CCL2 and chronic obstructive pulmonary disease: Inflammatory cells and mediators: some studies have shown that AA can significantly reduce the expression of IL-6, IL-2, MCP-1, and other inflammatory factors in the lung of COPD rats[23]; others have shown that AA can alleviate the symptoms of patients with COPD, improve the quality of life, reduce the secretion of systemic inflammatory factors and the levels of IL-8 and CRP inflammatory factors.[24]