Tocotrienols activate Nrf2 nuclear translocation and increase the antioxidant-related hepatoprotective mechanism in mice liver

Ahmed Atia, Nadia Salem Al-Rawaiq, Azman Abdullah

Curr Pharm Biotechnol . 2020 Sep 27. doi: 10.2174/1389201021666200928095950. Online ahead of print.

Abstract

Background: The most common preparation of tocotrienols is the tocotrienol-rich fraction (TRF). This study aimed to investigate whether TRF induced liver Nrf2 nuclear translocation and influenced the expression of Nrf2-regulated genes.

Methods: In the Nrf2 induction study, mice were divided into control, 2000 mg/kg TRF and diethyl maleate treated groups. After acute treatment, mice were sacrificed at specific time points. Liver nuclear extracts were prepared and Nrf2 nuclear translocation was detected through Western blotting. To determine the effect of increasing doses of TRF on the extent of liver nuclear Nrf2 translocation and its implication on the expression levels of several Nrf2-regulated genes, mice were divided into 5 groups (control, 200, 500 and 1000 mg/kg TRF, and butylated hydroxyanisole-treated groups). After 14 days, mice were sacrificed and liver RNA extracted for qPCR assay.

Results: 2000 mg/kg TRF administration initiated Nrf2 nuclear translocation within 30 min, reached maximum level around 1 h and dropped to half-maximal levels by 24 h. Incremental doses of TRF resulted in dose-dependent increases in liver Nrf2 nuclear levels, along with concomitant dose-dependent increases in the expressions of Nrf2-regulated genes.

Conclusion: TRF activated the liver Nrf2 pathway resulting in increased expression of Nrf2-regulated cytoprotective genes.

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4-HNE Immunohistochemistry and Image Analysis for Detection of Lipid Peroxidation in Human Liver Samples Using Vitamin E Treatment in NAFLD as a Proof of Concept

Maren C Podszun, Joon-Yong Chung, Kris Ylaya, David E Kleiner, Stephen M Hewitt, Yaron Rotman

J Histochem Cytochem . 2020 Sep;68(9):635-643. doi: 10.1369/0022155420946402.

Abstract

Lipid peroxidation is a common feature of liver diseases, especially non-alcoholic fatty liver disease (NAFLD). There are limited validated tools to study intra-hepatic lipid peroxidation, especially for small specimen. We developed a semi-quantitative, fully automated immunohistochemistry assay for the detection of 4-hydroxynoneal (4-HNE) protein adducts, a marker of lipid peroxidation, for adaptation to clinical diagnostics and research. We used Hep G2 cells treated with 4-HNE to validate specificity, sensitivity, and dynamic range of the antibody. Staining and semi-quantitative automated readout were confirmed in human needle-biopsy liver samples from subjects with NAFLD and normal liver histology. The ability to detect changes in lipid peroxidation was tested in paired liver biopsies from NAFLD subjects, obtained before and after 4 weeks of treatment with the antioxidant vitamin E (ClinicalTrials.gov NCT01792115n=21). The cellular calibrator was linear and NAFLD patients had significantly higher levels of 4-HNE adducts compared to controls (p=0.02). Vitamin E treatment significantly decreased 4-HNE (p=0.0002). Our findings demonstrate that 4-HNE quantification by immunohistochemistry and automated image analysis is feasible and able to detect changes in hepatic lipid peroxidation in clinical trials. This method can be applied to archival and fresh samples and should be considered for use in assessing NAFLD histology.

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Dietary Intervention Accelerates NASH Resolution Depending on Inflammatory Status with Minor Additive Effects on Hepatic Injury by Vitamin E Supplementation

Julie Hviid Klaebel, Günaj Rakipovski, Birgitte Andersen, Jens Lykkesfeldt, Pernille Tveden-Nyborg

Antioxidants (Basel) . 2020 Sep 1;9(9):E808. doi: 10.3390/antiox9090808.

