Therapeutic Peptides in Aged Skin

By: Farzam Gorouhi, MD, and Howard I. Maibach, MD, University of California School of Medicine

Posted: August 28, 2009, from the September 2009 issue of Cosmetics & Toiletries.

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The trial then continued with a comparison of the test serum to a tissue nutrient solution (TNS) cream in 20 test subjects.¹⁸ TNS contains growth factors including vascular endothelial growth factor, platelet-derived growth factor A, granulocyte colony-stimulating factor, hepatocyte growth factor, interleukin-6, interleukin-8, and TGF-β1 without vitamin C. Both creams were found to significantly improve wrinkle scores.

Growth factor and cytokine mixture: A bio-restorative skin cream was developed containing a proprietary growth factor and cytokine mixture extracted from cultured, first trimester fetal human dermal fibroblasts. In a placebo-controlled trial, Gold and colleagues concluded that some skin roughness parameters were significantly better in the group treated with the cream but that no statistical difference between two groups was detected.¹⁹

Soybean proteins: Soybean proteins or peptides are enzyme inhibitor peptides extracted from soybean seeds. Soy proteins inhibit the formation of proteinases and increase trichoblast and atrichoblast numbers without changing their localization pattern;²⁰ they are used as antiaging, skin moisturizer, anti-solar and hair-promoting agents.

In a randomized double blind placebo-controlled study, soy extract and placebo creams were applied to the forearms of 21 healthy women²¹ and overall, the papillae index increased greater with the application of the soy extract than with the placebo (p < 0.05).

Sericin: Another enzyme inhibitor protein, sericin or silk worm secretion, is extracted from the middle silk gland of the Bombyx mori silkworm. Sericin exhibits antioxidant properties and has a high affinity for chelating with copper. In addition, it inhibits lipid peroxidation, tyrosinase activity and keratinocyte apoptosis. In another study, silk protein was compared with bovine serum albumin in a vehicle found to better reduce UVB-induced symptoms in both short-term and chronic treatment courses.²²