Rat Intestinal Tissue Research Articles

CXCL1/CXCR2 is involved in white matter injury in neonatal rats via the gut–brain axis

BackgroundThis study aimed to investigate whether CXCL1/CXCR2 mediates intestinal injury or white matter injury by delivering inflammatory mediators through the gut–brain regulation axis.MethodsNeonatal SD rats, regardless of sex, were administered 3% dextran sulfate sodium via intragastric administration at different time points to construct necrotizing enterocolitis (NEC) models. Meanwhile, hypoxia and ischemia were induced in 3 day-old SD rats to construct hypoxic–ischemic brain injury (HIBI) and NEC + HIBI models, without gender discrimination. Hematoxylin–eosin staining was used to observe pathological changes in neonatal rat intestinal and brain tissues. Western blotting detected CXCL1 and CXCR2 expression in NEC, HIBI, and NEC + HIBI rat intestinal and brain tissues.ResultsCompared with normal rats, pathological damage to periventricular white matter was observed in the NEC group. In addition to the increased mortality, the histopathological scores also indicated significant increases in brain and intestinal tissue damage in both HIBI and NEC + HIBI rats. Western blotting results suggested that CXCL1 and CXCR2 expression levels were upregulated to varying degrees in the intestinal and brain tissues of NEC, HIBI, and NEC + HIBI neonatal rats compared to that in the normal group. Compared with the HIBI group, the expression of CXCL1 and CXCR2 continued to increase in NEC + HIBI rats at different time points.ConclusionsCXCL1/CXCR2 may be involved in white matter injury in neonatal rats by delivering intestinal inflammatory mediators through the gut–brain axis.

Effect of electroacupuncture at different acupoint combination on intestinal inflammatory response and intestinal flora in obese rats

To observe the effect of electroacupuncture (EA) at different acupoint combination on intestinal inflammatory response, intestinal flora structure and metabolic function in obese rats. Ninety male Wistar rats aged 8 weeks were collected. Ten rats were randomly collected from 15 rats fed with regular forage in a normal group and the rest 75 rats were fed with high-fat forage to induce obesity models. Forty rats were modeled successfully and randomized into a model group, a lower-limb EA group, an abdomen EA group and a biaoben acupoints group, 10 rats in each one. "Zusanli" (ST 36) and "Fenglong" (ST 40) were selected in the lower-limb EA group, "Zhongwan "(CV 12), "Tianshu "(ST 25) and "Guanyuan" (CV 4) were selected in the abdomen EA group. The acupoint prescriptions in the above two groups were combined in the biaoben acupoints group. EA was delivered in all of the intervention groups, with continuous wave, 2 Hz in frequency and 1 mA in current intensity. The intervention was administered three times weekly (on Monday, Wednesday and Friday), for consecutive 8 weeks. Before intervention and on the last day of the 8th week of intervention, the body weight and 24 h food intake were observed. After intervention, using Western blot method, the proteins expressions of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were detected in the tissue of the small intestine; 16S rRNA sequencing technology was adopted to detect the distribution structure and metabolic function of intestinal flora. Compared with the normal group, the body weight, the food intake and the proteins expressions of IL-6 and TNF-α in small intestine were all increased in the model group (P<0.01). The above indexes of each EA intervention group were all decreased (P<0.01) when compared with the model group. The proteins expressions of IL-6 and TNF-α in the small intestine tissue of rats in biaoben acupoints group were lower than those in the other two EA intervention groups (P<0.01). Compared with the normal group, the ratio of Firmicutes/Bacteroidetes was elevated (P<0.01), while the abundance of Lactobacillus, Muribaculaceae and Bifidobacteria decreased in the model group (P<0.01). When compared with the model group, the ratio of Firmicutes/Bacteroidetes in each EA intervention group was reduced (P<0.01) and the abundance of Lactobacillus, Bifidobacteria and Bacteroidetes increased (P<0.01). Compared with the other two EA intervention groups, the abundance of Lactobacillus and Muribaculaceae was increased (P<0.01), while the abundance of Collinsella and Ruminococcus Gauvreauii reduced (P<0.01) in the biaoben acupoints group. In the model group, the abundance of clusters of orthologous groups of proteins (COG) function of intestinal flora in the transportation and metabolism of carbohydrate, amino acid and lipid, as well as in the signal transduction mechanisms were reduced when compared with the normal group (P<0.01). In comparison with the model group, the abundance of the above COG function was increased in each EA intervention group (P<0.01, P<0.05). Electroacupuncture at biaoben acupoint combination may attenuate intestinal inflammatory response and effectively improve the structure and function of intestinal flora. The effect is superior to the intervention at the acupoints on the lower limbs and those on the abdomen, better regulating the abundance of specific intestinal flora.

