Spartium junceum L. pods as a new source for cosmetic use: extraction and encapsulation in ethosomes

The growing demand for sustainable cosmetic products is driving the exploration of new natural active compounds and greener extraction methods.1 This study investigates the antioxidant potential of Spartium junceum L. pods, a by-product of a plant widely used in the pharmaceutical and textile industries.2 Pods were selected based on their integrity and ground. The resulting powder was extracted using a 50:50 (v/v) water-ethanol mixture, with and without sonication. The extracts were phytochemically characterized for their polyphenolic content (TPC), flavonoid content (TFC) and antioxidant activity (AA%) and the biocompatibility of lyophilized extracts on WS1 fibroblasts was assessed. Encapsulation of the lyophilized extracts into ethosomes was achieved using the ethanol injection method. Both the sonication-maceration (SM) and conventional maceration (M) methods produced similar extraction yields of approximately 15%. The resulting extracts also showed comparable total flavonoid content (TFC: 31.4 ± 0.3 mg QE/L of the SM-extract and 27.6 ± 0.3 mg QE/L of the M-extract), total phenolic content (TPC: 399 ± 6 mg GAE/L of the SM-extract and 395 ± 4 mg GAE/L of the M-extract), and antioxidant activity (AA%: 93.8 ± 0.5%, 94,0 ± 0.5% for the SM and M extract, respectively). Both the extracts resulted biocompatible on WS1 cells up to the concentration of 1 mg/mL. Loaded ethosomes showed nanometric size (120.5 ± 0.7 nm), a low polydispersity index (0.165 ± 0.007) and zeta potential values around -23.5 mV. The results showed that the hydroalcoholic extracts are a promising source that could be used for its antioxidant activity in cosmetic products, particularly for anti-age formulations. This study was funded by the European Union Next Generation EU, in the framework of the “SBresswound”, PRIN 2022, project n. 2022JL9S9S, CUP J53D23001100006.