Antioxidant Activity and UV-Absorbing Properties of Artemisia annua L.: Phytochemical and In Silico Insights

Artemisia annua L. is a medicinal plant characterized by a chemically diverse phytochemical profile and potential relevance for cosmetic and dermatological applications. This study investigated a hydroethanolic A. annua extract through phytochemical characterization, antioxidant evaluation, UV–Vis-based assessment of UV absorption, and exploratory molecular docking. HPLC-DAD-MS/MS supported the assignment and quantitative determination of artemisinin, chlorogenic acid, and isoquercitrin at 0.09, 0.11, and 0.21 mg/mL extract, respectively. GC–MS revealed a diverse composition comprising primary and secondary metabolites, while separate essential oil characterization identified Artemisia ketone as the predominant volatile constituent. Total phenolic and flavonoid contents were 16.82 ± 0.29 mg GAE/g DW and 1.46 ± 0.14 mg RE/g DW, respectively. Concentration-dependent antioxidant activity was observed in DPPH and ABTS assays, with IC₅₀ values of 0.77 ± 0.13 and 0.092 mg dry plant material equivalent/mL reaction mixture, respectively. UV–Vis analysis showed concentration-dependent increases in spectrophotometrically estimated SPF within the evaluated analytical range. At 1.25 mg/mL, the extract exhibited an SPF estimate of 7.20 ± 0.35, a UVA/UVB absorbance ratio of 2.58, and a critical wavelength of 379.3 nm, indicating that UV absorption extended substantially into the UVA region. Exploratory molecular docking yielded the most favorable AutoDock Vina scores for chlorogenic acid toward MMP-1 (−9.0 kcal/mol) and isoquercitrin toward human neutrophil elastase (−8.0 kcal/mol). Overall, A. annua represents a source of phytochemicals with experimentally demonstrated antioxidant activity and measurable UV-absorbing properties, supporting further investigation in appropriately formulated and validated topical systems.