Effects of Pregnant Fatigue on the Development of Offspring in Rats.

To explore the correlation between pregnant fatigue and intrauterine physical and neural development of offspring in rats. Sprague-Dawley pregnant rats were randomly divided into a normal control group, a mild fatigue group (stand in water for 6 hours/day), and a severe fatigue group (stand in water for 15h/day). The levels of lactic acid, 5-Hydroxytryptamine and Interleukin-6 in cardiac serum of rats were used to evaluate the fatigue. The expression of S100β in the telencephalon, Insulin-like growth factor-1 (IGF-1) in the liver and Cyclooxygenage-2 (COX-2) in the small intestine tissues of fetal rats were examined. Frozen sections were taken from the telencephalon of rat pups to observe morphological changes in the hippocampal primordium. Pregnant fatigue led to a decrease in food intake (F = 37.586, p = 0.000) and water intake (F = 23.608, p = 0.000) in rats. The IGF-1 mRNA expression of fetal rats in the severe fatigue group was lower than that in the control group (p = 0.0003). The expression of S100β mRNA (p = 0.000) and COX-2 mRNA (p = 0.0002) of fetal rats were higher in the severe fatigue group than in the control group. HE staining of the telencephalon of fetal rats in the pregnant fatigue group revealed sparse and irregular cell arrangement and increased gaps in the hippocampal primordial site. Pregnant fatigue rats had both physical fatigue and mental fatigue. Fatigue during pregnancy affects physical development and neurodevelopment of offspring. Further research should elucidate the mechanisms of pregnant fatigue and its effects on offspring.

TAK-242 Ameliorates Hepatic Fibrosis by Regulating the Liver-Gut Axis.

Objective The aims of this study were to investigate the impact of TAK-242 on the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear transcription factor-κB (NF-κB) signal transduction pathway in rats with hepatic fibrosis (HF) using the liver gut axis and to investigate the molecular mechanism of its intervention on HF. Methods SPF grade SD male rats were randomly allocated to the control, model, and TAK-242 groups. For 8 weeks, the model and TAK-242 groups received 3 mL·kg−1 (the initial dose 5 mL·kg−1) intraperitoneal injections of 40% CCL4 olive oil solution. TAK-242 (5 mg·kg−1) was administered once a day for 5 days after modeling. The pathological alterations of liver and small intestine tissues in each group were observed using H&E and Masson staining. ELISA was used to measure serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), direct bilirubin (DBIL), total bilirubin (TBIL), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α). RT-qPCR was utilized to identify the mRNA expression level of IL-1β, IL-6, TNF-α, TLR4, MyD88, and NF-κB in rat liver and small intestine tissues. The protein level of IL-1β, IL-6, TNF-α, TLR4, MyD88, and NF-κB protein in rat liver and small intestine tissues was determined utilizing Western blot and IHC. Results TAK-242 significantly reduced AST, ALT, TBIL, and DBIL expression in HF rats' serum (P < 0.01) and alleviated liver tissue injury. Hematoxylin-eosin (H&E) and Masson staining revealed inflammatory cell infiltration and fibrous proliferation in the liver and small intestine tissue in the model group and partial cell swelling in the TAK-242 group, which indicated a considerable improvement compared to the model group. RT-qPCR, Western blot, and IHC data indicated that TAK-242 reduced the IL-1β, IL-6, TNF-α, TLR4, MyD88, and NF-κB expression in the liver and small intestine tissues of HF rats. Conclusion TAK-242 might downregulate the TLR4/MyD88/NF-κB signal pathway through the liver-gut axis, suppress the inflammatory response, and eventually alleviate HF in rats.

Comparisons of in Vitro Models to Evaluate the Membrane Permeability of Amorphous Drug Nanoparticles.

