A traditional East Asian herbal medicine composed of six herbs, including Ophiopogonis tuber, Pinelliae tuber, Glycyrrhizae radix, Zizyphi fructus, Ginseng radix, and Oryzae semen, with potential anti-tussive activity. Maekmoondong-tang is traditionally prescribed for respiratory symptoms to direct the qi downwards and compensate for lung-yin deficiency or dry lung by tonifying yin and moistening the lung. Although the exact mechanisms through which Maekmoondong-tang exerts its effects have yet to be fully elucidated, this agent may, upon administration, improve the severity of chronic cough, reduce airway hyper-responsiveness possibly by reducing the cough reflex and bronchodilation, and airway inflammation possibly through anti-inflammatory and immunomodulatory effects.