Vitamin E research: Past, now and future

The early history of vitamin E from its discovery by Herbert M. Evans and Katharine J. S. Bishop in 1922 up to its chemical synthesis by Paul Karrer and coworkers in 1938 and the development of the concept that vitamin E acts as an antioxidant in vivo are recalled. Some more recent results shedding doubt on this hypothesis are reviewed. They comprise influence of vitamin E on enzyme activities, signaling cascades, gene expression and biomembrane structure. The overall conclusion is that our knowledge of the vitamin's mechanism of action still remains fragmentary. The metabolism of tocopherols and tocotrienols is presented and discussed in respect to bioactivity of the metabolites, interference with drug metabolism and the future design of clinical trials. Some strategies are recommended how to reach the final goal: the identification of the primary vitamin E target(s) and the analysis of the downstream events up to the physiological phenomena.

Automated summary

The early history of vitamin E, its discovery and chemical synthesis, as well as the development of the concept of its antioxidant properties are recounted. Recent research has cast doubt on this hypothesis, including the effects of vitamin E on enzyme activities, signaling cascades, gene expression, and biomembrane structure. Overall, our knowledge of vitamin E's mechanism of action remains incomplete, with discussions on its metabolism, bioactivity of its metabolites, and implications for future clinical trials.