The spontaneous formation of amorphous drug nanoparticles following the release of a drug from a supersaturating formulation is gaining increasing attention due to their potential contribution to increased oral bioavailability. The formation of nanosized drug particles also has considerable implications for the interpretation of in vitro and in vivo data. However, the membrane transport properties of these drug particles remain less well understood. Herein, the membrane permeation of nanosized amorphous drug particles of a model drug atazanavir was evaluated using different artificial membrane-based, cell-based, and animal tissue-based models. Results showed that flux enhancement by particles was different for the various systems used. Generally, good agreement was obtained among experiments performed using the same apparatus with different model membranes, with the exception of the Madin-Darby canine kidney cell monolayer and the Long-Evans rat intestine tissue, which showed lower flux enhancements. Franz cell-based models showed slightly higher flux enhancements by particles compared to Transwell and intestinal tissue sac models. Mass transport analysis suggested that the extent of flux enhancement by particles is dependent on the geometry of the apparatus as well as the properties of the membrane and buffer used, whereas the flux plateau concentration is dependent on the unstirred water later (UWL) asymmetry. These results highlight the complexity in characterizing the permeability advantage of these nonmembrane permeable drug particles and suggest that caution should be used in selecting the appropriate in vitro model to evaluate the overall permeability of colloidal drug particles.

Evaluation of an Ussing Chamber System Equipped with Rat Intestinal Tissues to Predict Intestinal Absorption and Metabolism in Humans.

Oral bioavailability (F) is one of the key factors that need to be determined in drug discovery. This factor is determined by the permeability and solubility of new molecule entities (NMEs) according to the biopharmaceutics classification system (BCS). In the present study, we evaluated the permeability of 22 drugs in rat intestinal tissues using an Ussing chamber system and correlated the permeability with data on human intestinal absorption (Fa) and intestinal availability (Fa×Fg) reported in the literature. The rat intestinal permeability data were better correlated with the combined effect of the absorbed fraction (Fa) and the fraction escaping intestinal metabolism (Fg) than Fa itself. Clear regional dependent absorption was observed for most of the test drugs, and ileal Papp was generally higher than that in other segments. Finally, the function of the efflux transporter P-glycoprotein (P-gp) with regard to oral absorption of substrates was evaluated with an Ussing chamber. We also demonstrated that the rat intestinal stability of the three cytochrome P450 (CYP) substrates was consistent with the human data. An Ussing chamber system incorporating rat intestinal tissue would be a valuable tool to predict human intestinal absorption and metabolism for molecules with various physicochemical properties.

Curcumin Improved Intestinal Epithelial Barrier Integrity by Up-Regulating ZO-1/Occludin/Claudin-1 in Septic Rats.

Objective To investigate the protective effect and mechanism of curcumin on intestinal barrier function in rats with enterogenic sepsis. Methods Rats were divided into Sham group (Sham), Model group (Model), low-dose curcumin group (100 mg/kg), and high-dose curcumin group (200 mg/kg), with 10 rats in each group. Sepsis model was established in model group, low-dose curcumin group, and high-dose curcumin group. After drug intervention, hematoxylin-eosin (HE) staining was used to observe the histopathological changes of small intestine in each group. The levels of TNF-α, IL-1β, and IL-6 in serum and intestinal tissues of rats were determined by ELISA. The expression of ZO-1, occludin, and claudin-1 in ileum was detected by QRT-PCR and Western blot. Western blotting was used to detect the expression of ERK/JNK signaling pathway, NF-κB p65, apoptosis-related proteins Caspase-3, and TNF-α in rat intestinal tissues. Results HE staining showed that curcumin treatment reduced epithelial cell shedding, interstitial edema, and apoptosis. Compared with model group, DAO activity, serum intestinal fatty acid binding protein (I-FABP), TNF-α, IL-6, and IL-1β expression in curcumin group were decreased in a dose-dependent manner. Curcumin can upregulate the mRNA and protein expression levels of ZO-1, occludin, and claudin-1 in ileum of CLP-induced rats. In addition, curcumin inhibits NF-κB p65 activation and apoptosis by regulating ERK/JNK signaling pathway. Conclusion Curcumin can reduce inflammatory response and upregulate the expression of intestinal tight junction proteins ZO-1, occludin, and claudin-1 in rats with enterogenic sepsis, and protect intestinal barrier function.

