Efficacy of a Dermocosmetic Serum Combining Bakuchiol and Vanilla Tahitensis Extract to Prevent Skin Photoaging in vitro and to Improve Clinical Outcomes for Naturally Aged Skin

Background: Skin aging is characterized by slacking and loss of density, especially under ultraviolet (UV) radiation exposure.

Objective: To investigate the beneficial effects of a combination containing bakuchiol (BK) and vanilla tahitensis extract (VTE) to prevent skin photoaging in vitro and to improve clinical outcomes for naturally aged skin.

Materials and methods: Human dermal fibroblasts were treated with active compounds, exposed to an acute dose of UVA and analyzed by confocal microscopy: actin network for morphology, interleukin-8 (IL-8) for inflammation and p16 for senescence. Human skin was used to evaluate chronic UVA-induced glycosaminoglycan (GAG) loss and to assess the benefit of topical application of a BK+VTE serum (Alcian blue staining). An open-label clinical trial was conducted in women applying the serum twice daily for 56 days (n=43). Skin remodeling was assessed by FaceScan^®. Firmness was evaluated through Dynaskin^® and clinical scoring. Skin radiance was also rated on standardized full-face photographs.

Results: UVA induced a significant increase in IL-8 and p16 expression and marked morphological changes in fibroblasts. Treatment with BK or VTE alone prevented both actin network alteration and IL-8 upregulation. Interestingly, BK+VTE demonstrated synergistic protection against IL-8 and p16 overexpression. Serum application prevented GAG loss at the dermo-epidermal junction and increased dermal GAG in UVA-exposed skin explants. In the clinical trial, face ptosis was reduced by 11% on average for 26 responsive subjects and up to 23%. Depth of skin deformation was also reduced by 24% on average for 30 responsive subjects and up to 30%. This firming effect was confirmed by clinical scoring. Radiance was significantly improved by 29% on average for 33 responsive subjects. The serum demonstrated good tolerance/safety.

Conclusion: BK+VTE combination demonstrated anti-aging efficacy and might provide a substantial benefit in the daily care of naturally aged skin in women, through their synergistic effect on inflammaging and senescence.

Keywords: anti-aging therapy; clinical trial; inflammaging; senescence; skin model.