FR194738

Cell experiment:

HepG2 cells are grown in 225 cm2 culture flasks, and incubated for 18 h in medium A containing 10% human lipoprotein deficient serum and 1 μM L-654,969 to increase their squalene epoxidase activity. The HepG2 cells are washed and harvested by trypsin treatment. After centrifugation (1000×g, 5 min at 4°C), the supernatant fraction is removed by aspiration. The cell pellet is frozen and kept at -80 °C until use. On the day of the experiment, the stocked cell pellet is thawed, ruptured by sonication (5 s at 4°C) in 0.1 M Tris-HCl, pH 7.5 containing 1 mM EDTA, mixed with one-fourth volume of 2% Triton X-100, stood at 4°C for 30 min, and assayed for squalene epoxidase activity with some modifications. Aliquots of the mixture are incubated for 90 min at 37 °C with or without test compound (FR194738; 0.01 nM, 0.1 nM, 1 nM, 10 nM, 100 nM, 1 μM, and 10 μM) dissolved in DMSO (final 1%) in a final volume of 0.3 mL containing 0.1 M Tris-HCl, pH 7.5, 1 mM EDTA, 1 mM NADPH, 0.1 mM FAD, 0.3 mM AMO1618, an inhibitor of 2,3-oxidosqualene cyclase, 0.17% Triton X-100, and 8 μM [3H]squalene (3.7 kBq) dispersed in 0.075% Tween 80. The reaction is stopped by the addition of 0.3 mL of 10% ethanolic KOH. After incubation for 90 min at 75°C, non-saponifiable materials are extracted with 2 mL of petroleum ether. The extracts are evaporated under a nitrogen stream. The residue is taken up in a small volume of diethylether, spotted on a silica gel thin layer chromatography (TLC) plate and developed in benzene/ethyl acetate (99.5:0.5, v/v)[1].

Animal experiment:

Hamsters[3]Six-week-old male golden Syrian hamsters (70-110 g) are used. Drugs are administered as a diet mixture for 10 d. Blood samples are collected via heart puncture under ether anesthesia and serum is prepared by centrifugation. The dose of 0.32% in diet corresponds to 127 and 116 mg/kg/d for FR194738 and Pravastatin, respectively, calculated from body weight and food intake.

References:

[1]. Sawada M, et al. Effect of FR194738, a potent inhibitor of squalene epoxidase, on cholesterol metabolism in HepG2 cells. Eur J Pharmacol. 2001 Nov 9;431(1):11-6.
[2]. Sawada M, et al. Synthesis and biological activity of a novel squalene epoxidase inhibitor, FR194738. Bioorg Med Chem Lett. 2004 Feb 9;14(3):633-7.
[3]. Sawada M, et al. Inhibition of cholesterol synthesis causes both hypercholesterolemia and hypocholesterolemia in hamsters. Biol Pharm Bull. 2002 Dec;25(12):1577-82.