Intestinal Protective Efficacy of Gamma Co-60 Irradiated Chitosan and Vitamin E Combination on Lead acetate-induced Rats

As an organ that absorbs food, the intestine can be damaged when interacting directly with lead (Pb). Gamma Co-60 irradiated chitosan, and vitamin E combination potentially can help reduce free radical damage to intestinal organs. This study examines the efficacy of gamma Co-60 irradiated chitosan and vitamin E combination in protecting the intestinal tissue of rats exposed to Pb acetate. The 24 rats were grouped into 6 groups, each 4 rats; were induced with Pb acetate, except the control group. The negative control group was only induced Pb acetate. The positive control group had additional treatment of irradiated chitosan. The treatment group (1-3) was treated using the combination of gamma Co-60 irradiated chitosan at a dose of 64 mg/kg BW and vitamin E 1000 IU at a dose of 1.44; 2.16, 3.00 mg/kg BW, respectively, for forty days. The research parameters observed are edema, degeneration, necrosis, erosion of the intestinal villi, and lysis of the intestinal villi. Intestinal histology appearance data in all groups were analyzed descriptively. The result shows that a combination of Gamma Co-60 irradiated chitosan at a dose of 64 mg/kg BW and vitamin E at a dose of 1.44 mg/kg BW effectively reduced lead cytotoxicity in the intestinal tissue of Pb acetate-induced rats. The larger the dose of vitamin E has the potential to produce pro-oxidants, which will increase the toxic effect on intestinal tissue. Gamma Co-60 irradiated chitosan, and vitamin E combination at the right dose has the potential to be developed as a supplement to reduce the toxic effects of chronic lead exposure. Especially for people who, for some reason, cannot avoid chronic lead exposure.

New glucogenesis inhibition model based on complete α-glucosidases from rat intestinal tissues validated with various types of natural and pharmaceutical inhibitors.

Inhibition of intestinal α-glucosidases from rat intestinal acetone powder (RIAP) has been widely used in research focused on regulating glucogenesis to be applied as a strategy to control obesity and type II diabetes. However, the crude extract has different compositions of α-glucosidases than a complete RIAP suspension due to enzymes anchored on the intestinal tissues after the extraction. Here, the inhibitory effects of different pharmaceutical and food-grade inhibitors on the enzymes in the RIAP suspension were investigated. Instead of crude extracts from RIAP, the RIAP suspension without the extraction process was applied to optimize the α-glucosidase inhibitory model by pharmaceutical/natural inhibitors. The results clearly showed that the half-maximal inhibitory concentration ratios of four individual α-glucosidases by various inhibitors were different between the RIAP suspension and the crude extract. In particular, isomaltase from the RIAP suspension required more inhibitors than the crude extraction did, as this enzyme is still anchored to the remaining intestinal tissue from the extraction process. The crude extract from RIAP contains only a portion of the enzymes, which poses limitations for determining the precise inhibitory properties by various types of enzyme inhibitors. On the contrary, an in vitro assay with RIAP suspension that has all the α-glucosidases is a more suitable method for determining digestibility of glycemic carbohydrates. This new approach can be applied to the development of natural/synthetic α-glucosidase inhibitors to attenuate the postprandial glycemic response more accurately. © 2022 Society of Chemical Industry.

Resveratrol ameliorates necrotizing enterocolitis in neonatal rats through regulation of inflammatory and apoptotic pathways

Purpose: To determine the efficacy of resveratrol in mitigating necrotizing enterocolitis (NEC) in neonatal rats.Methods: Necrotizing enterocolitis (NEC) was induced in neonatal rats using hypoxia and hypothermia. At the completion of treatment, the intestinal tissues of the rats were isolated for evaluation of various biochemical parameters.Results: There was significant increase in the levels of proinflammatory cytokines (TNF-α, IL-6 and IL-1β) and oxidative stress markers (MDA, xanthine oxidase and nitric oxide) in intestinal tissues of NEC rats (p &lt; 0.05). However, resveratrol treatment led to significant decrease in the levels of cytokines and oxidative stress parameters, relative to the NEC group (p &lt; 0.05). Furthermore, Western blotting resultsshowed up-regulation in protein expressions of inflammatory cytokines in NEC rats. However, the protein expressions of inflammatory cytokines were down-regulated in the NEC rats on treatment with resveratrol. Moreover, resveratrol reversed the NEC-induced up-regulations of Bax and caspase-3, as well as NEC-mediated down-regulation of Bcl-2.Conclusion: These results demonstrate that resveratrol mitigates NEC-induced intestinal damage in neonatal rats via anti-inflammatory, anti-apoptotic and antioxidant mechanisms of action. Therefore, resveratrol is a potential therapeutic agent for NEC.

