Ursodeoxycholic acid dose-dependently improves liver injury in rats fed a methionine- and choline-deficient diet

Ursodeoxycholic acid ameliorates erectile dysfunction and corporal fibrosis in diabetic rats by inhibiting the TGF-β1/Smad2 pathway

Corporal tissue fibrosis is critical in diabetes-associated erectile dysfunction. Transforming growth factor-β1/Small mothers against decapentaplegic-2 (TGF-β1/Smad2) contributes to the induction of fibrosis in corporal tissue. Smad7 is accepted as a general negative regulator of Smad signaling, although its role in corporal fibrosis is unknown. Ursodeoxycholic acid (UDCA) is a hydrophilic bile acid used for biliary and liver related disorders and has antifibrotic effects in the liver. This study investigated the effects of UDCA on diabetic erectile dysfunction. Forty-eight male Spraque Dawley rats were divided into six groups: nondiabetic (n = 6), nondiabetic+20 mg/kg UDCA (n = 6), nondiabetic+80 mg/kg UDCA (n = 6), diabetic (n = 10), diabetic+20 mg/kg UDCA (n = 10), diabetic+80 mg/kg UDCA (n = 10). Diabetes was induced by intraperitoneal injection of 60 mg/kg Streptozocin. UDCA (20 and 80 mg/kg/day) or saline was subsequently administered via oral gavage for 56 days. Erectile function was evaluated as measurement of maximum intracavernosal pressure (m-ICP)/mean arterial pressure (MAP) and total ICP/MAP. Corporal tissues were evaluated by Western blotting and Masson's trichrome staining. Electrical stimulation-induced m-ICP/MAP responses were higher in UDCA-treated diabetic rats compared to untreated diabetic rats, respectively (20 mg/kg; 4 V: 0.77 ± 0.11 vs 0.45 ± 0.09, p = 0.0001 and 80 mg/kg; 4 V: 0.78 ± 0.11 vs 0.45 ± 0.09, p = 0.0001) UDCA prevented the increase in phospho-Smad2 and fibronectin protein expressions in diabetic corporal tissue both at 20 mg/kg (p = 0.0002, p = 0.002 respectively) and 80 mg/kg doses (p < 0.0001 for both). Smad7 protein expressions were significantly increased in the UDCA-treated diabetic groups compared to the untreated diabetic group (20 mg/kg: p = 0.0079; 80 mg/kg: p = 0.004). Furthermore, UDCA significantly prevented diabetes-induced increase in collagen (20 mg/kg: p = 0.0172; 80 mg/kg: p = 0.0003) and smooth muscle loss (20 mg/kg: p = 0.044; 80 mg/kg: p = 0.039). In conclusion, UDCA has a potential protective effect on erectile function in diabetic rats by altering fibrotic pathways via inhibition of TGF-β1/Smad2 and activation of Smad7.

Integrated traditional Chinese and Western medicine in the prevention and treatment of non-alcoholic fatty liver disease: future directions and strategies

Traditional Chinese medicine (TCM) has been widely used for several centuries for metabolic diseases, including non-alcoholic fatty liver disease (NAFLD). At present, NAFLD has become the most prevalent form of chronic liver disease worldwide and can progress to non-alcoholic steatohepatitis (NASH), cirrhosis, and even hepatocellular carcinoma. However, there is still a lack of effective treatment strategies in Western medicine. The development of NAFLD is driven by multiple mechanisms, including genetic factors, insulin resistance, lipotoxicity, mitochondrial dysfunction, endoplasmic reticulum stress, inflammation, gut microbiota dysbiosis, and adipose tissue dysfunction. Currently, certain drugs, including insulin sensitizers, statins, vitamin E, ursodeoxycholic acid and betaine, are proven to be beneficial for the clinical treatment of NAFLD. Due to its complex pathogenesis, personalized medicine that integrates various mechanisms may provide better benefits to patients with NAFLD. The holistic view and syndrome differentiation of TCM have advantages in treating NAFLD, which are similar to the principles of personalized medicine. In TCM, NAFLD is primarily classified into five types based on clinical experience. It is located in the liver and is closely related to spleen and kidney functions. However, due to the multi-component characteristics of traditional Chinese medicine, its application in the treatment of NAFLD has been considerably limited. In this review, we summarize the advances in the pathogenesis and treatment of NAFLD, drawn from both the Western medicine and TCM perspectives. We highlight that Chinese and Western medicine have complementary advantages and should receive increased attention in the prevention and treatment of NAFLD.

