Effects of Helichrysum italicum Essential Oil on Type I Procollagen Promotion and MMP-1 Expression in Human Dermal Fibroblasts and Clinical Efficacy for Wrinkle Improvement

Purpose: This study evaluated the anti-wrinkle potential of Helichrysum italicum essential oil (HIEO) as a cosmetic ingredient by assessing cytotoxicity, ultraviolet A radiation (UV-A)–induced matrix metalloproteinase-1 (MMP-1) expression inhibition, type I procollagen production stimulation in human dermal fibroblasts (HDFs), and periorbital wrinkle improvement in humans.Methods: Cytotoxicity in HDFs was identified using the MTT assay. The stimulatory effect of HIEO on type I procollagen and its inhibitory effect on UV-A–induced MMP-1 expression were quantified using enzyme-linked immunosorbent assay. Human use test was conducted in 21 healthy adults aged 40–60 years (mean age, 56 years). Periorbital wrinkle changes were analyzed with ANTERA three-dimensional at baseline, 2 weeks, and 4 weeks.Results: In the cytotoxicity assay, HIEO maintained ≥90% cell viability across 0.003125%–0.05% (v/v), indicating a non-cytotoxic range. Type I procollagen analysis revealed that HIEO significantly increased Type I procollagen production by 19.6% and 27.9% at 0.035% (v/v) and 0.05% (v/v), respectively (both <i>p</i><0.01). Furthermore, HIEO significantly suppressed UV-A–induced MMP-1 expression by 9.5% at 0.035% (v/v) (<i>p</i><0.05) and 15.1% at 0.05% (v/v) (<i>p</i><0.01). Clinical periocular wrinkle assessment revealed decreased Wrinkles-small index (arbitrary units) at the HIEO-treated site by 5.92% at 2 weeks and 11.63% at 4 weeks, whereas the control site (jojoba oil) decreased by 0.55% and 2.38%, respectively. Over 4 weeks, the experimental site exhibited a significantly reduced wrinkle index from baseline beginning at 2 weeks (<i>p</i><0.001).Conclusion: Within non-cytotoxic concentrations, HIEO demonstrated dual activity by inhibiting MMP-1 expression and enhancing type I procollagen production in HDFs. Moreover, it improved periorbital wrinkles in a 4-week human use test. These findings indicate that HIEO holds potential as an anti-wrinkle functional cosmetic ingredient.