1. ^*Duke University Medical Center, Durham, North Carolina, USA
2. ^†Chang Gung Memorial Hospital, Taipei, Taiwan
3. ^‡North Carolina State University, Raleigh, North Carolina, USA
4. ^§Zielinski Research, San Diego, California, USA

Correspondence: Sheldon R. Pinnell, MD, The J. Lamar Callaway Professor Emeritus of Dermatology, Duke University, Box 3135 Duke University Medical Center, Durham, North Carolina 27710, USA. Email: madey001@mc.duke.edu, pinne002@mc.duke.edu

Received 7 January 2005; Revised 10 February 2005; Accepted 15 February 2005.

Abstract

Ferulic acid is a potent ubiquitous plant antioxidant. Its incorporation into a topical solution of 15% L-ascorbic acid and 1% -tocopherol improved chemical stability of the vitamins (C+E) and doubled photoprotection to solar-simulated irradiation of skin from 4-fold to approximately 8-fold as measured by both erythema and sunburn cell formation. Inhibition of apoptosis was associated with reduced induction of caspase-3 and caspase-7. This antioxidant formulation efficiently reduced thymine dimer formation. This combination of pure natural low molecular weight antioxidants provides meaningful synergistic protection against oxidative stress in skin and should be useful for protection against photoaging and skin cancer.