of YXB that could be absorbed by the intestinal tract of rats. Unsupervised learning hierarchical clustering was used to calculate the degree of similarity of cellular functional fingerprints between these components and 121 marketed Western drugs whose indications are diseases and symptoms that YXB is commonly used to treat. Then, based on the Library of Integrated Network-based Cellular Signatures database, pathway analysis was performed for selected Western drugs with high similarity in cellular functional fingerprints with the components of YXB to discover the potential pharmacological effects of YXB, which were validated by animal experiments. We identified 40 intestinally absorbed components of YXB. Through predictive studies, we found that they have pharmacological effects very similar to non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids. In addition, we found that they have very similar pharmacological effects to anti-neuropathic pain medications (such as gabapentin, duloxetine, and pethidine) and may inhibit the NF-κB signaling pathway and biological processes related to pain perception. Therefore, YXB may have an antinociceptive effect on neuropathic pain. Finally, we demonstrated that YXB significantly reduced neuropathic pain in a rat model of sciatic nerve chronic constriction injury (CCI). Transcriptome analysis further revealed that YXB regulates the expression of multiple genes involved in nerve injury repair, signal transduction, ion channels, and inflammatory response, with key regulatory targets including Sgk1, Sst, Isl1, and Shh. This study successfully identified and confirmed the previously unknown pharmacological activity of YXB against neuropathic pain through unsupervised learning prediction and experimental verification.

Effects of forsythin extract in Forsythia leaves on intestinal microbiota and short-chain fatty acids in rats fed a high-fat diet

Forsythia suspensa, belonging to the deciduous shrubs of the Luteaceae family, a traditional Chinese medicine, has effects of alleviating swelling, clearing heat, detoxification and promoting blood circulation. The leaves of F. suspensa contain multiple chemical components and have a long history of use in folk medicines and health foods. The purpose of this study was to explore the effects of forsythin extract from F. suspensa leaves on intestinal microbiota and short-chain fatty acid (SCFA) content in rats with obesity induced by a high-fat diet. Forsythin extract in F. suspensa leaves increased the abundance of the intestinal microbiota, ameliorated intestinal microbiota disorders and inhibited the increase in total SCFA content in the intestinal tract in rats with obesity induced by a high-fat diet. These results suggested that forsythin extract in F. suspensa leaves may slow the development of obesity induced by a high-fat diet; thus, its active components and efficacy are worthy of further study.

PS-B07-3: ANGIOTENSIN I CONVERTING ENZYME INHIBITORY PEPTIDES DERIVED FROM KATSUOBUSHI

Purpose: Antihypertensive components are typically assessed by screening based on in vitro results; however, since intestinal absorption is closely involved in the antihypertensive mechanism of action, we attempted to analyze the absorption of bonito derived peptides, which have been found to have antihypertensive effects in animal experiments. Methods: The intestinal tracts of rats, 7 week old male SDrats, were excised after performing cervical dislocation. Incisions 5.5 cm were quickly made into the jejunum, one side was ligated and inverted, and after injecting 1 mL reaction solution, the other side was ligated to create an inverted sack. The sack was then quickly placed in 30 mL of the reaction solution, antihypertensive amount: KBP 0.3 mg/per animal and synthetic peptides: each 0.25 mM, and left to react for 30 min at 37°C after which the inverted sack was removed and washed gently with physiological saline before recovering all the internal fluid. Liquid chromatography tandem mass spectrometry LC/MS/MS was used for analysis and the intestinal fluid samples were measured after examining pretreatment and measurement conditions. Results: Pretreatment conditions involved adding 5 μL water, 5 μL IS L-Leu-D-Leu, and 5 μL of 20% sulfosalicylic acid to a 50 μL intestinal fluid sample, stirring the sample, transferring 0.22 μm to a centrifugal filter, performing centrifugation for 3 min at 20000 g and 4°C and then injecting the filtrate into the LC/MS/MS system. LC conditions included a 1.7 μL ACQUITY UPLC BEH C18 column; 2.1, 50 mM, 0%-100% acetonitrile/0.1% TFA linear gradient elution in the mobile phase. Based on the above analysis conditions, the GW, AW, VW, MW, IW, LW, and WL values ng/mL of KBP in the reaction solution were 34.0, 4.64, 7.11, 1.28, 12.7, 4.57, and 0.923, respectively, and 53.2, 3.92, 6.02, 1.10, 8.76, 5.76, and 0.785, respectively. Values for the reaction solution of additive-free peptides serving as a base were estimated at 13.5, 1.09, 2.06,0.350, 5.54, 1.72, and 0.189, respectively. The calibration curve range was set at 0.200–1000ng/ mL. Conclusion: The intestinal membrane permeability of dried bonito-derived dipeptides, which have an antihypertensive effect in vivo, suggests that dipeptides absorbed from the intestinal membrane may have an antihypertensive effect.

