## 4 Conclusions  
In present paper, a phytochemicalal comparative analysis of two extracts was conducted, which confirmed that the extract obtained using ultrasound had a higher content of polar compounds--polyphenols--with antioxidant properties than that obtained using supercritical carbon dioxide.  
In addition, the water-ethanol extract obtained by UAE was tested for biological properties of importance for potential cosmetic applications. The antimicrobial tests against 14 bacterial strains and one fungal strain showed the highest sensitivity for _C. albicans_, _P. aeruginosa_, _B. subtilis_, and _R. solanacearum_ and the lowest for _E. coli_ and _E. faecalis_. The extract exhibited antibiofilm properties against only four strains of _S. agalactiae_, _E. faecalis_, _S. mutans_, and _P. mirabilis_.  
The cytotoxicity study showed that the extract caused the greatest increase in metabolic activity in both keratinocytes and fibroblasts at a concentration of 1.0%. The assessment of inhibition of collagenase, elastase, and tyrosinase activity showed that the extracts (at 1% and 5%) inhibited the activity of these enzymes in a concentration-dependent manner. The results of the protective activity test showed that the _A. millefolium_ extract in the concentration range of 0.01-5.0% reduced the intracellular level of ROS in both UVB-irradiated and non-irradiated cells, both keratinocytes and fibroblasts.  
The rheological tests of the cosmetic creams based on the extract at concentrations of 1%, 5%, and 10% showed that the viscosity curves for all samples had a similar shape typical of non-Newtonian fluids thinned by shear. The _A. millefolium_ extract showed a high absorption capacity in the UV range, which indicates potential protection against both UVB (280-320 nm) and UVA (320-400 nm) radiation. The sun protection factor (SPF) of the creams was 10.2, 18.5, or 20.07, depending on the extract concentration (1%, 5%, and 10%, respectively), which is classified as medium sun protection. The data presented indicate that _A. millefolium_ extract can be a valuable material in the cosmetics industry, with antioxidant, antimicrobial, anti-ageing, and sun protective activity.  
Figure 12: SPF of cosmetic creams. E0, base cream; E1, cream with 1% extract; E5, cream with 5% extract; E10, cream with 10% extract.  
**Author Contributions:** Conceptualization, M.M.; methodology, M.Z.-D., P.Z., M.S., D.K., A.B.-J., K.P. and M.M.; formal analysis, M.Z.-D., P.Z., A.B.-J., M.S., M.M. and N.D.; investigation, M.M., M.Z.-D., P.Z., A.B.-J., M.S., N.D. and K.P.; resources, M.M. and D.K.; writing--original draft preparation, M.M., M.Z.-D., A.B.-J., P.Z. and N.D.; writing--review and editing, M.M. and K.P.; visualization, M.M., M.Z.-D. and A.B.-J.; supervision, M.M.; project administration, M.M.; funding acquisition, M.M. and P.Z. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This study was supported by a grant from the Jan Kochanowski University SUPB.RN.25.019, 2025 and co-financed by the Minister of Science (Poland) under the \"Regional Excellence Initiative\" program (project no.: RID/SP/0015/2024/01).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.  
**Conflicts of Interest:** The authors declare no conflicts of interest.