Gut microbiome and microbial metabolites in NAFLD and after bariatric surgery: Correlation and causality

Non-alcoholic fatty liver disease (NAFLD) is currently related to a heavy socioeconomic burden and increased incidence. Since obesity is the most prevalent risk factor for NAFLD, weight loss is an effective therapeutic solution. Bariatric surgery (BS), which can achieve long-term weight loss, improves the overall health of patients with NAFLD. The two most common surgeries are the Roux-en-Y gastric bypass and sleeve gastrectomy. The gut-liver axis is the complex network of cross-talking between the gut, its microbiome, and the liver. The gut microbiome, involved in the homeostasis of the gut-liver axis, is believed to play a significant role in the pathogenesis of NAFLD and the metabolic improvement after BS. Alterations in the gut microbiome in NAFLD have been confirmed compared to that in healthy individuals. The mechanisms linking the gut microbiome to NAFLD have been proposed, including increased intestinal permeability, higher energy intake, and other pathophysiological alterations. Interestingly, several correlation studies suggested that the gut microbial signatures after BS become more similar to those of lean, healthy controls than that of patients with NAFLD. The resolution of NAFLD after BS is related to changes in the gut microbiome and its metabolites. However, confirming a causal link remains challenging. This review summarizes characteristics of the gut microbiome in patients with NAFLD before and after BS and accumulates existing evidence about the underlying mechanisms of the gut microbiome.

Ursodeoxycholic Acid Treatment Restores Gut Microbiota and Alleviates Liver Inflammation in Non-Alcoholic Steatohepatitic Mouse Model

Gut microbiota dysbiosis plays an important role in the progression of non-alcoholic fatty liver disease (NAFLD), and no approved drugs are available for NAFLD treatment. In this study, we aimed to explore the dynamic changes of gut microbiota at the different stages of NAFLD and determine whether ursodeoxycholic acid (UDCA) could improve liver histopathological features of non-alcoholic steatohepatitis (NASH) mice induced by a high-fat high-cholesterol (HFHC) diet and its impact on gut microbiota. 6-week-old male C57BL/6 mice were fed with a HFHC or normal diet for 12, 18, and 24 weeks, respectively, to simulate the different stages of NAFLD. 16s ribosomal RNA genes from mice fecal samples at the different time points were sequenced to evaluate the dynamic changes of the gut microbiota. Then, C57BL/6 mice were fed with a HFHC diet for 24 weeks to establish the NASH model. Different doses of UDCA were administered intragastrically for additional 4 weeks. Normal diet-fed mice were taken as control. Serum samples, liver, and intestine tissues were harvested for biochemical tests and histopathological examinations. 16s ribosomal RNA genes from mice fecal samples were sequenced to assess the structural changes of gut microbiota. HFHC diet-fed mice developed simple steatosis, steatohepatitis, and fibrosis at 12, 18, and 24 weeks, respectively. The profile of gut microbiota dynamically changed with the different stages of NAFLD. NASH mice had significantly higher abundance of Fecalibaculum, Coriobacteriaceae_UCG-002, and Enterorhabdus, and lower abundance of norank_f_Muribaculaceae, Bacteroides, and Alistipes, which were partially restored by UDCA treatment. UDCA treatment significantly attenuated hepatic inflammation of NASH mice as indicated by the sum of ballooning and lobular inflammation of the NALFD activity score (3.2 ± 0.8 vs 1.8 ± 0.8, p = 0.029), and partially restored gut microbiota dysbiosis, and increased the expression of Claudin-1 and ZO-1 in the intestine, but did not activate the suppressed Farnesoid X receptor signal pathway. Conclusions: The gut microbiota dynamically changes with the different stages of NAFLD. UDCA treatment (120 mg/kg) could partially restore gut microbiota, repair gut barrier integrity, and attenuate hepatic inflammation in the NASH mouse model.

