Clinical Efficacy of Dermocosmetic Formulations Containing Spirulina Extract on Young and Mature Skin: Effects on the Skin Hydrolipidic Barrier and Structural Properties

Introduction: Spirulina is a unicellular blue-green alga rich in vitamins, minerals, pigments, proteins, polysaccharides, which indicates a high potential use in anti-aging cosmetic products as well as for skin protection. Preliminary studies showed antioxidant potential, immediate benefits on the skin microrelief and hydration and skin compatibility of formulations containing Spirulina extract. Thus, the objective of this study is to evaluate the long term clinical efficacy of dermocosmetic formulations containing Spirulina extract on young and mature skin using biophysical and skin imaging techniques. Methods: 40 healthy female volunteers participated in the clinical efficacy study, aged between 18- 39 (Young group) and 40- 65 (Mature group). The gel-cream formulation, supplemented, or not (vehicle - FGV) with 0.1% (w/w) of Spirulina extract (FGA) was applied twice daily on the volunteers face region. The effects were evaluated in terms of skin hydration, transepidermal water loss - TEWL, skin microrelief, sebum content and morphological and structural epidermal features before and after a 28-day-period of application of the formulations. Results: The formulation containing Spirulina extract increased stratum corneum water content and reduced the TEWL in both groups. However, a significant reduction in the older group, that received the formulation with Spirulina extract, was observed when compared to the younger group and to the vehicle formulation. Only the formulation containing the active ingredient under study reduced significantly the sebum content on the volunteer’s skin. It was also noted an improvement of the skin microrelief by the reduction of the surface roughness and after the treatment the keratinocytes were more uniformly distributed and homogeneous. Conclusion: The formulation containing Spirulina extract improved skin conditions and provided long term skin benefits such as hydration, protection of the skin barrier function and oil control. Finally, Spirulina extract stands out as a unique active ingredient for effective multifunctional dermocosmetic formulations for the care of young and mature skin.