Background: Fructus Schizandrae Sinensis bail, a traditional Chinese medicine, has been shown to lower the elevated serum level of liver enzymes of patients suffering from chronic active hepatitis. A synthetic derivative compound of Schisandrian, Dimethyl Diphenyl Bicarboxylate (DDB) is now used widely in clinical fields as a hepatoprotective drug. Thus it is important to know whether DDB has a beneficial effect on damaged liver or not.
Objective: To evaluate the protective effect of DDB on induced liver tissue injury in rats. Design: Experimental study.
Setting: National Hepatology and Tropical Medicine Research Institute. The study was conducted from October (2004) to February (2005).
Materials and methods: 120 male albino rats aged 6-8 weeks, weight 150-200g were grouped in six groups, 20 rats per group. Group 1 received food and water only, group 2 received food, water and DDB intragastric 6mg/kg daily for 12 weeks, group 3 received 20% ethanol instead of water, group 4 received 20% ethanol instead of water plus DDB, group 5 received thioacetamide (TAA) in a dose of 200mg/kg body weight intraperitoneal injection, group 6 received thioacetamide plus DDB at the same dose of the above group. At the end of the trial, blood samples were taken from all groups for biochemical analysis. Liver tissue excised from each rat was fixed in 10% neutral formalin, embedded in paraffin, and stained with Hematoxylin and Eosin, as well as Masson's trichome stain, for evaluation of hepatic injury and/or fibrosis.
Results: Statistical elevation of serum hepatic enzymes was noticed in rats received alcohol, Thioacetamide and alcohol + DDB (groups III, V and IV respectively) compared to the corresponding control (P= 0.000). On the other hand, administration of DDB to TAA treated group (group VI) induced significant improvement of liver function tests compared to other groups (P= 0.000). Histopathologically, the control livers showed normal lobular architecture without any pathological changes. Liver sections of animals administered alcohol, TAA respectively showed chronic inflammatory reaction, fat accumulation, hepatic parenchymal necrosis and/or hepatic fibrosis. Administration of DDB resulted in improvement of the pathological changes induced by TAA (group VI), but not that induced by alcohol (group IV).
Conclusion: Our results revealed that DDB has antitoxic effect against TAA and ameliorates the dangerous effect on the liver parenchyma, while it has no beneficial effect on alcoholic liver disease.