Background: The aim of the study was to investigate the effect of propranolol on systemic oxidative stress and endotoxemia in patients with liver cirrhosis and clinically significant portal hypertension evidenced by the presence of esophageal varices.
Methods: Fourteen patients with liver cirrhosis and esophageal varices, not previously been treated with non-selective beta-blockers (NSBB), were prospectively started on propranolol and followed up for three months. Serum early and late lipid peroxidation products (lipid hydroperoxides [LOOH] and malondialdehyde [MDA], respectively), and endotoxin concentrations in peripheral blood were measured. Fourteen age- and sex-matched healthy individuals were used as controls.
Results: Patients with liver cirrhosis presented significantly higher systemic oxidative stress and endotoxin concentrations compared to healthy controls (P<0.001). Propranolol treatment for one month significantly reduced serum MDA (P<0.05), LOOH (P<0.01), and endotoxin levels (P<0.01) compared to pre-treatment values, whilst LOOH reached control levels. At three months of propranolol treatment, serum LOOH did not differ significantly from the one-month values, whilst serum endotoxin and MDA levels were further reduced between 3- and 1-month period (P<0.05 and P<0.01, respectively), with the latter reaching control levels. Amelioration of systemic endotoxemia at the one- and three-month follow-up intervals (compared to pre-treatment values) was not correlated with the respective reductions in serum MDA and LOOH.
Conclusions: This is the first study to show that NSBB treatment in liver cirrhosis exerts a significant systemic antioxidant action. This effect seems to be, at least partly, independent of their beneficial effects on intestinal barrier function and endotoxemia.
Keywords: Cirrhosis; endotoxin; intestinal permeability; lipid peroxidation; non-selective beta-blockers; portal hypertension.