Cholestyramine

Cholestyramine (Colestyramine) is a bile acid binding resin and can inhibit intestinal bile acid absorption which results in the increasing bile acid synthesis from cholesterol. In Vitro: Cholestyramine (0.1-50 μg/mL) produced the most dramatic results after a 24-hour exposure; an efflux rate of 65% compared with control cells. Cholestyramine is an anion-exchange resin and is insoluble in water. alcohol, chloro-form, and ether. For the assay, cholestyramine is initially wetted with a small amount of DMSO further diluting with media. A blank sample prepared with dimethylsulfoxide DMSO without cholestyramine displayed no differences from the control samples^[3]. In Vivo: Cholestyramine (Colestyramine) is a bile acid binding resin and can inhibit intestinal bile acid absorption which results in the increasing bile acid synthesis from cholesterol^[1]. Results reveal that GSPE treatment alone, and co-administration with Cholestyramine (Colestyramine), regulate BA, cholesterol and TG metabolism differently compare to Cholestyramine administration alone. Notably, GSPE decreases intestinal apical sodium-dependent bile acid transporter (Asbt) gene expression, while Cholestyramine significantly induces expression. Administration with GSPE or Cholestyramine robustly induces hepatic BA biosynthetic gene expression, especially cholesterol 7α-hydroxylase (Cyp7a1), compare to control, while co-administration further enhances expression. Treatment with Cholestyramine induces both intestinal and hepatic cholesterologenic gene expression, while co-administration with GSPE attenuates the Cholestyramine-inducing increase in the liver but not in the intestine. Cholestyramine also induces hepatic lipogenic gene expression, which is attenuated by co-administration with GSPE^[2].