Obstructive jaundice promotes intestinal-barrier dysfunction and bacterial translocation: experimental study. Hepatol Int. 2007;1:444-448. [PMID: 19669340 DOI: 10.1007/s12072-007-9018-1]

The effect of carvacrol on reducing bacterial translocation, liver and intestinal damage in obstructive jaundice models of rats

BACKGROUND Obstructive jaundice is a common surgical issue caused by obstruction in the bile ducts, which can result from factors such as stones or cancers in the main bile duct. This study aimed to investigate the effects of carvacrol, a compound known for its strong antioxidant properties, on intestinal damage, liver damage, and bacterial translocation in an animal model of obstructive jaundice. METHODS The study utilized six groups of six Wistar Albino rats each. Obstructive jaundice was induced in the rats through a surgical procedure, resulting in the enlargement of the common bile duct. Carvacrol was administered at a dose of 100 mg/kg to evaluate its therapeutic effects. Blood samples were collected for biochemical analysis, and tissue samples were obtained from the ileum and liver for histopathological examination. Additionally, samples from the spleen and mesenteric lymph nodes were collected for microbiological analysis. RESULTS The findings revealed that carvacrol did not have a significant therapeutic effect on liver and bowel damage or on bacterial translocation in the rats with obstructive jaundice. Despite carvacrol's known antioxidant properties, it failed to show benefits in this experimental model. CONCLUSION Carvacrol, while recognized for its antioxidant effects, did not demonstrate therapeutic efficacy in treating obstructive jaundice in rats. The study suggests that further research with a larger sample size may be necessary to potentially uncover positive effects and better understand carvacrol's potential role in managing obstructive jaundice.

Standardized construction of a porcine model for acute obstructive jaundice and training of endoscopic ultrasound-guided choledochoduodenostomy

BACKGROUND

Endoscopic ultrasound-guided biliary drainage (EUS-BD) is an alternative to endoscopic retrograde cholangiopancreatography (ERCP) for patients with obstructive jaundice. However, it is still a challenge for many endoscopists because of its novelty and complexity. This study aimed to establish an ideal bile duct dilatation model for the training and practice of endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS).

METHODS

The 34 healthy Bama miniature pigs were divided into the part of developing the standardized EUS-CDS (n=9) and the part of trainees training (n=25). Part one, two different methods were used to clip Vater's ampulla using metal clips to establish an extrahepatic bile duct dilatation model. Part two, five trainees were trained on EUS-CDS with 25 pigs. Following a 2-week observation period, the feasibility and effectiveness of the technique were evaluated.

RESULTS

In the group with three metal clips perpendicular to the duodenal wall clipping Vater's ampulla, the success rate of extrahepatic bile duct dilation greater than 1 cm in 24 h was 5/6, whereas the remaining one pig was 48 h. All five trainees can finally complete the EUS-CDS independently. No death occurred during the 2-week observation period.

CONCLUSION

Clipping Vater's ampulla with three metal clips perpendicular to the duodenal wall is an effective and stable method to create a porcine bile duct dilatation model.

FXR Maintains the Intestinal Barrier and Stemness by Regulating CYP11A1-Mediated Corticosterone Synthesis in Biliary Obstruction Diseases

Biliary obstruction diseases are often complicated by an impaired intestinal barrier, which aggravates liver injury. Treatment of the intestinal barrier is often neglected. To investigate the mechanism by which intestinal bile acid deficiency mediates intestinal barrier dysfunction after biliary obstruction and identify a potential therapeutic modality, we mainly used a bile duct ligation (BDL) mouse model to simulate biliary obstruction and determine the important role of the bile acid receptor FXR in maintaining intestinal barrier function and stemness. Through RNA-seq analysis of BDL and sham mouse crypts and qRT-PCR performed on intestinal epithelial-specific Fxr knockout (FxrΔIEC) and wild-type mouse crypts, we found that FXR might maintain intestinal stemness by regulating CYP11A1 expression. Given the key role of CYP11A1 during glucocorticoid production, we also found that FXR activation could promote intestinal corticosterone (CORT) synthesis by ELISA. Intestinal organoid culture showed that an FXR agonist or corticosterone increased crypt formation and organoid growth. Further animal experiments showed that corticosterone gavage treatment could maintain intestinal barrier function and stemness, decrease LPS translocation, and attenuate liver injury in BDL mice. Our study hopefully provides a new theoretical basis for the prevention of intestinal complications and alleviation of liver injury after biliary obstruction.