Role of FXR in Bile Acid and Metabolic Homeostasis in NASH: Pathogenetic Concepts and Therapeutic Opportunities

Nonalcoholic fatty liver disease (NAFLD) has become the most prevalent cause of liver disease, increasingly contributing to the burden of liver transplantation. In search for effective treatments, novel strategies addressing metabolic dysregulation, inflammation, and fibrosis are continuously emerging. Disturbed bile acid (BA) homeostasis and microcholestasis via hepatocellular retention of potentially toxic BAs may be an underappreciated factor in the pathogenesis of NAFLD and nonalcoholic steatohepatitis (NASH) as its progressive variant. In addition to their detergent properties, BAs act as signaling molecules regulating cellular homeostasis through interaction with BA receptors such as the Farnesoid X receptor (FXR). Apart from being a key regulator of BA metabolism and enterohepatic circulation, FXR regulates metabolic homeostasis and has immune-modulatory effects, making it an attractive therapeutic target in NAFLD/NASH. In this review, the molecular basis and therapeutic potential of targeting FXR with a specific focus on restoring BA and metabolic homeostasis in NASH is summarized.

Efficacy and Safety of Biphenyl Dimethyl Dicarboxylate and Ursodeoxycholic Acid Combination in Chronic Hepatitis Related to Metabolic Syndrome Components

Backgrounds/Aims

Steatohepatitis related to metabolic syndrome is a chronic liver disease prevalent in patients not only with non-alcoholic steatohepatitis but also with alcoholic liver disease and chronic viral hepatitis. On the other hand, there is limited data on the effects of hepatotonic agents in these patients. Therefore, this study evaluated the efficacy of a combined hepatotonic agent in this population.

Methods

Thirty-three adults with chronic hepatitis and one or more components of metabolic syndrome were assigned randomly to receive biphenyl dimethyl dicarboxylate/ursodeoxycholic acid or a placebo for 24 weeks. The primary outcome was the normalization of ALT (≤40 U/L). The secondary outcomes were the change in controlled attenuation parameter, transient elastography, and Chronic Liver Disease Questionnaire score.

Results

The 33 patients were assigned randomly to two groups. Eight (50%) of 16 patients who received the intervention drug showed the normalization of ALT, whereas only one (6%) of 17 patients in the placebo group did so. In contrast, the change in controlled attenuation, transient elastography, and Chronic Liver Disease Questionnaire were similar in the two groups. ALT was changed significantly during the four assessment periods, and this change was affected by the group. The interaction between the group and time was also significant. AST was changed significantly during the same period. This change was not affected by the group.

Conclusions

Biphenyl dimethyl dicarboxylate/ursodeoxycholic acid combination reduced ALT in chronic liver disease related to metabolic syndrome. On the other hand, there is no evidence that this leads to improved hepatic steatosis and fibrosis within 6 months.

Efficacy and safety of drugs for nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is an inflammatory type of nonalcoholic fatty liver disease and is associated with the development and progression of cirrhosis. Lifestyle intervention is still the predominant treatment for NASH. So far, no drugs have been approved to treat NASH by the U.S. Food and Drug Administration (FDA). Vitamin E has been recommended for patients with NASH without type 2 diabetes mellitus (T2DM), whereas a combination of pioglitazone and vitamin E is recommended for patients with both NASH and T2DM. Encouragingly, drugs are currently being developed for different NASH mechanisms. Some of the drugs are at phase III clinical trials, including obeticholic acid (OCA), Elafibranor, Cenicriviroc, Selonsertib, Resmetirom, Emricasan and Aramchol. Due to its positive interim effect in attenuating the degree of hepatic fibrosis OCA was filing in FDA. However, it has been rejected by the U.S FDA and has been advised to conduct long-term studies. Therefore, in this article, we reviewed the efficacy and safety of drugs currently under clinical trials for NASH.

The effects of ursodeoxycholic acid on sepsis-induced cholestasis management in an animal model

Objectives

Cholestasis refers to a reduction in bile flow from the liver into the biliary system. Ursodeoxycholic acid (UDCA) is commonly used for the treatment of hepatic cholestasis. This study aimed to explore the role of UDCA in the treatment and prevention of lipopolysaccharide (LPS)-induced cholestasis.