An evaluation of the rat intestinal monoamine biogeography days following exposure to acute stress.

Stress-induced abnormalities in gut monoamine levels (e.g., serotonin, dopamine, norepinephrine) have been linked to gastrointestinal (GI) dysfunction, as well as the worsening of symptoms in GI disorders. However, the influence of stress on changes across the entire intestinal monoamine biogeography has not been well-characterized, especially in the days following stress exposure. Therefore, the aim of this study was to comprehensively assess changes to monoamine neurochemical signatures across the entire rat intestinal tract days after exposure to an acute stressor. To the end, adult male F344 rats were subjected to an episode of unpredictable tail shocks (acute stress) or left undisturbed. Forty-eight hours later rats were euthanized either following a 12h period of fasting or 30min of food access to evaluate neurochemical profiles during the peri- and early postprandial periods. Monoamine-related neurochemicals were measured via UHPLC in regions of the small intestine (duodenum, jejunum, ileum), large intestine (cecum, proximal colon, distal colon), cecal contents, fecal contents, and liver. The results suggest a relatively wide-spread increase in measures of serotonin activity across intestinal regions can be observed 48h after exposure to acute stress, however some evidence was found supporting localized differences in serotonin metabolization. Moreover, acute stress exposure reduced catecholamine-related neurochemical concentrations most notably in the ileum, and to a lesser extent in the cecal contents. Next, stress-related fecal serotonin concentrations were consistent with intestinal profiles. However, fecal dopamine was elevated in association with stress, which did not parallel findings in any other intestinal area. Finally, stress exposure and the food access period together only had minor effects on intestinal monoamine profiles. Taken together, these data suggest nuanced differences in monoaminergic profiles exist across intestinal regions the days following exposure to an acute stressor, highlighting the importance of assessments that consider the entire intestinal tract biogeography when investigating stress-related biological outcomes that may be relevant to GI pathophysiology.

Antidiabetic Effect of Millet Bran Polysaccharides Partially Mediated via Changes in Gut Microbiome.

Diabetes is a type of metabolic disease associated with changes in the intestinal flora. In this study, the regulatory effect of millet bran on intestinal microbiota in a model of type 2 diabetes (T2DM) was investigated in an effort to develop new approaches to prevent and treat diabetes and its complications in patients. The effect of purified millet bran polysaccharide (MBP) with three different intragastric doses (400 mg/kg, 200 mg/kg, and 100 mg/kg) combined with a high-fat diet was determined in a streptozotocin (STZ)-induced model of T2DM. By analyzing the changes in indicators, weight, fasting blood sugar, and other bio-physiological parameters, the changes in gut microbiota were analyzed via high-throughput sequencing to establish the effect of MBP on the intestinal flora. The results showed that MBP alleviated symptoms of high-fat diet-induced T2DM. A high dosage of MBP enhanced the hypoglycemic effects compared with low and medium dosages. During gavage, the fasting blood glucose (FBG) levels of rats in the MBP group were significantly reduced (p < 0.05). The glucose tolerance of rats in the MBP group was significantly improved (p < 0.05). In diabetic mice, MBP significantly increased the activities of CAT, SOD, and GSH-Px. The inflammatory symptoms of liver cells and islet cells in the MBP group were alleviated, and the anti-inflammatory effect was partially correlated with the dose of MBP. After 4 weeks of treatment with MBP, the indices of blood lipid in the MBP group were significantly improved compared with those of the DM group (p < 0.05). Treatment with MBP (400 mg/kg) increases the levels of beneficial bacteria and decreases harmful bacteria in the intestinal tract of rats, thus altering the intestinal microbial community and antidiabetic effect on mice with T2DM by modulating gut microbiota. The findings suggest that MBP is a potential pharmaceutical supplement for preventing and treating diabetes.

In vitro and in vivo evaluation of cinnamaldehyde Microemulsion-Mucus interaction.

