Investigation of antimicrobial and antioxidant activities of Achillea setacea Waldst. et Kit. extracts and extract loaded gel formulation

Antibiotic resistance poses a significant problem in the treatment of infections. Plants, with their rich content, may contain compounds that can be used for this purpose. The dried flowers of Achillea setacea Waldst. et Kit. are prepared as an infusion and used internally for hemorrhoids, as an anti-diarrheal and wound healing agent, and also against abdominal pain. The antioxidant activities of different extracts and extract-loaded gel formulations of A. setacea were determined using DPPH, FRAP, and CUPRAC methods, and the total phenolic content was determined using FCR methods. The antimicrobial efficacy of the different extracts and the extract-loaded gel formulation was investigated using agar well diffusion and microdilution methods. The chloroform extract of A. setacea was selected for gel production due to its significant antioxidant activity (particularly iron(III) ion reducing activity), broad-spectrum antimicrobial activity, and efficacy against Staphylococcus species identified as primary causative agents of wound and skin infections. A pharmaceutical gel was prepared from the obtained chloroform extract using alginate, a natural polymer, characterized by FTIR, subjected to in vitro release testing, and its antimicrobial and antioxidant activities were evaluated. According to the findings, although the antimicrobial and antioxidant activity of the produced gel was lower than that observed at the extract level, it was determined that its antimicrobial and antioxidant efficacy was preserved. Based on these results, it is thought that A. setacea-loaded gel could potentially be used in wound treatment due to its antimicrobial and antioxidant activities after the completion of cytotoxic studies.