pH-taxis drives aerobic bacteria in duodenum to migrate into the pancreas with tumors

As oral or intestinal bacteria have been found in pancreatic cystic fluid and tumors, understanding bacterial migration from the duodenum into the pancreas via hepato-pancreatic duct is critical. Mathematical models of migration of aerobic bacteria from the duodenum to the pancreas with tumors were developed. Additionally, the bacterial distributions under the pH gradient and those under flow were measured in double-layer flow based microfluidic device and T-shaped cylinders. Migration of aerobic bacteria from the duodenum into pancreas is counteracted by bile and pancreatic juice flow but facilitated by pH-taxis from acidic duodenum fluid toward more favorable slightly alkaline pH in pancreatic juice. Additionally, the reduced flow velocity in cancer patients, due to compressed pancreatic duct by solid tumor, facilitates migration. Moreover, measured distribution of GFP E. coli under the pH gradient in a microfluidic device validated pH-tactic behaviors. Furthermore, Pseudomonas fluorescens in hydrochloride solution, but not in bicarbonate solution, migrated upstream against bicarbonate flow of > 20 μm/s, with an advancement at approximately 50 μm/s.

Expression of TLR2 and TLR5 in distal ileum of mice with obstructive jaundice and their role in intestinal mucosal injury

INTRODUCTION

The aim was to investigate the expression of TLR2 and TLR5 in the distal ileum of mice with obstructive jaundice (OJ) and their role in intestinal mucosal injury.

MATERIAL AND METHODS

A total of 100 male C57BL/6J mice were randomly assigned to two groups: (I) sham operation (SH); (II) bile duct ligation (BDL). The mice were respectively sacrificed before operation and on the 1^st, 3^rd, 5^th and 7^th days after operation to collect specimens. Various indicators were detected by PCR, immunohistochemistry and other methods.

RESULTS

TLR2 was increased gradually with the extension of OJ time in the BDL group (p < 0.05). However, the changes in the expression of TLR5 were not obvious at different time points. The amount of Bifidobacteria and Lactobacillus showed downward trends in intestinal tract of the BDL group. Furthermore, the amount of Escherichia coli was increased in intestinal tract of the BDL group. The pathological score of intestinal mucosa and the expression of NF-κB increased gradually in the BDL group with the extension of OJ time. There were positive correlations between the pathological score of intestinal mucosa and expressions of TLR2(r = 0.767, p < 0.05) and NF-κB (r = 0.817, p < 0.05) in BDL group. NF-κB expression was positively correlated with TLR2 expression(r = 0.706, p < 0.05).

CONCLUSIONS

Disturbance of intestinal flora caused by OJ could increase the expression of NF-κB via up-regulating the expression of TLR2 to activate the downstream signaling pathway, thus aggravated the injury of intestinal mucosa.

Functional Changes of Paneth Cells in the Intestinal Epithelium of Mice with Obstructive Jaundice and After Internal and External Biliary Drainage

OBJECTIVE

To investigate the functional changes of Paneth cells in the intestinal epithelium of mice with obstructive jaundice (OJ) and after internal biliary drainage (ID) and external biliary drainage (ED).

METHODS

The experiment was divided into two stages. First stage: Mice were randomly assigned to two groups: (I) sham operation (SH); (II) OJ. The mice were sacrificed before the operation and on the 1st, 3rd, 5th and 7th day after the operation to collect specimens. Second stage: Mice were randomly assigned to four groups: (I) SH; (II) OJ; (III) OJ and ED; and (IV) OJ and ID. They were reoperated on day 5 for biliary drainage procedure. The specimens were collected on day 10.

