Antioxidant, Photoprotective, and Antimicrobial Potential of Oil Extract of Usnea barbata L. F.H.Wigg from Călimani Mountains, Romania.

In order to enhance the value and stability of vegetable oils, they may be enriched with essential oils and plant extracts with strong antioxidant activity, yielding innovative formulations with potential applications in skincare. The present research aims to investigate the bioactive properties of an Usnea barbata extract in Jojoba oil (JO) enriched with 5% Peppermint oil (PEO), and 10% vitamin E (PJO). The oil extract (UBPJO) was obtained through cold maceration. The UBPJO antioxidant activity was investigated using ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH (2,2-diphenyl-1-picrylhydrazyl)-based methods. The sunscreen capacity of UBPJO was evaluated by measuring their sun protection factor (SPF) values. The antimicrobial potential was investigated against S. aureus, E. coli, and C. albicans. The antioxidant activity of UBPJO was 1.5 times higher than that of PJO. Consequently, the sunscreen efficacy (assessed by SPF measurements) indicated satisfactory UVB protection abilities against S. aureus (UBPJO vs. PJO: 32.41 vs. 30.58). UBPJO exhibited significantly greater inhibitory effects compared to PJO against S. aureus (MIC = 18.75 ± 6.25 vs. 37.50 ± 0.00, p < 0.05). and C. albicans (9.62 ± 2.87 vs. 37.5 ± 12.5, p < 0.05). The bioactive properties investigated in the present study support the inclusion of UBPJO in various skin protective formulations with antiaging, antibacterial, and antifungal effects.