Elastogenic potential and antisagging properties of a novel Murraya koenigii extract.

BACKGROUND: The process by which functional elastic fibers are produced, namely elastogenesis, is complex and difficult to assess in vitro. Identifying efficient elasticity-boosting ingredients thus represents a challenge. AIMS: The elasticity-boosting properties of a novel extract of Murraya koenigii leafy stems were assessed in vitro in 3D culture models before being evaluated in human female volunteers. METHODS: Synthesis of elastic fiber related proteins was evaluated in a skin-equivalent model. Using multiphoton microscopy, the structural organization of elastin deposits was studied within a scaffold-free dermal microtissue. Biomechanical properties of the 3D microtissue were also measured by atomic force microscopy. In vivo, fringe-projection and image analysis were used to evaluate nasogenian fold severity in a panel of Caucasian female volunteers. The impact of gravity on visible signs of facial aging was assessed by clinical scoring carried out alternatively in the supine and sitting positions. RESULTS: We showed the Murraya koenigii extract increased protein expressions of elastin and fibrillin-1 in a 3D skin equivalent model. Using scaffold-free dermal microtissue, we confirmed that Murraya koenigii extract allowed a proper and ordered network of elastin deposits and consequently improved tissue elasticity. Clinical data showed that a twice-daily application for 98 days of the extract formulated at 1% allowed to visibly reduce nasogenian fold severity, jowl severity and to mitigate the impact of gravity on the facial signs of aging. CONCLUSION: The newly discovered extract of Murraya koenigii leafy stems represents an innovative antiaging ingredient suited for elasticity-boosting and antisagging claims.

Maintenance of Chronological Aging Features in Culture of Normal Human Dermal Fibroblasts from Old Donors.

Chronological aging is defined as a time-dependent decline of tissue homeostasis which severely impacts skin. Understanding the mechanisms of skin aging is an active research area limited by the lack of relevant in vitro models. Being a component of aging, replicative or stress-induced senescence is repeatedly used to mimic skin aging in vitro, thus presenting only a partial view of the complexity of aging. Herein, we aimed to clarify whether primary normal human dermal fibroblasts retained age-related characteristics when cultured in 2D monolayer, and could be used as a relevant model for aging research. We compared three groups of fibroblasts isolated from different aged donors. We observed strongly decreased population doubling capacities, a reduced clonogenic ability, an impairment in extracellular matrix production together with modifications of respiratory metabolism with an increase in age. These disruptions were particularly marked when comparing fibroblasts isolated from old individuals (over 70 years old) to those isolated from young individuals (18-37 years old), while cells from middle-aged donors exhibited an intermediate profile. These alterations of cell features can be related to the signs of dermis aging, thus showing that cultured primary cells indeed retain some characteristics of the original tissue from which they were extracted.