Vitamin E: the radical protector

Abstract

Since its discovery and isolation the importance of vitamin E in maintaining normal physiologic processes and its value in treating various disease states have been the subject of much controversy. It was our intention to review and highlight some of the arguments and problems regarding the usefulness of vitamin E and to try to put them into proper perspective. The major area of interest concerning vitamin E lies essentially in its role in preventing damage caused by free radicals. The latter are now known to play an important role in radiation induced carcinogenesis, photoaging and photosensitization. The chemistry of vitamin E, its physiological function as a major antioxidant and its interaction with other antioxidants are described by the sum of animal studies, in vitro research and epidemiological investigations. In preparing the current data, it appeared that despite the controversy and conflicting results the body of literature as a whole judges vitamin E to be useful as an antioxidant. Although, in principle, the use of vitamin E can be quite advantageous, the manner of its administration, especially regarding topical application, remains unclear.

Heterogeneous tempo and mode of evolutionary diversification of compounds in lizard chemical signals

“…It has been attributed important functions in metabolism, and thus, it might act as an indicator of male “quality” (Martín, Chamut, Manes, & López, 2011; Weldon et al., 2008); (6) α‐tocopherol (i.e., vitamin E), usually found in lizard species in high proportions. It is believed to have antioxidant properties, protecting other compounds in secretions (Brigelius‐Flohe & Traber, 1999; Wolf, Wolf, & Ruocco, 1998). Also, high levels of α‐tocopherol are linked to the quality of lizards, and therefore, it has been assigned an important role during competition over sexual mates (Kopena et al., 2011); (7) cholestanol, commonly found in lacertids, and thought to be related with healthy body condition (Weldon et al., 2008); and (8) cholesta‐5,7‐dien‐3‐ol, a steroid present in some lizard species, it is the precursor of vitamin D 3 .…”

Electrochemical oxidation of quercetin in hydro-alcoholic solution

“…5 Several of these biological effects are related to radical scavenging (antioxidant) properties of such compounds. 3,6,7 Radical reactions occur in many biological processes as a natural consequence of living in an oxidizing environment. However damaging radical reactions outcome when an unusual process takes place.…”

“…However damaging radical reactions outcome when an unusual process takes place. 7 Interesting reports on the role of free radicals and antioxidants were given by Thomas 6 and Wolf et al 7 Quercetin (3,3',4',5,7-pentahydroxy-flavone, Figure 1), is a flavonoid of widespread occurrence in nature whose medicinal properties have been extensively demonstrated in the literature, especially the antioxidant capacity. [8][9][10][11] The antioxidant properties of these compounds (flavonoids) have been attributed to their capacity to scavenge free radicals generated in aqueous phase, increasing the resistance of lipids against peroxidation.…”

Effect of the addition of IGF-I and vitamin E to stored boar semen

“…Thus, its use in artificial insemination is limited after storage at temperatures from 58C to 158C. During the storage of semen, in general way, antioxidants, such as vitamin E, are able to suppress lipid peroxidation by the capture of peroxyl radicals involved in the peroxidation chain (Wolf et al, 1998). In this way, the addition of vitamin E to diluents may increase sperm's resistance to lipid peroxidation in boars (Cerolini et al, 2000;Johannisson et al, 2003;Breininger et al, 2005).…”