Cosmeceuticals may help some of the time, but jury is out on wrinkles

Scottsdale, Ariz. - For dermatologists interested in the in-office dispensing of cosmeceuticals, three agents in particular - ferulic acid, idebenone and human growth factors - are gaining prominence, but is there evidence to back them up?

In some cases, yes, but in regard to improving wrinkles or skin texture, more research is needed for all three, said San Francisco dermatologist William Kwan, M.D., at a recent meeting of the Skin Disease Education Foundation, here.

Perhaps the most promising findings pertain to ferulic acid, a cell wall component derived from plants and grains. The antioxidant is a polyphenolic compound in the hydroxycinnamic acid group that is commonly used in sunscreens.

In combination with vitamins C and E, ferulic acid appears particularly effective. In a study comparing a 15 percent l-ascorbic acid and 1 percent alpha-tocopherol solution with and without ferulic acid, the solution containing the ferulic acid was found to double photoprotection to solar-simulated irradiation of skin from fourfold to eightfold, when measured according to erythema and sunburn cell formation. (J Invest Dermatol. 2005;125:826-833).

The study's authors suggest the combination could provide a meaningful protection against oxidative stress and should be useful against photoaging and skin cancer.

An earlier study, published in 1999, found that when ferulic acid was used on human melanoma cells and melanocytes, it inhibited melanization better than ascorbic acid and kojic acid and could possibly help mitigate damage induced by active oxygen species, suppressing skin carcinogenesis (Anticancer Res. 1999;19:3769-3774).

Idebenone

Idebenone gained recognition in its systemic use for Friedreich's ataxia and Alzheimer's disease, and its ability to reduce nerve cell damage induced by ischemia and to help enhance memory and learning.

Specifically, idebenone inhibits lipid peroxidation and protects against oxidative damage to cell membranes, Dr. Kwan says.

For cosmeceutical purposes, topical use of idebenone has been touted as being useful for the correction of fine lines, wrinkles, skin hydration and roughness. It is currently available in two topical formulations - a 1 percent physician-strength concentration and a 0.5 percent over-the-counter concentration.

Due to side effects that included acne, burning, stinging and allergic contact dermatitis, the manufacturer came out with a new formulation this year, but Dr. Kwan suggests patients still take precautions by applying it on their neck for the first two to three days to see if they develop a reaction before applying it to the full face.

Human growth factors

Finally, topical formulations of human growth factors are getting much attention in the cosmeceutical industry. The growth factors are regulatory proteins that attach to surface receptors, modulating activities including collagen production, protein synthesis and vascular neogenesis, Dr. Kwan says.

The growth factors concentrate at wound sites and interact to coordinate and initiate wound healing.

In one study from 2003, NouriCel-MD, a patented mixture of eight growth factors, was applied to 14 patients over 60 days. The results showed statistically significant reductions in periorbital region regional rhytids and epidermal thickening, and improvements in skin texture.

And in an unpublished multi-center topical growth factor study of 236 females and 19 males with moderate to severe photodamaged skin, 57 percent of patients reported improvement in the appearance of wrinkles, 87 percent reported improvement in skin texture and 93 percent desired to continue use of the topical growth factors.

Dr. Kwan emphasizes, however, that more clinical evidence is needed on all of the products' efficacy.

"In terms of wrinkle reduction, I don't think there are any great studies on these antioxidants," he says.

Disclosure: Dr. Kwan reports that he is on the speaker's bureaus for Allergan and Cynosure.