Hepatoprotective activities of rosmarinic acid against extrahepatic cholestasis in rats

Though rosmarinic acid possesses nutritional, pharmaceutical, and toxic properties and shows therapeutic potential on liver diseases, its therapeutic effects against cholestatic liver diseases have not been proven. Using an extrahepatic cholestasis rat model by bile-duct ligation (BDL), daily oral administration of rosmarinic acid showed improvement effects on liver histology, serum biochemicals, ductular reaction, oxidative stress, inflammation, and fibrosis. Rosmarinic acid alleviated BDL-induced transforming growth factor beta-1 (TGF-β1) production and hepatic collagen deposition, and the anti-fibrotic effects were accompanied by reductions in matrix-producing cells and Smad2/3. BDL rats showed increased hepatic NF-κB/AP-1 activities, inflammatory cell infiltration/accumulation, and cytokine production, and these signs of hepatic inflammation were ameliorated by rosmarinic acid. Mechanistic study revealed an inhibitory effect of rosmarinic acid on the axis of the high mobility group box-1 (HMGB1)/toll-like receptor-4 (TLR4) in BDL rats. Results of cultured hepatic stellate cells further showed the impacts of rosmarinic acid which attenuated TGF-β1-induced stellate cell mitogenic and fibrogenic activation. Our findings support the concept that rosmarinic acid could serve as a hepatoprotective agent, and dietary rosmarinic acid supplementation may be beneficial in terms of improving cholestasis-related liver injury via mechanisms involving resolution of oxidative burden and down-regulation of HMGB1/TLR4, NF-κB, AP-1, and TGF-β1/Smad signaling.

Antioxidant Effect of Sepia Ink Extract on Extrahepatic Cholestasis Induced by Bile Duct Ligation in Rats

OBJECTIVE

The aim of our study was to assess the complications of hepatic fibrosis associated with bile duct ligation and the potential curative role of sepia ink extract in hepatic damage induced by bile duct ligation.

METHODS

Rattus norvegicus rats were divided into 3 groups: Sham-operated group, model rats that underwent common bile duct ligation (BDL), and BDL rats treated orally with sepia ink extract (200 mg/kg body weight) for 7, 14, and 28 d after BDL.

RESULTS

There was a significant reduction in hepatic enzymes, ALP, GGT, bilirubin levels, and oxidative stress in the BDL group after treatment with sepia ink extract. Collagen deposition reduced after sepia ink extract treatment as compared to BDL groups, suggesting that the liver was repaired. Histopathological examination of liver treated with sepia ink extract showed moderate degeneration in the hepatic architecture and mild degeneration in hepatocytes as compared to BDL groups.

CONCLUSION

Sepia ink extract provides a curative effect and an antioxidant capacity on BDL rats and could ameliorate the complications of liver cholestasis.

Protective effects of thymoquinone against cholestatic oxidative stress and hepatic damage after biliary obstruction in rats

The aim of this study was to examine the preventive and therapeutic effects of thymoquinone (TQ) against cholestatic oxidative stress and liver damage in common bile duct ligated rats. A total of 24 male Sprague-Dawley rats were divided into three groups: control, bile duct ligation (BDL) and BDL + received TQ; each group contain 8 animals. The rats in TQ treated groups were given TQ (50 mg/kg body weight) once a day orally for 2 weeks starting 3 days prior to BDL operation. To date, no more biochemical and histopathological changes on common bile duct ligated rats by TQ treatment have been reported. The application of BDL clearly increased the tissue hydroxyproline (HP) content, malondialdehyde (MDA) levels and decreased the antioxidant enzyme [superoxide dismutase (SOD), glutathione peroxidase (GPx)] activities. TQ treatment significantly decreased the elevated tissue HP content, and MDA levels and raised the reduced of SOD, and GPx enzymes in the tissues. The changes demonstrating the bile duct proliferation and fibrosis in expanded portal tracts include the extension of proliferated bile ducts into lobules, mononuclear cells, and neutrophil infiltration into the widened portal areas were observed in BDL group. Treatment of BDL with TQ attenuated alterations in liver histology. The immunopositivity of alpha smooth muscle actin and proliferating cell nuclear antigen in BDL were observed to be reduced with the TQ treatment. The present study demonstrates that oral administration of TQ in bile duct ligated rats maintained antioxidant defenses and reduces liver oxidative damage and ductular proliferation. This effect of TQ may be useful in the preservation of liver function in cholestasis.

Antinecrotic and antiapoptotic effects of hepatocyte growth factor on cholestatic hepatitis in a mouse model of bile-obstructive diseases

Cholestasis, an impairment of bile outflux, frequently occurs in liver diseases. In this process, an overaccumulation of bile acids causes hepatocyte necrosis and apoptosis, leading to advanced hepatitis. Hepatocyte growth factor (HGF) is mitogenic toward hepatocytes, but it is still unclear whether HGF has physiological and therapeutic functions during the progression of cholestasis. Using anti-HGF IgG or recombinant HGF in mice that had undergone bile duct ligation (BDL), we investigated the involvement of HGF in cholestasis-induced hepatitis. After the BDL surgery, HGF and c-Met mRNA levels transiently increased in livers during the progression of cholestatic hepatitis. When c-Met tyrosine phosphorylation was blocked in the livers of BDL-treated mice by anti-HGF IgG, hepatic dysfunction became evident, associated with the acceleration of hepatocyte necrosis and apoptosis. Inversely, administration of recombinant HGF into the mice led to the prevention of cholestasis-induced inflammation: HGF suppressed the hepatic expression of intracellular adhesion molecule-1 and neutrophil infiltration in BDL-treated mice. As a result, parenchymal necrosis was suppressed in the HGF-injected BDL mice. In addition, HGF supplement therapy reduced the number of apoptotic hepatocytes in cholestatic mice, associated with the early induction of Bcl-xL. The administration of HGF enhanced hepatic repair, via accelerating G1/S progression in hepatocytes. Our study showed that 1) upregulation of HGF production is required for protective mechanisms against cholestatic hepatitis and 2) enhancement of the intrinsic defense system by adding HGF may be a reasonable strategy to attenuate hepatic inflammation, necrosis, and apoptosis under bile-congestive conditions.

