The combined use of oral and topical lipophilic antioxidants increases their levels both in sebum and stratum corneum

The concentration of Vitamin E (vit E) and ubiquinone (CoQ10), which together with squalene (SQ), play a key role against external oxidative insult, has been shown to decrease significantly during ageing. The aim of the present study is to inquire the effect of the combined use of topical bio-cosmetics containing natural active principles (including sebum-like lipid fractions, sebum and epidermal lipophilic and hydrophilic antioxidants), and oral antioxidant supplements on the antioxidant content of sebum and stratum corneum. We therefore treated the face and the back of 50 female volunteers aged 21-40, daily for two months, with a base cream containing 0.05% ubiquinone, 0.1% vit E, and 1% squalene. In addition 50 mg of CoQ10 + 50 mg of d-RRR-alpha-tocopheryl acetate + 50 microg of selenium were administered orally to half of the volunteers (Group A). Group B was represented by 25 volunteers who were treated only topically. Every 15 days during treatment the levels of CoQ10, vit E and SQ were verified in sebum, stratum corneum, and plasma. The daily topical application of the cream led to a significant increase, that peaked after 60 days, of the levels of CoQ10, d-RRR-alpha-tocopherol and SQ in the sebum (Group B), without significantly affecting the stratum corneum or plasma concentrations of the redox couple CoQ10H2/CoQ10 and vit E. The concomitant oral admistration of antioxidants produced in Group A a significant increase of the levels of CoQ10H2/CoQ10 and vit E both in plasma and stratum corneum after 15 and 30 days treatment respectively, compared to Group B. However the sebum levels of lipophilic antioxidants and SQ did not show a significant increase. After the treatments, the levels of CoQ10H2/CoQ10, vit E and SQ went back to basal levels within 6-8 days in sebum, 12-16 days in the stratum corneum, and 3-6 days in plasma. Therefore topical application of the antioxidants was able to increase their level in sebum, while the concomitant oral administration also affected the levels of vit E and CoQ10 in the stratum corneum.