Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 21 1 2022 02 06 65 72 Lijun Chen Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Ningxia Medical University (The First People’s Hospital of Yinchuan), Yinchuan, China Entezar Mehrabi Nasab Department of Cardiology, Tehran Heart Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Seyyed Shamsadin Athari Department of Immunology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran 2021 06 09 2021 07 06 Asthma is considered a complex disease of the respiratory system that is characterized by bronchoconstriction, airway inflammation, cough, dyspnea, and wheezing. Allergic reactions are the main reason behind asthma which is known as an important health problem with a high rate of morbidity and mortality in patients with respiratory diseases. Liquorice, the root of Glycyrrhiza, is primarily effective for asthma which is widely used in herbal medicine. In the present study, we designed nano-particles that carry Glycyrrhizic acid as the effective component of Liquorice. After Poly (D,L-lactide-co-glycolic acid) PLGA nanoparticle preparation and Glycyrrhizic acid loading, the morphology of the nanoparticle, the electric charge distribution, and drug-releasing ability were studied. Then the effect of Glycyrrhizic acid-PLGA on the animal model of allergic asthma was investigated. Glycyrrhizic acid-nanoparticle had a mean±SD size of 350±50 nm. about 67% of the effective component was released after 10 h. The interleukin (IL)-4, IL-5, IL-13, and IL-25 levels and the Muc5ac mRNA expression were decreased in the Glycyrrhizic acid-PLGA treated group. In addition, a significant decline was observed in goblet cell hyperplasia, mucus hyper-secretion, and eosinophilic inflammation around bronchi and vessels of the nano-drug treated group, compared with the asthmatic group. We found that Glycyrrhizic acid-PLGA nanoparticle had an anti-asthma effect which may be used as a new drug to cure asthma. It can prevent bronchial obstruction, breathlessness, and asthma attacks. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3254 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/3254/1794