Fig. 3

Comparison in histopathology of nasal polyps before and 2 weeks after licorice treatment (n = 3). A Under H&E staining (400× and 800×), the nasal polyps before licorice treatment were infiltrated with numerous eosinophils (black arrow No.1), lymphocytes (black arrow No.2), neutrophils (black arrow No.3) and plasma cells (black arrow No.4). After licorice treatment for 2 weeks, the relative numbers per field (400×) of eosinophils, lymphocytes, neutrophils and plasma cells reduced by an average of 54.9% (p < 0.01), 80.2% (p < 0.01), 18.8% (p < 0.05) and 49.2% (p < 0.05), respectively. B Changes in TGF-β1 staining (200x and 400x; black arrows) in nasal polyps before and after treatment were not statistically different. C Changes of vimentin staining in specimens before and after treatment. The staining area (black arrows) was relatively reduced by 20% after the treatment, but the difference was not statistically significant. D The staining difference in α-SMA in polyp specimens before and after treatment. The statistics showed an average 50% reduction in the stained area (p < 0.001). E Comparing the staining fibroblast activation protein (FAP) in the nasal polyps before and after treatment. The difference showed a significant 40% reduction of staining area (p < 0.05). F Differences in Masson’s trichrome staining in the polyp tissue before and after treatment. The results showed an average of 30% reduced stained collagen after treatment (p < 0.01)