Abstract

Despite the lack of effective pharmacotherapy against nonalcoholic steatohepatitis (NASH) and liver fibrosis, vitamin E (vitE) supplementation and lifestyle modifications are recommended for the management of NASH due to promising clinical results. We recently reported a positive effect of supplementation with 800 IU vitE and atorvastatin on NASH resolution in guinea pigs. In the present study, we investigated the effect of high-dose vitE therapy combined with dietary intervention against progressive NASH and advanced fibrosis in the guinea pig model. Sixty-six guinea pigs received either high-fat (HF) or standard guinea pig chow diet (Control) for 25 weeks. Prior to eight weeks of intervention, HF animals were allocated into groups; dietary intervention (Chow) or dietary intervention with 2000 IU/d vitE supplementation (CvitE). Both Chow and CvitE reduced dyslipidemia, hepatic lipid accumulation and liver weight (p < 0.05), while CvitE further decreased hepatocellular ballooning (p < 0.05). Subanalyses of individual responses within intervention groups showed significant correlation between the hepatic hallmarks of NASH and lipid accumulation vs. inflammatory state (p < 0.05). Collectively, our results indicate that individual differences in sensitivity towards intervention and inflammatory status determine the potential beneficial effect of dietary intervention and high-dose vitE supplementation. Moreover, the study suggests that inflammation is a primary target in NASH treatment.

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Vitamin E treatment in NAFLD patients demonstrates that oxidative stress drives steatosis through upregulation of de-novo lipogenesis

Maren C Podszun, Ahmad S Alawad, Shilpa Lingala, Nevitt Morris, Wen-Chun A Huang, Shanna Yang, Megan Schoenfeld, Adam Rolt, Ronald Ouwerkerk, Kristin Valdez, Regina Umarova, Yanling Ma, Syeda Zaheen Fatima, Dennis D Lin, Lakshmi S Mahajan, Niharika Samala, Pierre-Christian Violet, Mark Levine, Robert Shamburek, Ahmed M Gharib, David E Kleiner, H Martin Garraffo, Hongyi Cai, Peter J Walter, Yaron Rotman

Redox Biol . 2020 Sep 1;37:101710. doi: 10.1016/j.redox.2020.101710. Online ahead of print.

Abstract

Oxidative stress (OS) in non-alcoholic fatty liver disease (NAFLD) promotes liver injury and inflammation. Treatment with vitamin E (α-tocopherol, αT), a lipid-soluble antioxidant, improves liver injury but also decreases steatosis, thought to be upstream of OS, through an unknown mechanism. To elucidate the mechanism, we combined a mechanistic human trial interrogating pathways of intrahepatic triglyceride (IHTG) accumulation and in vitro experiments. 50% of NAFLD patients (n = 20) treated with αT (200-800 IU/d) for 24 weeks had a ≥ 25% relative decrease in IHTG by magnetic resonance spectroscopy. Paired liver biopsies at baseline and week 4 of treatment revealed a decrease in markers of hepatic de novo lipogenesis (DNL) that strongly predicted week 24 response. In vitro, using HepG2 cells and primary human hepatocytes, αT inhibited glucose-induced DNL by decreasing SREBP-1 processing and lipogenic gene expression. This mechanism is dependent on the antioxidant capacity of αT, as redox-silenced methoxy-αT is unable to inhibit DNL in vitro. OS by itself was sufficient to increase S2P expression in vitro, and S2P is upregulated in NAFLD livers. In summary, we utilized αT to demonstrate a vicious cycle in which NAFLD generates OS, which feeds back to augment DNL and increases steatosis.

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Delta-tocotrienol supplementation improves biochemical markers of hepatocellular injury and steatosis in patients with nonalcoholic fatty liver disease: A randomized, placebo-controlled trial

Muhammad Amjad Pervez, Dilshad Ahmed Khan, Atiq Ur Rehman Slehria, Aamir Ijaz

Complement Ther Med . 2020 Aug;52:102494. doi: 10.1016/j.ctim.2020.102494. Epub 2020 Jun 23.

