PTAFR and chronic obstructive pulmonary disease: The main pharmacological effects of safflor yellow A are that it is an antagonist for platelet-activating factor receptor, and platelet-activating factor receptor in the lung tissue of patients with COPD was obviously upregulated [11], which increased airway inflammation, so we used hydroxysafflor yellow A to block upregulated platelet-activating factor receptor in AECOPD, which reduced pathogen adhesion and airway response.