Methods

Sixty male albino rats were randomly classified into five groups of 12 rats each: the control group (received saline and water), UDCA group (received UDCA), LPS group (received LPS), treatment group (received LPS followed by UDCA), and prevention group (received UDCA followed by LPS). Changes in gamma-glutamyl transferase (GGT), plasma aspartate transferase (AST), plasma alkaline transferase (ALT), plasma alkaline phosphatase (ALP), total bilirubin (TBIL), hepatocyte apoptosis, immunomodulatory activity, plasma pro-inflammatory cytokines (TNF-α, IL-1α, and IL-4), and liver histology were assessed.

Results

UDCA improved serum liver chemical markers (GGT, ALP, and AST) in both the prevention and treatment groups (p < 0.05 and p < 0.05, respectively). CD3 count was higher in the UDCA treatment group compared to the LPS group (p < 0.001). UDCA caused a reduction in plasma TNF-α in the prevention group (P < 0.05); however, it had no effect on the treatment group, as compared to the LPS group. Similarly, UDCA had no effect on IL-1α or IL-4. UDCA treatment resulted in improved liver histological features and a significant reduction in liver tissue apoptosis in both the treatment and prevention groups, as compared to the LPS group (p = 0.013 and p = 0.002, respectively).

Conclusions

This study provides evidence of the effectiveness of UDCA for the treatment and prevention of sepsis-induced cholestasis.

Ursodeoxycholic acid alleviates experimental liver fibrosis involving inhibition of autophagy

AIMS

Ursodeoxycholic acid (UDCA) has been widely used in the treatment of primary biliary cholangitis (PBC) with chronic liver fibrosis, but its detailed mechanism remains unclear. This study was aimed to determine whether autophagic signaling is involved in the therapeutic effect of UDCA on liver fibrosis.

METHODS

By using hepatic stellate cell (HSC) line LX2 and CCl₄-induced fibrotic rat model, autophagy signaling was investigated by western blotting and mRFP-EGFP-LC3 tandem fluorescent tagged plasmid (ptfLC3) transfection technique. Anti-fibrotic profile was determined by western blotting, qRT-PCR, MTT assay, trypan blue, hydroxyproline assay and Masson staining.

KEY FINDINGS

TGFβ1 treatment decreased P62 accumulation and increased both autophagosomes and autolysosomes in LX2 cells, thereby elevated autophagic flux. Hydroxychloroquine (HCQ), antagonist of autophagy, was found to dramatically inhibit COL1A2 mRNA expression and cell proliferation in a dose-dependent manner. This coincides with the effect of UDCA intervention on collagen aggradation and cell viability. Meanwhile, UDCA inhibited TGFβ1-induced autophagy flux. And rapamycin, agonist of autophagy, was found to impair the anti-fibrotic effect of UDCA. Moreover, study in vivo showed that UDCA alone or in combination with HCQ restored the CCl₄-induced liver fibrosis in rodent models with autophagy inhibited profile.

SIGNIFICANCE

Taken together, our study revealed that UDCA displays anti-fibrotic role by protecting HSC against production of collagen and inhibiting cellular viability involving autophagy inhibition and provide a new insight into the pharmacological basis of UDCA treatment for hepatic fibrosis.

Ursodeoxycholate Restores Biliary Excretion of Methotrexate in Rats with Ethinyl Estradiol Induced-Cholestasis by Restoring Canalicular Mrp2 Expression

The in vivo relevance of ursodeoxycholate (UDCA) treatment (100 mg/kg/day, per oral tid for 5 days before cholestasis induction followed by the same dosing for 5 days) on hepatic function was investigated in rats with 17α-ethinylestradiol (EE, 10 mg/kg, subcutaneous for 5 days)-induced experimental cholestasis. The bile flow rate and the expression level of hepatic multidrug resistance-associated protein 2 (Mrp 2) that were decreased in cholestasis were restored after UDCA treatment. Consistent with this, the biliary excretion clearance (CL_exc,bile) of a representative Mrp2 substrate—methotrexate (MTX)—was decreased in cholestatic rats but was restored after UDCA treatment. Consequently, the plasma concentrations of MTX, which were increased by cholestasis, were decreased to control levels by UDCA treatment. Thus, the restoration of CL_exc,bile appears to be associated with the increase in Mrp2 expression on the canalicular membrane by UDCA treatment followed by Mrp2-mediated biliary excretion of MTX. On the other hand, the hepatic uptake clearance (CL_up,liver) of MTX was unchanged by cholestasis or UDCA treatment, suggestive of the absence of any association between the uptake process and the overall biliary excretion of MTX. Since UDCA has been known to induce the expression of canalicular MRP2 in humans, UDCA treatment might be effective in humans to maintain or accelerate the hepatobiliary elimination of xenobiotics or metabolic conjugates that are MRP2 substrates.

