Fig. 1

A Preparation and operating processes of nasal irrigation with licorice extract. (i) Sections of licorice root (Glycyrrhiza glabra) boiled in a high-pressure cooker, then filtered, and concentrated to obtain the crude extract; (ii) the crude extract processing lyophilization to obtain licorice powder; (iii) the licorice powder was added to a squeeze bottle and mixed with warm water to form a licorice suspension with 3 mg/mL concentration; (iv) the prepared licorice extract used to clean the nasal passages and treat sinonasal diseases through nasal irrigation. B Therapeutic effect of nasal irrigation with licorice extract on nasal polyps. (i) Overall, 29 patients with nasal polyps received 1 month of nasal irrigation with licorice extract. The cross-sectional area of their polyps was recorded and measured using video-endoscopy. The changes in the area before and after treatment were also compared. (ii) The degree of area reduction of the nasal polyp images after treatment. They were categorized into three groups (0–30%, 30–60%, and 60–100%), and the proportions of the three groups were calculated. C Endoscopic findings in patients with nasal polyps under nasal irrigation with licorice extract. Three patients with nasal polyps underwent nasal irrigation with licorice extract for one month, and video-endoscopy was performed to image-record the changes in size of their nasal polyps (black arrows) before and one month after treatment