The current investigation explores the possible mechanism of the microemulsion drug delivery system to improve the oral bioavailability of cinnamaldehyde (CA), an important food spice, from the perspective of the microemulsion-mucus system. The cinnamaldehyde microemulsion (CA-ME) was prepared by the water titration method combined with the pseudo-ternary phase diagram. The dynamic analysis was applied to detect the drug release in vitro. An intestinal mucosal injury test was conducted to evaluate the safety of CA-ME and drug absorption across the intestinal tract of rats was investigated through an Ussing chamber system. The rheology of blank mucus and drug-loaded mucus was investigated using a rheometer. The bioavailability of CA-ME in rats was evaluated through pharmacokinetic characteristics. The ratio of optimal prescription was Tween 80: 1,2-propanediol: vitamin E oil: CA: water=24.3:4.8:5:7.5:58.4. The droplets were uniform in size and evenly dispersed. Rheological studies showed that the microemulsion-mucus system all exhibit pseudoplastic fluid behavior, and CA-ME increased the viscosity of the mucus to a certain extent. Compared with CA solution, CA-ME promoted the absorption of CA in various intestinal segments, especially the ileum. Pharmacokinetic experiments showed that the relative bioavailability of CA-ME was enhanced 2.5-fold higher than that of CA solution. ME as a carrier for lipophobic substances, may increase the viscosity of the intestine mucus system to obtain longer residue time and better absorption. PRACTICAL APPLICATIONS: In this study, in vitro absorption Ussing model was combined with rheological and pharmacokinetic analysis to systematically analyze the intestinal mucus mechanism of microemulsion to improve the oral bioavailability of cinnamic aldehyde. It laid the foundation for exploring the absorption and transport of drugs in the intestinal mucus barrier.

Construction and identification of an immortalized rat intestinal smooth muscle cell line.

Although intestinal smooth muscle cells (ISMCs) play an important role in the remodeling of the intestinal structure, considerably less is known about the molecular mechanisms that mediate the development and growth of ISMCs. A possible reason for this lag is the lack of cell lines that recapitulate ISMCs in vivo. In this study, we separated the primary ISMCs from the rat intestinal tract and integrated the Simian Vacuolating virus 40 Large T antigen (SV40 LT) gene into the genome of the primary ISMC to construct an immortalized cell line named ISMC-Hc. ISMC-Hc proliferated persistently without any signs of senescence up to 50 passages and without neoplasticity. Analysis of the genome isolated from ISMC-Hc confirmed that the SV40LT gene recombined in the genome, and mRNA reverse transcription PCR suggested that SV40LT could be expressed normally. In addition, ISMC-Hc had few morphological differences compared with the primary ISMC. Furthermore, ISMC-Hc showed the expression of the specific protein markers (alpha-smooth muscle actin and desmin) through immunofluorescence analysis. Further studies showed that ISMC-Hc had enhanced contractility and expressed the glial-derived neurotrophic factor, nerve growth factor, ciliary neurotrophic factor, and leukemia inhibitory factor after co-stimulation with IL-1 beta and TNF-alpha. ISMC-Hc showed characteristics similar to that of primary ISMC and can be used as an in vitro model to explore the cellular and molecular mechanisms of ISMC. Additionally, the immortalized ISMCs could help investigate the basic functional mechanisms of intestinal diseases.

Egg Yolk Phospholipids Modulate Microbial Imbalance in the Intestinal Tract of Rats on a High‐Fructose Diet

AbstractHigh‐fructose diet (HFD), a cause of excessive obesity and destruction of the structure of the intestinal ecosystem, has become a common eating habit. This study aims to explore the effect and mechanism of egg yolk phospholipids (EPLs) on improving obesity, intestinal short‐chain fatty acids (SCFAs), and intestinal bacterial structure in rats induced by HFD. Results indicate that EPLs exhibit better effects on anti‐obesity than those of soy phospholipids (SPLs). EPLs increase the reduction of SCFAs caused by HFD, increased acetic acid, propionic acid, isobutyric acid, and total SCFAs, which effectively regulate the environment of intestinal microbial metabolism. Moreover, EPLs decrease Firmicutes/Bacteroides ratio (F/B) and the relative abundance of Streptomyces, Arthrobacter, and Desulfovibrio, and increase the relative abundance of Mucilaginibacter and Cellulomonas. These results suggest that EPLs have a potential modulating effect on intestinal disorders caused by HFD.Practical Applications: The results of this study illustrate that phospholipids are a promising supplement to alleviate the intestinal flora disorder caused by a high‐fructose diet, and its protective effect is mainly to regulate the composition of intestinal short‐chain fatty acids.

