Ingestion of mannose ameliorates thioacetamide-induced intrahepatic oxidative stress, inflammation and fibrosis in rats

Life Sci. 2021 Dec 1:286:120040. doi: 10.1016/j.lfs.2021.120040. Epub 2021 Oct 9.

Abstract

Background and aims: The monosaccharide mannose has gained recent interest for its beneficial effect against certain inflammatory disorders. Nevertheless, the influence of mannose on experimentally-induced liver fibrosis and the ensued inflammation is still not fully clear to date.

Main methods: The current study investigated the outcomes of treating rats with mannose (0.2 ml of 20% w/v, oral gavage) 30 min before the twice weekly intoxication with thioacetamide (TAA) (200 mg/kg, intraperitoneal) for a total period of 8 weeks.

Key findings: The data indicated that mannose markedly dampened TAA-induced liver fibrosis, as indicated by lowering the fibrotic bridges shown by Masson's trichrome staining. This effect was consistent with reducing TAA-induced hepatocellular injury, as evidenced biochemically (serum ALT and AST activities) and pathologically (necroinflammation score). These hepatoprotective effects mediated by mannose were attributed to i) reversing TAA-induced rise in malondialdehyde (MDA) and decrease in reduced glutathione (GSH) expressions in the liver, ii) limiting TAA-induced release of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), iii) impairing TAA-induced activation of hepatic stellate cells by downregulating α-smooth muscle actin expression (α-SMA), and more importantly, iv) dampening TAA-induced fibrogenesis driven by transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF).

Significance: Mannose may be a valuable candidate for preventing oxidative stress, inflammation and fibrogenesis in the liver.

Keywords: Hepatic fibrosis; Mannose; Mannose phosphate isomerase; Thioacetamide; Transforming growth factor-β1.

MeSH terms

  • Animals
  • Cytokines / metabolism
  • Hepatic Stellate Cells / drug effects
  • Hepatic Stellate Cells / metabolism
  • Inflammation
  • Liver / drug effects
  • Liver / pathology*
  • Liver Cirrhosis / drug therapy
  • Liver Cirrhosis / pathology
  • Liver Cirrhosis / prevention & control*
  • Male
  • Malondialdehyde / metabolism
  • Mannose / metabolism
  • Mannose / pharmacology*
  • Oxidative Stress / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects
  • Thioacetamide / adverse effects
  • Thioacetamide / pharmacology

Substances

  • Cytokines
  • Thioacetamide
  • Malondialdehyde
  • Mannose