RESULTS

The expressions of lysozyme and cryptdin-4 increased first and then decreased over time in group OJ, and the number of Paneth cells decreased gradually with the extension of OJ time（p<0.05. After the secondary operation on the mice to relieve OJ, the number of Paneth cells and expressions of lysozyme and cryptdin-4 in group ID increased more significantly than those in group ED（p<0.05）.

CONCLUSION

OJ could cause intestinal Paneth cells to dysfunction in mice. ID was more significant than ED in restoring the function of Paneth cells. It might be one of the mechanisms that make ID superior to ED.

Houttuynia cordata polysaccharide alleviated intestinal injury and modulated intestinal microbiota in H1N1 virus infected mice

Houttuynia cordata polysaccharide (HCP) is extracted from Houttuynia cordata, a key traditional Chinese medicine. The study was to investigate the effects of HCP on intestinal barrier and microbiota in H1N1 virus infected mice. Mice were infected with H1N1 virus and orally administrated HCP at a dosage of 40 mg(kg⁻¹(d⁻¹. H1N1 infection caused pulmonary and intestinal injury and gut microbiota imbalance. HCP significantly suppressed the expression of hypoxia inducible factor-1α and decreased mucosubstances in goblet cells, but restored the level of zonula occludens-1 in intestine. HCP also reversed the composition change of intestinal microbiota caused by H1N1 infection, with significantly reduced relative abundances of Vibrio and Bacillus, the pathogenic bacterial genera. Furthermore, HCP rebalanced the gut microbiota and restored the intestinal homeostasis to some degree. The inhibition of inflammation was associated with the reduced level of Toll-like receptors and interleukin-1β in intestine, as well as the increased production of interleukin-10. Oral administration of HCP alleviated lung injury and intestinal dysfunction caused by H1N1 infection. HCP may gain systemic treatment by local acting on intestine and microbiota. This study proved the high-value application of HCP.

Effects of Probiotic Use on Bacterial Translocation in Created Rat Models with Biliary Obstructions

Objective

The aim of this study was to investigate the protective effects of the combined use of probiotic strains on the development of bacterial translocation in addition to liver and intestinal tissue damage due to biliary obstruction in rats.

Materials and Methods

Here, 3 groups each consisting of 10 rats were created:group 1 (sham group), group 2 (obstructive jaundice), and group 3 (obstructive jaundice+probiotic). Groups 1 and 2 were given 1 cc physiological saline solution by oral gavage twice a day; group 3 was given a probiotic solution that included Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, Enterococcus faecium, and Bifidobacterium longum microorganisms by oral gavage twice a day.

Results

Markers for liver damage were also found to be significantly improved (p<0.05) in the treatment group (group 3). When compared with groups 2 and 3 in terms of liver histology, damage was found to be significantly more severe in group 2 (p<0.01). With regard to ileal villous depth and ileal inflammation, the pathology was found to be significantly more severe in group 2 than that in group 3 (p<0.05). In blood, spleen, and mesenteric lymph node cultures, group 2 showed a microbiological growth rate of 33.8-58.8%, whereas group 3 showed a microbiological growth rate of 14.3-28.6%. This reduction was evaluated to be statistically significant (p<0.05).

Conclusion

Our study showed that the combined use of a probiotic in bile duct obstructions reduced bacterial translocation and alleviated pathological changes arising in the liver and terminal ileum histology.

