Spanish Broom Flower Extracts: A Promising Natural Product For Skin Wounds Treatment

The present study explores the therapeutic potential of Spanish broom (Spartium junceum L.) (SB) flower extracts, particularly emphasizing the role of polyphenols, flavonoids, and antioxidant species, in promoting wound healing. Wound management poses a significant economic challenge, justifying the development of innovative treatments such as natural product-based dressings. SB was processed to extract bioactive compounds using fresh (FF) and lyophilized (LF) flowers with water, ethanol, and a hydroalcoholic mixture. The extraction process involved ultrasound-assisted extraction and maceration, yielding the highest production with the hydroalcoholic solvent from LF. The extracts were analyzed for total phenolic and flavonoid content and antioxidant activity, revealing that ethanol enriched flavonoids the most, while the hydroalcoholic mixture increased antioxidant species. Cytotoxicity was tested on human fibroblast WS1cells, showing that, after 48 h treatment, cell viability was maintained in the concentration range 1.5–0.09 mg/mL and that only the hydroalcoholic extract from FF and the aqueous extract from LF were not cytotoxic even at 3 mg/mL. To enhance their chemical and biological stability, the extracts were encapsulated in nanocarriers, namely liposomes and ethosomes. The latter were smaller than the former, and both showed minimal changes in size and polydispersity index after 30 days at 4°C, ensuring the formulations' stability. Encapsulation influence on vesicles’ physical features was evaluated by loading the carriers with the hydroalcoholic extract from LF. Overall, encapsulation increased particle sizes slightly but preserved their stability. The study demonstrates that SB extracts could be a promising natural source of polyphenolic compounds and flavonoids, which, through nanoencapsulation, could aid in the inflammatory phase of wound healing. This approach could serve as a natural alternative to synthetic drugs, aligning with sustainability.