Comparative study of extraction methods and process parameters of polyphenolic content obtained from Celosia argentea L. Flower for herbal sunscreen

Ultraviolet (UV) radiation is a key environmental factor causing skin damage, including DNA mutations, oxidative stress, photoaging, and immunosuppression. Concerns over the toxicity and environmental impact of synthetic sunscreens have spurred interest in plant-based alternatives. This study explores the photoprotective potential of Celosia argentea L., a polyphenol-rich ornamental and medicinal plant. Extracts were prepared using ultrasonic-assisted extraction (UE) and ethanol-based solvent extraction (70, 80, and 100%). The UE extract showed the highest yield (5.67 ± 0.30%), TPC (118.53 ± 0.05 mg GAE/mL), TFC (300.6 ± 0.20 µg CE/mL), and DPPH scavenging activity (47.4 ± 0.10%), with a skin-compatible pH (4.82 ± 0.03). Extraction parameters were optimised via ANOVA and regression (p < 0.05). HPLC profiling identified 13 phenolic and flavonoid compounds, confirming antioxidant and UV-protective properties. These findings support C. argentea L. as an effective, eco-friendly herbal sunscreen candidate.