Combined pantethine and probucol therapy for Japanese patients with non-alcoholic steatohepatitis

Lipolysis stimulating peptides of potato protein hydrolysate effectively suppresses high-fat-diet-induced hepatocyte apoptosis and fibrosis in aging rats

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is one of the most common outcomes of obesity and is characterized by the accumulation of triglycerides, increased tissue apoptosis, and fibrosis. NAFLD is more common among elderly than in younger age groups, and it causes serious hepatic complications.

OBJECTIVE

In this study, alcalase treatment derived potato protein hydrolysate (APPH) with lipolysis-stimulating property has been evaluated for its efficiency to provide hepato-protection in a high-fat-diet (HFD)-fed aging rats.

DESIGN

Twenty-four-month-old SD rats were randomly divided into six groups (n=8): aged rats fed with standard chow, HFD-induced aged obese rats, HFD with low-dose (15 mg/kg/day) APPH treatment, HFD with moderate (45 mg/kg/day) APPH treatment, HFD with high (75 mg/kg/day) APPH treatment, and HFD with probucol.

RESULTS

APPH was found to reduce the NAFLD-related effects in rat livers induced by HFD and all of the HFD-fed rats exhibited heavier body weight than those with control chow diet. However, the HFD-induced hepatic fat accumulation was effectively attenuated in rats administered with low (15 mg/kg/day), moderate (45 mg/kg/day), and high (75 mg/kg/day) doses of APPH. APPH oral administration also suppressed the hepatic apoptosis- and fibrosis-related proteins induced by HFD.

CONCLUSIONS

Our results thus indicate that APPH potentially attenuates hepatic lipid accumulation and anti-apoptosis and fibrosis effects in HFD-induced rats. APPH may have therapeutic potential in the amelioration of NAFLD liver damage.

Did we abandon probucol too soon?

PURPOSE OF REVIEW

Probucol is a potent antioxidative drug that has been used for prevention and treatment of atherosclerotic cardiovascular diseases and xanthoma. Probucol has been used as a lipid-lowering drug for a long time especially in Japan, although Western countries quitted its use because of the reduction in serum HDL-cholesterol (HDL-C). This review highlights both basic and clinical studies that provide new insights into the pleiotropic effects of probucol.

RECENT FINDINGS

Recently, the mechanisms for the pharmacologic actions of probucol have been elucidated at the molecular level with a special focus on HDL metabolism and its functions. Probucol enhances plasma cholesteryl ester transfer protein activity and hepatic scavenger receptor class B type I, causing a decrease in HDL-C. It also accelerates the antioxidative function of HDL via increase in paraoxonase 1 activity. Recent retrospective analyses of probucol-treated patients with heterozygous familial hypercholesterolemia and those after coronary revascularization demonstrated a strong beneficial effect of probucol on secondary prevention of cardiovascular events and mortality.

SUMMARY

Probucol has pleiotropic and beneficial therapeutic effects on cardiovascular system. Although statins are effective for lowering LDL-cholesterol (LDL-C) and reducing coronary heart disease risk, probucol should be considered as an option in case statins are not effective.

Efficacy and tolerability of coenzyme A vs pantethine for the treatment of patients with hyperlipidemia: A randomized, double-blind, multicenter study

BACKGROUND

New, safer, and more effective agents to treat hyperlipidemia and thereby prevent cardiovascular events are under research.

OBJECTIVE

To evaluate the lipid-lowering effects and safety of a natural hypolipidemic compound, coenzyme A (CoA) capsule, in Chinese patients with moderate dyslipidemia, compared with pantethine.

METHODS

Overall, 216 subjects (124 males and 92 females; age, 18-75 years) with moderate dyslipidemia (triglyceride [TG], 2.3-6.5 mmol/L) were randomly divided into 2 groups administered CoA 400 U/d (n = 111) or pantethine 600 U/d (n = 105). Blood lipoproteins, liver and renal function, blood glucose, and complete blood count were measured at baseline and after 4- and 8-week treatment.

RESULTS

TG reduction was 26.0% with CoA and 17.4% with pantethine after 4 weeks and 33.3% and 16.5% after 8 weeks; compared with baseline, the reduction was significant (P < .01) in both groups. The difference between the 2 groups was significant at both 4 weeks (P = .0413) and 8 weeks (P < .001). Compared with baseline, total cholesterol and non-high-density lipoprotein cholesterol (non-HDL-C) were reduced, whereas HDL-C was increased with CoA after 8 weeks (all P < .05). Compared with pantethine, total cholesterol (P = .026) and non-HDL-C (P = .005) were significantly reduced after 8 weeks of CoA treatment. There was no statistical difference in low-density lipoprotein cholesterol or HDL-C between the 2 groups (P > .05) and no difference in blood glucose, hepatic or renal function, myopathy, or gastrointestinal tract symptoms.

CONCLUSIONS

CoA can improve TG and other lipoprotein parameters to a greater extent than pantethine in moderate dyslipidemia, with no obvious adverse effects.

Efficacy of probucol for the treatment of non-alcoholic steatohepatitis with dyslipidemia: An open-label pilot study

AIM

Oxidative stress plays a pivotal role in the transition from simple steatosis to non-alcoholic steatohepatitis (NASH). Probucol is a lipid-lowering agent with strong antioxidant properties, and is reported to be effective for the treatment of NASH in several studies. The aim of the present study was to evaluate the efficacy of probucol for the treatment of NASH with dyslipidemia.

