Apocynin is a methoxy-subsituted catechol that is commonly used as an inhibitor of NADPH oxidase (IC50=10  μM). Because of Abocynin’s inhibition of NADPH oxidase, ROS production is also inhibited. Studies show the compound’s ability to decrease superoxide generation in bovine pulmonary arteries as well as neutrophils and macrophages (10 mM). In experimental rats, apocynin has displayed anti-inflammatory activity and can improve endothelial function by reducing oxidative stress and improved NO bioavailability. Reportedly prevents phagocytosis of MBP (myelin) by macrophages. Also has proven to be a useful product for studying NO-regulated processes in plants.

Apocynin (4-hydroxy-3-methoxy-acetophenone) inhibits NADPH oxidase in activated polymorphonuclear (PMN) leukocytes, preventing the generation of reactive oxygen species.