Effects of probiotics on intestinal flora, inflammation and degree of liver cirrhosis in rats with liver cirrhosis by regulating Wnt/β-catenin signaling pathway.

We aimed to explore the effects of probiotics on intestinal flora, inflammation and degree of liver cirrhosis in rats with liver cirrhosis, and to verify the Wnt/β-catenin signaling pathway that regulates this process. A total of 30 SD rats were randomly divided into 3 groups, namely, control group (n=10), model group (n=10) and probiotic group (n=10). Rats in the model group were used to construct liver cirrhosis models using carbon tetrachloride (CCL4) method, and those in the probiotic group were administered with probiotic preparations by gavage for 8 weeks. Then the feces of rats in each group were taken to detect the composition of intestinal flora, and changes in the content of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), monocyte chemotactic protein 1 (MCP-1) and interferon-gamma (IFN-γ), in peripheral blood collected were examined by enzyme-linked immunosorbent assay (ELISA). Next, changes in the degree of liver cirrhosis were analyzed by hematoxylin and eosin (H&E) staining, and the expression levels of the Wnt/β-catenin signaling pathway-related molecules, including β-catenin, glycogen synthase kinase (GSK)-3β and Frizzled-2, in liver tissues in each group were detected via polymerase chain reaction (PCR) and Western blotting (WB). Compared with rats in the control group, those in the model group had a disordered structure of hepatic lobule and hyperplasia of a large number of fibrous tissues. In contrast to those in the model group, the liver lobule structure was greatly improved, the edema cells were obviously reduced, and the hyperplasia of collagen fibers was remarkably alleviated in the probiotic group. Moreover, the degree of liver cirrhosis in the probiotic group was significantly reduced compared with that in the model group. Moreover, the rats in the model group exhibited a higher Bifidobacterium level in the intestinal tract, while those in the probiotic group displayed higher levels of microorganisms in the intestinal tract, such as Lachnospiraceae, Ruminococcaceae, Actinbacteria, Slackia and Pasteurellaceae. In comparison with that in the control group, the level of salt-tolerant Lactobacillus in the intestinal tract of rats in the model group was significantly decreased, while that in the probiotic group was partially increased (P=0.023). Meanwhile, some intestinal flora of rats in the control group, model group and probiotic group were closely correlated. Specifically, highly positive correlations were found between Bacteroidetes and Paraeggerthella (r=0.423, P=0.034) and between Firmicutes and Lactobacillus (r=0.318, P=0.027), but strongly negative associations were detected between Firmicutes and Paraeggerthella (r=-0.691, p=0.004) and between Paraeggerthella and Lactobacillus (r=-0.384, P=0.047). In addition, the levels of inflammatory cytokines TNF-α IL-6, MCP-1 and IFN-γ in the plasma of rats in the model group were markedly higher than those in the control group (P<0.05), whereas such levels in the probiotic group were decreased compared with those in the model group (P<0.05). PCR results revealed that the expression levels of β-catenin and Frizzled-2 in the model group were higher than those in the control group, whereas they were lower in the probiotic group than those in the model group (P<0.05). Furthermore, the model group had a decreased level of GSK-3β in comparison with the control group, but the probiotic group had a higher level of GSK-3β than the model group (P<0.05). WB results were consistent with PCR results. Probiotics can affect intestinal flora, inflammation and degree of liver cirrhosis in rats with liver cirrhosis, and its mechanism may be related to the Wnt/β-catenin signaling pathway.

Regulation and analysis of the diversity of intestinal microbiota in SD rats by Danggui Buxue Tang (DBT) fermented with Bacillus subtilis

