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-alpha (TNF-alpha) and interleukin-6 (IL-6), iii) impairing TAA-induced activation of hepatic stellate cells by downregulating alpha-smooth muscle actin expression (alpha-SMA), and more importantly, iv) dampening TAA-induced fibrogenesis driven by transforming growth factor-beta 1 (TGF-beta 1) and connective tissue growth factor (CTGF).
Significance: Mannose may be a valuable candidate for preventing oxidative stress, inflammation and fibrogenesis in the liver.