Combined Effectiveness of Honey and Immunonutrition on Bacterial Translocation Secondary to Obstructive Jaundice in Rats: Experimental Study

BACKGROUND Obstructive jaundice is a serious, life-threatening condition that can lead to death as a result of sepsis and multiorgan failure due to bacterial translocation. Treatment should be started as soon as possible after diagnosis. MATERIAL AND METHODS Forty 24-week-old male Sprague Dawley rats, with an average weight of 250 g to 300 g, were included in this study. The rats were randomly placed into five groups, each group consisted of eight rats. The sham group underwent only common bile duct (CBD) dissection and no ligation was performed. CBD ligation was applied to the other groups. After the operation, one CBD group was fed with rat chow only, the others were fed with rat chow supplemented with honey, or immunonutrients, or honey plus immunonutrients. After 10 to 12 days, all rats were sacrificed; blood and tissue samples were collected for biochemical, microbiological, and histopathological evaluation. RESULTS In the groups that were fed with honey and immunonutrients, alanine aminotransferase (ALT) levels were decreased significantly compared to the other groups. Statistically significant differences were detected in terms of bacterial translocation (BT) rates among liver and spleen samples, and laboratory values of serum, except for MLNs of the BDL+HI group, when compared to other groups. We found mean mucosal thickness of ileum samples have been improved notably in the BDL+HI group compared to the other groups, especially compared to the C/BDL group. CONCLUSIONS Immunonutrition applied with honey had immunostimulant effects, decreased BT due to an additive effect, and had positive effects on intestinal mucosa.

Immune dysfunction in patients with obstructive jaundice before and after endoscopic retrograde cholangiopancreatography

This prospective observational study investigated monocyte cytokine responses to lipopolysaccharide (LPS) in patients with obstructive jaundice (OJ) before and after endoscopic biliary drainage. Dendritic cell (DC) subsets and their expression of co-stimulatory molecules were also studied. Forty patients with OJ and ten non-jaundiced patients with normal gastroscopy findings were recruited. Ten healthy volunteers provided control blood samples for immunological assays. Patients with OJ had blood and duodenal mucosa sampled at the time of endoscopic retrograde cholangiopancreatography (ERCP) and further blood sampled during the recovery phase. Monocyte cytokine responses to LPS, DC subsets and co-stimulatory molecule expression were compared with controls. Duodenal morphology and occludin expression were also assessed. Monocytes obtained before ERCP from jaundiced patients demonstrated reduced cytokine responses to endotoxin compared with controls (IL-1β: 2678 compared with 4631 pg/ml, P=0.04 and IL-6: 3442 compared with 6157 pg/ml, P=0.002). Monocytes from patients with malignancy had poorer responses to endotoxin than from those with benign OJ (IL-1β: 2025 compared with 3332 pg/ml, P=0.001). After ERCP, the secretion of inflammatory cytokines by monocytes obtained from jaundiced patients increased (IL-1β: 2150 compared with 2520 pg/ml, P=0.03 and IL-6: 2488 compared with 3250 pg/ml, P=0.01). Occludin expression (85 compared with 95%, P=0.004) and mean duodenal villus height (334 compared with 404 μm, P=0.03) were lower in jaundiced patients. Before biliary drainage, patients with OJ had a higher percentage of myeloid dendritic cells (mDCs) and greater mDC expression of CD40 (P=0.04) and CD86 (P=0.04). Monocytes from patients with OJ had lower proinflammatory cytokine secretion in response to LPS, an effect reversed following biliary drainage.

Establishment and evaluation of a rat model of reversible obstructive jaundice

AIM: To establish a rat model of reversible obstructive jaundice and to evaluate its clinical practical value.

METHODS: Thirty-two Wistar rats were randomly divided into a reversible obstructive jaundice group (ROJ) and an obstructive jaundice group (OJ). In the ROJ group, bile duct obstruction was induced by ligation of the bile duct and a PICC catheter in parallel. After 5 d, the PICC catheter was pulled out to allow the recanalization of the bile duct. In the OJ group, complete obstructive jaundice was induced. Eight rats from each group were sacrificed on days 5 and 8, respectively, which were designated as ROJ5, ROJ8, OJ5 and OJ8, respectively. Serum total bilirubin (TBIL), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels were measured before operation and on days 5, 6 and 8 after operation. Intestinal mucosal tissue samples were taken and stained with hematoxylin and eosin to observe the changes in intestinal mucosal morphology and damage.

