Divergent effects of irritants on the gastric mucosa in rats during various stages after bile duct ligation

Portal Hypertensive Polyps as Gastroscopic Finding in Liver Cirrhosis

Background

Portal hypertensive polyps in patients with portal hypertension are described.

Aims

The most significant and serious complication in liver cirrhosis proves to be portal hypertension. Polypoid lesions, which can be seen in the stomach as endoscopic finding in patients with portal hypertension, have not quite been defined in the literature. The aim of this study, therefore, was to define polypoid lesion formation due to portal hypertension in the upper gastrointestinal system in patients with portal hypertension. Study Design. Cross-sectional study.

Methods

The study covered a group of patients with liver cirrhosis and a healthy control group that did not have portal hypertension. All individuals covered by the study received upper GI endoscopy, while the endoscopic features and pathological characteristics of the identified polypoid lesions were defined. Standard histological criteria were used in polyp diagnosis.

Results

A total of 400 individuals were included in the study. Upper GI endoscopy was performed for 200 patients with liver cirrhosis and another 200 healthy individuals with no portal hypertension in the control group. When the cases were gastroscopically assessed with regard to polypoid lesion presence, it was seen that a total of 87 (21.8%) individuals had polyps. While 67 (33.5%) cirrhotic patients were identified to have polyps, 20 (10%) individuals in the healthy control group had polyps. When the results of those with liver cirrhosis who received esophageal variceal endoscopic band ligation (EVL) and who did not were compared, it was observed that a higher number of individuals in the group with EVL had polypoid lesions. When the patient and control groups were compared as to Helicobacter pylori presence, the results showed that it was slightly higher in the dyspepsia group but the difference was not statistically significant (p > 0.05).

Conclusion

Portal hypertension-associated polypoid lesions are common in advanced liver cirrhosis cases. The pathological analyses of these polyps pointed out that they were all benign and no malignant cases were detected. It was argued that these polypoid lesions, referred to as portal hypertensive polyps, were associated with elevated angiogenesis in the gastric mucosa.

Suppression of oxidative stress and improvement of liver functions in mice by ursolic acid via LKB1-AMP-activated protein kinase signaling

BACKGROUND AND AIM

Hepatic cirrhosis is the final stage of liver dysfunction, characterized by diffuse fibrosis, which is the main response to the liver injury. This study is to investigate the effects of ursolic acid (UA) on liver functions and fibrosis in bile duct ligation (BDL) mice and to determine the underlying mechanisms.

METHODS

Cultured hepatocytes were treated with lipopolysaccharide (LPS) in the presence or absence of UA. The reactive oxygen species (ROS) level, protein levels of IκBα, iNOS and Cox-2, and NF-κB activation were detected, respectively. C57/BL6 and AMP-activated protein kinase (AMPK)α2(-/-) mice were subjected to BDL for 14 days. UA was administered by gavage. The markers of liver function and oxidative stress, and liver histopathology were analyzed after treatment.

RESULTS

Treatment of hepatocytes with UA dose-dependently activates AMPK, which is abolished by silence of liver kinase B1 (LKB1). LPS significantly increased ROS productions, apoptosis, NF-κB activation, and expressions of iNOS and Cox-2 in cultured hepatocytes. All these effects were blocked by co-incubation with UA. Importantly, silence of LKB1, AMPK, or iNOS/Cox-2 by small interference RNA transfection reversed UA-induced effects in cultured cells. In an animal study, 14-day BDL induced liver fibrosis and liver injury, accompanied with increased oxidative stress and protein expressions of iNOS and Cox-2 in liver. Treatment of UA significantly attenuated the BDL-induced detrimental effects in wild-type mice but not in AMPKα2(-/-) mice.

CONCLUSION

UA via LKB1-AMPK signaling offers protective effects on BDL-induced liver injury in mice, which may be related to inhibition of oxidative stress.