Progesterone Metabolism by Human and Rat Hepatic and Intestinal Tissue.

Following oral administration, the bioavailability of progesterone is low and highly variable. As a result, no clinically relevant, natural progesterone oral formulation is available. After oral delivery, first-pass metabolism initially occurs in the intestines; however, very little information on progesterone metabolism in this organ currently exists. The aim of this study is to investigate the contributions of liver and intestine to progesterone clearance. In the presence of NADPH, a rapid clearance of progesterone was observed in human and rat liver samples (t1/2 2.7 and 2.72 min, respectively). The rate of progesterone depletion in intestine was statistically similar between rat and human (t1/2 197.6 min in rat and 157.2 min in human). However, in the absence of NADPH, progesterone was depleted at a significantly lower rate in rat intestine compared to human. The roles of aldo keto reductases (AKR), xanthine oxidase (XAO) and aldehyde oxidase (AOX) in progesterone metabolism were also investigated. The rate of progesterone depletion was found to be significantly reduced by AKR1C, 1D1 and 1B1 in human liver and by AKR1B1 in human intestine. The inhibition of AOX also caused a significant reduction in progesterone degradation in human liver, whereas no change was observed in the presence of an XAO inhibitor. Understanding the kinetics of intestinal as well as liver metabolism is important for the future development of progesterone oral formulations. This novel information can inform decisions on the development of targeted formulations and help predict dosage regimens.

Administration of cyclophosphamide to rats induces pica and potentiates 5-hydroxytryptamine synthesis in the intestine without causing severe intestinal injury

The effects of cyclophosphamide on 5-hydroxytryptamine (5-HT) synthesis in the intestinal tissue of rats were investigated. Rats received 120 mg/kg cyclophosphamide intraperitoneally as a single administration, and kaolin and food intake was measured by an automatic monitoring apparatus. Ileal tissues were collected at either 24 or 72 h after administration. Cyclophosphamide caused a significant increase in kaolin intake at the acute and the delayed phases and was associated with a decrease in food intake, and body weight. Cyclophosphamide had no significant effect on intestinal mucosal morphology, or inducible nitric oxide synthase and cyclooxygenase-2 expression in the intestine. Cyclophosphamide significantly increased tryptophan hydroxylase 1 (TPH1) mRNA expression, number of anti-TPH antibody-positive cells, and 5-HT content in the intestine. Cyclophosphamide also significantly increased the expression of Tac1 mRNA, encoding preprotachykinin-1, which is a preprotein of substance P, and the number of anti-substance P antibody-positive cells in the intestine. Cyclophosphamide significantly increased Lgr5, Bmi1, and Atoh1 mRNA levels, which are markers for the proliferation and differentiation of stem cells. This study demonstrated that cyclophosphamide induced pica in rats, and potentiated 5-HT synthesis associated with hyperplasia of substance P-containing enterochromaffin cells without causing severe intestinal injury.

Gut modulation of dysbiosis induced by dextran sulfate sodium

Inflammatory bowel disease is one of the serious burdens of clinical medicine and healthcare. This study investigated the potential of a biological product based on mare's milk and metabolites of symbiotic microflora for modulation of intestinal microflora affected by dextran sulfate sodium (DSS)-induced dysbiosis. Symbiotic microflora was isolated from the stool of healthy volunteers. Lysates for the production of short-chain fatty acids of screened microorganisms were mixed with mare's milk. The activity of the biological product was evaluated on the DSS model of induced colitis. Histological changes in the intestinal epithelium were determined. The structure of the microbiome was evaluated based on the analysis of 16S rRNA microbial sequences. Histological examination of rat intestinal tissues after application of the biological product showed reduced infiltration of granulocytes, macrophages, and lymphocytes. The results of sequencing demonstrated a decrease in the biological diversity of microbiota affected by colitis. The full recovery was observed after 21 days of the application of the biological product. The product induced the structural changes of the microbiome damaged by DSS. Likewise, the number of the pathogenic intestinal microflora was decreased Representatives of SCFA producing bacteria increased concentrations of genus Lactobacillus.