Cohort study of surgical bypass to the gallbladder or bile duct for the palliation of jaundice due to pancreatic cancer

OBJECTIVE

To compare patterns in mortality and the use of subsequent biliary drainage interventions (surgical, endoscopic, and percutaneous) associated with the different types of biliary bypass.

SUMMARY BACKGROUND DATA

Surgical palliation of obstructive jaundice due to pancreatic cancer is often accomplished with an intestinal bypass to either the gallbladder or the bile duct. It is not known whether a gallbladder bypass, which is a simpler operation and more amenable to laparoscopic surgery, performs as well as a bypass to the bile duct.

METHODS

The authors conducted a retrospective cohort study of 1,919 patients 65 years of age or older who had a surgical biliary bypass for pancreatic cancer diagnosed between 1991 and 1996 using Medicare claims data and the Surveillance, Epidemiology and End Results (SEER) database.

RESULTS

At 1, 2, and 5 years, 7.5%, 17.4%, and 26.0% of 945 patients initially treated with a gallbladder bypass had additional biliary interventions, as compared with 2.9%, 11.0%, and 13.3% of 974 patients initially treated with a bile duct bypass. Patients who initially had a gallbladder bypass were 4.4 times as likely to have additional biliary surgery and 2.9 times as likely to have any subsequent biliary intervention as were patients who initially had a bile duct bypass. Median survival was longer following bile duct bypass. The adjusted hazard ratio for death associated with gallbladder bypass was 1.2.

CONCLUSIONS

Compared to patients whose initial biliary bypass was to the bile duct, the risk of having one or more additional surgical, endoscopic, or percutaneous biliary drainage procedures is substantially greater in patients whose initial bypass was to the gallbladder.

Extrahepatic biliary obstruction: can silymarin protect liver function?

The hepatoprotective property of silymarin is well known. However, it is not known whether the antioxidant silymarin might have a beneficial effect in extrahepatic cholestasis in common bile duct ligated rats. Malonaldehyde property concentrations, the hydrogen-donating ability and reducing power were measured in liver homogenates by spectrophotometry, as well as free SH-group levels and glutathione-reductase activities in sera. The total scavenger capacity of the livers was quantified by a chemiluminometric method. The elevated lipid peroxidation and decreased antioxidant capacity of liver homogenates and sera could be observed in ligated rats. Silymarin pretreatment improved the antioxidant capacity of the liver, diminished the direct bilirubin concentration and caused an increase of liver enzyme activities compared with the groups without treatment. These effects of silymarin suggest that it may be a useful agent for improving the antioxidant defensive system in extrahepatic cholestasis, but its choleretic property should be considered.

Prevention of biliary stent occlusion using cyclical antibiotics and ursodeoxycholic acid

This study reports an open randomised controlled trial of cyclical antibiotics and ursodeoxycholic acid in prevention of plastic biliary stent occlusion. Seventy patients with malignant distal bile duct obstruction were randomised to either active treatment with cyclical antibiotics (ampicillin, metronidazole, ciprofloxacin) and ursodeoxycholic acid or no treatment after successful stent insertion. The two groups were well matched. The follow up was complete with stent occlusion or death being the end points. There was no difference in the incidence of stent occlusion between the two groups and the overall survival was similar. In conclusion, this study did not show any benefit of treatment with antibiotics and ursodeoxycholic acid in prolonging stent patency or improving survival.

Late complications in long-term survivors of biliary atresia

Ninety patients with biliary atresia surviving more than 5 years were analysed with respect to late complications occurring after the age of 4 years. Thirty-five had complications including cholangitis, portal hypertension, hypersplenism, gastrointestinal bleeding, and esophageal varices. These complications occurred at various times. The background factors of late complications were past history of cholangitis soon after the operation, advanced age at operation, re-operation, high portal pressure at initial operation, and a long interval before disappearance of jaundice after surgery. These factors are mostly related to the first operation and its postoperative course. Therefore, we stress that late complications can be prevented by intensive treatment of the patient at the time of the first operation.

A placebo-controlled study on the efficacy of aspirin and doxycycline in preventing clogging of biliary endoprostheses

Sixty patients in whom a biliary endoprosthesis was inserted were randomized to receive: (1) placebo, (2) aspirin, or (3) doxycycline, to study the effect on the process of sludge formation. After 2 months all endoprostheses were changed, and the amount and composition of the sludge in the patent stents was analyzed. Half of the patients dropped out. The major component (56%) of the sludge of all groups was protein. No insoluble residue was present. Major deposits of sludge were found at irregularities in the stent wall (side flaps). Both doxycycline and aspirin reduced the dry weight of the sludge. Doxycycline significantly reduced the amount of protein, but scanning electron microscopy still showed abundant bacterial growth. Aspirin reduced the content of all sludge components including protein, suggesting that it decreases "stickiness" of bile. Surprisingly, doxycycline significantly decreased the death rate in the 2 months of the study. We present further evidence for a primary role of protein deposition in the early stages of stent occlusion. This process can be partly inhibited by doxycycline and probably also by aspirin, which could lead to a significant increase in stent patency.