Dandelion total flavonoids could upregulate the mRNA levels of antioxidant genes (Nrf2 and SOD1), could regulate the expression levels of proteins related to the Nrf2 signaling pathway, might play a protective role in COPD induced by cigarette smoke by regulating Nrf2 antioxidant signaling pathway. Here, SOD1 is linked to chronic obstructive pulmonary disease.