Floroindole confers protection against cecal ligation and puncture-induced sepsis via inhibition of NF-kB p65 phosphorylation

Purpose: To investigate the protective effect of floroindole against cecal ligation and puncture (CLP)- induced sepsis, as well as the underlying mechanism of action.&#x0D; Methods: Thirty-five 10–week-old male Wistar rats weighing 190 - 210 g (mean: 200.00 ± 10.10 g) were used for this study. The rats were randomly assigned to seven groups of five rats each, viz, normal control group, and six CLP groups. The CLP groups were those subjected to cecal ligation and puncture (CLP). The first 5 CLP groups received 2, 4, 6, 8 or 10 mg/kg floroindole, respectively, 1 h after CLP, via intraperitoneal route (i.p.) while the 6th CLP group served as untreated control. Western blotting, enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (qRT-PCR) were used for the assessment of the expression levels of tumor necrosis factor-α (TNF- α), interleukn-6 (IL-6), nucleotide-binding oligomerization domain 2 (NOD2) and p-NF-κB p65.&#x0D; Results: Cecal ligation and puncture (CLP) significantly and time-dependently upregulated the expressions of TNF-α, IL-6 and NOD2 in intestinal tissues of rats (p &lt; 0.05). However, treatment with floroindole significantly, and dose-dependently down-regulated CLP-induced expressions of these proteins (p &lt; 0.05). Treatment of rats with floroindole also significantly and dose-dependently inhibited CLP-induced phosphorylation of NF-κB p65 in rat ileum (p &lt; 0.05).&#x0D; Conclusion: The results obtained in this study demonstrate that floroindole confers some degree of protection against CLP-induced sepsis via inhibition of NF-κB p65 phosphorylation.

Permeability-enhancing effects of three laurate-disaccharide monoesters across isolated rat intestinal mucosae

Laurate (C12)-sucrose esters are established intestinal epithelial permeation enhancers (PEs) with potential for use in oral delivery. Most studies have examined blends of ester rather than specific monoesters, with little variation on the sugar moiety. To investigate the influence of varying the sugar moiety on monoester performance, we compared three monoesters: C12-sucrose, C12-lactose, and C12-trehalose. The assays were: critical micellar concentration (CMC) in Krebs-Henseleit buffer, MTS and lactate dehydrogenase assays in Caco-2 cells, transepithelial electrical resistance (TEER) and apparent permeability coefficient (Papp) of [14C] mannitol across isolated rat intestinal mucosae, and tissue histology. For CMC, the rank order was C12-trehalose (0.21 mM) < C12-sucrose (0.34 mM) < C12-lactose (0.43 mM). Exposure to Caco-2 cells for 120 min produced TC50 values in the MTS assay from 0.1 to 0.4 mM. Each ester produced a concentration-dependent decrease in TEER across rat mucosae with 80% reduction seen with 8 mM in 5 min, but C12-trehalose was less potent. C12-sucrose and C12-lactose increased the Papp of [14C] mannitol across mucosae with similar potency and efficacy, whereas C12-trehalose was not as potent or efficacious, even though it still increased flux. In the presence of the three esters, gross intestinal histology was unaffected except at 8 mM for C12-sucrose and C12-lactose. In conclusion, the three esters enhanced permeability likely via tight junction modulation in rat intestinal tissue. C12-trehalose was not quite as efficacious, but neither did it damage tissue to the same extent. All three can be considered as potential PEs to be included in oral formulations.

Effect of acupuncture on intestinal flora and TLR4 in brain and intestinal tissues in rats with stress gastric ulcer

