Antioxidants beef up photoprotection by up to 90%

May 1, 2006

New Orleans - Conventional sunscreens have a number oflimitations that can be improved upon if used in combination withantioxidants, says Mostafa M. Omar, Ph.D.

New Orleans - Conventional sunscreens have a number of limitations that can be improved upon if used in combination with antioxidants, says Mostafa M. Omar, Ph.D.

Dr. Omar says, "We have found that applying antioxidants to the skin before sunscreens will stop free radical reactions before they can happen."

Sunscreens on the U.S. market provide excellent UVB protection if used properly, but often fall short in the UVA department. Filling this gap is important, since UVA is the prime suspect in photoaging. Dr. Omar says using his antioxidant formulations before sunscreen application can improve the overall efficacy of sunscreens by four to eight times.

With funding from the National Cancer Institute, Dr. Omar set up clinical trials at Duke University to test almost 50 natural antioxidants. His goal was to optimize a topical formula with regard to concentration and pH for maximum photoprotective benefits to the dermis and epidermis.

After evaluating the compounds, he selected a formula that contains vitamin C (5 percent to 25 percent), vitamin E (1 percent to 5 percent), vitamin A (1 percent), and olive leaf extract (1 percent to 10 percent).

Vitamin C is the focus, Dr. Omar tells Dermatology Times, "because after the age of 25, the body doesn't synthesize enough C, and if I eat an orange, less than 0.1 percent reaches the skin." He uses L-ascorbic acid, he argues, because the skin does not absorb ester versions of vitamin C or any other salt derivatives of vitamin C.

Olive leaves have been used for centuries to treat fevers, malaria, high blood pressure and intestinal muscle spasms. They contain oleuropein and hydroxytyrosol, which inhibit pro-oxidative processes. Olive oil extract is antibacterial, antiviral and anti- inflammatory.

In evaluating the impact of the different ingredients, investigators at Duke took 8 mm punch biopsy specimens from antioxidant-treated and control skin that had received solar-simulated radiation at 1-10x MED. They then calculated the number of sunburn cells per linear mm of epidermis. Both control skin and vehicle skin had approximately the same results: 35 sunburn cells/mm of epidermis. (Beyond 35 sunburn cells/mm, the damage is too great to count precisely. This makes it the practical upper limits.) Best protection results of approximately 10 sunburn cells/mm were obtained with vitamins C, E, A, plus olive leaf extract. Vitamins C, E and A without olive oil extract allowed 27 sunburn cells/mm.

Also evaluated was the antioxidant protection factor (APF), a ratio of healed cells to burned cells. The vehicle alone has an APF of approximately 10, while vitamins C, E and A with olive leaf extract had an APF of 70.

Dr. Omar says tests are now under way which indicate that the efficacy of sunscreens improve 80 percent to 90 percent when used in combination with antioxidants. His ultimate goal is to develop a formula that combines sunscreen ingredients with natural antioxidants in a single product.

Disclosure: PhytoCeuticals Inc. has an agreement with Innovative Skincare of Los Angeles for exclusive rights to manufacture and distribute Dr. Omar's vitamin C-based formulations.