Flavonoids extracted from the roots of Petasites japonicus were evaluated for their cytoprotective, antioxidant, and anti-aging effects. The MTT assay confirmed that cell viability remained above 95% across concentrations up to 12 μg/mL, indicating no cytotoxicity. The extract demonstrated strong DPPH radical scavenging activity in a concentration-dependent manner, reaching 86.7% at 12 μg/mL, which is comparable to vitamin C. ROS scavenging activity also increased with dosage, showing significant suppression at concentrations of 6 μg/mL and above, thus effectively mitigating oxidative stress. Collagen synthesis assays revealed an initial decrease at low concentrations, followed by a clear recovery and significant enhancement at higher doses (10–12 μg/mL). Additionally, the extract inhibited collagenase activity, with notable suppression occurring at concentrations above 10 μg/mL, suggesting protective effects against collagen degradation. Elastase activity was reduced in a dose-dependent manner, achieving over 60% inhibition at 10–12 μg/mL. These results imply that flavonoids have dual functions: they stimulate collagen production while suppressing the enzymes that degrade collagen and elastin. The strong antioxidant and anti-inflammatory potential of these flavonoids likely contributes to their protective effects on dermal structure and function. Collectively, these findings highlight the potential of flavonoids as promising natural ingredients for anti-aging cosmetics and skin health applications.

Abstract
Introduction
Materials and Methods
    1. Flavonoids preparation
    2. Measurement of cell viability
    3. Measurement of DPPH radical scavenging activity
    4. Measurement of reactive oxygen species scavengingactivity
    5. Measurement of collagen synthesis
    6. Measurement of collagenase inhibitory activity
    7. Measurement of elastase inhibitory activity
    8. Statistical analysis
Results and discussion
    1. Cell viability
    2. DPPH radical scavenging effect
    3. ROS scavenging activity
    4. Collagen synthesis effect
    5. Collagenase inhibitory activity
    6. Elastase inhibitory activity
Conclusion
Acknowledgments
References

• Jin Jeong(Professor, Dept. of Science and Technology Convergence, Graduate School of Chosun University, Gwangju 61452, Korea)
• DuBok Choi(Professor, Dept. of Science and Technology Convergence, Graduate School of Chosun University, Gwangju 61452, Korea) Corresponding author
• Hyun-Suk Choi(Associate Professor, Dept. of Hotel Culinary Arts Patissier, Chungcheong University, Cheongju 28171, Korea)