Changes in Bile Acid Profile After Laparoscopic Sleeve Gastrectomy are Associated with Improvements in Metabolic Profile and Fatty Liver Disease

BACKGROUND

Bile acids (BA) modulate lipid and glucose metabolism in a feedback loop through production of fibroblast growth factor (FGF) 19 in the terminal ileum. Changes in BA after bariatric surgery may lead to improvements in the metabolic syndrome, including fatty liver disease. This study investigated the relationship between BA and metabolic and inflammatory profiles after laparoscopic sleeve gastrectomy (LSG).

METHODS

Patients undergoing LSG had fasting blood samples taken pre-operatively and 6 months post-surgery. Liver injury was measured using cytokeratin (CK) 18 fragments. BA were measured using liquid chromatography tandem-mass spectrometry. FGF-19 was measured using enzyme-linked immunosorbent assay.

RESULTS

The study included 18 patients (12 females), with mean age 46.3 years (SEM ± 2.9) and BMI 60.1 kg/m(2) (±2.6). After 6 months, patients lost 39.8 kg (±3.1; p < 0.001). Fourteen patients (78 %) had steatosis. FGF-19 increased from median 128.1 (IQR 89.4-210.1) to 177.1 (121.8-288.9, p = 0.045) at 6 months. Although total BA did not change, primary glycine- and taurine-conjugated BA, cholic acid decreased, and secondary BA, glycine-conjugated urodeoxycholic acid increased over the study period. These changes are associated with reduction in insulin resistance, pro-inflammatory cytokines and CK-18 levels.

CONCLUSIONS

The profile of individual BA is altered after LSG. These changes occur in the presence of reductions in inflammatory cytokines and markers of liver injury. This study supports evidence from recent animal models that LSG may have an effect on fatty liver through changes in BA metabolism.

Ursodeoxycholic Acid Suppresses Lipogenesis in Mouse Liver: Possible Role of the Decrease in β-Muricholic Acid, a Farnesoid X Receptor Antagonist

The farnesoid X receptor (FXR) is a major nuclear receptor of bile acids; its activation suppresses sterol regulatory element-binding protein 1c (SREBP1c)-mediated lipogenesis and decreases the lipid contents in the liver. There are many reports showing that the administration of ursodeoxycholic acid (UDCA) suppresses lipogenesis and reduces the lipid contents in the liver of experimental animals. Since UDCA is not recognized as an FXR agonist, these effects of UDCA cannot be readily explained by its direct activation of FXR. We observed that the dietary administration of UDCA in mice decreased the expression levels of SREBP1c and its target lipogenic genes. Alpha- and β-muricholic acids (MCA) and cholic acid (CA) were the major bile acids in the mouse liver but their contents decreased upon UDCA administration. The hepatic contents of chenodeoxycholic acid and deoxycholic acid (DCA) were relatively low but were not changed by UDCA. UDCA did not show FXR agonistic or antagonistic potency in in vitro FXR transactivation assay. Taking these together, we deduced that the above-mentioned change in hepatic bile acid composition induced upon UDCA administration might cause the relative increase in the FXR activity in the liver, mainly by the reduction in the content of β-MCA, a farnesoid X receptor antagonist, which suggests a mechanism by which UDCA suppresses lipogenesis and decreases the lipid contents in the mouse liver.

Beneficial effects of combined ursodeoxycholic acid and angiotensin-II type 1 receptor blocker on hepatic fibrogenesis in a rat model of nonalcoholic steatohepatitis

BACKGROUND AND AIMS

Ursodeoxycholic acid (UDCA) is considered to be effective in the treatment of nonalcoholic steatohepatitis (NASH), particularly in combination with other pharmacological agents. UDCA reportedly counteracts the effects of endotoxemia. Previously, we demonstrated attenuated hepatic fibrogenesis and suppression of activated hepatic stellate cells (Ac-HSC) with an angiotensin-II (AT-II) type 1 receptor blocker (ARB). Here we evaluated the simultaneous effect of both agents on hepatic fibrogenesis in a rat model of NASH.

