## 5 Tomato Bioactives as Ingredients in Sun Oils for Skin Care
### In Vivo Studies--Main Findings  
5.3.1 Vitamin C and E-Synergistic Behavior  
Studies on humans and animals have demonstrated that topically administered vitamin E and, to a lesser extent, vitamin C offer UV protection. It is possible to modify a number of endpoints that show phototoxic damage, including DNA damage, lipid peroxidation, UV-dependent erythema, sunburn cell development, and wrinkles in the skin. In comparison to sunscreen alone, adding botanical antioxidants and vitamins C and E to a broad-spectrum sunscreen may significantly reduce UV-induced damage. It has been demonstrated that these medicines improve defense against UV-induced epidermal thickening, MMP-1 and MMP-9 overexpression, and CD1a, Langerhans cell reduction. When applied topically to human skin in vivo, non-sunscreen substances like antioxidants, DNA repair enzymes, and plant extracts can be beneficial [45; 46]. 5.3.2. Tocopherol  
Tocopherol is a naturally occurring lipophilic vitamin with strong antioxidant properties. It has also been shown to have cytoprotective properties and to be a scavenger of ROS, specifically peroxyl radicals, which prevents the oxidation of biomolecules like proteins and lipids. It helps prevent oxidative stress on the cell membrane and resists UV-induced cellular deterioration, including photoaging, lipid peroxidation, immunosuppression, andphotocarcinogenesis [47; 48]. Pre-treatment with formulations containing vitamin E offers strong protection against photosensitivity, while areas treated with topical vitamin E formulation showed better results in comparison to areas treated with the simple vehicle or with vitamin A.  
Nevertheless,tocopherol has low photo- and chemical stability as well as a unique vulnerability to alkoxyl radical oxidation, which leads to the production of chromanoxyl radicals. Tocophenyl acetate and tocophenyl glucoside are two novel derivatives that have been developed as a result of molecular alterations to the original molecule [47]. While tocopherol acetate results from the acetylation of the free aromatic hydroxyl group of \(\alpha\)-tocopherol, tocophenyl glucoside results from the addition of a glucose sugar unit. Furthermore, tocopherol has poor water solubility and topical formulation due to its high hydrophobicity; however, these issues may be resolved with the use of both these forms of vitamin E. These forms of vitamin E have no action on their own, and thus cutaneous phosphatases or esterases activate them in order to release the active vitamin E at the desired location. More specifically, even though tocophenyl acetate presents a more lipophilic character than its parent compound, the higher stabilization, and less probability of being oxidized, along with its insertion in the skin phospholipid bilayer, potentiates the neutralization of free radicals. Thus, \(\alpha\)-tocopherol acetate is often used in dermatological products such as skin creams, as it is not easily oxidized and can penetrate through the skin to the living cells, where about 5% is converted to free tocopherol, with claims for beneficial antioxidant effects. \(\alpha\)-Tocophenyl acetate is used as an alternative to tocopherol itself because the phenolic hydroxyl group is blocked, providing a less acidic product with a longer shelf life. It is believed that the acetate is slowly hydrolyzed after it is absorbed into the skin, regenerating tocopherol and providing protection against the sun's ultraviolet rays. Subsequently, vitamin E and its derivative tocopheryl acetate are placed in the first and second positions, respectively, among the top six most commonly used antioxidants in sunscreens [47]. The opposite was seen with the glycosylated tocophenyl derivative (tocophenyl glucoside), which was found to be used in a much lower number of sunscreen formulations, among all the formulations analyzed. Tocophenyl glucoside turns into a more lipophilic and active molecule from which free tocopherol is released after cleavage of the glycosidic bond, catalyzed by \(\beta\)-glucocerebosidase in the stratum corneum.