RESUMEN
The colloidal stability, in vitro toxicity, cell association, and in vivo pharmacokinetic behavior of liposomes decorated with monomethoxy-poly(ethylene glycol)-lipids (mPEG-lipids) with different chemical features were comparatively investigated. Structural differences of the mPEG-lipids used in the study included: (a) surface-anchoring moiety [1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE), cholesterol (Chol), and cholane (Chln)]; (b) mPEG molecular weight (2 kDa mPEG45 and 5 kDa mPEG114); and (c) mPEG shape (linear and branched PEG). In vitro results demonstrated that branched (mPEG114)2-DSPE confers the highest stealth properties to liposomes (â¼31-fold lower cell association than naked liposomes) with respect to all PEGylating agents tested. However, the pharmacokinetic studies showed that the use of cholesterol as anchoring group yields PEGylated liposomes with longer permeance in the circulation and higher systemic bioavailability among the tested formulations. Liposomes decorated with mPEG114-Chol had 3.2- and â¼2.1-fold higher area under curve (AUC) than naked liposomes and branched (mPEG114)2-DSPE-coated liposomes, respectively, which reflects the high stability of this coating agent. By comparing the PEGylating agents with same size, namely, linear 5 kDa PEG derivatives, linear mPEG114-DSPE yielded coated liposomes with the best in vitro stealth performance. Nevertheless, the in vivo AUC of liposomes decorated with linear mPEG114-DSPE was lower than that obtained with liposomes decorated with linear mPEG114-Chol. Computational molecular dynamics modeling provided additional insights that complement the experimental results.
Asunto(s)
Colanos/administración & dosificación , Colesterol/administración & dosificación , Portadores de Fármacos/farmacocinética , Fosfatidiletanolaminas/administración & dosificación , Polietilenglicoles/administración & dosificación , Animales , Disponibilidad Biológica , Colanos/química , Colanos/farmacocinética , Colesterol/química , Colesterol/farmacocinética , Composición de Medicamentos/métodos , Estabilidad de Medicamentos , Células HeLa , Humanos , Lípidos , Liposomas , Ratones , Ratones Endogámicos BALB C , Simulación de Dinámica Molecular , Peso Molecular , Fosfatidiletanolaminas/química , Fosfatidiletanolaminas/farmacocinética , Polietilenglicoles/química , Polietilenglicoles/farmacocinética , Propiedades de SuperficieRESUMEN
Non-alcoholic steatohepatitis (NASH) is a highly prevalent chronic liver disease. Here, we have investigated whether BAR502, a non-bile acid, steroidal dual ligand for FXR and GPBAR1, reverses steato-hepatitis in mice fed a high fat diet (HFD) and fructose. After 9 week, mice on HFD gained ≈30% of b.w (P < 0.01 versus naïve) and were insulin resistant. These overweighting and insulin resistant mice were randomized to receive HFD or HFD in combination with BAR502. After 18 weeks, HFD mice developed NASH like features with severe steato-hepatitis and fibrosis, increased hepatic content of triacylglycerol and cholesterol and expression of SREPB1c, FAS, ApoC2, PPARα and γ, α-SMA, α1 collagen and MCP1 mRNAs. Treatment with BAR502 caused a ≈10% reduction of b.w., increased insulin sensitivity and circulating levels of HDL, while reduced steatosis, inflammatory and fibrosis scores and liver expression of SREPB1c, FAS, PPARγ, CD36 and CYP7A1 mRNA. BAR502 increased the expression of SHP and ABCG5 in the liver and SHP, FGF15 and GLP1 in intestine. BAR502 promoted the browning of epWAT and reduced liver fibrosis induced by CCl4. In summary, BAR502, a dual FXR and GPBAR1 agonist, protects against liver damage caused by HFD by promoting the browning of adipose tissue.
