Background & Aims: Rifampicin (RIFA) and ursodeoxycholic acid (UDCA) improve symptoms and biochemical markers of liver injury in cholestatic liver diseases by largely unknown mechanisms. We aimed to study the mole...Background & Aims: Rifampicin (RIFA) and ursodeoxycholic acid (UDCA) improve symptoms and biochemical markers of liver injury in cholestatic liver diseases by largely unknown mechanisms. We aimed to study the molecular mechanisms of action of these drugs in humans. Methods: Thirty otherwise healthy gallstone patients scheduled for cholestectomy were randomized to RIFA (600 mg/day for 1 week) or UDCA (1 g/day for 3 weeks) or no medication before surgery. Routine biochemistry, lipids, and surrogate markers for P450 activity (4β -hydroxy cholesterol, 4β -OH-C) and bile acid synthesis (7α -hydro-xy-4-cholesten-3-one,C-4) were measured in serum. Bile acids were analyzed in serum, urine, and bile. A wedge liver biopsy specimen was taken to study expression of hepatobiliary ABC transporters as well as detoxification enzymes and regulatory transcription factors. Results: RIFA enhanced bile acid detoxification as well as bilirubin conjugation and excretion as reflected by enhanced expression of CYP3A4, UGT1A1, and MRP2. These molec-ular effects were paralleled by decreased bilirubin and deoxycholic acid concentrations in serum and decreased lithocholic and deoxycholic acid concentrations in bile. UDCA on the other hand stimulated the expression of BSEP, MDR3, and MRP4. UDCA became the predominant bile acid after UDCA treatment and lowered the biliary cholesterol saturation index. Conclusions: RIFA enhances bile acid detoxification as well as bilirubin conjugation and export systems, whereas UDCA stimulates the expression of transporters for canalicular and basolateral bile acid export as well as the canalicular phospholipid flippase. These independent but complementary effects may justify a combination of both agents for the treatment of cholestatic liver diseases.展开更多
Intrahepatic cholestasis of pregnancy (ICP) is characterized by troublesome maternal pruritus, elevated serum bile acids (≥ 10 μ mol/L) and increased fetal risk. Recently we determined a cutoff level of serum bile a...Intrahepatic cholestasis of pregnancy (ICP) is characterized by troublesome maternal pruritus, elevated serum bile acids (≥ 10 μ mol/L) and increased fetal risk. Recently we determined a cutoff level of serum bile acids, ≥ 40 μ mol/L, to be associated with impaired fetal outcome. We have now studied the effects of ursodeoxycholic acid (UDCA) and dexamethasone on pruritus, biochemical markers of cholestasis, and fetal complication rates in a double-blind, placebo-controlled trial. For this purpose, 130 women with ICP were randomly allocated to UDCA (1 g/day for three weeks), or dexamethasone (12 mg/day for 1 week and placebo during weeks 2 and 3), or placebo for 3 weeks. Pruritus and biochemical markers of cholestasis were analyzed at inclusion and after 3 weeks of treatment. Fetal complications (spontaneous preterm delivery; asphyxial events; and meconium staining of amniotic fluid, placenta, and membranes) were registered at delivery. An intention-to-treat analysis showed significant reduction of alanine aminotransferase (ALT) (P = .01) and bilirubin (P = .002) in the UDCA group only. In a subgroup analysis of ICP women with serum bile acids ≥ 40 μ mol/L at inclusion (n = 34), UDCA had significant effects on pruritus (- 75% ), bile acids (- 79% ), ALT (- 80% ), and bilirubin (- 50% ) as well, but not on fetal complication rates. Dexamethasone yielded no alleviation of pruritus or reduction of ALT and was less effective than UDCA at reducing bile acids and bilirubin. In conclusion, 3 weeks of UDCA treatment improved some biochemical markers of ICP irrespective of disease severity, whereas significant relief from pruritus and marked reduction of serum bile acids were only found in patients with severe ICP.展开更多
文摘Background & Aims: Rifampicin (RIFA) and ursodeoxycholic acid (UDCA) improve symptoms and biochemical markers of liver injury in cholestatic liver diseases by largely unknown mechanisms. We aimed to study the molecular mechanisms of action of these drugs in humans. Methods: Thirty otherwise healthy gallstone patients scheduled for cholestectomy were randomized to RIFA (600 mg/day for 1 week) or UDCA (1 g/day for 3 weeks) or no medication before surgery. Routine biochemistry, lipids, and surrogate markers for P450 activity (4β -hydroxy cholesterol, 4β -OH-C) and bile acid synthesis (7α -hydro-xy-4-cholesten-3-one,C-4) were measured in serum. Bile acids were analyzed in serum, urine, and bile. A wedge liver biopsy specimen was taken to study expression of hepatobiliary ABC transporters as well as detoxification enzymes and regulatory transcription factors. Results: RIFA enhanced bile acid detoxification as well as bilirubin conjugation and excretion as reflected by enhanced expression of CYP3A4, UGT1A1, and MRP2. These molec-ular effects were paralleled by decreased bilirubin and deoxycholic acid concentrations in serum and decreased lithocholic and deoxycholic acid concentrations in bile. UDCA on the other hand stimulated the expression of BSEP, MDR3, and MRP4. UDCA became the predominant bile acid after UDCA treatment and lowered the biliary cholesterol saturation index. Conclusions: RIFA enhances bile acid detoxification as well as bilirubin conjugation and export systems, whereas UDCA stimulates the expression of transporters for canalicular and basolateral bile acid export as well as the canalicular phospholipid flippase. These independent but complementary effects may justify a combination of both agents for the treatment of cholestatic liver diseases.
文摘Intrahepatic cholestasis of pregnancy (ICP) is characterized by troublesome maternal pruritus, elevated serum bile acids (≥ 10 μ mol/L) and increased fetal risk. Recently we determined a cutoff level of serum bile acids, ≥ 40 μ mol/L, to be associated with impaired fetal outcome. We have now studied the effects of ursodeoxycholic acid (UDCA) and dexamethasone on pruritus, biochemical markers of cholestasis, and fetal complication rates in a double-blind, placebo-controlled trial. For this purpose, 130 women with ICP were randomly allocated to UDCA (1 g/day for three weeks), or dexamethasone (12 mg/day for 1 week and placebo during weeks 2 and 3), or placebo for 3 weeks. Pruritus and biochemical markers of cholestasis were analyzed at inclusion and after 3 weeks of treatment. Fetal complications (spontaneous preterm delivery; asphyxial events; and meconium staining of amniotic fluid, placenta, and membranes) were registered at delivery. An intention-to-treat analysis showed significant reduction of alanine aminotransferase (ALT) (P = .01) and bilirubin (P = .002) in the UDCA group only. In a subgroup analysis of ICP women with serum bile acids ≥ 40 μ mol/L at inclusion (n = 34), UDCA had significant effects on pruritus (- 75% ), bile acids (- 79% ), ALT (- 80% ), and bilirubin (- 50% ) as well, but not on fetal complication rates. Dexamethasone yielded no alleviation of pruritus or reduction of ALT and was less effective than UDCA at reducing bile acids and bilirubin. In conclusion, 3 weeks of UDCA treatment improved some biochemical markers of ICP irrespective of disease severity, whereas significant relief from pruritus and marked reduction of serum bile acids were only found in patients with severe ICP.
