1999 ANNUAL SCIENTIFIC MEETING 41 The rationale for the use of antioxidants for photoaging is the fact that free radicals enhance skin carcinogenesis and photoaging. UVL increases the production of free radicals and decreases antioxidants in the skin. Vitamins C, E and K, Beta-carotene, alpha lipoic acid, superoxide dismutase, glutathione, coenzyme Q10, oligomeric proanthocyanidins, flavinoids and melatonin are examples of antioxidants used tbr the treatment of aging skin. Newer antiaging treatments include Kinerase, Ethocyn, estrogens and botanicals. Chemical peels, dermabrasion, laser resurfacing, Botox injections and collagen injections are some of the surgical options. A review of the clinical features, diagnosis and treatment of aging skin will be presented in further detail. References: 1. Gilchrest BA. Photodamage. Cambridge, Massachussetts, Blackwell Science, Inc., 1995. 2. Bergfeld WF. The Aging Skin. lnt J Ferti142(2): 57-66, 1997. 3. Lewis AB, Gendler EC. Resurfacing with Topical Agents. Sem Cutan Med Surg 15(3): 139-44, 1996. 4. Gilchrest BA. A Review of Skin Ageing and its Medical Therapy. Br J Dermatol 135: 867-75, 1996.

42 JOURNAL OF COSMETIC SCIENCE EFFECTS OF ANTIOXIDANT INGREDIENTS ON HUMAN SKIN: FROM CELL CULTURE TESTING TO HUMAN CLINICAL STUDIES James A. Greene, M.S.' and Richard L. Roberts, Ph.D. 2 •Shaklee Corporation, Hayward, C,4 94545-1702 and 2R.L. Roberts and ,4ssociates, Germantown, TN Introduction: Cosmetic chemists have included Vitamins A, C, and E and other similar ingredients into skin care and cosmetic products for many years now. These ingredients and their derivatives were originally incorporated into those products for their effects in improving the appearance and feel of the skin. It has been well documented that Vitamins A and C help make the skin appear younger looking. It is also well known that Vitamin E improves the feel of the skin making it smoother and softer. Because of the readily perceived efficacy of these ingredients, consumers seek out products featuring these ingredients. Based upon the efficacy and consumer desirability, these ingredients have become very prevalent in skin care, cosmetic and even over-the-counter (OTC) drug products. The levels of these materials incorporated into personal care products are generally low since high concentrations can cause contact irritation and/or allergic contact dermatitis. Additionally, these materials are relatively expensive and some of them are difficult to stabilize in formulations. During the past three decades, research has shown the importance of these ingredients among the various antioxidant components of the skin. Research has also shown that following a significant exposure of the skin to the ultraviolet light, the amounts of these antioxidants present in the skin are significantly depleted. However, the topical application of antioxidants as delivered from cosmetic, skincare, and over-the-counter (OTC} drug products have been shown to help boost the skin's antioxidant capacity. Materials and Methods: All testing conducted on formulations containing antioxidant materials was carried out at outside laboratories under the direction of the authors. The protocols employed to evaluate the various materials were developed by the testing laboratories and used with only minor modifications. The source of the ultraviolet light employed in all experiments requiring such exposure was a xenon arc light source with appropriate filtering to mimic the terrestrial solar ultraviolet spectrum or for the transmission of only long wavelength ultraviolet light. The other instruments employed in this testing were commercially available equipment, unmodified and used according to manufacturer's instructions. Antioxidant Cell Culture Testing: Individual antioxidant materials and mixtures were tested using cell cultures purchased from MatTek. Each material evaluated was tested on three separate cell cultures. For the non-irradiated cultures, water was used as the negative control and Triton X-100 was used as the positive control. For the cultures irradiated with solar simulated ultraviolet light experiments, irradiated cell cultures to which no antioxidants materials were added were the positive control and unirradiated cell cultures were the negative control. The percentage cell viability was determined by uptake of MTT and conversion to the insoluble formazin crystals that were extracted from the cells at the conclusion of the test and evaluated by a spectroscopic technique. Production of Prostaglandin E2 was evaluated using a standard assay kit and procedure from Perspective Diagnostics. Antioxidant Activity Tested on Human Skin: The effectiveness of a mixture of antioxidants in finished formulations was conducted using the known bleaching effect of beta-carotene when exposed to long wavelength solar ultraviolet (UVA} light. This method is appropriately called the beta-