Abstract

Objective: The aim of this study was to examine the effects of delta-tocotrienol (δ-tocotrienol) supplementation on biochemical markers of hepatocellular injury and steatosis in patients with nonalcoholic fatty liver disease (NAFLD).

Design: The study design was a two-group, randomized, double-blind, placebo-controlled trial. The patients with NAFLD were randomly assigned to receive δ-tocotrienol 300 mg twice daily or placebo for 24 weeks.

Endpoints: The primary endpoints were change from baseline in fatty liver index (FLI) and homeostasis model of insulin resistance (HOMA-IR) after 24 weeks. Secondary endpoints included change from baseline in high sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), alanine transaminase (ALT), aspartate transaminase (AST) and grading of hepatic steatosis on ultrasound. Between-group differences were tested for significance using ANCOVA. Mean differences (MD) with 95 % CIs are reported.

Results: A total of 71 patients (tocotrienol=35, placebo=36) were randomized and included in the intention to treat analysis. Compared with placebo, δ-tocotrienol significantly reduced (MD [95 % CI]) FLI (-8.52 [-10.7, -6.3]; p < 0.001); HOMA-IR (-0.37 [-0.53, -0.21]; p < 0.001), hs-CRP (-0.61[-0.81, -0.42]; p < 0.001), MDA (-0.91 [-1.20, -0.63]; p < 0.001), ALT (-8.86 [-11.5, -6.2]; p < 0.001) and AST (-6.6 [-10.0, -3.08]; p < 0.001). Hepatic steatosis was also reduced by a significantly greater extent with tocotrienol than with placebo (p =0.047). No adverse events were reported.

Conclusion: δ-tocotrienol effectively improved biochemical markers of hepatocellular injury and steatosis in patients with NAFLD. δ-tocotrienol supplementation might be considered as a therapeutic option in the management of patients with NAFLD.

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The wonders of palm oil

Ahmad Parveez Ghulam Kadir

The Malaysian Palm Oil Board (MPOB)’s research and collaborations with local and overseas institutions have scientifically proven that palm-derived Vitamin E tocotrienols are important for human health as they can prevent many non-communicable diseases. Through the continuous and dedicated research conducted by MPOB, the health benefits of palm oil and its phyto-nutrients are being explored extensively.

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Systematic review with meta-analysis: The effect of vitamin E supplementation in adult patients with non-alcoholic fatty liver disease

Andreas Vadarlis, Christina Antza, Dimitra Rafailia Bakaloudi, Ioannis Doundoulakis, Georgios Kalopitas, Myrto Samara, Theodoros Dardavessis, Theofanis Maris, Michael Chourdakis

J Gastroenterol Hepatol . 2020 Aug 18. doi: 10.1111/jgh.15221. Online ahead of print.

Abstract

Background: Νon-alcoholic fatty liver disease (NAFLD) is estimated to be the most common cause of end-stage liver disease in the next years. Vitamin E has shown beneficial effects as a possible “scavenger” of oxidative stress products, which play a major role in pathogenesis of the disease.

Aims: The purpose of the present meta-analysis is to investigate the effects of vitamin E supplementation in biochemical and histological parameters in adult patients with NAFLD.

Methods: Literature search was performed in major electronic databases (MEDLINE, CENTRAL and EMBASE) up to June 2020 for randomized clinical trials, which examined vitamin E versus placebo treatment in adults with NAFLD. Changes in liver enzymes were considered as primary outcomes, while changes in histology, biochemical and metabolic parameters as secondary. Quality of evidence was assessed through risk of bias according to the Cochrane risk of bias tool.

