Effect of ursodeoxycholic acid on hepatic steatosis in rats

Evaluating the effect of ursodeoxycholic acid (UDCA) in comparison with dexamethasone and diclofenac in a rat model of rheumatoid arthritis

Ursodeoxycholic acid (UDCA) is known for its major effects on the liver, but its impact on autoimmune diseases is not well understood. This study aimed to assess the effectiveness of UDCA in controlling rheumatoid arthritis (RA) in an in vivo setting. Experimental RA was induced in rats using Freund's complete adjuvant, and the effects of UDCA (50,100 mg/kg) were compared to those of dexamethasone and diclofenac by measuring changes in paw size, IL-17, pro-inflammatory cytokines, oxidative stress (GSH, MDA), and radiological changes. The administration of UDCA resulted in decreased cartilage damage, reduced paw edema, and a decrease in the release of pro-inflammatory cytokines and oxidative stress. Additionally, X-ray joint alterations were observed in the UDCA-treated group compared to the dexamethasone and diclofenac groups. These results suggest that UDCA has anti-rheumatoid arthritis properties due to its ability to minimize oxidative stress and inflammation in arthritis-affected rats.

Effects of bile duct ligation and cholic acid treatment on fatty liver in two rat models of non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease, one of the most prevalent liver disorders in Western countries, is characterized by hepatic accumulation of triglycerides. Bile acids have long been known to affect triglyceride homeostasis through a not completely understood mechanism.

AIM

To analyse the effects of two different manipulations of bile acid circulation on non-alcoholic fatty liver disease.

METHODS

Two animal models of non-alcoholic fatty liver disease were developed by either feeding rats with a choline deficient or with a high fat diet. After 4 weeks, rats were randomized to undergo either bile duct ligation, sham operation or cholic acid administration.

RESULTS

During cholestasis there was an increased CYP7A1 expression, the rate limiting enzyme in bile acid synthesis, and a reduction of hepatic concentration of oxysterols, ligands of the liver X receptors. Target genes of the liver X receptors, involved in fatty acid and triglyceride synthesis, were down-regulated in association with decreased hepatic triglyceride content and improvement of fatty liver. Administration of cholic acid, ligand of farnesoid X receptor, also had a beneficial effect on fatty liver in rats on choline deficient diet.

CONCLUSION

These results indicate that pharmacological approaches increasing the expression of CYP7A1 or stimulating farnesoid X receptor pathway could represent a promising treatment for non-alcoholic fatty liver disease.

The vitamin E reduces liver lipoperoxidation and fibrosis in a model of nonalcoholic steatohepatitis

CONTEXT

No effective treatment is available for nonalcoholic steatohepatitis in nowadays.

OBJECTIVES

To develop a model of nonalcoholic steatohepatitis induced by a methionine and choline deficient diet, as well as to evaluate the role of metformin, vitamin E and simvastatin in the nonalcoholic steatohepatitis progression.

METHODS

The study analyzed prospectively 50 Wistar rats for a 90-day period and divided them into five groups of 10 rats. One group was given standard rat diet and the others received the methionine and choline deficient diet. Among the four groups that received this diet, one received saline 0,9% and the others received metformin, vitamin E or simvastatin. After the study period, the animals were sacrificed and their blood was collected for biochemical analysis. The livers were removed for lipoperoxidation analysis and for the histological examinations.

RESULTS

The methionine and choline deficient diet was able to induce steatosis in 100% of the animals and nonalcoholic steatohepatitis in 27 (69.2%). The alanine aminotransferase levels were significantly higher in the simvastatin group. The aspartate aminotransferase levels were also higher in the simvastatin group, but were statistically significant only in relation to the standard diet group. When lipoperoxidation values were compared, the groups that received standard rat diet and methionine and choline deficient with vitamin E presented significantly lower rates than the others. The presence of fibrosis was significantly smaller in the group receiving vitamin E.

CONCLUSIONS

The diet used was able to induce steatosis and nonalcoholic steatohepatitis. Besides vitamin E showed to reduce the liver oxidative stress, as well as the fibrosis development.

Therapeutic use of cytoprotective agents in canine and feline hepatobiliary disease

Many medicinal, nutraceutical, and botanic extracts have been used as cytoprotective agents in liver disease. This article explains the mechanisms of action, pertinent pharmacokinetics, side effects, and clinical indications for the use of S-adenosylmethionine, N-acetylcysteine, ursodeoxycholic acid, silymarin, and vitamin E. The literature pertaining to in vitro studies, laboratory animal models, and human and veterinary clinical trials is reviewed with regards to the efficacy and use of these cytoprotective agents in hepatobiliary disease.

