Suppression of <i>Propionibacterium acnes</i>-Induced Skin Inflammation by <i>Laurus nobilis</i> Extract and Its Major Constituent Eucalyptol

• Main Authors: Eun Hye Lee, Jin Hak Shin, Seon Sook Kim, Ji-Hye Joo, Eunmi Choi, Su Ryeon Seo
• Format: Article
• Language: English
• Published: MDPI AG 2019-07-01
• Series: International Journal of Molecular Sciences
• Subjects: <i>Laurus nobilis</i> L.; inflammation; eucalyptol; <i>Propionibacterium acnes</i>; proinflammatory cytokines; NF-κB
• Online Access: https://www.mdpi.com/1422-0067/20/14/3510

Acne is an inflammatory skin disorder in puberty with symptoms including papules, folliculitis, and nodules. <i>Propionibacterium acnes</i> (<i>P. acnes</i>) is the main anaerobic bacteria that cause acne. It is known to proliferate within sebum-blocked skin hair follicles. <i>P. acnes</i> activates monocytic cell immune responses to induce the expression of proinflammatory cytokines. Although the anti-inflammatory function of the <i>Laurus nobilis</i> (<i>L. nobilis</i>) extract (LNE) on several immunological disorders have been reported, the effect of LNE in <i>P. acnes</i>-mediated skin inflammation has not yet been explored. In the present study, we examined the ability of the LNE to modulate the <i>P. acnes</i>-induced inflammatory signaling pathway, and evaluated its mechanism. LNE significantly suppressed the expression of <i>P. acnes</i>-mediated proinflammatory cytokines, such as IL-1&#946;, IL-6, and NLRP3. We also found that LNE inhibited the inflammatory transcription factor NF-&#954;B in response to <i>P. acnes</i>. In addition, eucalyptol, which is the main constituent of LNE, consistently inhibited <i>P. acnes</i>-induced inflammatory signaling pathways. Moreover, LNE significantly ameliorated <i>P. acnes</i>-induced inflammation in a mouse model of acne. We suggest for the first time that LNE hold therapeutic value for the improvement of <i>P. acnes</i>-induced skin inflammation.