Vaccinium myrtillus L. extract associated with octocrylene, bisoctrizole, and titanium dioxide: in vitro and in vivo tests to evaluate safety and efficacy

Objective: The harmful effects induced by ultraviolet exposition and the significant increment in skin cancer diagnosis confirm the necessity to develop effective and safe sunscreens. Limited efficacy and cutaneous adverse reactions of traditional formulations drove the incorporation of natural extracts into multifunctional sunscreens. Vaccinium myrtillus L. extract (VME), that contains anthocyanins and flavonoids, is a potential candidate for such systems. Methods: Considering that, we performed in vitro and in vivo tests to evaluate the sun protection factor (SPF), photostability, and safety of sunscreen samples containing VME. Results: As main results, the SPF was reduced in both in vitro and in vivo evaluation in the presence of VME; nonetheless, the samples were photostable and safe. Conclusion: Further investigation is required to better understand the unexpected effects of VME over photoprotection, decreasing the SPF value. As a conclusion, even with interesting findings, we highlight the importance of case-by-case investigations to develop multifunctional bioactive sunscreens.