Tocopherols in the Prevention and Treatment of Atherosclerosis and Related Cardiovascular Disease

Abstract

Oxidants/antioxidants play an important role in cellular homeostasis. The human body has endogenous molecules that work as antioxidants, such as glutathione, superoxide dismutase, peroxidases, and catalase. Exogenous substances in the diet, such as β‐carotene, ascorbate, and vitamin E, are vital antioxidants. Of these, vitamin E is likely the most important antioxidant in the human diet, and many studies have been performed to elucidate its role in health and disease. Vitamin E is a family of several compounds, of which α‐tocopherol is the most widely known analog. α‐Tocopherol exhibits antioxidative property in vitro and inhibits oxidation of low‐density lipoprotein cholesterol. In addition, α‐tocopherol shows anti‐inflammatory activity and modulates expression of proteins involved in the uptake, transport, and degradation of atherogenic lipids. Though α‐tocopherol exhibits important antioxidant, anti‐inflammatory, and antiatherogenic features in vitro, α‐tocopherol supplements have failed to consistently reduce atherosclerosis‐related events in human trials. The conflicting results have led to reconsideration of the importance previously given to α‐tocopherol and led to interest in other members of vitamin E family, especially γ‐tocopherol, which exerts a much more potent antioxidant, anti‐inflammatory, and cardioprotective effect than α‐tocopherol. This reconsideration has been backed by solid laboratory and clinical research. We suggest that the absence of γ‐tocopherol in traditional preparations may be one reason for the lack of consistent salutary effects of vitamin E preparations in clinical trials. This review summarizes our current understanding of tocopherols as antioxidant molecules and emerging evidence of an important role of γ‐tocopherol in the pathophysiology of atherosclerosis‐related cardiovascular disease.

Protective Effects of Vitamin E on Diabetes-induced Oxidative Stress Status and Homocysteine in the Rat Heart

“…It is said that this increase occurs because of the increase in the production of free radicals in diabetic rats. The increase in the amount of free radicals is the result of an increase in the incidence of hyperglycemia [23].…”

Egg Consumption Increases Vitamin E Absorption from Co-Consumed Raw Mixed Vegetables in Healthy Young Men

“…AUCs 0-10 h , 0-to 10-h AUCs; CON, control (raw mixedvegetable salad without eggs); HE, high egg (raw mixed-vegetable salad with 150 g scrambled whole eggs); LE, low egg (raw mixed-vegetable salad with 75 g scrambled whole eggs; SWE, scrambled whole egg (150 g scrambled whole eggs without raw mixed-vegetable salad); TRL, TG-rich lipoprotein fraction. 2 Values are least-squares means 6 SEs, n = 16. 3 Values are means 6 SEs, n = 9.…”

Understanding oxidants and antioxidants: Classical team with new players

“…The oxidized tocopheryl radical is then reconverted back via ascorbic acid facilitated pathway to tocopherol (Traber & Stevens, 2011). Though αT is the most abundant and the predominantly investigated form, the other isoforms such as γ-tocopherol, δ-tocopherol, and γ-tocotrienol also have antioxidative and anti-inflammatory activity and play a vital role in the pathophysiology of a number of diseases (Mathur, Ding, Saldeen, & Mehta, 2015).…”