Is vitamin E beneficial in chronic liver disease?

Vitamin E improves serum markers and histology in adults with metabolic dysfunction-associated steatotic liver disease: Systematic review and meta-analysis

BACKGROUND AND AIM

Multiple clinical trials have been conducted to study the potential benefits of vitamin E for the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD). Despite available evidence, vitamin E is not widely used. This study aimed to assess the effect of vitamin E on serum markers of liver inflammation, specifically serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and histology, including resolution of metabolic dysfunction-associated steatohepatitis (MASH), in adult patients with MASLD.

METHODS

A systematic literature search on randomized controlled trials published in English was conducted using electronic databases. Standardized mean difference (SMD) and mean difference (MD) were used for continuous outcomes, while risk ratio (RR) was used for dichotomous outcomes, with corresponding 95% confidence interval (CI).

RESULTS

A total of eight studies were included in the qualitative synthesis while seven studies were included in the meta-analysis. Vitamin E significantly reduced serum ALT and AST levels with SMD of -0.82 (95% CI, -1.13 to -0.51) and -0.68 (95% CI, -0.94 to -0.41), respectively. Vitamin E significantly reduced steatosis, lobular inflammation, and hepatocyte ballooning with a MD of -0.60 (95% CI, -0.83 to -0.37), -0.34 (95% CI, -0.53 to -0.16), -0.32 (95% CI, -0.53 to -0.12), and increased MASH resolution with a RR of 1.9 (95%CI, 1.20 to 3.02). However, vitamin E did not reduce fibrosis, with a MD of -0.23 (95% CI, -0.51 to 0.05).

CONCLUSION

Vitamin E resulted in significant improvement in serum markers of liver inflammation and histology in patients with MASLD.

Oxidative Stress as a Target for Non-Pharmacological Intervention in MAFLD: Could There Be a Role for EVOO?

Oxidative stress plays a central role in most chronic liver diseases and, in particular, in metabolic dysfunction-associated fatty liver disease (MAFLD), the new definition of an old condition known as non-alcoholic fatty liver disease (NAFLD). The mechanisms leading to hepatocellular fat accumulation in genetically predisposed individuals who adopt a sedentary lifestyle and consume an obesogenic diet progress through mitochondrial and endoplasmic reticulum dysfunction, which amplifies reactive oxygen species (ROS) production, lipid peroxidation, malondialdehyde (MDA) formation, and influence the release of chronic inflammation and liver damage biomarkers, such as pro-inflammatory cytokines. This close pathogenetic link has been a key stimulus in the search for therapeutic approaches targeting oxidative stress to treat steatosis, and a number of clinical trials have been conducted to date on subjects with NAFLD using drugs as well as supplements or nutraceutical products. Vitamin E, Vitamin D, and Silybin are the most studied substances, but several non-pharmacological approaches have also been explored, especially lifestyle and diet modifications. Among the dietary approaches, the Mediterranean Diet (MD) seems to be the most reliable for affecting liver steatosis, probably with the added value of the presence of extra virgin olive oil (EVOO), a healthy food with a high content of monounsaturated fatty acids, especially oleic acid, and variable concentrations of phenols (oleocanthal) and phenolic alcohols, such as hydroxytyrosol (HT) and tyrosol (Tyr). In this review, we focus on non-pharmacological interventions in MAFLD treatment that target oxidative stress and, in particular, on the role of EVOO as one of the main antioxidant components of the MD.

Association between serum Vitamin E concentrations and the presence of Metabolic Syndrome: A population-based cohort study

BACKGROUND

Metabolic syndrome (MetS) is a cluster of clinical and metabolic features that include central obesity, dyslipidemia, hypertension and impaired glucose tolerance. These features are accompanied by increased oxidative stress and impaired antioxidant defenses. Vitamin E is a major factor in the non-enzymatic antioxidant defenses. The aim of present study was to investigate the association between serum levels of vitamin E and the presence of MetS and its components in a sample population of Mashhad stroke and heart atherosclerotic disorder (MASHAD) cohort study.

METHODS

This cross-sectional study was carried out in 128 subjects with MetS and 235 subjects without MetS. MetS was defined according to the International-Diabetes-Federation criteria. Serum levels of vitamin E were measured using the HPLC method. Anthropometric and biochemical parameters were measured using standard protocols.  Results. MetS patients had significantly lower serum levels of vitamin E (Vit E), Vit E/Total cholesterol (TC), and Vit E/ (TC+triglyceride(TG)) compared to the control group (P < 0.05).  Vit E/ (TG+TC) was also significantly lower in diabetics or those with elevated levels of high sensitive C-reactive protein (hs-CRP). Additionally, there was a significant association between Vit E/ (TG + Total Cho) and the number of components of the metabolic syndrome (p= 0.02) Conclusions. There is a significant inverse association between indices of Vit E status and the presence of MetS. Moreover, a significantly lower Vit E/ (TC+TG) was observed along with individuals with increasing numbers of components of the MetS.

