Chemometric-Assisted Extraction Optimization and HPLC-MS Profiling of Mentha × villosa Targeting Photoprotective Activity.

Mentha × villosa is a food and medicinal plant with long history of use. However, its use as potential ingredient for cosmetic formulations continues underexplored. Based on that, the present study sought to optimize the extraction of M. × villosa (MV-OE), characterize its composition, evaluate its antioxidant capacity and photoprotective effects alone and in combination with ethylhexyl methoxycinnamate (EHMC), a commercial sunscreen filter, in prototype formulations. Extraction was optimized through DoE, total phenolic content, and rosmarinic acid were quantified, while antioxidant activity was determined by DPPH and ABTS assays. The chemical profile of extracts was analyzed by HPLC-DAD-ESI-MSn and by HPLC-ESI-HRMS, supported by PCA. The sun protection factor (SPF) was determined using an in vitro UV-transmission method. MV-OE showed significant phenolic content and antioxidant activity, PCA proved effective for discriminating the extracts according to their phenolic composition. Besides, dereplication led to tentative assignment of 30 compounds. Formulation prototypes 5 and 6 achieved significant SPF values and enhanced EHMC performance. Altogether, these findings highlight MV-OE as a potential ingredient for future sunscreen formulations.