Impact of vitamin E on redox biomarkers in non-alcoholic fatty liver disease

Abstract

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder in Western nations and characterized by excessive accumulation of lipids in the liver. In this narrative review, we summarize the evidence from human trials that free radical-induced oxidation of macromolecules, in particular of lipids, is a characteristic feature of NAFLD and non-alcoholic steatohepatitis (NASH). We further synthesize the data in the scientific literature describing the impact of vitamin E (mainly α-tocopherol) on concentrations of redox biomarkers in liver biopsies from patients with NAFLD as well as animal experiments. In summary, the available evidence from clinical trials suggests that reactive species-mediated damage to macromolecules, predominantly lipids, occurs in NAFLD and NASH and that daily supplementation with at least 200 I.U. α-tocopherol may alleviate oxidative stress in the liver of NAFLD patients. We propose α-tocopherol as a useful model substance to identify and validate suitable redox biomarkers that may be employed in future clinical trials of new therapeutics for NAFLD.

The Role of Vitamins in Non-Alcoholic Fatty Liver Disease: A Systematic Review

“…Vitamin E, a lipophilic compound, exists naturally as tocopherol (alpha, beta, gamma, delta) and tocotrienol (alpha, beta, gamma, delta) [ 6 ]. Among these, alpha-tocopherol is the most abundant and most potent antioxidant, which acts as scavengers of free radicals [ 21 ].…”

“…Notably, a dose of 800 IU daily can improve histologic findings in non-diabetic patients with biopsy-proven NASH [ 5 , 21 ]. Although the safety profile of Vitamin E is still in question due to its controversial adverse effects with long-term use such as prostate cancer in men [ 5 ] and hemorrhagic stroke [ 1 ], the intake of alpha-tocopherol is currently the only intervention that leads to mortality rate drop and transplant-free survival improvement among NASH patients [ 6 ].…”

“…On the other hand, NASH presents with steatosis in combination with inflammation and ballooning, with or without fibrosis [ 9 ]. Due to evidence of hepatic cell death, inflammation, fibrogenesis, and reactive species, patients with NASH have an increased risk for hepatocellular carcinoma and may require liver transplantation [ 6 ].…”

Special issue on ‘Biomarkers of Oxidative Stress, Aging and Nutrition in Human Studies’

“…Other reviews focus more on the disease aspects of redox biomarkers [ [12] , [13] , [14] , [15] ]. Cardiovascular diseases are highly common and associated with oxidative stress.…”

“…Podszun and Frank discuss the recent findings of vitamin E and NAFLD, showing that daily supplementation with at least 200 I.U. α-tocopherol may alleviate oxidative stress in the liver of NAFLD patients [ 15 ].…”