285 A new scalp treatment for anti-ageing hair

Abstract

Hair aging is commonly defined as hair graying, hair loss and fragility. Today, hair care treatments fighting against hair ageing focus directly on the hair fibers. However, as well as the skin, the scalp needs care. Indeed, the scalp contains hair follicles that produces hair fibers. The scalp directly provides nutrition to the hair follicles and consequently to the hair fibers. By taking care of the scalp, the hair quality can be improved. We screened multiple botanical extracts and discovered one having anti-inflammatory and anti-oxidative properties along with reducing UVB-induced DNA fragmentation and increasing repair in keratinocytes (comet assay, thymine dimers, Gadd45). One active ingredient was particularly selected for its ability to reduce activation of a specific stress sensor in human hair follicle melanocytes. To assess the anti-aging hair potential of this selected plant extracts in more realistic conditions of use, we designed in vivo protocols to monitor graying (chromametry), hair growth (Phototrichogram) and fiber mechanical properties (tensile stress-strain) on hair neo-fibers, over a six-month period, to have numerous and long enough growing hair fibers for assessment (at least 6cm from the root). This newly designed protocol allows to observe that after six months, hair color became increasingly white (+5%), hair loss was increased (+13%) and break extension and post-yield gradient of hair fibers was modified (+3% and -5% respectively). Contrariwise, the ingredient stabilized hair loss and preserved natural hair pigmentation and strength during the study. In conclusion, this study on emerging fibers shows that it is possible to follow in vivo perceivable benefits of a protecting scalp treatment on the hair structure and function. However, the clinical study should be long enough to have neo-fibers to evaluate hair mechanical properties and color.