Objective: Hair greying (i.e., canities) is a component of chronological ageing and occurs regardless of gender or ethnicity. Canities is directly linked to the loss of melanin and increase in oxidative stress in the hair follicle and shaft. To promote hair pigmentation and reduce the hair greying process, an agonist of α-melanocyte-stimulating hormone (α-MSH), a biomimetic peptide (palmitoyl tetrapeptide-20; PTP20) was developed. The aim of this study was to describe the effects of the designed peptide on hair greying.
Methods: Effect of the PTP20 on the enzymatic activity of catalase and the production of H2 O2 by Human Follicle Dermal Papilla Cells (HFDPC) was evaluated. Influence of PTP20 on the expression of melanocortin receptor-1 (MC1-R) and the production of melanin were investigated. Enzymatic activity of sirtuin 1 (SIRT1) after treatment with PTP20 was also determined. Ex vivo studies using human micro-dissected hairs allowed to visualize the effect of PTP20 on the expression in hair follicle of catalase, TRP-1, TRP-2, Melan-A, ASIP, and MC1-R. These investigations were completed by a clinical study on 15 human male volunteers suffering from premature canities.
Results: The in vitro and ex vivo studies revealed the capacity of the examined PTP20 peptide to enhance the expression of catalase and to decrease (30%) the intracellular level of H2 O2 . Moreover, PTP20 was shown to activate in vitro and ex vivo the melanogenesis process. In fact, an increase in the production of melanin was shown to be correlated with elevated expression of MC1-R, TRP-1, and Melan-A, and with the reduction in ASIP expression. A modulation on TRP-2 was also observed. The pivotal role of MC1-R was confirmed on protein expression analysed on volunteer's plucked hairs after 3 months of the daily application of lotion containing 10 ppm of PTP20 peptide.
Conclusion: The current findings demonstrate the ability of the biomimetic PTP20 peptide to preserve the function of follicular melanocytes. The present results suggest potential cosmetic application of this newly designed agonist of α-MSH to promote hair pigmentation and thus, reduce the hair greying process.
Keywords: canities; clinical assay; hair treatment; peptide; α-MSH/MC1-R.
© 2018 The Authors. International Journal of Cosmetic Science published by John Wiley & Sons Ltd on behalf of Society of Cosmetic Scientists and Société Française de Cosmétologie.