The efficacy of vitamin E in reducing non-alcoholic fatty liver disease: a systematic review, meta-analysis, and meta-regression

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) affects up to 30% of the population. Clinical trials have questioned the role of vitamin E in the treatment of NAFLD with or without other interventions, with still no firm conclusion reached. This study aims to examine the efficiency of vitamin E alone or combined in the management of NAFLD.

METHODS

We performed a systematic literature search on PubMed, Scopus, Embase, Ovid, EBSCO host, Science Direct, Web of Science, and Cochrane CENTRAL for randomized controlled trials (RCTs) of the role of vitamin E alone or combined in NAFLD patients. Extracted manuscripts reported data on biochemical, histological, anthropometric, and metabolic outcomes. Baseline characteristics, settings, dosage, and frequency were also collected.

RESEARCH

A total of 1317 patients from 15 RCTs were included in our systematic review and meta-analysis. Vitamin E was superior at improving alanine aminotransferase (ALT), aspartate aminotransferase (AST), NAFLD activity score (NAS), and fibrosis in short- and long-term follow up in the adult population, and long-term follow up in the pediatric population. Improvements in metabolic outcomes were best noticed in pediatric patients. Results from multiple regression models showed a significant association between ALT-AST levels and vitamin E dose. AST levels had a significant effect on NAS, and patients with a baseline AST > 50 IU/l showed more promising results. Changes in weight and body mass index (BMI) were strongly associated with changes in NAS.

CONCLUSION

Current evidence affirms that vitamin E - whether alone or combined - improves biochemical and histological outcomes in adults and pediatric patients.

Recent Advances in Nanomedicine for the Diagnosis and Therapy of Liver Fibrosis

Liver fibrosis, a reversible pathological process of inflammation and fiber deposition caused by chronic liver injury and can cause severe health complications, including liver failure, liver cirrhosis, and liver cancer. Traditional diagnostic methods and drug-based therapy have several limitations, such as lack of precision and inadequate therapeutic efficiency. As a medical application of nanotechnology, nanomedicine exhibits great potential for liver fibrosis diagnosis and therapy. Nanomedicine enhances imaging contrast and improves tissue penetration and cellular internalization; it simultaneously achieves targeted drug delivery, combined therapy, as well as diagnosis and therapy (i.e., theranostics). In this review, recent designs and development efforts of nanomedicine systems for the diagnosis, therapy, and theranostics of liver fibrosis are introduced. Relative to traditional methods, these nanomedicine systems generally demonstrate significant improvement in liver fibrosis treatment. Perspectives and challenges related to these nanomedicine systems translated from laboratory to clinical use are also discussed.

Hydrogen inhalation alleviates nonalcoholic fatty liver disease in metabolic syndrome rats

Hydrogen exhibits therapeutic and preventive effects against various diseases. The present study investigated the potential protective effect and dose-dependent manner of hydrogen inhalation on high fat and fructose diet (HFFD)-induced nonalcoholic fatty liver disease (NAFLD) in Sprague-Dawley rats. Rats were randomly divided into four groups: i) Control group, regular diet/air inhalation; ii) model group, HFFD/air inhalation; iii) low hydrogen group, HFFD/4% hydrogen inhalation; and iv) high hydrogen group, HFFD/67% hydrogen inhalation. After a 10-week experiment, hydrogen inhalation ameliorated weight gain, abdominal fat index, liver index and body mass index of rats fed with HFFD and lowered the total area under the curve in an oral glucose tolerance test. Hydrogen inhalation also ameliorated the increase in liver lipid content and alanine transaminase and aspartate transaminase activities. Liver histopathologic changes evaluated with hematoxylin and eosin as well as Oil Red O staining revealed lower lipid deposition in hydrogen inhalation groups, consistent with the decrease in the expression of the lipid synthesis gene SREBP-1c. The majority of the indicators were affected following treatment with hydrogen in a dose-dependent manner. In conclusion, hydrogen inhalation may play a protective role by influencing the general state, lipid metabolism parameters, liver histology and liver function indicators in the rat model of metabolic syndrome with NAFLD.

