Absolute and Relative Activity Values in Assessing the Effect of NADPH Oxidase Inhibitors

This Letter addresses the following publication: Hirano K, Chen, WS, Chueng ALW, Dunne AA, Seredenina T, Filippova T, Ramachandran S, Bridges A, Chaudry L, Pettman G, Allan C, Duncan S, Lee KC, Lim J, Ma MT, Ong AB, Ye NY, Nasir S, Mulyanidewi S, Aw CC, Oon PP, Liao S, Li D, Johns DG, Miller ND, Davies CH, Browne ER, Matsuoka Y, Chen DW, Jaquet V, and Rutter AR. Discovery of GSK2795039, a novel small molecule NADPH oxidase 2 inhibitor. Antiox Redox Signal 23: 358-374, 2015. The article by Hirano et al. describes the discovery of an NADPH oxidase inhibitor specific for Nox2. This is an important finding at both the theoretical and applicative levels. However, the article fails in the proper use of a canonical methodology and in the expression of the results derived from it. This refers principally to the execution of and interpretation of data derived from cell-free NADPH oxidase activation assays.