Protective effect of mixture of Aloe and Silybum on carbon tetrachloride-induced acute hepatotoxicity and liver fibrosis
The present study was carried out to investigate the hepatoprotective effects of mixture of aloe and silybum against acute and chronic carbon tetrachloride (CCl4)-induced liver injury. Acute liver damage was induced by intraperitoneal injection of CCl4 (50µl/kg) and mixture of aloe and silybum was administered orally 48h, 24h, 2h before and 6h after the injection of CCl4. Hepatotoxicity was assessed 24h after the CCl4 treatment. Chronic liver damage was induced by intraperitoneal injection of CCl4 for 5 weeks (0.5ml/kg, twice per week) and mixture of aloe (70mg/kg) and silybum (100mg/kg) was treated once a day (p.o). In both acute hepatotoxicity and liver fibrosis induced by CCl4, serum alanine aminotransferase (ALT; 2112.7±263 IU/L; 1208.9±99.8 IU/L), aspartate aminotransferase (AST) levels (1086.7±165.4 IU/L; 2188.8±270.2 IU/L) and lipid peroxidation (MDA; 0.52±0.03 nmol/mg protein; 0.607±.0.09 nmol/mg protein) were increased and the content of hepatic glutathione (GSH; 5.5±0.4µmol/g liver; 5.2±0.2µmol/g liver) were decreased. These changes were prevented by mixture of aloe and silybum (p<0.05). The mixture of aloe and silybum attenuated the increase in the expression of tumor necrosis factor-α (72% of CCl4 alone, p<0.05), inducible nitric oxide synthase (78%, of CCl4 alone, p<0.05), cyclooxygenase-2 mRNA (72% of CCl4 alone, p<0.05), proinflammatory mediators in acute hepatotoxicity. In antifibrotic experiments, the expression of tissue inhibitor of metalloprotease-1 mRNA (1200-fold increase vs. control) was attenuated by the mixture of aloe and silybum treatment (p<0.01). The mixture of aloe and silybum decreased the hepatic hydroxyproline contents (69% of CCl4 alone, p<0.05) and transforming growthfactor-beta1 level (64% of CCl4 alone, p<0.05). Our results suggest that the mixture of aloe and silybum has hepatoprotective effect in both acute and chronic liver injury induced by CCl4.