METHODS

Fischer 344 rats were fed a choline-deficient L-amino-acid-defined (CDAA) diet for 8 weeks. The therapeutic effect of UDCA and ARB was evaluated along with hepatic fibrogenesis, lipopolysaccharide (LPS)-Toll-like receptor 4 (TLR4) regulatory cascade, and intestinal barrier function. The direct inhibitory effect of both UDCA and ARB on Ac-HSC was assessed in vitro.

RESULTS

Both UDCA and ARB had a potent inhibitory effect on hepatic fibrogenesis with suppression of the HSC activation and hepatic expression of transforming growth factor (TGF)-β1 and TLR4. UDCA decreased intestinal permeability by ameliorating zonula occuludens-1 (ZO-1) disruption induced by the CDAA diet. ARB was found to directly suppress regulation of Ac-HSC.

CONCLUSIONS

UDCA and ARB have a synergistic repressive effect on hepatic fibrogenesis by counteracting endotoxemia induced by intestinal barrier dysfunction and suppressing the activation of Ac-HSC. Because both agents are currently used in clinical practice, combined UDCA and ARB may represent a promising novel therapeutic approach for NASH.

An open-label randomized control study to compare the efficacy of vitamin e versus ursodeoxycholic acid in nondiabetic and noncirrhotic Indian NAFLD patients

BACKGROUND/AIM

The study was carried out to compare the efficacy of Vitamin E versus Ursodeoxycholic acid (UDCA) in nondiabetic nonalcoholic fatty liver disease (NAFLD) patients.

PATIENTS AND METHODS

We randomized 250 non cirrhotic and non diabetic NAFLD patients diagnosed on ultrasound, with raised alanine aminotransferase (ALT) level. (>40 IU/L), to receive Vitamin E 400 mg twice a day (Group A) or UDCA 300 mg twice a day (Group B) for 52 weeks. Lifestyle modification to achieve at least 5% weight reduction and subsequent weight control and regular exercise was advised to both groups. The primary study endpoint was normalization of ALT. Secondary endpoints were the proportion of patients with reduction in ALT, relative reduction in the NAFLD Fibrosis score (NFS), symptomatic improvement and tolerability.

RESULTS

One hundred and fifty patients received UDCA as compared to 100 patients receiving Vitamin E. The treatment groups were comparable at entry with regard to age (44.1 vs 42.4 years), gender (67% vs 63% female), risk factors for nonalcoholic steatohepatitis, hypochondriac pain, serum liver biochemistries, and NAFLD Fibrosis score. The primary endpoint was achieved in 21 (14%) and 19 (19%) of patients in Group A and Group B, respectively (P = 0.2). The proportion of patients with reduction in ALT (56% vs 63%, P = 0.2), symptomatic improvement (78% vs 67%, P= 0.058), reduction in the NFS (44% vs 47%, P= 0.69), and tolerability (98% vs 95%, P= 0.2) were similar between Group A and Group B, respectively.

CONCLUSION

UDCA is an effective and safe alternative to Vitamin E in nondiabetic-noncirrhotic Indian NAFLD patients.

Piperine prevents cholesterol gallstones formation in mice

Biliary cholesterol may contribute to the formation of cholesterol gallstones, and regulation of these levels could be a useful therapeutic strategy for gallstones disease. Piperine (PA) is a potential cholesterol lowering agent. In this study, we assessed the effect and mechanism of PA in preventing cholesterol gallstones formation induced by feeding lithogenic diet containing high cholesterol levels to mice. C57BL/6 inbred mice were fed lithogenic or chow diets for 10 weeks, with or without PA (15, 30 and 60 mg/kg) or ursodeoxycholic acid (UDCA, 60 mg/kg) administration. Cholesterol, phospholipids and crystals in bile, the lipid in serum, pathological changes and proteins expression in liver were analyzed. The results showed that PA could decrease the cholesterol potency and crystals in bile, reduce total cholesterol (TC), triglycerides (TG) and increase high-density lipoprotein/low-density lipoprotein (HDL/LDL) levels in serum. Furthermore, PA treatment reduced liver lipid peroxidation and protected hepatobiliary cells from liver injury by decreasing malondialdehyde (MDA) and increasing superoxide dismutase (SOD). In addition, PA inhibited the expression of ATP-binding cassette transporters G5/8 (ABCG5/8) and liver X receptor (LXR) in liver, and reduced cholesterol transport from the hepatocytes to the gallbladder. It may be the mechanism of PA in preventing cholesterol gallstones formation. PA as a potential drug for prevention cholesterol gallstones merits further investigation.

