Ameliorative Effects of Liquiritin Carbomer Gel on Dinitrofluorobenzene-Induced Atopic Dermatitis in Mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by dryness and itching. Steroids are the most common therapeutic agents, may induce skin atrophy, and damage the skin barrier. Therefore, we need to find a safer alternative option. Liquiritin (LQ), a flavonoid compound extracted from licorice rhizomes, possesses anticancer, anti-inflammatory, and antioxidant effects. This study aimed to investigate the therapeutic effects of LQ on AD, focusing on its potential skin barrier-protective and anti-inflammatory mechanisms. In this research, we prepared liquiritin carbomer gel (LQ-CG) and assessed its treatment effects on mice with AD triggered by 2,4-dinitrofluorobenzene (DNFB). It effectively attenuated AD progression by ameliorating skin lesions, decreasing epidermal thickness and mast cell infiltration, downregulating inflammatory cytokine levels, and restoring the expression of claudin-1, loricrin, and occludin. It also inhibited the release of TNF-α, IL-1β, and IL-6 in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and showed no significant toxicity to major organs in mice. In summary, our findings demonstrate that LQ-CG can effectively alleviate atopic symptoms by repairing the skin barrier and inhibiting inflammatory responses without causing significant changes in organ indices.