Exploration of old-age odor inhibition and reduction by <i>Leuconostoc mesenteroides</i> THF-10 isolated from oriental melon

Old age odor is associated with delayed skin renewal and fatty acid oxidation by skin bacteria, potentially causing discomfort and health issues. While previous studies primarily targeted 2-nonenal inhibition, this study examined the antibacterial, antioxidant, biofilm inhibition, SDS-PAGE analysis, and trans-2-nonenal scavenging effects of Leuconostoc mesenteroides THF-10, a lactic acid bacterium isolated from Cucumis melo. The cell-free supernatant inhibited <i>S. epidermidis</i>, <i>S. aureus</i>, and <i>P. aeruginosa</i>, with MIC values of 1.25 mg/mL, which decreased to 0.31, 0.62, and 0.04 mg/mL after ethyl acetate fractionation. THF-10 effectively inhibited biofilm formation and exhibited enhanced antioxidant activity, leading to radical scavenging and a 39% reduction in ROS production at 20 µg/mL. The trans-2-nonenal scavenging assay demonstrated a 73% inhibition rate, with no observed toxicity in HaCaT cells. These findings suggest that <i>L. mesenteroides</i> THF-10 possesses strong antimicrobial and antioxidant properties, supporting its potential for mitigating old age odor.