Modelo experimental de esteatohepatite não-alcoólica com dieta deficiente em metionina e colina

CONTEXTO: Ainda existem vários aspectos desconhecidos a respeito da esteatohepatite não-alcoólica, principalmente em relação à fisiopatologia e ao seu tratamento medicamentoso. Dessa forma, os modelos experimentais são importante para o melhor entendimento dessa doença, bem como para a avaliação do efeito das drogas. OBJETIVO: Desenvolver um modelo experimental de esteatohepatite não-alcoólica a partir do uso de dieta deficiente em metionina e colina. MÉTODOS: Foram utilizados 50 ratos machos da linhagem Wistar. A dieta deficiente em metionina e colina foi processada de forma artesanal. Um grupo de 40 animais recebeu a dieta durante 90 dias e utilizou-se um grupo controle com 10 ratos que recebeu ração padronizada pelo mesmo período. Após, os animais foram mortos por decapitação e foi realizada laparotomia com hepatectomia total e preparo do material para análise macroscópica e histológica. O nível de significância foi a = 0,05. RESULTADOS: Os ratos que receberam a dieta apresentaram perda significativa de peso, com achados de desnutrição e todos mostraram, pelo menos, algum grau de esteatose macrovesicular. O diagnóstico de esteatohepatite não-alcoólica foi realizado em 27 (70%) dos 39 ratos que receberam a dieta. Nenhum dos 10 ratos que recebeu ração apresentou alterações histológicas. CONCLUSÃO:A dieta com restrição de metionina e colina desenvolvida apresenta índices elevados de indução de esteatose e esteatohepatite em modelo animal com baixo custo.

Treating nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a chronic illness with multiple consequences. The spectrum of disease ranges from simple steatosis, with benign prognosis, to a potentially progressive form, nonalcoholic steatohepatitis, which may lead to liver fibrosis and cirrhosis, leading to an increase in morbidity and mortality. Furthermore, hepatocellular carcinoma incidence in NAFLD is comparable with that observed in hepatitis C-infected patients once cirrhosis is established. Current therapy is limited to lifestyle changes and control of associated metabolic disorders; however, new treatments are on the way from basic research to bedside. A review of the current literature on treatment of nonalcoholic fatty liver disease is presented in this article.

Present and future therapeutic strategies in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is found in individuals who do not drink or abuse alcohol and represents a significant health burden for the general community. NAFLD is often associated with one or more features of the metabolic syndrome and has potential for evolution towards non-alcoholic steatohepatitis (NASH), the necro-inflammatory form of liver steatosis. The most worrisome evolutive events in a subgroup of NASH patients include advanced liver fibrosis, cirrhosis, and hepatocellular carcinoma. Pathophysiology of NAFLD/NASH is complex, but studies point to a pre-eminent role of oxidative stress and lipid peroxidation in the liver, including early mitochondrial dysfunction. Changes follow an insulin resistance status with a background of a chronic pro-inflammatory status due to an excess of visceral adiposity. Although no established therapy exists for NAFLD/NASH, potential therapeutic approaches are discussed in this review.

A growing burden: the pathogenesis, investigation and management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common hepatic disorder in western countries, and its incidence is increasing. This review outlines the significant health burden posed by NAFLD and discusses what is presently known about its pathogenesis, including the roles of the metabolic syndrome, obesity, insulin resistance, hepatic steatosis, reactive oxygen species, inflammatory cytokines and adipocytokines. The way in which NAFLD is clinically diagnosed is described, and areas of uncertainty surrounding its investigation are identified, before discussing the relative merits of the limited treatment options available and looking ahead to potential therapeutic strategies for the future.

Medical treatment of non-alcoholic steatohepatitis

There is no proven medical treatment of non-alcoholic steatohepatitis (NASH). Most prior therapeutic trials have had methodologic limitations. Insulin sensitizers are the more promising therapeutic candidates among categories that include antioxidants, lipid-lowering agents, and antiobesity drugs. The future will see the evaluation of novel agents and a comprehensive treatment strategy that addresses the risk factors for the metabolic syndrome. This article reviews the current status of medical management options for NASH.

