Abstract
Acne is a common skin disease that is closely associated with Cutibacterium acnes (C. acnes) and the inflammatory response it induces. Existing antibiotic treatments are often rendered ineffective due to the development of bacterial resistance, while Scutellaria barbata (SLB) has attracted widespread attention for its remarkable anti-inflammatory and antibacterial properties. However, its role in acne treatment has not been comprehensively studied. This study used high-performance liquid chromatography (HPLC) to analyze the bioactive components in a 70% ethanol extract of SLB. The antibacterial activity against C. acnes was systematically evaluated using well diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and biofilm formation assays. Additionally, the effects of SLB on nitric oxide (NO) production and phagocytic activity were tested in RAW 264.7 cells. An acne skin model was established by treating HaCaT keratinocytes with heat-inactivated C. acnes. The results demonstrated that SLB significantly inhibited the growth of C. acnes and disrupted its biofilm formation. Moreover, SLB markedly reduced the secretion of inflammatory cytokines such as interleukin (IL)-6, IL-1β, IL-8, and tumor necrosis factor (TNF)-α in HaCaT keratinocytes stimulated by C. acnes. Moreover, SLB effectively alleviated skin barrier damage caused by C. acnes by suppressing the expression of matrix metalloproteinases (MMPs)-1, -3, -9, and -13. In conclusion, this study demonstrates that SLB possesses potent antibacterial, anti-inflammatory, and barrier-protective properties, making it a promising candidate for developing anti-acne products and exploring alternative antibiotic therapies.