To observe the effect of acupuncture at "Guanyuan" (CV 4) and "Xiajuxu" (ST 39) on intestinal flora and Toll-like receptors-4 (TLR4) in brain and intestinal tissue in rats with stress gastric ulcer (SGU), and to explore the possible mechanism of acupuncture for SGU. Thirty-one male SD rats were randomly divided into a blank group (n=7), a model group (n=8), an acupuncture group (n=8) and a drug group (n=8). The rats in the model group, acupuncture group and drug group were treated with modified restraint plus water-immersion stress method to establish SGU model. After modeling, the rats in the acupuncture group were treated with acupuncture at "Guanyuan" (CV 4) and "Xiajuxu" (ST 39), 20 min each time, and the needles were twirled for 30 s every 5 min. The rats in the drug group were treated with intragastric administration of 2 mL omeprazole enteric-coated tablets (20 mg/mL). Both the treatments were given once a day for 5 days. After the intervention, the gastric mucosal damage index was calculated by Guth method; the morphological changes of gastric mucosa were observed by HE staining; the diversity of intestinal flora was detected by 16S rDNA high-throughput sequencing; TLR4 contents in brain and intestinal tissues were determined by ELISA. Compared with the blank group, the gastric mucosal damage index was significantly increased in the model group (P<0.01); the morphological changes of gastric mucosa were obvious; the Observed Species index and Shannon index of α diversity index of intestinal flora were decreased (P<0.05); the β diversity showed that the spatial distance between the model group and the blank group was far; the TLR4 contents in the brain and intestinal tissue were increased (P<0.05, P<0.01). Compared with the model group, the gastric mucosal damage index was decreased in the acupuncture group and the drug group (P<0.05); the morphology of gastric mucosa was improved; the Observed Species index and Shannon index of α diversity index of intestinal flora in the acupuncture group was increased (P<0.05), and the Shannon index in the drug group was increased (P<0.05); the β diversity showed that the spatial distance between the acupuncture group and the blank group was close; the TLR4 contents in the brain and intestinal tissues of the acupuncture group were decreased (P<0.01). Compared with the drug group, the contents of TLR4 in the intestinal tissue of the acupuncture group were decreased (P<0.05). Acupuncture at "Guanyuan" (CV 4) and "Xiajuxu" (ST 39) could alleviate SGU in rats, and its mechanism may be related to increasing the diversity of intestinal flora, promoting the disorder of intestinal flora to normal, and reducing the overexpression of TLR4 in brain and intestinal tissues.

Comparison of the effects of the intestinal permeation enhancers, SNAC and sodium caprate (C10): Isolated rat intestinal mucosae and sacs

SNAC and C10 are intestinal permeation enhancers (PEs) used in formulations of peptides for oral delivery in clinical trials. Our aims were to compare their: (i) mechanism of action in isolated rat intestinal mucosae mounted in Ussing chambers and in non-everted gut sacs, (ii) effects on mucosa integrity in those models and also in in situ intra-jejunal instillations and (iii) interactions with intestinal mucus. SNAC increased the apparent permeability coefficient (Papp) of the paracellular marker, FITC-dextran 4000 (FD4), across isolated rat gastric mucosae in concentration-dependent fashion, whereas C10 did not, while both reduced the transepithelial electrical resistance (TEER). In isolated jejunal and colonic mucosae, both agents increased the Papp of [14C]-mannitol and FD4 whereas C10 but not SNAC reduced TEER. 20 mM SNAC was required to achieve the efficacy of 10 mM C10 in jejunal and colonic mucosae. In isolated non-everted jejunal and colonics sacs, FD4 flux increases were observed in the presence of both PEs. Histology of mucosae revealed that both PEs induced minor epithelial damage to the mucosa at concentrations that increased fluxes. Jejunal tissue withstood epithelial damage in the following order: intra jejunal in situ instillations > jejunal sacs > isolated jejunal mucosae. Both PEs modulated viscoelastic properties of porcine jejunal mucus without altering rheological properties. In conclusion, SNAC and C10 are reasonably efficacious PEs in rat intestinal tissue with common overall mechanistic features. Their potency and toxic potential are low, in agreement with clinical trial data.

Efficacy of Compound Herbal Medicine Tong-Xie-Yao-Fang for Acute Radiation Enteritis and Its Potential Mechanisms: Evidence from Transcriptome Analysis.