METHODS

Twenty-six patients with biopsy-proven NASH accompanied by dyslipidemia were treated with 500 mg of probucol daily for 48 weeks. Body mass index, visceral fat area, liver function tests, serum lipids, fibrosis markers, ferritin, adiponectin, leptin, urinary 8-hydroxy-2'-deoxyguanosine (U-8OHdG) and elasticity were measured periodically during the study. Follow-up liver biopsy was performed in 18 patients.

RESULTS

Serum levels of aminotransferases, total cholesterol and U-8OHdG significantly decreased (P < 0.01). Levels of hemoglobin A1c (HbA1c), the Homeostasis Model of Assessment - Insulin Resistance index and serum levels of ferritin, type IV collagen 7S and hyaluronic acid significantly decreased (P < 0.05). The serum levels of adiponectin tended to be increased. Liver stiffness significantly decreased from 8.8 ± 6.8 to 6.6 ± 4.0 kPa (P < 0.01). Non-alcoholic fatty liver disease activity scores were significantly improved from 4.2 ± 1.4 to 3.4 ± 1.6 (P < 0.05) and fibrotic stages tended to be improved from 1.6 ± 0.8 to 1.3 ± 1.1, respectively. No adverse effects of this treatment were noted.

CONCLUSION

Probucol improved clinical and histological findings probably through its ability to reduce insulin resistance and oxidative stress. Probucol therapy was safe and effective for Japanese NASH patients with dyslipidemia.

The role of antioxidants and other agents in alleviating hyperglycemia mediated oxidative stress and injury in liver

Several antioxidants and agents having similar antioxidant effects are known to exert beneficial effects in ameliorating the injurious effects of hyperglycemia on liver in different diabetic in vitro and in vivo models. The review deals with some of the agents which have been shown to exert protective effects on liver against hyperglycemic insult and the various mechanisms involved. The different classes of agents which protect the diabetic liver or decrease the severity of hyperglycemia mediated injury include flavonoids, catechins, and other polyphenolic compounds, curcumin and its derivatives, certain vitamins, hormones and drugs, trace elements, prototypical antioxidants and amino acids. Some of the pronounced changes mediated by the antioxidants in liver exposed to hyperglycemia include decreased oxidative stress, and alterations in carbohydrate and lipid metabolism. Other mechanisms through which the agents ameliorate hyperglycemia mediated liver injury include decrease in oxidative DNA and protein damage, restoration of mitochondrial structural and functional integrity, decrease in inflammation and improved insulin signaling. Thus, antioxidants may prove to be an important mode of defense in maintaining normal hepatic functions in diabetes.

Nonalcoholic fatty liver disease and nonalcoholic steatohepatitis in Japan

During the past 20 to 30 years, the frequency of patients presenting with nonalcoholic fatty liver diseases (NAFLD) has increased gradually in Japan in proportion to the increase in the population with life-style related diseases. We describe here the current status of the clinical and basic aspects of research into NAFLD in Japan. The increase in the incidence of life-style-related diseases has resulted in an increase in NAFLD throughout the past 20 to 30 years. The rate of obesity in the population is not high compared to western countries but the incidence of NAFLD is similar to those countries. In 2008 we started a nationwide study of NAFLD which has been supported by the Ministry of Labor and Welfare Japan. In this project, we planned to investigate the epidemiology, genetic backgrounds and biochemical markers, and liver injury in patients with diabetes mellitus (DM) and hepatocellular carcinoma in NASH, and treatment of NASH. Approximately 20 to 25% of DM patients showed NAFLD in which the prevalence of NASH might be more than 30 to 40%. Fortunately, we have been able to obtain very interesting results from our group studies, including single necleotide polymorphisms (SNPs) which will be published in the near future.

Pharmacologic therapy of non-alcoholic steatohepatitis

Specific therapy for non-alcoholic steatohepatitis (NASH) is needed because of the potential severity of this liver disease. NASH is a recognized cause of cryptogenic cirrhosis and, increasingly, of hepatocellular carcinoma. Therefore, there is an unmet medical need for the therapy of NASH. This article discusses this therapy, with particular emphasis on pharmacologic therapy.

Treatment of nonalcoholic steatohepatitis with colestimide

AIM

To clarify the usefulness of colestimide in patients with nonalcoholic steatohepatitis (NASH) with hyperlipidemia.

METHODS

In an open-label randomized controlled trial, 17 NASH patients with hyperlipidemia received colestimide (3 g/day) for 24 weeks. There were 21 control patients. All patients received lifestyle modification therapy. Efficacy was assessed based on metabolic profile, insulin resistance, transaminases, serum hepatic fibrosis markers, adipokine levels, visceral fat on computed tomography (CT), and the fatty liver grade on CT. NASH patients with moderate to severe steatosis by histology were also evaluated separately.

RESULTS

Baseline clinical characteristics of the two groups were similar. Both groups experienced a significant decrease of BMI with no difference between them. However, visceral fat decreased significantly more in the colestimide group (P = 0.046). Aspartate aminotransferase (AST) showed a significantly greater decrease in the colestimide group compared with the control group (P = 0.042). In patients with moderate to severe histological steatosis, there were significant differences between the two groups regard to HbA(1c), transaminases, and hyaluronic acid (P = 0.018 for HbA(1c), P = 0.003 for AST, P = 0.042 for alanine aminotransferase, and P = 0.042 for hyaluronic acid). Steatosis significantly improved in patients in the colestimide group who had fatty liver on CT (P = 0.049). In the colestimide group, abdominal distension and/or constipation were seen, but mostly tolerable, no other clinical or laboratory adverse events associated with the use of this medicine were not observed.

CONCLUSIONS

Colestimide seems to increase the efficacy of lifestyle modification in NASH patients with hyperlipidemia. Its beneficial effects were more prominent in NASH patients with moderate to severe histological steatosis.