Pharmacological Profile of SMP-797, a Novel Acyl-Coenzyme A: Cholesterol Acyltransferase Inhibitor with Inducible Effect on the Expression of Low-Density Lipoprotein Receptor

Research Division, Sumitomo Pharmaceuticals Co., Ltd., Osaka, Japan.
Journal of Cardiovascular Pharmacology (Impact Factor: 2.14). 03/2006; 47(2):322-9. DOI: 10.1097/01.fjc.0000205498.67895.7e
Source: PubMed


We investigated the pharmacological profile of SMP-797, a novel hypocholesterolemic agent. SMP-797 showed inhibitory effects on acyl-coenzyme A: cholesterol acyltransferase (ACAT) activities in various microsomes and in human cell lines, and hypocholesterolemic effects in rabbits fed a cholesterol-rich diet and hamsters fed a normal diet. In hamsters, the reduction of total cholesterol level by SMP-797 was mainly due to the decrease of low-density lipoprotein (LDL) cholesterol level rather than that of very low-density lipoprotein (VLDL) cholesterol level. Interestingly, SMP-797 increased the hepatic low-density lipoprotein receptor expression in vivo when it decreased the low-density lipoprotein cholesterol level. SMP-797 also increased low-density lipoprotein receptor expression in HepG2 cells like atorvastatin, an HMG-CoA reductase inhibitor, although other acyl-coenzyme A: cholesterol acyltransferase inhibitor had no effect. In addition, SMP-797 had no effect on cholesterol synthesis in HepG2 cells. These results suggested that the increase of low-density lipoprotein receptor expression by SMP-797 was independent of its acyl-coenzyme A: cholesterol acyltransferase inhibitory action and did not result from the inhibition of hepatic cholesterol synthesis. In conclusion, these results suggest that SMP-797 is a novel hypocholesterolemic agent showing a cholesterol-lowering effect in which the increase of hepatic low-density lipoprotein receptor expression as well as the inhibition of acyl-coenzyme A: cholesterol acyltransferase is involved.

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    ABSTRACT: It is possible that SMP-797 will be administered frequently in combination with statins to hyperlipidemic patients. OATP1B1 is thought to be the major transporter that mediates the hepatic uptake of statins. This study investigated whether SMP-797 interacts with statins via OATP1B1 by two approaches. Firstly, the effects of SMP-797 on OATP1B1-mediated uptake of estrone-3-sulfate (ES) by human hepatocytes and by oocytes expressing OATP1B1 were examined. Since OATP1B1-mediated uptake of ES is known to be biphasic (high- and low-affinity sites), concentrations of [(3)H]ES were set lower than the respective K(m) values. Two representative statins were used to assure that statins share OATP1B1 with [(3)H]ES in this in vitro system. Rosuvastatin inhibited OATP1B1-mediated uptake of [(3)H]ES through both sites and pravastatin inhibited a high-affinity site. The inhibition by the positive control (cyclosporin A) was significant. Thus, it is considered that this system was applicable to examine drug-drug interaction with statins on OATP1B1-mediated uptake. In this condition, no apparent inhibition to each site by SMP-797 was observed up to a concentration 3,000-fold higher than the clinical level. Secondly, the uptake of [(14)C]SMP-797 by oocytes expressing OATP1B1 was examined and the activity was negligible. In conclusion, these data suggest that SMP-797 has little potential to interact with statins on OATP1B1.
    Biopharmaceutics & Drug Disposition 12/2007; 28(9):517-25. DOI:10.1002/bdd.581 · 2.34 Impact Factor
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    ABSTRACT: A family of 1,4-diarylpiperidine-4-methylureas were designed and synthesized as novel dual effectors on ACAT and LDL receptor expression. We examined SAR of the synthesized compounds focusing on substitution at the three aromatic parts of the starting compound 1 and succeeded in identifying essential substituents for inhibition of ACAT and up-regulation of hepatic LDL receptor expression. Especially, we found that compound 12f, which can easily be prepared, has biological properties comparable to those of SMP-797, a promising ACAT inhibitor. In addition, the in vitro effects of 12f on lipid metabolism were substantially superior to those of a known ACAT inhibitor, Avasimibe.
    Bioorganic & medicinal chemistry letters 02/2009; 19(4):1062-5. DOI:10.1016/j.bmcl.2009.01.020 · 2.42 Impact Factor
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    ABSTRACT: Based on 1,4-diarylpiperidine-4-methylureas, a new class of ACAT inhibitors, we examined in the study the SAR of a series of compounds prepared by replacing the substituent at the three aromatic parts. Introduction of long alkoxy group onto the phenyl moiety at the B-part was effective in improving both the inhibitory activity for ACAT and the up-regulatory activity for LDL-R expression. Particularly, 3-hydroxypropoxy group (43) on the phenyl moiety of B-part led to improved solubility, while keeping both biological activities. Compound 43 inhibited ACAT activity with an IC(50) value of 18 nM, which is superior to that of a known ACAT inhibitor, CI-1011. In addition, compound 43 revealed an LDL-R up-regulatory activity comparable to that of SMP-797. We therefore expect this compound to be a novel ACAT inhibitor.
    Bioorganic & medicinal chemistry 08/2009; 17(13):4636-46. DOI:10.1016/j.bmc.2009.04.059 · 2.79 Impact Factor
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