Acute radiation enteritis (ARE) is a common complication with radiotherapy for pelvic and abdominal malignancy. This research is designed to investigate the efficacy of Tong-Xie-Yao-Fang (TXYF) on ARE and to explore the underlying mechanisms by microarray analysis. The ARE rat model was established by a single abdominal irradiation with a gamma-ray dose of 10 Gy. Next, the ARE rats were treated with distilled water, TXYF, and glutamine by gavage for 7 consecutive days according to the scheduled groups. For each group, the jejunal tissue was taken at 6 h after gastric lavage. The morphology of intestinal tissue was observed by hematoxylin and eosin (H&E) stain under a light microscope. The height of the villus and the thickness of the whole layer of the TXYF-treated groups were significantly ameliorative than that of the model control group. The transcriptome analysis was produced using the Agilent SurePrint G3 Rat GE V2.0 microarray. A total of 90 differentially expressed genes (DEGs), including 48 upregulated genes and 42 downregulated genes, were identified by microarray and bioinformatics analysis. Protein–protein interaction (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) were conducted to explore the possible mechanisms of DEGs taking part in the TXYF-mediated therapeutic process for ARE. In conclusion, we reveal that TXYF has a protective effect on the intestinal tissue of rats with ARE and summarize several DEGs, suggesting the possible mechanisms of TXYF-mediated efficacy for ARE.

Curcumin improves necrotising microscopic colitis and cell pyroptosis by activating SIRT1/NRF2 and inhibiting the TLR4 signalling pathway in newborn rats

This study aimed to explore comprehensively the biological function of curcumin, and its underlying mechanism, in protecting from necrotising microscopic colitis in newborn rats. A total of 20 normal healthy rats were selected, and a necrotising enterocolitis (NEC) model was established. After hypoxia and hypothermia stimulation, these rats were treated with different doses of curcumin (control group, NEC model group, NEC+20 mg/kg curcumin and NEC+50 mg/kg curcumin). Inflammation was identified using hematoxylin and eosin staining, and inflammatory factors were detected via ELISA. The mRNA and protein levels of SIRT1, NRF2, TLR4, NLRP3 and caspase-1 were determined by quantitative RT-PCR and Western blotting, respectively. Curcumin improved the inflammatory condition of NEC and inhibited the expression of inflammatory factors in NEC newborn rat intestinal tissue. Furthermore, the SIRT1/NRF2 pathway was inhibited in the intestinal tissue of NEC newborn rats, whereas curcumin treatment induced the activation of the SIRT1/NRF2 pathway and inhibited TLR4 expression in these animals. In addition, curcumin could also inhibit the expression of inflammatory factors and alleviate the LPS/ATP-induced focal death pathway in intestinal epithelial cells through the SIRT1 pathway. Curcumin can improve necrotising microscopic colitis and cell pyroptosis by attenuating NEC-induced inhibition of SIRT1/NRF2 and inhibiting the TLR4 signalling pathway in newborn rats.

Protective Effects of an Oxovanadium(IV) Complex with N2O2 Chelating Thiosemicarbazone on Small Intestine Injury of STZ-Diabetic Rats.

Vanadium compounds are being investigated as potential therapeutic agents in the treatment of many health problems, primarily diabetes. We aimed to provide the effect of N(1)-4-hydroxysalicylidene-N(4)-salicylidene-S-methyl-isothiosemicarbazidato-oxovanadium(IV) (VOL) on small intestinal injury in experimental male diabetic rats. Four groups were created of 3.0-3.5-month-old rats. The rats were made diabetic by a single dose of streptozotocin (STZ) at 65 mg/kg and grouped as follows: control animals, VOL-given control animals, STZ-induced diabetic animals and STZ-induced diabetic animals given VOL. A daily dose of 0.2 mM/kg vanadium complex was administered orally for 12 days after the inducement of diabetes. On the 12th day, small intestine tissue samples were taken. According to the data obtained from the biochemical analysis, reduced glutathione (GSH) level, catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), superoxide dismutase (SOD), Na+/K+-ATPase and paraoxanase (PON) activities were increased, whereas sialic acid (SA), xanthine oxidase (XO) and disaccharidases (maltase and saccharidase) activities were decreased in the small intestine tissue of VOL-treated diabetic rats. Microscopic examinations revealed a remarkable decrease in the mucosal necrotic areas, discontinuity in the brush border, deterioration of the villi integrity and oedema inside the villi, but with a mild decrease in the inflammatory cells, deterioration and loss of integrity of the gland in the small intestine of VOL-treated diabetic rats. Moreover, VOL treatment markedly decreased the proliferation of villus cells and especially inflammatory cells in the small intestine of diabetic rats. According to the obtained data, the administration of VOL is a potentially convenient strategy to reducing small intestine injury in diabetic rats.