Antibacterial, In Vitro Anti-Inflammatory and Anti-Acne Activities of Patchouli Essential Oil

Objectives: The study aimed to investigate the antibacterial, in vitro anti-inflammatory and anti-acne properties of Patchouli essential oil (PEO). Methods: PEO components were quantified by gas chromatography–mass spectrometry (GC-MS). The antibacterial activity of PEO against Cutibacterium acnes (C. acnes) and Staphylococcus epidermidis (S. epidermidis) was evaluated via MIC detection and growth curve analysis. Bacterial membrane integrity was assessed by detecting intracellular substance leakage. LPS-induced RAW264.7 cells inflammatory models and heat-inactivated C. acnes-stimulated human epidermal keratinocytes (HaCaT) cells acne models were constructed to explore the in vitro anti-inflammatory and anti-acne activities of PEO by measuring the secretion levels of pro-inflammatory cytokines. Results: PEO primarily contained α-guaiene, patchouli alcohol and α-bulnesene. It showed potent antibacterial activity with an MIC of 0.50 mg/mL, inhibiting bacterial growth and disrupting cell membrane integrity. PEO significantly alleviated cell damage and reduced the secretion of TNF-α, IL-1β and IL-6 in two inflammatory cell models, and suppressed excessive keratinocyte proliferation. Conclusions: PEO exerts anti-acne effects via dual antibacterial and anti-inflammatory pathways. This work provides valid experimental evidence for the application of PEO as a novel natural anti-acne agent.