Antioxidant Activity and Inhibitory Effects of Fermented Lavandula angustifolia Flower Extract on UVB-Induced Skin Aging

Purpose: This study investigated the antioxidant and anti-photoaging activities of water extract (LAFDE), 50% ethanol extract (LAFEE), and fermented extract (LAFFE) prepared from <i>Lavandula angustifolia</i> flowers and evaluated their potential as functional cosmetic ingredients. Methods: Antioxidant activities were determined by measuring total polyphenol and flavonoid contents as well as DPPH and ABTS radical scavenging activities. Anti-photoaging effects were evaluated in UVB-irradiated HaCaT keratinocytes by assessing elastase inhibition, type I procollagen production, matrix metalloproteinase (MMP) expression, and skin barrier- and hydration-related gene expression. Results: Among the tested extracts, LAFFE exhibited the highest levels of total polyphenols and flavonoids and demonstrated the strongest radical scavenging activities. In UVB-irradiated HaCaT cells, LAFFE significantly increased elastase inhibitory activity and type I procollagen production in a concentration-dependent manner. Moreover, LAFFE markedly reduced MMP-1 production and suppressed the mRNA expression of <i>MMP-3, MMP-9</i>, and <i>MMP-13</i>, which are closely associated with collagen degradation and skin photoaging. In addition, LAFFE enhanced the expression of skin barrier- and moisturizing-related genes, including filaggrin (<i>FLG</i>), keratin 1 (<i>KRT1</i>), hyaluronan synthase 2 (<i>HAS-2</i>), hyaluronidase 3 (<i>HYAL3</i>), and aquaporin 3 (<i>AQP3</i>). Conclusion: These findings indicate that fermented <i>L. angustifolia</i> flower extract possesses potent antioxidant, anti-wrinkle, and skin barrier-enhancing activities. Therefore, it may serve as a promising natural cosmetic ingredient for preventing UVB-induced skin photoaging and improving skin health.