Asunto(s)
Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/efectos de los fármacos , Colanos/administración & dosificación , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Células 3T3-L1 , Tejido Adiposo Blanco/metabolismo , Animales , Biomarcadores/metabolismo , Tetracloruro de Carbono/toxicidad , Colanos/farmacología , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Fructosa/efectos adversos , Masculino , Ratones , Enfermedad del Hígado Graso no Alcohólico/inducido químicamente , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Receptores Citoplasmáticos y Nucleares/agonistas , Receptores Acoplados a Proteínas G/agonistasRESUMEN
3alpha-6alpha-Dihydroxy-7alpha-fluoro-5beta-cholanoate (UPF-680), the 7alpha-fluorine analog of hyodeoxycholic acid (HDCA), was synthesized to improve bioavailability and stability of ursodeoxycholic acid (UDCA). Acute rat biliary fistula and chronic cholestasis induced by 17alpha-ethynyl-estradiol (17EE) models were used to study and compare the effects of UPF-680 (dose range 0.6-6.0 micromol/kg min) with UDCA on bile flow, biliary bicarbonate (HCO(3)(-)), lipid output, biliary bile acid composition, hepatic enzymes and organic anion pumps. In acute infusion, UPF-680 increased bile flow in a dose-related manner, by up to 40.9%. Biliary HCO(3)(-) output was similarly increased. Changes were observed in phospholipid secretion only at the highest doses. Treatment with UDCA and UPF-680 reversed chronic cholestasis induced by 17EE; in this model, UDCA had no effect on bile flow in contrast to UPF-680, which significantly increased bile flow. With acute administration of UPF-680, the biliary bile acid pool became enriched with unconjugated and conjugated UPF-680 (71.7%) at the expense of endogenous cholic acid and muricholic isomers. With chronic administration of UPF-680 or UDCA, the main biliary bile acids were tauro conjugates, but modification of biliary bile acid pool was greater with UPF-680. UPF-680 increased the mRNA for cytochrome P450 7A1 (CYP7A1) and cytochrome P450 8B (CYP8B). Both UDCA and UPF-680 increased the mRNA for Na(+) taurocholate co-transporting polypeptide (NCTP). In conclusion, UPF-680 prevented 17EE-induced cholestasis and enriched the biliary bile acid pool with less detergent and cytotoxic bile acids. This novel fluorinated bile acid may have potential in the treatment of cholestatic liver disease.
Asunto(s)
Colanos/farmacología , Colestasis/prevención & control , Ácido Desoxicólico/análogos & derivados , Etinilestradiol/toxicidad , Esteroides Fluorados/farmacología , Animales , Bilis/química , Bilis/efectos de los fármacos , Conductos Biliares/efectos de los fármacos , Conductos Biliares/metabolismo , Colanos/administración & dosificación , Colanos/química , Colestasis/inducido químicamente , Colestasis/metabolismo , Colesterol 7-alfa-Hidroxilasa/genética , Colesterol 7-alfa-Hidroxilasa/metabolismo , Cromatografía Líquida de Alta Presión , Ácido Desoxicólico/administración & dosificación , Ácido Desoxicólico/química , Ácido Desoxicólico/farmacología , Relación Dosis-Respuesta a Droga , Etinilestradiol/antagonistas & inhibidores , Cromatografía de Gases y Espectrometría de Masas , Masculino , Micelas , Estructura Molecular , Fosfolípidos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Esteroide 12-alfa-Hidroxilasa/genética , Esteroide 12-alfa-Hidroxilasa/metabolismo , Esteroides Fluorados/administración & dosificación , Esteroides Fluorados/química , Ácido Ursodesoxicólico/administración & dosificación , Ácido Ursodesoxicólico/farmacologíaRESUMEN
In 4 patients studied after cholecystectomy and common-duct exploration for cholesterol gallstones, bile salt (BS) and phospholipid (PL) output and bile flow increased significantly in response to breakfast, but cholesterol (Ch) output was unaltered. Simultaneously, Ch concentration decreased while PL and BS concentrations did not change. The degree of Ch saturation of bile, [BS PLUS PL]/[ch], decreased in each study, whether or not the original ratio indicated Ch supersaturation; in 3 of 5 studies, an initially super-saturated bile became unsaturated with Ch in response to breakfast. No significant changes were noted after lunch. During interruption of enterohepatic circulation (EHC), studies with radiolabeled bile acids indicated that the increased bile acid output in response to meals was secondary to increased recirculation of intestinal bile acids rather than to de novo bile acid synthesis. This mechanism may account for the adequate delivery of BS and for the decreased degree of Ch saturation of bile postprandially in cholecystectomized patients.