Healing effect of a spray containing Rhealba oat colloidal extract in an in vitro reconstitution model of skin

By using a reconstituted skin model, we aimed to evaluate the efficacy of a spray containing Rhealba oat extract on the rapidity of healing and the extension of the newly formed epithelium. A dermal equivalent was first made in a petri dish by combining skin fibroblasts with collagen type I. Then a punch biopsy as a source of epidermal cells was implanted on this dermal equivalent, where a multilayered epidermis developed. The spray containing Rhealba oat extract was added to the culture medium to evaluate epidermal growth by immunohistochemical analysis of mitotic activity (5-bromo-2'-deoxyuridine [BrDu] incorporation). The extension of the neoepithelium in comparison with untreated reconstituted skin over 22 days was evaluated histologically. On day 12, 16% of positive BrDu basal cells was detected after spray treatment in comparison with 4.2% positive cells in untreated reconstituted skin (p < 0.05). During epidermal differentiation between days 12 and 22, we observed a significant increase in the number of cellular epithelial layers after 16 and 18 days of spray treatment. Moreover the extension of re-epithelialization was also significantly increased after spray treatment on days 16 and 18. In conclusion, our results demonstrate a positive modulation of re-epithelialization on a newly formed epithelium by a spray containing Rhealba oat extract displaying a healing effect.