Protective Effects of Norursodeoxycholic Acid Versus Ursodeoxycholic Acid on Thioacetamide-induced Rat Liver Fibrosis

BACKGROUND/OBJECTIVES

Effects of norursodeoxycholic acid (norUDCA) and ursodeoxycholic acid (UDCA) on liver fibrosis progression and liver fibrosis reversal in thioacetamide (TAA)-treated rats were studied.

METHODS

Advanced liver fibrosis was induced by TAA treatment (200 mg/kg, i.p.) for 12 weeks. In the second experiment resolution of liver fibrosis was assessed after 8 weeks of TAA withdrawal. During 8 last weeks of each trial, fibrotic rats were daily administered with UDCA (80 mg/kg) and norUDCA (equimolar to 80 mg/kg of UDCA) by oral gavage. Liver fibrosis was assessed by Sirius red staining, liver hydroxyproline and serum fibrosis markers determination.

RESULTS

The TAA treatment resulted in advanced fibrosis and increase in liver hydroxyproline content and serum fibrosis markers. These signs of fibrosis were less pronounced in rats after TAA withdrawal. Treatment with of norUDCA significantly decreased the total and relative liver hydroxyproline contents in rats with fibrosis reversal, whereas UDCA did not change these parameters. Both compounds decreased serum TGFβ and type IV collagen contents, whereas other serum markers did not differ from the placebo group. In the fibrosis progression model the square of connective tissue was decreased by norUDCA. Serum type IV collagen and procollagen III-NT contents in these experiments were lowered by both UDCA and norUDCA, whereas rest of serum fibrosis markers were diminished only by norUDCA.

CONCLUSIONS

Both norUDCA and UDCA showed therapeutic and prophylactic antifibrotic effect in rats with TAA-induced liver fibrosis. For most of tested parameters norUDCA was more effective than UDCA, especially in the experiment with liver fibrosis regression.

Ursodeoxycholic acid alleviates cholestasis-induced histophysiological alterations in the male reproductive system of bile duct-ligated rats

Ursodeoxycholic acid is the most widely used drug for treating cholestatic liver diseases. However, its effect on the male reproductive system alterations associated with cholestasis has never been studied. Thus, this study aimed to investigate the effect of ursodeoxycholic acid on cholestasis-induced alterations in the male reproductive system. Cholestasis was induced by bile duct ligation. Bile duct-ligated rats had higher cholestasis biomarkers and lower levels of testosterone, LH and FSH than did the Sham rats. They also had lower reproductive organs weights, and lower sperm motility, density and normal morphology than those of Sham rats. Histologically, these animals suffered from testicular tubular atrophy, interstitial edema, thickening of basement membranes, vacuolation, and depletion of germ cells. After ursodeoxycholic acid administration, cholestasis-induced structural and functional alterations were significantly ameliorated. In conclusion, ursodeoxycholic acid can ameliorate the reproductive complications of chronic cholestasis in male patients, which represents an additional benefit to this drug.

The role of ursodeoxycholic acid in non-alcoholic steatohepatitis: a systematic review

Background

Non-alcoholic steatohepatitis (NASH) is a condition that occurs during the progression of non-alcoholic fatty liver disease. Effective therapy for NASH is still lacking. In this study, we investigated the effects of Ursodeoxycholic acid (UDCA) in the treatment of NASH.

Methods

Western and Chinese databases were searched by independent investigators using appropriate MESH headings to identify randomized, controlled Western and Chinese clinical trials, published between January 1990 and October 2012, testing the effects of UDCA in patients with NASH. Patient characteristics and trial endpoints were analyzed, with quality assessment according to widely acknowledged criteria. P < 0.05 was defined as statistically significant in all trials.

