Rosmarinus officinalis ethanol extract suppresses sebocyte lipid accumulation and exhibits antioxidant, antiinflammatory, and anti-cutibacterium acnes activities
Rosmarinus officinalis ethanol extract (REE) was evaluated for its potential anti-acne activity by assessing its antioxidant, anti-sebogenic, anti-inflammatory, and antibacterial properties. Phytochemical characterization showed that REE contained 144.66 ± 2.43 mg GAE/g REE of total phenolic content and 25.55 ± 0.42 mg/g REE of rosmarinic acid. REE exhibited potent DPPH radicalscavenging activity (IC₅₀=62.96 μg/mL) and markedly reduced intracellular reactive oxygen species (ROS) in HaCaT keratinocytes. In SEB-1 sebocytes, REE inhibited linoleic acid-induced sebum synthesis by up to 81.02% without inducing cytotoxicity, as confirmed by Oil Red O and Nile Red staining. Furthermore, REE significantly attenuated Cutibacterium acnes lysate-induced inflammatory responses in HaCaT cells by reducing the secretion of pro-inflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α). REE also demonstrated dose-dependent antibacterial activity against C. acnes, as evidenced by progressively increased inhibition zone diameters with higher extract concentrations. Western blot analysis revealed that REE downregulated peroxisome proliferatoractivated receptor gamma (PPAR-γ) and sterol regulatory element-binding protein 1 (SREBP-1), key transcriptional regulators of lipid biosynthesis. Collectively, these findings suggest that REE may alleviate acne-related pathological processes by reducing sebocyte lipid accumulation through the downregulation of PPAR-γ and SREBP-1 expression, while also exerting antioxidant, antiinflammatory, and antibacterial effects.