Tocotrienols, the vitamin E of the 21st century: Its potential against cancer and other chronic diseases

Abstract

Initially discovered in 1938 as a "fertility factor," vitamin E now refers to eight different isoforms that belong to two categories, four saturated analogues (α, β, γ, and δ) called tocopherols and four unsaturated analogues referred to as tocotrienols. While the tocopherols have been investigated extensively, little is known about the tocotrienols. Very limited studies suggest that both the molecular and therapeutic targets of the tocotrienols are distinct from those of the tocopherols. For instance, suppression of inflammatory transcription factor NF-κB, which is closely linked to tumorigenesis and inhibition of HMG-CoA reductase, mammalian DNA polymerases and certain protein tyrosine kinases, is unique to the tocotrienols. This review examines in detail the molecular targets of the tocotrienols and their roles in cancer, bone resorption, diabetes, and cardiovascular and neurological diseases at both preclinical and clinical levels. As disappointment with the therapeutic value of the tocopherols grows, the potential of these novel vitamin E analogues awaits further investigation.

Hen egg carotenoids (lutein and zeaxanthin) and nutritional impacts on human health: a review

“…tocos) are fat-soluble vitamins and are generically regarded as vitamin E, for which the antioxidant properties are well studied. Vitamin E is thought to prevent atherosclerosis, protect against coronary disease, and prevent neurons from oxidative stress and the development of AD and possibly cancers (Aggarwal, Sundaram, Prasad, & Kannappan, 2010;Rong et al, 2013).…”

Vitamine E et physiologie du tissu adipeux

“…Le terme generique vitamine E regroupe deux grands groupes de molecules : les tocopherols et les tocotrienols, comprenant chacun 4 vitameres a, b, g et d (Jensen et Lauridsen, 2007 ;Aggarwal et al, 2010 ;Brigelius-Flohe, 2009 ;Azzi, 2007 ;Traber et Atkinson, 2007). Leurs structures chimiques se composent d'un cycle chromanol mono-, di-, ou trimethyle auquel est rattachee une chaîne laterale a 16 atomes de carbone, de structure isoprenique (figure 1).…”

Effects of α‐tocopherol on the early phase of osteoporotic fracture healing

“…Among the vitamin E isomers, a-tocopherol has the highest bioavailability as it is preferentially absorbed by the body. 19,20 This is the reason why a-tocopherol is the most studied and widely available vitamin E. 21 aTocopherol has also been claimed to be the most important lipid-soluble anti-oxidant, and that it protects membranes from oxidation by reacting with lipid radicals produced during the lipid peroxidation chain reaction. 22,23 Studies have shown mixed results on the effects of a-tocopherol on fracture healing but all these studies were conducted in normal bone.…”