Effect of vitamin E in non-alcoholic fatty liver disease: a systematic review and meta-analysis of randomised controlled trials

The efficacy of vitamin E among patients with non-alcoholic fatty liver disease (NAFLD) is unclear. The current qualitative and quantitative analyses aimed to ascertain the efficacy of vitamin E on clinical outcomes of patients with NAFLD. A systematic search of randomised controlled trials (RCTs) was performed using databases (PubMed, ProQuest, Scopus, EBSCOhost and Ovid) from inception to July 2018. Trials meeting the inclusion criteria were subjected to quality assessment using the Jadad Scoring. All trials meeting the prerequisites information for meta-analysis were subjected to quantitative synthesis of results. Nine RCTs (five in adults and four in children) were included. Four of the five RCTs on adults demonstrated significant improvements in alanine transaminase and other liver function surrogates in patients with NAFLD. On the other hand, only one of the four RCTs conducted on children showed significant improvements in liver functions with the use of vitamin E. Although quantitative synthesis of available data revealed insignificant differences between vitamin E and placebo, still the use of vitamin E improves the level of alanine transaminase and aspartate transaminase by -1.96 and -0.59, with heterogeneity of I²=67% and I²=0%, respectively. Adjuvant vitamin E therapy provides significant biochemical and histological improvements in adult patients with NAFLD, while paediatric patients showed insignificant efficacy compared with placebo. Lifestyle interventions along with vitamin E can provide much better results. Data, including the impact of vitamin E on hepatic histology, are still lacking. Moreover, the short duration of trials limits the conclusion on the safety and efficacy of proposed treatments.

Effect of vitamin E in nonalcoholic fatty liver disease with metabolic syndrome: A propensity score-matched cohort study

Background/Aims

Vitamin E improves the biochemical profiles and liver histology in nonalcoholic steatohepatitis, but the role of vitamin E is not clearly defined in the management of nonalcoholic fatty liver disease (NAFLD) which includes both simple steatosis and steatohepatitis. Co-morbid metabolic syndrome increases the probability of steatohepatitis in NAFLD. In this study, we aimed to determine the short-term effects of vitamin E and off-treatment durability of response in a propensity-score matched cohort of NAFLD patients with metabolic syndrome.

Methods

A retrospective cohort was constructed by retrieving 526 consecutive NAFLD patients from the electronic medical record data warehouse of a tertiary referral hospital in South Korea. Among them, 335 patients (63.7%) had metabolic syndrome and were eligible for vitamin E therapy. In order to assess the effect of vitamin E, propensity score matching was used by matching covariates between control patients (n=250) and patients who received vitamin E (n=85).

Results

The PS-matched vitamin E group (n=58) and control group (n=58) exhibited similar baseline metabolic profiles. After 6 months of vitamin E therapy, the mean ALT levels decreased significantly compared to PS-matched control (P<0.01). The changes in metabolic profiles (body weight, lipid and glucose levels) did not differ between control and vitamin E groups during the study period.

Conclusions

Short-term vitamin E treatment significantly reduces ALT levels in NAFLD patients with metabolic syndrome, but metabolic profiles are not affected by vitamin E.

Pharmacological agents for NASH

NASH is a common liver disease that increases liver-related mortality and reduces survival. The need for optimal management of NASH is therefore a priority for today's practicing hepatologist. The rationale for specific pharmacological therapy for NASH is based on the potential for disease progression and the difficulties that many patients have successfully implementing, in the long term, diet and lifestyle changes. Even in those that succeed, limited evidence exists that severe liver injury in patients with NASH can be reversed by diet and lifestyle measures alone. This Review provides a personal and critical assessment of the histological efficacy and safety of agents tested in randomized trials in patients with NASH.

Impact of pan-caspase inhibition in animal models of established steatosis and non-alcoholic steatohepatitis

BACKGROUND & AIMS

Non-alcoholic fatty liver disease is a progressive condition comprising steatosis, steatohepatitis, and cirrhosis. Caspase activation mediates apoptosis and the inflammatory response. Studies demonstrate increased apoptotic activity in NASH although its pathophysiological importance is uncertain. We sought to determine the effects of irreversible pan-caspase inhibition in murine models of established steatosis (high fat diet, HFD) and steatohepatitis (methionine-choline deficient diet, MCD).

METHODS

In one study arm, male C3H/HeN mice were fed HFD; in the other, Db/Db mice were fed MCD. Once disease was established, animals were randomised to receive caspase inhibitor (VX-166), TPGS/PEG vehicle or no additional therapy until the end of the study. Biochemical and histological indices were examined to determine NASH activity and tissue oxidative stress. Apoptotic activity and cell turnover were assessed immunohistochemically by staining for caspase-cleaved CK-18 and PCNA.

RESULTS

MCD and HFD significantly increased apoptosis, which was reduced by VX-166 treatment. VX-166 did not reduce steatosis but reduced histological inflammation, serum ALT levels, and oxidative stress, particularly in the MCD model. TPGS/PEG vehicle also exhibited some anti-inflammatory activity.

CONCLUSIONS

In both models, VX-166 inhibited apoptosis and reduced histological inflammatory infiltrate although there was a more modest impact on other indices of liver injury. In addition, TPGS/PEG vehicle also exhibited some anti-inflammatory activity, likely through the antioxidant effects of vitamin E and changes in gut flora/mucosal interactions. These data suggest that caspase inhibition may represent a valid therapeutic approach; however, further studies to assess the long-term value of more selective caspase inhibition are merited.