The invention concerns novel uses of d-xylose, the esters thereof and oligosaccharides containing D-xylose for improving the functionality of epidermal cells. More particularly, it concerns the use of a compound selected among the group consisting of D-xylose, its esters, in particular fatty acid esters or D-galacturonic acid ester, and oligosaccharides containing D-xylose, as cosmetic or dermatological agent for stimulating synthesis and/or secretion of proteoglycans (PG) and/or glycosaminoglycans (GAG) by keratinocytes, in particular keratinocytes of the epidermis and of tissues with a keratinocyte coating compartment such as the mucous membranes, in particular the lips, and the skin appendages, in particular hair follicles, said agent being incorporated in a cosmetic or pharmaceutical composition.