Melatonin and Mesenchymal Stem Cells Co-Administration Alleviates Chronic Obstructive Pulmonary Disease via Modulation of Angiogenesis at the Vascular-Alveolar Unit

The COPD model was established using cigarette smoking and lipopolysaccharide. The COPD rats were divided into four groups: COPD group, Melatonin-treated group, MSC-treated group, and combined treated group, Melatonin–MSCs.