Scientists in Japan have shown that zinc salt of l-pyrrolidone carboxylate (zinc PCA) is a promising topical agent not only for prevention of intrinsic skin ageing but also for that of photo ageing by controlling the balance between the synthesis and degradation of the dermal collagen.
Zinc PCA has long been used as a cosmetic ingredient because of its astringent and anti-microbial properties, and zinc itself exerts protective effects on UV damage in keratinocytes and fibroblasts in vitro and in vivo.
Despite evidence suggesting the protective role of zinc compounds against UV-induced skin damage, there are no direct data for either its suppression of UV-induced matrix metalloproteinase-1 (MMP-1) expression or its enhancement of dermal collagen production.
Time to find direct data
Therefore, in this study, published in the International Journal of Cosmetic Science, the scientists investigated the effects of zinc on collagen degradation and production in normal human dermal fibroblasts (NHDFs) in order to gather direct data on the subject.
The researchers investigated these effects by employing zinc salts of pyrrolidone carboxylic acid; a water-soluble, organic zinc salt used as a cosmetic ingredient.
“We found that Zinc PCA suppressed UVA-induced activation of activator protein-1 (AP-1) and reduced matrix metalloproteinase-1 production in these cells, which is thought to be involved in collagen degradation in photoaged skin,” said the researchers.
“By using cultured NHDFs, we demonstrated that Zinc PCA prevents the UV-induced MMP-1 production in vitro by suppressing the activation of activator protein-1 (AP-1),” noted the research.
Combating skin ageing head on
Furthermore, the study found that Zinc PCA was also able to enhance type I collagen synthesis in NHDFs, which suggests its promising effect against not only photo-aged skin but also for the simple atrophic change of intrinsic skin ageing.
Reduced collagen matrix in the dermis constitutes one of the characteristic features of chronologically aged skin, which is further enhanced on the sun-exposed portions of the body by chronic UV irradiation. This induces the unique changes associated with skin photo ageing.
It is based on these in vitro findings, that the scientists consider Zinc PCA to be a promising candidate for an anti-skin ageing agent.
The research was supported by specialty chemicals manufacturer Ajinomoto.