Results: Eight studies were included in qualitative analysis and seven in quantitative analysis. Vitamin E reduced the values of liver enzymes compared to placebo (-7.37 IU/L, 95% CI: -10.11 to -4.64 for ALT and -5.71 IU/L, 95% CI: -9.49 to -1.93 for AST) Additionally, vitamin E improved statistically significantly liver pathology in every individual histologic parameter as well LDL, FBG and serum leptin values.

Conclusions: Vitamin E can improve biochemical and histological characteristics of NAFLD patients, especially of NASH patients. The results indicate that vitamin E could be a promising choice and be considered as a treatment option in patients with NAFLD.

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Role of Vitamin E in Olanzapine-Induced Hepatotoxicity

Hiren Patel, Daisy Shirk, Joshua Lowery

J Child Adolesc Psychopharmacol . 2020 Aug 3. doi: 10.1089/cap.2020.0042. Online ahead of print.

To the Editor: Introduction Elevated transaminases are a common complication of many drugs, occurring in up to 27% of patients taking atypical antipsychotics medications (Atasoy et al. 2007). For patients who have no other options than remaining on certain antipsychotics such as olanzapine, physicians must weigh the risks versus benefits of continuing antipsychotic medications. We present a case study that attempted to replicate a previous single case study in which vitamin E therapy successfully reduced damaging effects of olanzapine on liver enzymes (Do¨nmez et al. 2017).

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Vitamin E as an Adjuvant Treatment for Non-alcoholic Fatty Liver Disease in Adults: A Systematic Review of Randomized Controlled Trials

Muhammad Usman, Nabiyah Bakhtawar

Cureus . 2020 Jul 6;12(7):e9018. doi: 10.7759/cureus.9018.

Abstract

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease. It is characterized by a variety of pathologies, ranging from benign fatty liver to extensive fibrosis and even hepatocellular cancer. Among the several potential risk factors, insulin resistance and increased oxidative stress are the most important. Vitamin E is an antioxidant with a potential to be used as a treatment for NAFLD. Therefore, we carried out a structured systematic review of all RCTs conducted between 2010 and January 2020. After screening, eight RCTs were included. Our systematic review showed that vitamin E has clinical utility in improving biochemical (ALT and AST levels) and histological abnormalities in NAFLD (hepatic steatosis and lobular inflammation). However, vitamin E does not seem to have significant effects on liver fibrosis. Still, vitamin E has the potential to be used as an adjuvant for the treatment of NAFLD, and its use in clinical practice should be advocated.

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Inflammatory Diseases and Vitamin E – What Do We Know and Where Do We Go?

Maria Wallert, Lisa Börmel, Stefan Lorkowski

Mol Nutr Food Res . 2020 Jul 21;e2000097. doi: 10.1002/mnfr.202000097. Online ahead of print.

Abstract

Inflammation-driven diseases and related comorbidities, such as the metabolic syndrome, obesity, fatty liver disease and cardiovascular diseases cause significant global burden. There is a growing body of evidence that nutrients alter inflammatory responses and can therefore make a decisive contribution to the treatment of these diseases. Recently, the inflammasome, a cytosolic multiprotein complex, was identified as a key player in inflammation and the development of various inflammation-mediated disorders, with nucleotide-binding domain and leucine-rich repeat pyrin domain (NLRP) 3 being the inflammasome of interest. Here we provide an overview about the cellular signaling pathways underlying nuclear factor ‘kappa-light-chain-enhancer’ of activated B-cells (NF-κB)- and NLRP3-mediated inflammatory processes, the pathogenesis of the inflammatory diseases atherosclerosis and non-alcoholic fatty liver disease (NAFLD); next, we discuss the current state of knowledge for drug-based and dietary-based interventions for treating cardiovascular diseases and NAFLD. To date one of the most important antioxidant in the human diet is vitamin E. Various in vitro and in vivo studies suggest that the different forms of vitamin E and also their derivatives have anti-inflammatory activity. Recent publications suggest that vitamin E – and possibly metabolites of vitamin E – are a promising therapeutic approach for treating inflammatory diseases such as NAFLD.

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