Antioxidant activity and anti-wrinkle potential of Hemerocallis fulva young leaf extract

This study investigated the antioxidant properties, elastase inhibitory activity, and collagen synthesis-promoting effects of water (HF-WE) and ethanol (HF-EE) extracts derived from Hemerocallis fulva young leaves. The contents of total polyphenols and flavonoids were higher in HF-EE (27.26 mg GAE/g DW and 12.44 mg RE/g DW, respectively) than in HF-WE (18.52 mg GAE/g DW and 8.93 mg RE/g DW). Multiple in vitro antioxidant assays, including DPPH, ABTS, FRAP, and SOD-like assays, were employed to evaluate antioxidant potential, and the results indicated concentration-dependent increases in both extracts, with consistently greater responses observed in HF-EE. At 800 μg/mL, HF-EE achieved a DPPH radical scavenging activity of 87.20%, whereas HF-WE reached 70.35%. Both extracts exhibited strong elastase inhibitory activity, with inhibition rates exceeding 88% at 500 μg/mL. Cytotoxicity evaluation using CCD-986Sk fibroblasts indicated that cell viability remained above 70% at concentrations up to 200 μg/mL, suggesting negligible cytotoxic effects. Additionally, both extracts enhanced type I collagen synthesis, with HF-WE and HF-EE producing approximately 338 ng/mL and 350 ng/mL at 100 μg/mL, respectively. Collectively, these results indicate that young leaves of H. fulva, particularly the ethanol extract, exhibit substantial antioxidant activity, elastase inhibition, and enhanced collagen synthesis in human dermal fibroblasts at the in vitro level, thus suggesting their potential application as wrinkle-related functional ingredients.