Results

Twelve qualified randomized clinical trials, including six from China and involving 1160 subjects, were selected. Seven of these trials assessed the effects of UDCA Monotherapy, with the other five testing combinations of UDCA with vitamin E, polyene phosphatidylcholine, silymarin, glycyrrhizin and tiopronin. The duration of therapy ranged from 3 to 24 months, with two studies using high doses of UDCA (23–35 mg/kg/d). The average quality point was 2.69, and was significantly lower in articles from China than in those from Western countries (2.2 ± 0.4 vs. 3.8 ± 1.1, respectively, p < 0.05). UDCA Monotherapy significantly improved liver function in five studies and improved steatosis and fibrosis in two studies. All five studies assessing UDCA combination therapy showed significant improvements liver function, while two studies also improved steatosis and inflammation. One study of high-dose UDCA showed significant improvements in ALT, γGT and liver fibrosis, whereas the other study showed no significant change in ALT and liver pathology.

Conclusions

UDCA therapy is effective in NASH, especially when combined with other drugs. However, the low quality of these studies and the heterogeneity of their results precluded further meta-analysis. Additional carefully designed clinical trials are needed, especially in China.

miR-34a/SIRT1/p53 is suppressed by ursodeoxycholic acid in the rat liver and activated by disease severity in human non-alcoholic fatty liver disease

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) comprises a spectrum of stages from simple steatosis to non-alcoholic steatohepatitis (NASH). However, disease pathogenesis remains largely unknown. microRNA (miRNA or miR) expression has recently been reported to be altered in human NASH, and modulated by ursodeoxycholic acid (UDCA) in the rat liver. Here, we aimed at evaluating the miR-34a/Sirtuin 1(SIRT1)/p53 pro-apoptotic pathway in human NAFLD, and to elucidate its function and modulation by UDCA in the rat liver and primary rat hepatocytes.

METHODS

Liver biopsies were obtained from NAFLD morbid obese patients undergoing bariatric surgery. Rat livers were collected from animals fed a 0.4% UDCA diets. Primary rat hepatocytes were incubated with bile acids or free fatty acids (FFAs) and transfected with a specific miRNA-34a precursor and/or with a p53 overexpression plasmid. p53 transcriptional activity was assessed by ELISA and target reporter constructs.

RESULTS

miR-34a, apoptosis and acetylated p53 increased with disease severity, while SIRT1 diminished in the NAFLD liver. UDCA inhibited the miR-34a/SIRT1/p53 pathway in the rat liver in vivo and in primary rat hepatocytes. miR-34a overexpression confirmed its targeting by UDCA, which prevented miR-34a-dependent repression of SIRT1, p53 acetylation, and apoptosis. Augmented apoptosis by FFAs in miR-34a overexpressing cells was also inhibited by UDCA. Finally, p53 overexpression activated miR-34a/SIRT1/p53, which in turn was inhibited by UDCA, via decreased p53 transcriptional activity.

CONCLUSIONS

Our results support a link between liver cell apoptosis and miR-34a/SIRT1/p53 signaling, specifically modulated by UDCA, and NAFLD severity. Potential endogenous modulators of NAFLD pathogenesis may ultimately provide new tools for therapeutic intervention.

Treatment of NASH with ursodeoxycholic acid: pro

Ursodeoxycholic acid (UDCA) is one of hepatologists'oldest friends, always ready to help, throughout the years, in numerous and various liver and biliary tract diseases. On paper, it has had an impeccable track record of cytoprotection in vitro and in vivo due to its pleiotropic effects on many pathways leading to cell injury. Most of its hepatoprotective effects demonstrated under experimental conditions proved able to counteract pathogenic mechanisms involved in the transition from steatosis to steatohepatitis, and early clinical studies suggested a potentially beneficial effect in non-alcoholic steatohepatitis (NASH) as well. Yet, only scant data on the efficacy of UDCA specifically in experimental models of steatosis/NASH are available, and the few available randomized controlled clinical studies have substantial methodological issues and are discussed in this review. Thus, at this point, there is not enough evidence to either confirm or reject the efficacy of UDCA in NASH, although many NASH patients clearly experience biochemical improvements with prolonged UDCA treatment. Also, a few new UDCA derivatives have shown promising activity in preclinical models and may be worth testing in clinical trials.