Photoprotective Properties of Extracts Derived from Neoglaziovia variegata (Arruda) Mez Incorporated into Mesoporous TiO2.

The development of safe and effective photoprotective agents has gained increasing interest in recent years, particularly through the incorporation of natural compounds into inorganic matrices. In this study, sunscreen formulations were developed by incorporating Neoglaziovia variegata (Arruda) Mez extracts into mesoporous TiO2, using different solvent fractions: ethyl acetate, ethanol, chloroform, and hexane. Structural characterization confirmed the efficient incorporation of the extracts into the mesoporous channels of TiO2, without compromising its crystallinity. Chemical analysis showed that the ethanolic and ethyl acetate extracts had the highest total phenolic content (1.550 ± 0.041 and 1.346 ± 0.004 mg GAE g-1, respectively) and the highest antioxidant activity (IC50 values of 49.03 ± 1.24 and 59.34 ± 1.44 μg mL-1, respectively). These results directly correlated with higher Sun Protection Factor (SPF) values. The pure ethyl acetate and ethanol extracts showed the highest SPF values, reaching 26 and 10.5, respectively. Notably, the incorporation of the extracts into TiO2 resulted in a marked increase in photoprotective efficacy. For example, the chloroform and hexane extracts, which had isolated SPF values of 3.9 and 1.1, reached values of 35 and 33, respectively, after incorporation, demonstrating a synergistic effect between the inorganic matrix and the plant's bioactive compounds. Toxicological tests performed on blood agar and Artemia salina indicated that the presence of TiO2 significantly reduced the toxicity of the pure extracts, demonstrating their biocompatibility. Spreadability tests revealed good coverage capacity for all formulations, favoring easy and uniform skin application. These results suggest that the developed hybrid systems represent a promising and safe alternative for the formulation of natural sunscreen products.