Pirfenidone (5-methyl-1-phenyl-2(1H)-pyridone, PFD) is a small-molecule compound acting on multiple targets involved in pathological fibrogenesis and is effective to increase the survival of patients with fibrosis, such as idiopathic pulmonary fibrosis. However, PFD is not active enough, requiring a high daily dose. In this study, to keep the multiple target profiles, N₁-substituted phenylhydroquinolinone derivatives, which retain the 1-phenyl-2(1H)-pyridone scaffold were designed and synthesized. The preliminary anti-fibrosis activities for all target compounds were evaluated on a NIH3T3 fibroblast cell line using MTT assay methods. Most compounds showed significant inhibition on NIH3T3 cell proliferation with a IC₅₀ range of 0.09–26 mM, among which 5-hydroxy-1-(4'-bromophenyl)-5,6,7,8-tetrahydroquinolin-2(1H)-one (6j) displayed 13 times higher potency (IC₅₀ = 0.3 mM) than that of AKF-PD (IC₅₀ = 4.2 mM). These results suggest that N₁-substituted phenylhydroquinolinone is a promising scaffold which can be applied for further investigation and for developing novel anti-fibrosis agents.

The overproduction of cortisol is associated with many severe and life-threatening diseases, such as Cushing’s syndrome (CS) and chronic wound healing. 11β-Hydroxylase (CYP11B1) is considered as an attractive target for treating these diseases, since it is a key enzyme responsible for the last step in cortisol biosynthesis. Nowadays, medical therapy has become increasingly important for CS patients, especially for those who are in need of surgery or suffer from surgery failure and those in early phases of radiation therapy. In clinic, steroidogenesis blockers including CYP11B1 inhibitors are utilized most frequently. Nevertheless, drugs that inhibit CYP11B1 are inevitably with side effects due to lack of selectivity over other steroidogenesis enzymes. Recent advances in the development of novel CYP11B1 inhibitors might overcome these limitations. In addition, the beneficial effects of down-regulation of cortisol levels to wound closure have been recently disclosed and have stimulated topical application of CYP11B1 inhibitors as a novel therapeutic strategy for curing chronic wounds. Herein, we provide a review of the current CYP11B1 inhibitors in clinic combating CS and the latest development of novel CYP11B1 inhibitors for treating CS and chronic wounds.