PurposeTo investigate the effect of Danggui Buxue Tang (DBT) on intestinal microbiota diversity after fermentation by Bacillus subtilis.MethodsB. subtilis was used to ferment DBT. Sprague Dawley (SD) rats were randomly divided into the following four groups with six rats in each group: the control group, DBT nonfermentation group, B. subtilis group, and DBT fermentation group. Rats were fed continuously for 14 days. The 16S rRNA of faecal samples was analysed by high-throughput Illumina sequencing.ResultsIn total, 3483 operational taxonomical units (OTUs) were identified in this study, and 1236 OTUs were shared among all samples. Moreover, the most abundant phyla identified in this study were Bacteroidetes (29.65–38.19%) and Firmicutes (48.30–67.04%). The F/B ratios of the DBT nonfermentation group (1.07%) and the DBT fermentation group (1.78%) were slightly lower than those of the control group (2.29%). Lactobacillus was most upregulated in the DBT fermentation group (38.4%), followed by the DBT nonfermentation group (18.97%), control group (14.61%), and probiotics group (8.39%). Moreover, the pathogenic bacteria Alistipes and Parabacteroides were found to be downregulated in the DBT fermentation group (the percentages of Alistipes and Parabacteroides were as follows: control group, 8.09% and 0.16%; DBT nonfermentation group, 4.31% and 0.37%; DBT fermentation group, 1.96 and 0.09%; and probiotics group, 6.25% and 0.12%, respectively).ConclusionThis study is the first to research systematically the effects of DBT on the diversity of rat intestinal microbiota before and after fermentation. The structural characteristics of complex bacterial community in each group were clearly analysed, and DBT significantly increases probiotics and inhibits pathogenic bacterial growth in the intestinal tract of rats after fermentation, which plays a significant role in maintaining the balance of the intestinal microbiota of the rats. This research provides new insights into the development and utilization of traditional Chinese medicine.

Protective Effect of Salvianolic Acid B on Intestinal Ischemia-reperfusion Injury in Rats

Objective To investigate the protective effect of salvianolic acid B(SAB)on the intestinal tract of rats after intestinal ischemia-reperfusion injury(IIRI). Methods Forty-eight healthy male SD rats were equally randomized into IIRI group,SAB+IIRI group,sham control group,and SAB+sham control group. The malonyldialdehyde(MDA)level and superoxide dismutase(SOD)activity in the ileum were measured in each group according to the kit instructions,the transcription levels of inflammatory factors in the ileum of rats were detected by real-time fluorescence quantitative RT-PCR,the secretion level of inflammatory factors was detected by ELISA,and the effects of intestinal ischemia-reperfusion on intestinal permeability and histological lesions were measured by histopathology. Results The MDA level in IIRI group was significantly higher than those in negative control group(P=0.005)and SAB+IIRI group(P=0.012). SOD activity of IIRI group was significantly lower than those of negative control group(P=0.006)and SAB+IIRI group(P=0.017). The optical densities of tumor necrosis factor-α(TNF-α)(P=0.003,P=0.009),interleukin(IL)-1β(P=0.026,P=0.005),IL-6(P=0.015,P=0.003),and nuclear factor kappa-B(NF-κB)(P=0.007,P=0.015)in IIRI group were significantly higher than those in sham control group and SAB+IIRI group. The TNF-α(P=0.002,P=0.006),IL-1β(P=0.002,P=0.006),IL-6(P=0.008,P=0.002),and NF-κB(P=0.026,P=0.005)levels in IIRI group were significantly higher than those in sham control group and SAB+IIRI group. The inulin level in IIRI group was significantly lower than that in negative control group(P=0.015)and significantly higher than that in SAB+IIRI group(P=0.011). The dextran level in IIRI group was significantly lower than those in sham control group(P=0.011)and SAB+IIRI group(P=0.012). The dextran gel level in IIRI group was significantly higher than those in sham control group(P=0.031)and SAB+IIRI group(P=0.020). SAB pretreatment remarkably improved the edema,necrosis,and villus stripping of the intestinal mucosa in the ileum of rats. The Chiu score was significantly higher in SAB+sham control group than in sham control group(P=0.001)and was significantly lower in SAB+IIRI group than in IIRI group(P=0.001). Conclusion SAB pretreatment can alleviate IIRI in rat models,and this protective effect may be achieved by alleviating oxidative stress and inflammation in the intestinal tract.

Polysaccharides from Polygonatum kingianum improve glucose and lipid metabolism in rats fed a high fat diet

