Anti-Inflammatory Effects and Human Skin Safety of the Eastern Traditional Herb Mosla japonica

Traditional knowledge has long provided natural solutions for disease prevention and treatment, complementing modern medicine. <i>Mosla japonica</i> (Korean mint) has been traditionally valued for its pesticidal, dehumidifying, anti-swelling, and detoxifying properties. This study explores its anti-inflammatory potential using <i>M. japonica</i> extract (MJE) in LPS-stimulated RAW 264.7 macrophages and evaluates its safety for human skin applications. MJE significantly reduced inflammatory mediators such as nitric oxide (NO), prostaglandin E₂ (PGE₂), and key cytokines (IL-1β, IL-6, TNF-α) in a dose-dependent manner. It also suppressed the expression of iNOS and COX-2, enzymes crucial for inflammation. Mechanistically, MJE inhibited NF-κB activation by stabilizing IκBα, thereby reducing inflammation-related gene expression. Additionally, it downregulated ERK, JNK, and p38 in the MAPK signaling pathway, further contributing to its anti-inflammatory effects. A primary skin irritation test confirmed MJE's safety, showing no significant skin reactions at 100 μg/mL. These findings highlight MJE's strong anti-inflammatory properties and potential for dermatological applications. This study underscores the pharmacological value of <i>M. japonica</i> and its integration into modern scientific research, aligning with global biodiversity frameworks such as the Nagoya Protocol. Future research may further expand its applications in medicine and skincare.