Candesartan, rather than losartan, improves motor dysfunction in thioacetamide-induced chronic liver failure in rats

Braz J Med Biol Res. 2017 Sep 21;50(11):e6665. doi: 10.1590/1414-431X20176665.

Abstract

Minimal hepatic encephalopathy is more common than the acute syndrome. Losartan, the first angiotensin-II receptor blocker (ARB), and candesartan, another widely-used ARB, have protected against developing fibrogenesis, but there is no clear data about their curative antifibrotic effects. The current study was designed to examine their effects in an already-established model of hepatic fibrosis and also their effects on the associated motor dysfunction. Low-grade chronic liver failure (CLF) was induced in 3-month old Sprague-Dawley male rats using thioacetamide (TAA, 50 mg·kg-1·day-1) intraperitoneally for 2 weeks. The TAA-CLF rats were randomly divided into five groups (n=8) treated orally for 14 days (mg·kg-1·day-1) as follows: TAA (distilled water), losartan (5 and 10 mg/kg), and candesartan (0.1 and 0.3 mg/kg). Rats were tested for rotarod and open-field tests. Serum and hepatic biochemical markers, and hepatic histopathological changes were evaluated by H&E and Masson's staining. The TAA-CLF rats showed significant increases of hepatic malondialdehyde, hepatic expression of tumor necrosis factor-α (TNF-α), and serum ammonia, alanine aminotransferase, γ-glutamyl transferase, TNF-α, and malondialdehyde levels as well as significant decreases of hepatic and serum glutathione levels. All treatments significantly reversed these changes. The histopathological changes were moderate in losartan-5 and candesartan-0.1 groups and mild in losartan-10 and candesartan-0.3 groups. Only candesartan significantly improved TAA-induced motor dysfunction. In conclusion, therapeutic antifibrotic effects of losartan and candesartan in thioacetamide-induced hepatic fibrosis in rats are possibly through angiotensin-II receptor blocking, antioxidant, and anti-inflammatory activities. Improved motor dysfunction by candesartan could be attributed to better brain penetration and slower "off-rate" from angiotensin-II receptors. Clinical trials are recommended.

Publication types

  • Evaluation Study

MeSH terms

  • Alanine Transaminase / blood
  • Ammonia / blood
  • Angiotensin II Type 1 Receptor Blockers / pharmacology
  • Angiotensin II Type 1 Receptor Blockers / therapeutic use*
  • Animals
  • Benzimidazoles / pharmacology
  • Benzimidazoles / therapeutic use*
  • Biphenyl Compounds
  • Disease Models, Animal
  • End Stage Liver Disease / complications*
  • End Stage Liver Disease / pathology
  • End Stage Liver Disease / physiopathology
  • Enzyme-Linked Immunosorbent Assay
  • Glutathione / analysis
  • Liver / drug effects
  • Liver / pathology
  • Liver Cirrhosis / complications
  • Liver Cirrhosis / pathology
  • Liver Cirrhosis / physiopathology
  • Locomotion / physiology
  • Losartan / pharmacology
  • Losartan / therapeutic use*
  • Male
  • Malondialdehyde / analysis
  • Motor Disorders / drug therapy*
  • Motor Disorders / etiology
  • Motor Disorders / physiopathology
  • Random Allocation
  • Rats, Sprague-Dawley
  • Reproducibility of Results
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tetrazoles / pharmacology
  • Tetrazoles / therapeutic use*
  • Thioacetamide
  • Treatment Outcome
  • Tumor Necrosis Factor-alpha / blood
  • gamma-Glutamyltransferase / blood

Substances

  • Angiotensin II Type 1 Receptor Blockers
  • Benzimidazoles
  • Biphenyl Compounds
  • Tetrazoles
  • Tumor Necrosis Factor-alpha
  • Thioacetamide
  • Malondialdehyde
  • Ammonia
  • gamma-Glutamyltransferase
  • Alanine Transaminase
  • Glutathione
  • Losartan
  • candesartan