Anti-inflammatory activity of anti-hyperlipidemic drug, fenofibrate, and its phase-I metabolite fenofibric acid: in silico, in vitro, and in vivo studies.

Fenofibrate, an anti-hyperlipidemic drug and its phase-I biotransformed metabolite fenofibric acid, was studied for COX-1 (PDB ID: 3N8Y) and COX-2 (PDB ID: 1PXX) inhibition potentials in silico and in vitro for their effects on human recombinant COX-2 enzyme isolated from a Baculovirus expression system in sf21 cells (EC 1.14.99.1) using a conventional spectrophotometric assay. Furthermore, the compounds were also screened for their anti-inflammatory potentials in vivo using carrageenan-induced paw oedema method in Wistar rats. The test compounds fenofibric acid, fenofibrate, and the standard drug diclofenac exhibited binding energies of - 9.0, - 7.2, and - 8.0 kcal mol-1, respectively, against COX-2 and - 7.2, - 7.0, and - 6.5 kcal mol-1, respectively, against COX-1. In in vitro studies, both the test compounds inhibited COX-2 enzyme activity. Fenofibric acid showed an IC50 value of 48 nM followed by fenofibrate (82 nM), while diclofenac showed an IC50 value of 58 nM. Furthermore, under in vivo conditions in carrageenan-induced paw oedema rodent model, fenofibric acid exhibited relatively potent anti-inflammatory activity compared with fenofibrate. Hence, we conclude that fenofibric acid and fenofibrate are not only anti-hyperlipidemic but also shows potent anti-inflammatory activity, which may have an additional impact in the treatment of diabetic complications, viz., hyperlipidemia and inflammation leading to atherosclerosis.

Fungal mediated generation of mammalian metabolites of fenofibrate and enhanced pharmacological activity of the main metabolite fenofibric acid.

Different fungi viz. Aspergillus niger NCIM 589, A.ochraceous NCIM 1140, Cunninghamella blakesleeana NCIM 687, C. echinulata NCIM 691, Rhizopus stolonifer NCIM 880, Mucor rouxi MTCC 386, Trichothecium roseum NCIM 1147 were screened for their potential to biotransform anti-hyperlipidemia and anti-hypertriglyceridemia drug, fenofibrate to fenofibric acid, the active metabolite and other mammalian metabolites. Among the fungi screened C. blakesleeana transformed fenofibrate to fenofibric acid and other three metabolites. HPLC, LC-MS/MS analysis and previous reports confirmed the transformation of fenofibrate and metabolites as fenofibric acid (M1), reduced fenofibric acid (M2), reduced fenofibric acid taurine conjugate (M3), reduced fenofibric acid ester glucuronide (M4), the mammalian metabolites reported previously. The results proved the potential of C.blakesleeana NCIM 687 in the production of mammalian phase I (M1 and M2) and phase II (M3 and M4) metabolites in large quantities and also as an in vitro model for drug metabolism studies.