A preventive and curative combo against aging

According to Dr. Arking (1998) from Wayne State University, the maximum human life span is estimated to be 121 years old. A person cannot, however, expect to live that long. Life expectancy for men and women born in 1850 and living in the United States was about 38 years old. Hundred and fifty years later, men and women born in 2000 and living in the United States can expect to live to be 78 years old. Death is now associated with age-related diseases such as cancer and other cardiovascular disorders. General wear-and-tear and genetic instability (e.g. defects in DNA repair), mitochondrial genome damage (e.g. higher susceptibility to mutations), telomere shortening (e.g. drop in telomerase activity), genetic aging programs (e.g. expression of progerin), oxidative damage (e.g. presence of reactive oxygen species) and epigenetics (e.g. levels of DNA methylation and histone deacetylation) have all been linked with this aging process and the appearance of age-related disorders (S.F. Gilbert, 2000). The concept of human aging is, therefore, a relatively new one and humans are now more likely to demonstrate a senescent phenotype, which includes graying hair, loss of muscular power, joint rigidity and wrinkling skin amongst others. For these reasons, the personal care and cosmetics industry has developed exponentially over the recent years and scientists in the field have put a considerable effort into finding new ways to not only maintain a healthy skin but also repair the damaged tissue in the process.

With that in mind, Dr. Mondon and colleagues from Sederma (France) worked on developing a one-step approach combining prophylactic and therapeutic effects against skin aging. Two palmitoylated peptides (Pal-GHK and Pal-GQPR) were produced by a solid-phase method and their identities confirmed by HPLC and mass spectrometry. The first peptide was previously shown to increase proliferation ex vivo and facilitate wound healing in vitro, ex vivo and in vivo while the second peptide was found capable of down-regulating the secretion of IL-6 and IL-8 in control and UV-treated samples and was identified as an inhibitor of stress signals and inflammatory responses. Upon reconstitution, these peptides were mixed at a 2:1 ratio (PEP 3%: 3ppm of Pal-GHK and 1.5ppm of Pal-GQPR and PEP 5%: 5ppm of Pal-GHK and 2.5ppm of Pal-GQPR) and tested in in vitro, ex vivo and in vivo experiments. Both PEP 3% and PEP 5% led to a marked and significant decrease in senescence-associated β-galactosidase (SA β-gal) activity in senescent human dermal fibroblasts when compared with untreated control cells. Using quantitative PCR, they demonstrated that progerin, a truncated component of the lamina in the nuclear membrane which is linked with a rare genetic disorder called progeria that is characterized by a dramatic accelerated aging, was significantly down-regulated in cells incubated in presence of PEP 3% or 5%.

Papillary dermis, an area critical to the three-dimensional structure of the derm, was further studied. Using immunofluorescence, collagens I, IV, VII and XVII were found to be markedly decreased at the protein level in the papillary dermis of aged skin explants (61±5 years old) when compared with young aged skin explants (36±6 years old). The effects of aging on the levels of collagens were, however, reversed in skins treated with the peptide-containing cream when compared with the vehicle control cream. These results correlated with those obtained in volunteers by both echography and in vivo reflectance confocal microscopy (RCM). The latter was used to look at the structural changes of fibers in the papillary dermis. After two months of treatment of the outer corner of the eyes, they noticed that thanks to the combination of peptides, there was a significant increase in fiber perimeter accompanied by a decrease in fiber fragmentation, a phenomenon indicative of a repair of the dermal-epidermal junction. Altogether, these data suggest that pre-emptive and restorative processes are closely connected and that combining inherently active peptides capable of targeting these two processes should be considered when designing novel anti-aging skincare products.

Enzo Life Sciences offers a comprehensive portfolio for advancing your research in personal care and anti-aging such as the Cellular Senescence live cell analysis assay which is an ideal tool for the measurement of senescence-associated β-galactosidase activity in live cells. In addition, Enzo offers antibodies, enzymatic assays, immunoassays, live cell analysis assays and other qPCR products, some of which are listed below:

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