ObjectivePolygonatum kingianum is a traditional Chinese medicine commonly used to treat diabetes and hyperlipidemia. Polysaccharides from Polygonatum kingianum could regulate glucose and lipid metabolism in high-fat diet (HFD) rats. MethodsThe gel permeation chromatography (GPC), liquid chromatography (HPLC) and chemical analysis were used to determine the molecular weight, monosaccharide composition, protein, polysaccharide and uronic acid content of the polysaccharide from Polygonatum kingianum, respectively. Total (PS) and high molecular weight (PSF) polysaccharides (> 100 KDa) were isolated and treated HFD rats for a 14-week period. TC, TG contents in blood samples were measured every two weeks, and HDL-C, LDL-C was measured at 12 and 14 weeks evaluating of blood lipids regulation activity of polysaccharide. The stool samples were used for 16S rDNA V4 highly variable region measurement method to regulate the role of polysaccharide in the intestinal microflora. The content of short chain fatty acid (SCFAs) in faeces was determined by gas chromatography (GC) to investigate the effect of polysaccharides on the content of SCFAs in the intestinal tract of rats. The expression of tight junction protein ZO-1 and occludin of intestinal tissue, and detection of the key protein expression in the LPS-TLR4/NFκB signaling pathway were detected by Western blot technique. ResultsWe found that PS and PSF improved both diabetic symptoms and lipid metabolism. PS and PSF also modulated the gut microbiota composition, abundance and diversity of HFD rats, increased the relative abundance of short chain fatty acid (SCFA) producing bacteria and increased SCFA production, reduced intestinal permeability, relieved gastrointestinal inflammation, and improved lipid metabolism. ConclusionPolygonatum kingianum polysaccharides regulated the abundance and diversity of the intestinal microbial community through increasing the relative abundance of SCFA-producing bacteria. This promotes recovery of the intestinal permeability barrier, inhibits LPS entry into the circulation, alleviates inflammation, and prevents glucose and lipid metabolic disorders.

Gastrointestinal Tracking and Gastric Emptying of Coated Capsules in Rats with or without Sedation Using CT imaging.

Following oral administration, gastric emptying is often a rate-limiting step in the absorption of drugs and is dependent on both physiological and pharmaceutical factors. To guide translation into humans, small animal imaging during pre-clinical studies has been increasingly used to localise the gastrointestinal transit of solid dosage forms. In contrast to humans, however, anaesthesia is usually required for effective imaging in animals which may have unintended effects on intestinal physiology. This study evaluated the effect of anaesthesia and capsule size on the gastric emptying rate of coated capsules in rats. Computed tomography (CT) imaging was used to track and locate the capsules through the gastrointestinal tract. Two commercial gelatine mini-capsules (size 9 and 9h) were filled with barium sulphate (contrast agent) and coated using Eudragit L. Under the effect of anaesthesia, none of the capsules emptied from the stomach. In non-anaesthetised rats, most of the size 9 capsules did not empty from the stomach, whereas the majority of the smaller size 9h capsules successfully emptied from the stomach and moved into the intestine. This study demonstrates that even with capsules designed to empty from the stomach in rats, the gastric emptying of such solid oral dosage forms is not guaranteed. In addition, the use of anaesthesia was found to abolish gastric emptying of both capsule sizes. The work herein further highlights the utility of CT imaging for the effective visualisation and location of solid dosage forms in the intestinal tract of rats without the use of anaesthesia.

Effects and Mechanisms of Dendrobium officinalis Six Nostrum for Treatment of Hyperuricemia with Hyperlipidemia.

Objectives. Hyperuricemia (HUA) is a disease caused by increased production of uric acid (UA) or reduced excretion of UA in the body. Results of an epidemiological survey show that 60% of patients with HUA have hyperlipidemia (HPA). Dendrobium officinalis (DOF) six nostrum (DOS) is based on the theory of traditional Chinese medicine for the transformation of the traditional Chinese nostrum Si Miao Wan. In this article, we aim to discuss the efficacy and mechanism of DOS in reducing UA and regulating lipid metabolism. The rat model of HUA with HPA was induced by potassium oxonate (PO) combined with high-fat sorghum feed. We monitored the serum UA and blood lipids. Liver xanthine oxidase (XOD), adenosine deaminase (ADA), lipoprotein lipase (LPL), and fatty acid-binding protein (FABP1) activities were measured by enzyme-linked immunosorbent assay (ELISA) after the last administration of DOS. We performed a histopathological examination of rat kidney and intestine. Immunohistochemistry (IHC) was used to detect the expression of renal inflammatory proteins NLRP3 / Caspase-1 and intestinal inflammatory proteins TLR4 / NLRP3. We used western blot for measurement of liver hypoxanthine-guanine phosphoribosyl transferase (HPRT1) protein expression and renal PDZ domain protein kidney 1 (PDZK1) protein expression. DOS administration significantly reduced serum UA, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c) level, and improved liver steatosis in the model rat. At the same time, DOS treatment effectively inhibited liver XOD and ADA, increased the level of liver HPRT1, and reduced the production of UA. Additional studies had shown that DOS can restore normal UA excretion function in the intestine and kidney and regulated liver lipids metabolism. IHC and histopathological sections showed that DOS reduced the level of kidney, intestinal inflammatory body (NLRP3, Caspase-1, and TLR4), improved inflammation of the kidney and intestinal tract in rats. DOS is a promising drug that can effectively reduce serum UA and lipid level in the model rat. The mechanism of action may be related to inhibition of UA production, promotion of UA excretion, regulation of lipids metabolism, and anti-inflammatory response.