RESULTS: The changes in serum TBIL, ALT and ALP in the ROJ5 group were similar to those in the OJ5 group on day 5 after the model establishment, and there was no difference in liver function parameters between the two groups at each time point. Three days after the catheter was removed in the ROJ group, serum levels of TBIL, ALT and ALP quickly recovered, and the damage of the intestinal mucosa was significantly reduced. The intestinal mucosal injury index in the ROJ8 group was significantly lower than that in the OJ8 group.

CONCLUSION: The rat model of reversible obstructive jaundice developed by "ligation of the bile duct and removal of support catheter" is a stable and reliable animal model.

Inhibition of Toll-like receptor 4 suppresses liver injury induced by biliary obstruction and subsequent intraportal lipopolysaccharide injection

The objective of this study was to elucidate the role of Toll-like receptor 4 (TLR4) in liver injury induced by biliary obstruction and subsequent intraportal lipopolysaccharide (LPS) infusion in rats. Biliary obstruction often leads to the development of bacterial translocation. Rats were subjected to either a sham operation (Sham group) or bile duct ligation for 7 days (BDL group). Seven days after each operation, LPS (0.5 μg) was injected through the ileocecal vein. In other experiments, rats that had undergone BDL were pretreated, before LPS challenge, with internal biliary drainage (Drainage group); intravenous TAK-242, a TLR4 inhibitor (TAK group); or intravenous GdCl3, a Kupffer cell deactivator (GdCl3 group). The expression of the TLR4 protein and the number of Kupffer cells in the liver were significantly increased in the BDL group compared with the Sham group. These changes were normalized after biliary drainage. The expression of TLR4 colocalized with Kupffer cells, which was confirmed by double immunostaining. Serum levels of liver enzymes and proinflammatory cytokines after intraportal LPS injection were significantly higher in the BDL group than in the Sham group. However, pretreatment with TAK-242 or GdCl3 strongly attenuated these changes to levels similar to those seen with biliary drainage. These results imply that blocking TLR4 signaling effectively attenuates liver damage to the same level as that observed with biliary drainage in rats with BDL and subsequent intraportal LPS infusion. TAK-242 treatment may be used for patients who are susceptible to liver damage by biliary obstruction and endotoxemia.

Combined effects of tauroursodeoxycholic Acid and glutamine on bacterial translocation in obstructive jaundiced rats:

BACKGROUND

Bacterial Translocation is believed to be an important factor on mortality and morbidity in Obstructive Jaundiced.

AIMS

We investigated the probable or estimated positive effects of tauroursodeoxycholic acid, which has antibacterial and regulatory effects on intestinal flora, together with glutamine on BT in an experimental obstructive jaundiced rat model.

STUDY DESIGN

Animal experimentation.

METHODS

Forty adult, male, Sprague Dawley rats were used in this study. Animals were randomised and divided into five groups of eight each: sham (Sh); control (common bile duct ligation, CBDL); and supplementation groups administered tauroursodeoxycholic acid (CBDL+T), glutamine (CBDL+G), or tauroursodeoxycholic acid plus glutamine (CBDL+TG). Blood and liver, spleen, MLN, and ileal samples were taken via laparotomy under sterile conditions for investigation of bacterial translocation and intestinal mucosal integrity and hepatic function tests on the tenth postoperative day.

RESULTS

There were statistically significant differences in BT rates in all samples except the spleen of the CBDL+TG group compared with the CBDL group (p=0.041, p=0.026, and p=0.041, respectively).

CONCLUSION

It is essential to protect hepatic functions besides maintaining intestinal mucosal integrity in the active struggle against BT occurring in obstructive jaundice. The positive effect on intestinal mucosal integrity can be increased if glutamine is used with tauroursodeoxycholic acid, which also has hepatoprotective and immunomodulatory features.