Fenofibrate

Fenofibrate is a selective PPARα agonist with an EC₅₀ of 30 μM. Fenofibrate also inhibits human cytochrome P450 isoforms, with IC₅₀s of 0.2, 0.7, 9.7, 4.8 and 142.1 μM for CYP2C19, CYP2B6, CYP2C9, CYP2C8, and CYP3A4, respectively. IC50 & Target:IC50: 0.2 μM (CYP2C19), 0.7 μM (CYP2B6)^[1]
EC50: 2.39±0.4 μM (CYP2C), 30 μM (PPARα)^[2] In Vitro: Fenofibrate is a relatively potent inhibitor of CYP2B6 (IC₅₀=0.7±0.2 μM) and CYP2C19 (IC₅₀=0.2±0.1 μM). Fenofibrate is also a moderate inhibitor of CYP2C8 (IC₅₀=4.8±1.7 μM) and CYP2C9 (IC₅₀=9.7 μM)^[1]. Fenofibrate binds to and inhibits cytochrome P450 epoxygenase (CYP)2C with higher affinity than to PPARα. Fenofibrate is a well-known PPARα agonist, but an in vitro assessment of 209 frequently prescribed drugs and related xenobiotics suggests that Fenofibrate is also a potent inhibitor of cytochrome P450 epoxygenase (CYP)2C. The affinity of Fenofibrate to CYP2C is >10 times higher (EC₅₀=2.39±0.4 μM) than to PPARα (EC₅₀=30 μM). Fenofibrate at a low dose inhibits CYP2C8 activity without PPARα activation^[2]. In Vivo: Daily intake of Fenofibrate at this low dose (10 μg/g/day) inhibits retinal and choroidal neovascularization induced by CYP2C8 overexpression by 29% (P=0.021) and 36% (P=1.2×10^?9) respectively^[2].