Nonalcoholic steatohepatitis: recent advances from experimental models to clinical management

A condition defined as nonalcoholic fatty liver disease (NAFLD) is frequently found in humans. Deemed as a benign condition until recently, more emphasis is now put on the potential harmful evolution of the inflammatory form, that is, nonalcoholic steatohepatitis (NASH), toward end-stage liver disease. This review highlights the major morphologic and pathophysiological features of NASH. The link between experimental biochemical findings in animal models and clinical and therapeutic approaches in humans is discussed. Once all the other causes of persistent elevation of serum transaminase levels have been excluded, the diagnosis of NASH can be only confirmed by liver histology. Other noninvasive diagnostic tools, however, are being investigated to assess specific subcellular functions and to allow the follow-up of patients at higher risk for major liver dysfunction. A better understanding of various pathogenic aspects of NASH will help in identifying potential therapeutic approaches in these patients.

Tratamiento médico de la hepatopatía grasa no alcohólica primaria

The need for an effective and safe medical treatment of nonalcoholic fatty liver disease is urgent due to its high prevalence and progressive character. At the moment, therapeutic strategies are largely empirical and based on the control of associated clinical conditions (especially obesity, type 2 diabetes mellitus, and hypertriglyceridemia) and the use of some specific drugs (insulin sensitizing agents, cytoprotectives, antioxidants, and anticytokines) as an attempt to counteract known elements of the pathogenesis. None of these specifics measures have been found to display enough evidence to recommend their clinical use. It is indispensable to join efforts in coordinated networks to define, as soon as possible, the best treatment and the best time to start it.

Effects of ursodeoxycholic acid and/or low-calorie diet on steatohepatitis in rats with obesity and hyperlipidemia

AIM

To evaluate the effects of ursodeoxycholic acid (UDCA) and/or low-calorie diet (LCD) on a rat model of nonalcoholic steatohepatitis (NASH).

METHODS

Fifty-five Sprague-Dawley rats were divided into five groups. The control group (n = 9) was fed with standard rat diet for 12 wk, NASH group (n = 10) was fed with high-fat diet consisted of normal diet, 10% lard oil and 2% cholesterol for 12 wk, UDCA group (n = 10) was fed with high-fat diet supplemented with UDCA at a dose of 25 mg/(kg.d) in drinking water for 12 wk, LCD group (n = 10) was fed with high-fat diet for 10 wk and then LCD for 2 wk, and UDCA+LCD group (n = 15) was fed with high-fat diet for 10 wk, followed by LCD+UDCA for 2 wk. At the end of the experiment, body weight, serum biochemical index, and hepatopathologic changes were examined.

RESULTS

Compared with the control group, rats in the NASH group had significantly increased body weight, liver weight, and serum lipid and aminotransferase levels. All rats in the NASH group developed steatohepatitis, as determined by their liver histology. Compared with the NASH group, there were no significant changes in body weight, liver weight, blood biochemical index, the degree of hepatic steatosis, and histological activity index (HAI) score in the UDCA group; however, body and liver weights were significantly decreased, and the degree of steatosis was markedly improved in rats of both the LCD group and the UDCA+LCD group, but significant improvement with regard to serum lipid variables and hepatic inflammatory changes were seen only in rats of the UDCA+LCD group, and not in the LCD group.

CONCLUSION

LCD might play a role in the treatment of obesity and hepatic steatosis in rats, but it exerts no significant effect on both serum lipid disorders and hepatic inflammatory changes. UDCA may enhance the therapeutic effects of LCD on steatohepatitis accompanied by obesity and hyperlipidemia. However, UDCA alone is not effective in the prevention of steatohepatitis induced by high-fat diet.

Feline hepatic lipidosis

We have come a long way in understanding and managing the FHL syndrome since it was first described nearly 30 years ago. Increased sensitivity of clinicians for recognizing the syndrome has improved case outcome by arresting this metabolic syndrome in its earliest stages. Simply ensuring adequate intake of a complete and balanced feline diet can rescue cats just developing clinical signs; however, full metabolic support as described herein provides the best chance for recovery of cats demonstrating the most severe clinicopathologic features. It remains possible that adjustments in recommended micronutrient and vitamin intake for healthy cats may pivotally change feline susceptibility to FHL over the coming years.

Metabolic, antioxidant, nutraceutical, probiotic, and herbal therapies relating to the management of hepatobiliary disorders

Many nutraceuticals, conditionally essential nutrients, and botanical extracts have been proposed as useful in the management of liver disease. The most studied of these are addressed in terms of proposed mechanisms of action, benefits, hazards, and safe dosing recommendations allowed by current information. While this is an area of soft science, it is important to keep an open and tolerant mind, considering that many major treatment discoveries were in fact serendipitous accidents.