Chemotherapy-associated steatohepatitis induced by irinotecan: a novel animal model.

PURPOSE: Nonalcoholic steatohepatitis (NASH) has been associated with irinotecan (IRI)-based cancer chemotherapy regimens. The purpose of this study was to propose and test a consistent model of IRI-induced NASH, filling a gap in the medical literature. METHODS: Swiss male mice were distributed in groups (n = 8) and injected with saline (5 mL/kg, i.p.; control) or IRI (25, 50, 75 or 100 mg/kg, i.p.) thrice a week for 7 weeks. Blood samples were collected to measure the serum concentrations of proteins, alanine and aspartate aminotransferases (ALT and AST). Each week animals were euthanized, and the livers were submitted to myeloperoxidase (MPO) assay, lipid dosage, immunohistochemistry for inducible nitric oxide synthase (iNOS), TNF-α and interleukin-1ß (IL-1ß), and histopathological analysis. Survival rates were also determined. RESULTS: Mice treated with IRI had a significantly (p < 0.05) lower survival rate than controls and time- and dose-dependent body weight loss. ALT and AST plasma levels increased in relation to controls only in mice receiving IRI 50 mg/kg (p < 0.05). The histopathological features characteristic of NASH was observed, including steatosis, lobular neutrophil infiltration and ballooning hepatocytic degeneration. Additional findings included increased MPO, lipid accumulation, portal neutrophil infiltration, IL-1ß and iNOS expression and fibrosis in liver tissues and low serum protein levels compared to controls. CONCLUSION: This is the first report of a consistent model of IRI-induced NASH capable of mimicking clinical findings.

Angiogenesis inhibition by green propolis and the angiogenic effect of L-lysine on bladder cancer in rats.

PURPOSE: To determine the effects of water-soluble derivative of green propolis in bladder cancer angiogenesis in rats given N-butyl-(-4-hydroxybutyl) nitrosamine (BBN). METHODS: Nine groups were established, where six of them (Groups 1 to 6), the animals received 0.05% BBN in their drinking water for 14 weeks. From the 32nd to the 40th week, Groups 1, 2, 3 and 4 were treated respectively with water, L-lysine (300 mg/kg/day), celecoxib (30 mg/kg/day) and propolis (300 mg/kg/day). Groups 5 and 6 were given propolis and L-lysine from the 1st to the 40th week (150 mg/kg/day). Microvascular density was determined by histological sections stained for the marker CD-31 and analyzed with specific software. RESULTS: The microvascular density in bladder carcinomas was lower (p<0.01) in rats receiving propolis than in controls given carcinogen only. On the other hand, the microvascular density of tumors in rats receiving carcinogen and L-lysine for 40 weeks from the beginning of carcinogen treatment was significantly higher (p<0.01) than in the corresponding controls. CONCLUSION: Water-soluble derivative of propolis inhibits angiogenesis in BBN-induced rat bladder cancer, while L-lysine treatment stimulates angiogenesis if initiated concurrently with BBN.