The beneficial effect of aspirin and enoxaparin on fibrosis progression and regenerative activity in a rat model of cirrhosis.

The aim of this study was to examine the effect of the antithrombotic drugs aspirin and enoxaparin on fibrosis progression and regenerative activity in a rat model of liver cirrhosis and to determine if these two drugs are beneficial in animals with advanced fibrosis or with established cirrhosis undergoing partial hepatectomy. Thioacetamide-induced cirrhotic rats received saline (N=10), aspirin (N=7), or enoxaparin (N=11) for a 5-week treatment period. Hepatic fibrosis was assessed according to METAVIR score. Liver regeneration was monitored using PCNA immunostaining. Compared to untreated cirrhotic controls, a significant improvement in fibrosis grade was observed in the aspirin (43%; chi(2)=54, P<0.001) and enoxaparin (36%; chi(2)=43, P<0.001) treated groups. Postoperatively, total serum bilirubin levels were lower in the aspirin (1.4+/-0.18 mg/dl; P<0.01) and enoxaparin (1.8+/-0.35 mg/dl; P<0.05)-treated groups compared to untreated cirrhotic controls (3.2+/-0.6 mg/dl). Hepatic regenerative activity was significantly improved in the aspirin group (57.3%+/-6.8%, versus 34.2%+/-7.2% in untreated cirrhotic controls; P<0.01) but unchanged in the enoxaparin group. We conclude that aspirin and enoxaparin hold promise as a useful therapy for patients with extensive fibrosis.