RESUMO
A series of 5-aryl-3,3-dibutyl-7-(dimethylamino)-1,2-benzothiazepin-4-ol 1,1-dioxides were prepared and were found to inhibit the apical sodium co-dependent bile acid transporter (ASBT) for the potential treatment for hyperlipidemia. Several 1,2-benzothiazepines exhibited low nanomolar in vitro activity. The synthesis and initial in vitro potency data is presented for this novel class of compounds.
Assuntos
Hipolipemiantes/síntese química , Hipolipemiantes/farmacologia , Transportadores de Ânions Orgânicos Dependentes de Sódio/antagonistas & inibidores , Simportadores/antagonistas & inibidores , Tiazepinas/síntese química , Tiazepinas/farmacologia , Animais , Linhagem Celular , Cricetinae , Elétrons , Humanos , Indicadores e Reagentes , Oxirredução , PolietilenoglicóisRESUMO
Blocking intestinal bile acid absorption by inhibiting the apical sodium codependent bile acid transporter (ASBT) is a target for increasing hepatic bile acid synthesis and reducing plasma LDL cholesterol. SC-435 was identified as a potent inhibitor of ASBT (IC50 = 1.5 nM) in cells transfected with the human ASBT gene. Dietary administration of 3 mg/kg to 30 mg/kg SC-435 to apolipoprotein E-/- (apoE-/-) mice increased fecal bile acid excretion by >2.5-fold. In vivo inhibition of ASBT also resulted in significant increases of hepatic mRNA levels for cholesterol 7alpha-hydroxylase and HMG-CoA reductase. Administration of 10 mg/kg SC-435 for 12 weeks to apoE-/- mice lowered serum total cholesterol by 35% and reduced aortic root lesion area by 65%. Treatment of apoE-/- mice also resulted in decreased expression of ileal bile acid binding protein and hepatic nuclear hormone receptor small heterodimer partner, direct target genes of the farnesoid X receptor (FXR), suggesting a possible role of FXR in SC-435 modulation of cholesterol homeostasis. In dogs, SC-435 treatment reduced serum total cholesterol levels by =12% and, in combination with atorvastatin treatment, caused an additional reduction of 25%. These results suggest that specific inhibition of ASBT is a novel therapeutic approach for treatment of hypercholesterolemia resulting in a decreased risk for atherosclerosis.