MMP9 and inflammation: According to the study by Tan et al., andrographolide prevented lung inflammation, induced by non-typeable Haemophilus influenza infection (NTHi) in a cigarette smoke-exposed mouse model, by decreasing lung cellular infiltrates and the expression of cytokines and chemokines, including TNF-α, IL-1β, CXCL1/KC, 8-OHdG, matrix metalloproteinase-8 (MMP-8), and MMP-9, as well as regulating the expression of Nrf2 and its downstream genes [146].