Topical composition (A), contains as active ingredient, one or more fragments (I) of hyaluronate with molecular weight 50-750 kD. ACTIVITY : Dermatological. MECHANISM OF ACTION : (I) increases the number of proliferating cells, particularly fibroblasts, in the epidermis and dermis, so induce epidermal thickening. A standard cosmetic vehicle contained 0.2 % hyaluronate fragments of molecular weight 50-250 kD and was applied twice daily to the skin of SKH1 hairless mice. After an unspecified treatment time, epidermal thickness and the number of proliferating cells were determined. The mean thickness was 0.32 mm (compare 0.07 mm in controls) and the number of cells (per microscope field) was 257 compared with 96 in controls. Also the mean number of proliferating cells (positive for the marker Ki67； per field) was 96 in the epidermis and 5 in the dermis； compare 26 and 0.95 in controls.Compositions destinées à l'application topique caractérisées en ce qu'elles comprennent à titre de principe actif un ou plusieurs fragments de hyaluronate dont le poids moléculaire est compris entre 50 000 et 750 000 Da et éventuellement un rétinoïde.
