Plant extract-enriched hydrogels: Exploring the therapeutic potential, biocompatibility and antioxidant activity of propolis, Echinacea, and turmeric for skin regeneration

Hydrogels, particularly those derived from natural polymers, serve as effective delivery systems for active compounds, improving stability, bioavailability, and therapeutic outcomes in wound healing and skin regeneration. The use of antioxidant substances such as propolis, Echinacea, or turmeric as ingredients enriching hydrogel dressings is increasingly being considered [ 1 ] [ 2 ] [ 3 ]. Propolis is characterized by its flavonoid content and caffeic acid derivatives, Echinacea for alkylamides and polysaccharides, while Turmeric is primarily recognized for curcumin, all contributing to their antioxidant potential. This research aimed to develop a hydrogel dressing enriched with skin-regenerating substances and antioxidant plant extracts. Hydrogels based on polyvinylpyrrolidone and gellan gum, enriched with allantoin (0.5%) and D-panthenol (0.5%), and 1% extracts of propolis, echinacea, and turmeric, were investigated. Cytotoxicity, assessed using the MTT assay in accordance with ISO 10993-12:2012, revealed high biocompatibility for the hydrogel with 1% propolis, while echinacea and turmeric showed slightly lower biocompatibility but maintained viability above 70%. Antioxidant activity was measured using the ABTS method, assessing the ability to scavenge the ABTS radical cation, reduced by antioxidants. The resulting color intensity was measured using UV-Vis spectroscopy at 734 nm. The concentration of antioxidant substances released from the hydrogel was determined at 2, 4, 6, 8, and 24 hours. The results showed a gradual release of antioxidants, with the hydrogel’s antioxidant effect increasing within 8 hours, followed by stabilization. The tested hydrogels demonstrated high biocompatibility and antioxidant activity, especially with 1% propolis extract, enhancing their potential for wound healing and skin regeneration. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany