Factors of natural aging
Natural aging of the skin results in decreased production and increased degradation of extracellular matrix proteins such as collagen, fibronectin, elastin and laminin. The extracellular matrix, in addition to providing structural support, also influences cellular behaviors such as differentiation and proliferation. These functions are mediated through small peptides (matrikines) derived from proteolytic degradation of extracellular matrix proteins. These matrikines act as signal proteins between matrix component and cell wall receptors.
An overview of pentapeptide-3
Various peptides affect the aging process by modulating collagen homeostasis. Pentapeptide-3 (Lys-Thr-Thr-Lys-Ser, KTTKS) is one of the earliest oligopeptides to be developed as a cosmetic agent. It is a subfragment of the carboxyl-terminal propeptide of type I collagen. This peptide fragment dramatically augments extracellular matrix production in the fibroblasts. It also stimulates type I and type III collagen and fibronectin production in a dose- and time-dependent manner with no effect on total protein synthesis or the ratio of secreted proteins to cell-associated proteins. When such peptides are used topically, their instability on or in the skin and poor permeability across the skin are challenges for successful dermal delivery. To overcome this handicap, the peptide is conjugated with a fatty acid, i.e., palmitic acid (pal-KTTS) to increase stability and permeability of the skin. A study on 180 women by Osborne et al. showed that pal-KTTKS significantly decreased the bumpy texture and fine lines compared to controls. Pentapeptide-3 acts as a competitive antagonist of the acetylcholine postsynaptic membrane receptor, preventing sodium ion channels from opening, thus inhibiting depolarization and muscle contraction. In vitro studies have demonstrated that pentapeptide-3 significantly reduces muscle cell contraction by 71% within 1 minute of application and reduces muscle cell contraction by 58% after 2 hours.
Function of pentapeptide-3
Pentapeptide-3, or Vialox, can prevent wrinkles from getting deeper because the muscle fibers are still immotile two hours later. In vivo and in vitro studies showed that this product can soften wrinkles and reduce skin roughness, especially against expression lines. It can be used at concentrations of 0.05%-0.3% to treat facial wrinkles and to tighten skin.
References:
1. Reddy, B. Y., Jow, T., & Hantash, B. M. (2012). Bioactive oligopeptides in dermatology: Part II. Experimental dermatology, 21(8), 569-575.
2. Gorouhi, F., & Maibach, H. I. (2009). Role of topical peptides in preventing or treating aged skin. International journal of cosmetic science, 31(5), 327-345.
3. Zhang, L., & Falla, T. J. (2009). Cosmeceuticals and peptides. Clinics in dermatology, 27(5), 485-494.
4. Katayama, K., Seyer, J. M., Raghow, R., & Kang, A. H. (1991). Regulation of extracellular matrix production by chemically synthesized subfragments of type I collagen carboxy propeptide. Biochemistry, 30(29), 7097-7104.
5. Osborne, R., Robinson, L., Mullins, L., & Raleigh, P. (2005). Use Of A Facial Moisturizer Containing Palmitoyl Pentapeptide Improves The Appearance Of Aging Skin: P1050. Journal of the American Academy of Dermatology, 52(3), P96.
