PAULINE ROUAUD*, DAVID BOUDIER, ELODIE AYMARD, BRIGITTE CLOSS
*Corresponding author
SILAB, BP 213 19108 Brive cedex, France

Abstract

The distribution and functionality of adipose tissue change with age, leading to a reduction of facial volumes. While ultraviolet (UV) radiation acts indirectly on deep tissues via negative cell communication, age-related effects on adipose tissue are accentuated and accelerated in photoexposed skin. In this study, the aim is (1) to understand and to characterise the negative cellular communication between UV-stressed reticular fibroblasts and adipocytes and (2) to demonstrate that a natural active ingredient obtained from the roots of peony and rich in oligosaccharides (i.e. PRE) restores the positive communication between the dermis and the hypodermis. Through innovative in vitro models, we highlight that reticular fibroblasts stressed by a solar simulator secrete a set of pro-inflammatory molecules (i.e. secretome) that inhibits adipocyte differentiation. Tested on these models, PRE restores the positive communication between reticular fibroblasts and adipocytes. Moreover, tested in vivo on photoexposed skins, this natural active ingredient corrects slack skin and restores volumes to the face.

INTRODUCTION

Adipose tissue and facial ageing
Adipose tissue and facial muscles are a support "mattress" that ensures the shapes and harmonious contours of the outline of the face (1).
Muscle tone in general decreases with age, the subcutaneous fat mass is reduced and redistributed, and skin elasticity is attenuated (2). This loss of matter and structure weakens tissues and changes harmonious volumes: the face is hollowed, lines and deep wrinkles form, and jowls and ptosis appear. In addition to the appearance of wrinkles, the loss of facial volume is one of the most visible characteristics of skin ageing (3).

UV, stress and functionality of the hypodermis
These pronounced manifestations of ageing appear relatively late: the mass and functional capacities of adipose tissue decline substantially after the age of 70. This decline is accelerated and aggravated in subjects with photoexposed skin (4).
Excessive exposure to ultraviolet (UV) radiation results in a variety of clinical manifestations in photoexposed zones: the skin becomes slack and rough, with deep wrinkles and hyper- or ...