title: Evaluation of the antioxidant capacity and preventive effects of a topical emulsion and its vehicle control on the skin response to UV exposure.
abstract: Supplying topical exogenous antioxidants to the skin may prevent or minimize free radical-induced damaging. This study determines antioxidative capacity of a topical skin care emulsion (an oil-in-water vitamin E-containing formulation) versus its vehicle on human skin that was exposed to ultraviolet radiation (UVR) by utilizing a photochemiluminescence device and biophysical methods. Ten healthy Caucasians (3 male and 7 female; mean age 47 +/- 10 years) were enrolled. In a randomized and double-blind manner, a pH-balanced vitamin E emulsion or its vehicle control was applied onto predesignated forearm prior to UVR exposure. Thirty minutes after application, these test sites were exposed to a UV light to induce the minimal erythema dose. One untreated site served as a blank control. Visual scoring and instrumental measurements were recorded at baseline and at 24 h and 48 h thereafter. At day 3, after completing instrumental measurements, each test site was stripped three times in a consecutive manner with a proprietary adhesive tape disc. These tapes were quantified for antioxidant capacity using a photochemiluminescence device. Vitamin E emulsion and vehicle control significantly (p < 0.05) suppressed visual scores when compared with blank control at day 2 and day 3 after UV exposure. However, vitamin E emulsion showed significantly (p < 0.05) lower visual scores when compared with vehicle control at day 2 and day 3 after UV exposure.Also,vitamin E emulsion and its vehicle control significantly (p < 0.05) diminished skin color measurement (a*) values when compared with blank control at day 2 and day 3 after UV exposure. At day 2 after UV exposure, only vitamin E emulsion significantly (p < 0.05) reduced skin blood flow volume when compared with blank control. Vitamin E emulsion and its vehicle control showed significant (p < 0.05) reduction of blood flow volume when compared with blank control at day 3 after UV exposure. Vitamin E emulsion and its vehicle control proved effective in preventing induction of erythema and reducing inflammatory damage caused by UV exposure. The effect of vitamin E emulsion exceeded that of an 'active control'.
authors.affiliation: Department of Dermatology, School of Medicine, University of California, San Francisco, 94143, USA. hongbo@itsa.ucsf.edu
authors.forename: H
authors.initials: H
authors.lastname: Zhai
authors.forename: S
authors.initials: S
authors.lastname: Behnam
authors.forename: C D
authors.initials: CD
authors.lastname: Villarama
authors.forename: M
authors.initials: M
authors.lastname: Arens-Corell
authors.forename: M J
authors.initials: MJ
authors.lastname: Choi
authors.forename: H I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D004311:Double-Blind Method; D025802:Electric Capacitance; D004655:Emulsions; D004890:Erythema / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000187:drug effects; D012867:Skin / Q000098:blood supply / Q000187:drug effects* / Q000528:radiation effects; D013997:Time Factors; D014466:Ultraviolet Rays; D014810:Vitamin E / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D004655:Emulsions; D014810:Vitamin E