High Fat High Calories Diet (HFD) Increase Gut Susceptibility to Carcinogens by Altering the Gut Microbial Community.

Objective: To investigate the risk of colorectal cancer and its relationship with colonic flora and microenvironment under high-fat and high-calorie diet. Methods: Wistar rats were used to study, and they were given normal diet, high-fat diet, and dimethyl hydrazine (DMH) to induce the occurrence of colorectal cancer. Then observe the difference in tumor formation and the relationship among microbial community, inflammatory factors and metabolism. Results: No tumors were found in the normal diet group (G1) and the high-fat diet group (G3). Four nodules were found in the four rats in the normal diet + DMH group (G2) and 8 cancerous nodules were formed in 7 rats (70%) from high-fat diet + DMH group (G4). Cholesterol and TNF-α increased, IL-1, IL-6 and LEP decreased in the high-fat diet group. The difference was statistically significant. In the cancer-inducing group, only the difference in cholesterol was statistically significant. Compared with the normal diet group (G1) and the high-fat diet group (G3), the rat's gut bacterial abundance was not significantly different, but the gut flora structure was significantly changed. The content of Candida in the intestinal tract of rats in the high-fat diet group was reduced (P = 0.015), while the content of Verrucomicrobia increased (P = 0.035); In the comparison of genus content, Ruminococcus, Candida, Saccharibacteria genera incertae sedis, Enterobacter, Clostridium IV, Enterococcus, Enterorhabdus, Acetivibrio, Adlercreutzia, Lactococcus, etc., decreased significantly, while Akkermansia, Warthococcus, Staphylococcus, Butyricimonas, Clostridium XVIII, etc. increased significantly.Conclusion: This study found that high-fat, high-calorie diet can increase the susceptibility of the intestine to carcinogenic factors. The reason may be that the high-fat diet causes the body to appear inflammatory states and microbial community imbalance, especially rumenococcus, candida, Saccharomyces, Enterobacter, Clostridium IV, Enterococcus, Enterobacter, Vibrioaceticus and other genus reduction are important links. Exploring ways to improve these floras is an important factor to improve the resistance of the intestinal tract to cancer-inducing agents.

Combined Buckwheat d-Fagomine and Fish Omega-3 PUFAs Stabilize the Populations of Gut Prevotella and Bacteroides While Reducing Weight Gain in Rats.

Some functional food components may help maintain homeostasis by promoting balanced gut microbiota. Here, we explore the possible complementary effects of d-fagomine and ω-3 polyunsaturated fatty acids (ω-3 PUFAs) eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA 1:1) on putatively beneficial gut bacterial strains. Male Sprague–Dawley rats were supplemented with d-fagomine, ω-3 PUFAs, or both, for 23 weeks. Bacterial subgroups were evaluated in fecal DNA by quantitative real-time polymerase chain reaction (qRT-PCR) and short-chain fatty acids were determined by gas chromatography. We found that the populations of the genus Prevotella remained stable over time in animals supplemented with d-fagomine, independently of ω-3 PUFA supplementation. Animals in these groups gained less weight than controls and rats given only ω-3 PUFAs. d-Fagomine supplementation together with ω-3 PUFAs maintained the relative populations of Bacteroides. ω-3 PUFAs alone or combined with d-fagomine reduced the amount of acetic acid and total short-chain fatty acids in feces. The plasma levels of pro-inflammatory arachidonic acid derived metabolites, triglycerides and cholesterol were lower in both groups supplemented with ω-3 PUFAs. The d-fagomine and ω-3 PUFAs combination provided the functional benefits of each supplement. Notably, it helped stabilize populations of Prevotella in the rat intestinal tract while reducing weight gain and providing the anti-inflammatory and cardiovascular benefits of ω-3 PUFAs.

