Phenolic Profile and Antioxidant Potential of Calendula Officinalis and Achillea Millefolium Eco-friendly Extracts: A Comparative Study

Calendula officinalis and Achillea millefolium are two medicinal species belonging to the Asteraceae family with significant therapeutic potential, owing to their high concentrations of bioactive compounds. The current study aimed to evaluate and compare the amount of total flavonoid and polyphenolic content, the phenolic profile, and antioxidant efficacy of the two plant extracts using different solvents: water, 70% ethanol, ethyl acetate, and ethyl lactate to find the appropriate solvent choice for further applications. The total phenolic content was quantified using the Folin-Ciocalteu method, while the total flavonoid content was determined via the aluminum chloride colorimetric assay. The phenolic profile was characterized using high-performance liquid chromatography (HPLC), and the antioxidant properties of the samples were assessed using two different methods: DPPH radical scavenging assay and ABTS radical scavenging activity. The results indicated significant variations in the values obtained from the different solvents. Ethanolic extracts exhibited the highest concentration of phenolic compounds (59.932 mg/g Calendula officinalis; 73.794 mg/g Achillea millefolium) and demonstrated important antioxidant activity, thus serving as a basis for future investigations. The study underscores the significance of the solvent choice in the extraction of bioactive compounds, influencing the phenolic profile and antioxidant potency of the two plants in topical applications on skin wounds.