Análise dos efeitos anti-inflamatórios, antioxidantes e anti-fibróticos do carvedilol em modelo de esteato-hepatite alcoólica induzida em ratos Wistar.

ethanol-induced liver injury model; carvedilol; inflammation

Aim: To evaluate the anti-inflammatory, anti-oxidant and antifibrotic effects of carvedilol (CARV) in rats with ethanol-induced liver injury.

Methods: Liver injury was induced by gavage administration of alcohol (7 g/kg) for 28 consecutive days. Eighty Wistar rats were pretreated with oral CARV at 1, 3, or 5 mg/kg or with saline 1 h before exposure to alcohol. Liver homogenates were assayed for interleukin (IL)-1β, IL-10, and tumor necrosis factor (TNF)-α level as well as for myeloperoxidase (MPO) activity and malonyldialdehyde (MDA) and glutathione (GSH) levels. Serum aspartate aminotransfer-ase (AST) activity and liver triglyceride (TG) levels were also assayed. Immunohistochemi-cal analyses of cyclooxygenase 2 (COX-2), receptor activator of nuclear factor kappa-B/ ligand (RANK/RANKL), suppressor of cytokine signalling (SOCS1), the Kupffer cell marker IBA-1 (ionized calcium-binding adaptor molecule 1), intercellular adhesion molecule 1 (ICAM-1), superoxide dismutase (SOD-1), and glutathione peroxidase (GPx-1) expression were performed. Confocal microscopy analysis of IL-1β and NF-κB expression and real-time quantitative PCR analysis for TNFα, PCI, PCIII, and NF-κB were performed.

Results:CARV treatment (5 mg/kg) during the alcohol exposure protocol was associated with reduced steatosis, hepatic cord degeneration, fibrosis and necrosis, as well as reduced levels of AST (p < 0.01), ALT (p < 0.01), TG (p < 0.001), MPO (p < 0.001), MDA (p < 0.05), and proinflammatory cytokines (IL-1β and TNF-α, both p < 0.05), and increased levels of the anti-inflammatory cytokine IL-10 (p < 0.001) and GSH (p < 0.05), compared to the alco-hol-only group. Treatment with CARV 5 mg/kg also reduced expression levels of COX-2, RANK, RANKL, IBA-1, and ICAM-1 (all p < 0.05), while increasing expression of SOCS1, SOD-1, and GPx-1 (all p < 0.05) and decreasing expression of IL-1β and NF-κB (both, p < 0.05). Real-time quantitative PCR analysis showed that mRNA production of TNF-α, procollagen type I (PCI), procollagen type III (PCIII), and NF-κB were decreased in the alcohol-CARV 5 mg/kg group relative to the alcohol-only group.
Conclusions: CARV can reduce the stress oxidative, inflammatory response and fibrosis in ethanol-induced liver injury in a rat model by downregulating signalling of Kuppfer cells and hepatic stellate cells (HSCs) through suppression of inflammatory cytokines.