Immunohistochemical localization of afatinib in male rat intestines and skin after its oral administration

Afatinib, a second-generation tyrosine kinase inhibitor, was designed to bind covalently to and irreversibly inhibit active ErbB family receptors. The major metabolites of afatinib in human plasma are adducts of afatinib covalently bound to plasma proteins via. the Michael addition reaction. These findings suggest that afatinib may form covalent bonds with proteins in tissue and be localized in tissue. However, there is no method for the specific detection of afatinib-protein conjugates localized in tissue. In this paper, we aimed to develop an immunohistochemical protocol to detect afatinib-protein conjugates. Immunostainings were performed with male rat intestinal tract and skin at 24 h after an oral administration of afatinib. In the intestinal tract, strong staining was observed in the ileum and colon, but only slight staining was observed in the duodenum and jejunum. In the skin, strong staining was observed in the epidermis, sebaceous glands and hair follicles. Immunohistochemistry for afatinib-protein conjugates could be a useful tool to detect the localization of such conjugates. This study is the first to elucidate the localization of afatinib-protein conjugates in the rat intestinal tract and skin and is expected to be of great use in efforts to clarify the mechanism underlying afatinib-induced diarrhoea or skin toxicities.

Effect of PA-MSAH preprocessing on the expression of TLR-4-NF-κB pathway and inflammatory factors in the intestinal tract of rats with septic shock.

Effects of Pseudomona blank s aeruginosa-mannose sensitive hemagglutini (PA-MSHA) preprocessing on toll like receptor (TLR)-4-NF-κB pathway and inflammatory factors expression in the intestinal tract of rats with septic shock were investigated. A total of 30 rats were randomly divided into 3 groups (n=10): Blank control, septic shock, and PA-septic shock group. After the model was successfully established, the average arterial pressure in rats was monitored. The concentration of cytokine interleukin-l (IL-1), IL-6 and tumor necrosis factor-α (TNF-α) were determined by ELISA method. Flow cytometry was performed to detect TLR-4 expression. Number of in vitro chemotaxised neutrophils was detected by Transwell chamber. The expression of TLR-4, NF-κB and ICAM-1 and VCAM-1 was detected by western blot analysis. The concentration of cytokine IL-1, IL-6, TNF-α in the peritoneal lavage fluid and the intestinal tissue significantly increased in the septic shock group and the PA-septic shock group (P<0.05), and the concentration in the PA-septic shock group was significantly lower than that of the septic shock group (P<0.05). Compared to the control group, the expression of TLR-4, NF-κB and ICAM-1 and VCAM-1 increased in the septic shock and PA-septic shock group (P<0.05), and the expression level of PA-septic shock group was lower than the septic shock group (P<0.05). The expression of TLR-4 in the PA-septic shock group was lower than the septic shock group (P<0.05). PA-MSHA pretreatment reduced inflammation, thus preventing the intestinal injury caused by septic shock.

Bacterial community mapping of the intestinal tract in acute pancreatitis rats based on 16S rDNA gene sequence analysis.

Numerous studies have revealed that the status of intestinal microbiota has a marked impact on inflammation, which may progressively aggravate the systemic inflammatory response caused by acute pancreatitis (AP). However, our understanding of microbial communities in the intestinal tract is still very limited. Therefore, the aim of this paper is deciphering bacterial community changes in AP rats. In this study, samples taken from AP rats were subjected to 16S rDNA gene sequence-based analysis to examine the characteristic bacterial communities along the rat intestinal tract, including those present in the small intestine, colon and feces, with samples from rats with a sham operation (SO) as the control group. Operational taxonomic units (OTUs) network analyses displayed that the small intestine and colon of the AP rats had a “core microbiota” composed of bacteria belonging to Firmicutes, Proteobacteria and Bacteroidetes, whereas the “core microbiota” of feces included Firmicutes, Bacteroidetes, Proteobacteria, Tenericutes and Actinobacteria. Bacterial diversity analysis showed that the species richness and diversity of the small intestine, colon and feces in AP rats were lower than those in the SO rats, and species difference between the AP and SO groups were observed. In addition, at different levels of bacterial classification, dramatic alterations in the predominant intestinal microbiota were observed along intestinal tracts in AP rats compared to the SO rats. COG and KEGG analyses indicated that the significantly differential flora were involved several clusters and signaling networks. Thus, this work systematically characterizes bacterial communities from the intestinal tract of AP rats and provides substantial evidence supporting a prospective strategy to alter the intestinal microbiota improving AP.