Vitamin E is a family of eight separate but related molecules: four tocopherols (alpha, beta, gamma, and delta) and four tocotrienols (alpha, beta, gamma, and delta).
While alpha-tocopherol is found in most multivitamins and is supplemented in foods, there have been reports that alpha-tocopherol may interfere with the uptake and function of tocotrienols.
However, the new study, published in the PubMed listed journal Oxidative Medicine and Cellular Longevity, found that the potential protective effect of alpha-, delta-, and gamma tocotrienol for endothelial health were only observed when the tocotrienols were present with alpha-tocopherol. The new study used the commercial tocotrienol/tocopherol complex known as Tocomin (now known as EVNol, manufactured by ExcelVite).
‘Superior antioxidant activity’
“It has been suggested that tocotrienols may have superior antioxidant activity to tocopherols, and we did find that to be true,” wrote Saher Ali and Owen Woodman from the Royal Melbourne Institute of Technology University (RMIT) in Australia. “By contrast alpha-, delta-, and gamma-tocotrienols were largely ineffective in improving NO mediated, endothelium-dependent relaxation in the presence of oxidative stress.
“However, Tocomin, an extract from palm oil rich in tocotrienols and with a minor component of alpha-tocopherol, was found to be the most effective compound tested. The efficacy of Tocomin could be replicated by the presence of alpha-tocopherol with alpha-, delta-, and gamma-tocotrienols but not by the combined presence of the 3 tocotrienols alone.
“Thus the combination of tocotrienol isomers and tocopherol may prove to be an effective approach to the preservation of endothelial function where there is disease-induced oxidative stress such as in diabetes and hypertension.”
Study details
Ali and Woodman investigated the effects of single, pure tocotrienols (alpha, gamma, and delta) versus alpha-tocopherol alone, or a tocotrienol complex (EVNol; 78% tocotrienols and 22% alpha-tocopherol) in reducing oxidative stress and restoring endothelium-dependent relaxation in lab rats.
Results showed that the individual tocotrienols did effectively scavenge superoxide ions, but they did not improve endothelial function unless alpha-tocopherol was present. Alpha-tocopherol alone was able to restore endothelial function, said the researchers. The tocotrienol/tocopherol complex was found to be more potent than alpha-tocopherol at restoring endothelial function with the effectiveness of EVNol observed at 100 times lower concentration than that of alpha-tocopherol, said the researchers.
“Thus we speculated that the combination of multiple tocotrienol isomers and/or the additional presence of α-tocopherol was necessary to preserve endothelium-dependent relaxation,” they wrote. “By testing the preparations with the same proportion of alpha, gamma, and delta-tocotrienols and alpha-tocopherol present in tocomin, we determined that only the preparation containing alpha-tocopherol plus alpha, gamma, and delta -tocotrienol preserved endothelial function in the presence of oxidative stress.
“This data suggests an important interaction between alpha -tocopherol and tocotrienols to promote protection of vascular function.
“The mechanism of this positive interaction between alpha -tocopherol and the tocotrienols is worthy of further investigation.”
‘Exciting’
The study was described as WH Leong, CEO of ExcelVite Inc (formerly Carotech). “This study provides new evidence showing that alpha-tocopherol plays an important role in preserving endothelial function by itself as well as in an increased synergy with the tocotrienols. The natural complex of tocotrienols and alpha-tocopherol in EVNol function synergistically to prevent oxidative stress and restore endothelial function at a very low concentration.
“There are 8 isoforms of vitamin E in nature, and all vitamin E forms exist for important reasons as nature knows best that for vascular protection, both tocotrienols and tocopherols work together synergistically to confer a higher beneficial effect.
“This also reflects recent European research studies that show high blood levels of all vitamin E forms (mixed tocopherols and mixed tocotrienols) protect elderly people from the risk of mild cognitive impairment and Alzheimer’s disease,” he added.
Source: Oxidative Medicine and Cellular Longevity
Volume 2015, Article ID 150829, doi: 10.1155/2015/150829
“Tocotrienol Rich Palm Oil Extract Is More Effective Than Pure Tocotrienols at Improving Endothelium-Dependent Relaxation in the Presence of Oxidative Stress”
Authors: S.F. Ali, O.L. Woodman